Flow direction variations of low energy ions as measured by the ion electron sensor (IES) flying on board of Rosetta

NASA Astrophysics Data System (ADS)

Szegö, Karoly; Nemeth, Zoltan; Foldy, Lajos; Burch, James L.; Goldstein, Raymond; Mandt, Kathleen; Mokashi, Prachet; Broiles, Tom

2015-04-01

The Ion Electron Sensor (IES) simultaneously measures ions and electrons with two separate electrostatic plasma analyzers in the energy range of 4 eV- 22 keV for ions. The field of view is 90ox360o, with angular resolution 5ox45o for ions, with a sector containing the solar wind being further segmented to 5o × 5o. IES has operated continuously since early 2014. In the ion data a low energy (<50-100 eV) component is well separated from the higher energy ions. Here we analyze the arrival direction of this low energy component. The origin of these low energy ions is certainly the ionized component of the neutral gas emitted due to solar activity from comet 67P/Churiumov-Gerasimenko. The low energy component in general shows a 6h periodicity due to cometary rotation. The data show, however, that the arrival direction of the low energy ions is smeared both in azimuth and elevation, due possibly to the diverse mechanisms affecting these ions. One of these effects is the spacecraft potential (~-10V), which accelerates the ions towards the spacecraft omnidirectionally. To characterize the flow direction in azimuth-elevation, we have integrated over the lowest 8 energy channels using weighted energy: sum(counts * energy)/sum(counts); and considered only cases when the counts are above 30. When we apply higher cut for counts, the flow direction became more definite. For this analysis we use data files where the two neighbouring energy values and elevation values are collapsed; and the azimuthal resolution is 45o, that is the solar wind azimuthal segmentation is also collapsed. Here we use day 2014.09.11. as illustration. On that day a solar wind shock reached the spacecraft at about ~10 UT. After the shock transition the energy of the solar wind became higher, and after ~12 UT the flow direction of the solar wind fluctuated, sometimes by 35o. On this day Rosetta flew at about 29.3-29.6 km from the nucleus. In the azimuth-elevation plots summed over "weighted energy" (as defined above) we were able to identify two flow directions: one close to the anti-solar direction, and one perpendicular to it. The occurrence and variations of these directions are still under investigation. A possible cause of the acceleration of low energy ions along the solar wind might be that electrons produced by the ionization of neutrals are immediately picked up by the solar wind generating a polarization electric field that accelerates the ions. This effect is similar to the generation of ionospheric holes at Venus [Hartle and Grebowsky, Adv. Space Res., 4, 1995]. The acceleration perpendicular to the solar wind might be due to the v x B electric field. The variations of the low energy flow direction is analyzed in detail in the presentation.

Enhancement of wind energy harvesting by interaction between vortex-induced vibration and galloping

NASA Astrophysics Data System (ADS)

He, Xuefeng; Yang, Xiaokang; Jiang, Senlin

2018-01-01

Most wind energy harvesters (WEHs) that have been reported in the literature collect wind energy using only one type of wind-induced vibration, such as vortex-induced vibration (VIV), galloping, and flutter or wake galloping. In this letter, the interaction between VIV and galloping is used to improve the performance of WEHs. For a WEH constructed by attaching a bluff body with a rectangular cross-section to the free end of a piezoelectric cantilever, the measures to realize the interaction are theoretically discussed. Experiments verified the theoretical prediction that the WEHs with the same piezoelectric beam may demonstrate either separate or interactive VIV and galloping, depending on the geometries of the bluff bodies. For the WEHs with the interaction, the wind speed region of the VIV merges with that of the galloping to form a single region with high electrical outputs, which greatly increases the electrical outputs at low wind speeds. The interaction can be realized even when the predicted galloping critical speed is much higher than the predicted VIV critical speed. The proposed interaction is thus an effective approach to improve the scavenging efficiencies of WEHs operating at low wind speeds.

Complex behaviour in complex terrain - Modelling bird migration in a high resolution wind field across mountainous terrain to simulate observed patterns.

PubMed

Aurbach, Annika; Schmid, Baptiste; Liechti, Felix; Chokani, Ndaona; Abhari, Reza

2018-06-03

Crossing of large ecological barriers, such as mountains, is in terms of energy considered to be a demanding and critical step during bird migration. Besides forming a geographical barrier, mountains have a profound impact on the resulting wind flow. We use a novel framework of mathematical models to investigate the influences of wind and topography on nocturnal passerine bird behaviour, and to assess the energy costs for different flight strategies for crossing the Jura Mountains. The mathematical models include three biological models of bird behaviour: i) wind drift compensation; ii) adaptation of flight height for favourable winds; and, iii) avoidance of obstacles (cross over and/or circumvention of an obstacle following a minimum energy expenditure strategy), which are assessed separately and in combination. Further, we use a mesoscale weather model for high-resolution predictions of the wind fields. We simulate the broad front nocturnal passerine migration for autumn nights with peak migration intensities. The bird densities retrieved from a weather radar are used as the initial intensities and to specify the vertical distributions of the simulated birds. It is shown that migration over complex terrain represents the most expensive flight option in terms of energy expenditure, and wind is seen to be the main factor that influences the energy expenditure in the bird's preferred flight direction. Further, the combined effects of wind and orography lead to a high concentration of migratory birds within the favourable wind conditions of the Swiss lowlands and north of the Jura Mountains. Copyright © 2018 Elsevier Ltd. All rights reserved.

Horizontal geometrical reaction time model for two-beam nacelle LiDARs

NASA Astrophysics Data System (ADS)

Beuth, Thorsten; Fox, Maik; Stork, Wilhelm

2015-06-01

Wind energy is one of the leading sustainable energies. To attract further private and state investment in this technology, a broad scaled drop of the cost of energy has to be enforced. There is a trend towards using Laser Doppler Velocimetry LiDAR systems for enhancing power output and minimizing downtimes, fatigue and extreme forces. Since most used LiDARs are horizontally setup on a nacelle and work with two beams, it is important to understand the geometrical configuration which is crucial to estimate reaction times for the actuators to compensate wind gusts. In the beginning of this article, the basic operating modes of wind turbines are explained and the literature on wind behavior is analyzed to derive specific wind speed and wind angle conditions in relation to the yaw angle of the hub. A short introduction to the requirements for the reconstruction of the wind vector length and wind angle leads to the problem of wind shear detection of angled but horizontal homogeneous wind fronts due to the spatial separation of the measuring points. A distance is defined in which the wind shear of such homogeneous wind fronts is not present which is used as a base to estimate further distance calculations. The reaction time of the controller and the actuators are having a negative effect on the effective overall reaction time for wind regulation as well. In the end, exemplary calculations estimate benefits and disadvantages of system parameters for wind gust regulating LiDARs for a wind turbine of typical size. An outlook shows possible future improvements concerning the vertical wind behavior.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huskey, A.; Bowen, A.; Jager, D.

This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project. This project was established to help reduce the barriers to wind energy expansion by providing independent testing results for small wind turbines (SWT). In total, five turbines were tested at the National Wind Technology Center (NWTC) as a part of this project. Safety and function testing is one of up to five tests performed on the turbines, including power performance, duration, noise, and power-quality tests. NWTC testing results provide manufacturers with reports that may be used to meet part of small wind turbine certificationmore » requirements. The test equipment includes a Mariah Windspire wind turbine mounted on a monopole tower. L&E Machine manufactured the turbine in the United States. The inverter was manufactured separately by Technology Driven Products in the United States. The system was installed by the NWTC site operations group with guidance and assistance from Mariah Power.« less

76 FR 45786 - Advanced Scientific Computing Advisory Committee; Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-01

... updates. EU Data Initiative. HPC & EERE Wind Program. Early Career Research on Energy Efficient Interconnect for Exascale Computing. Separating Algorithm and Implentation. Update on ASCR exascale planning...

Thin film separators with ion transport properties for energy applications

NASA Astrophysics Data System (ADS)

Li, Zhongyuan

2017-09-01

Recent years, along with the increasing need of energy, energy storage also becomes a challenging problem which we need to deal with. The batterieshave a good developing prospect among energy storage system in storing energy such as wind, solar and geothermal energy. One hurdle between the lab-scale experiment and industry-scale application of the advanced batteries is the urgent need for limiting charging capacity degradation and improving cycling stability, known as the shuttle effect in lithium-sulfur batteries or electroosmotic drag coefficient in fuel-cell batteries. The microporous separator between the cathode and anode could be molecular engineered to possessesion selective permeation properties, which can greatly improves the energy efficiency and extends application range of the battery. The present review offers the fundamental fabrication methods of separator film with different material. The review also contains the chemical or physical structure of different materials which are used in making separator film. A table offers the reader a summary of properties such as ionic conductivity, ionic exchange capacity and current density etc.

Towers for Offshore Wind Turbines

NASA Astrophysics Data System (ADS)

Kurian, V. J.; Narayanan, S. P.; Ganapathy, C.

2010-06-01

Increasing energy demand coupled with pollution free production of energy has found a viable solution in wind energy. Land based windmills have been utilized for power generation for more than two thousand years. In modern times wind generated power has become popular in many countries. Offshore wind turbines are being used in a number of countries to tap the energy from wind over the oceans and convert to electric energy. The advantages of offshore wind turbines as compared to land are that offshore winds flow at higher speed than onshore winds and the more available space. In some land based settings, for better efficiency, turbines are separated as much as 10 rotor diameters from each other. In offshore applications where only two wind directions are likely to predominate, the distances between the turbines arranged in a line can be shortened to as little as two or four rotor diameters. Today, more than a dozen offshore European wind facilities with turbine ratings of 450 kw to 3.6 MW exist offshore in very shallow waters of 5 to 12 m. Compared to onshore wind turbines, offshore wind turbines are bigger and the tower height in offshore are in the range of 60 to 80 m. The water depths in oceans where offshore turbines can be located are within 30 m. However as the distance from land increases, the costs of building and maintaining the turbines and transmitting the power back to shore also increase sharply. The objective of this paper is to review the parameters of design for the maximum efficiency of offshore wind turbines and to develop types offshore towers to support the wind turbines. The methodology of design of offshore towers to support the wind turbine would be given and the environmental loads for the design of the towers would be calculated for specific cases. The marine corrosion on the towers and the methods to control the corrosion also would be briefly presented. As the wind speeds tend to increase with distance from the shore, turbines build father offshore will be able to capture more wind energy. Currently two types of towers are considered. Cylindrical tubular structures and truss type structures. But truss type structures have less weight and flexibility in design. The construction of the offshore towers to harness the wind energy is also presented. The results will include the calculation of wind and wave forces on the tower and the design details for the tower.

A FOUR-FLUID MHD MODEL OF THE SOLAR WIND/INTERSTELLAR MEDIUM INTERACTION WITH TURBULENCE TRANSPORT AND PICKUP PROTONS AS SEPARATE FLUID

DOE Office of Scientific and Technical Information (OSTI.GOV)

Usmanov, Arcadi V.; Matthaeus, William H.; Goldstein, Melvyn L., E-mail: arcadi.usmanov@nasa.gov

2016-03-20

We have developed a four-fluid, three-dimensional magnetohydrodynamic model of the solar wind interaction with the local interstellar medium. The unique features of the model are: (a) a three-fluid description for the charged components of the solar wind and interstellar plasmas (thermal protons, electrons, and pickup protons), (b) the built-in turbulence transport equations based on Reynolds decomposition and coupled with the mean-flow Reynolds-averaged equations, and (c) a solar corona/solar wind model that supplies inner boundary conditions at 40 au by computing solar wind and magnetic field parameters outward from the coronal base. The three charged species are described by separate energy equationsmore » and are assumed to move with the same velocity. The fourth fluid in the model is the interstellar hydrogen which is treated by separate continuity, momentum, and energy equations and is coupled with the charged components through photoionization and charge exchange. We evaluate the effects of turbulence transport and pickup protons on the global heliospheric structure and compute the distribution of plasma, magnetic field, and turbulence parameters throughout the heliosphere for representative solar minimum and maximum conditions. We compare our results with Voyager 1 observations in the outer heliosheath and show that the relative amplitude of magnetic fluctuations just outside the heliopause is in close agreement with the value inferred from Voyager 1 measurements by Burlaga et al. The simulated profiles of magnetic field parameters in the outer heliosheath are in qualitative agreement with the Voyager 1 observations and with the analytical model of magnetic field draping around the heliopause of Isenberg et al.« less

Modeling of the coupled magnetospheric and neutral wind dynamos

NASA Technical Reports Server (NTRS)

Thayer, Jeff P.

1993-01-01

The solar wind interaction with the earth's magnetosphere generates electric fields and currents that flow from the magnetosphere to the ionosphere at high latitudes. Consequently, the neutral atmosphere is subject to the dissipation and conversion of this electrical energy to thermal and mechanical energy through Joule heating and Lorentz forcing. As a result of the mechanical energy stored within the neutral wind (caused in part by Lorentz--and pressure gradient--forces set up by the magnetospheric flux of electrical energy), electric currents and fields can be generated in the ionosphere through the neutral wind dynamo mechanism. At high latitudes this source of electrical energy has been largely ignored in past studies, owing to the assumed dominance of the solar wind/magnetospheric dynamo as an electrical energy source to the ionosphere. However, other researchers have demonstrated that the available electrical energy provided by the neutral wind is significant at high latitudes, particularly in the midnight sector of the polar cap and in the region of the magnetospheric convection reversal. As a result, the conclusions of a number of broad ranging high-latitude investigations may be modified if the neutral-wind contribution to high-latitude electrodynamics is properly accounted for. These include the following: studies assessing solar wind-magnetospheric coupling by comparing the cross polar cap potential with solar wind parameters; research based on the alignment of particle precipitation with convection or field aligned current boundaries; and synoptic investigations attributing seasonal variations in the observed electric field and current patterns to external sources. These research topics have been initiated by satellite and ground-based observations and have been attributed to magnetospheric causes. However, the contribution of the neutral wind to the high-latitude electric field and current systems and their seasonal and local time dependence has yet to be quantitatively evaluated. In this program, we are evaluating the coupled magnetospheric and neutral wind dynamos at high latitudes under various conditions. In addition to examining the impact of seasonal variations, we are investigating the consequences of the separate dynamos having pure current-source or voltage-source behaviors.

Numerical investigations on the aerodynamic performance of wind turbine: Downwind versus upwind configuration

NASA Astrophysics Data System (ADS)

Zhou, Hu; Wan, Decheng

2015-03-01

Although the upwind configuration is more popular in the field of wind energy, the downwind one is a promising type for the offshore wind energy due to its special advantages. Different configurations have different aerodynamic performance and it is important to predict the performance of both downwind and upwind configurations accurately for designing and developing more reliable wind turbines. In this paper, a numerical investigation on the aerodynamic performance of National Renewable Energy Laboratory (NREL) phase VI wind turbine in downwind and upwind configurations is presented. The open source toolbox OpenFOAM coupled with arbitrary mesh interface (AMI) method is applied to tackle rotating problems of wind turbines. Two 3D numerical models of NREL phase VI wind turbine with downwind and upwind configurations under four typical working conditions of incoming wind velocities are set up for the study of different unsteady characteristics of the downwind and upwind configurations, respectively. Numerical results of wake vortex structure, time histories of thrust, pressure distribution on the blade and limiting streamlines which can be used to identify points of separation in a 3D flow are presented. It can be concluded that thrust reduction due to blade-tower interaction is small for upwind wind turbines but relatively large for downwind wind turbines and attention should be paid to the vibration at a certain frequency induced by the cyclic reduction for both configurations. The results and conclusions are helpful to analyze the different aerodynamic performance of wind turbines between downwind and upwind configurations, providing useful references for practical design of wind turbine.

Tornado and extreme wind design criteria for nuclear power plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1973-12-01

Nuclear power plant design criteria for tornadoes and extreme winds are presented. Data, formulas, and procedures for determining maximum wind loading on structures and parts of structures are included. Extreme wind loading is applied to structures using methods and procedures consistent with ANSI Building Code A58.1- 1972. The design wind velocities specified generally exceed 100-year recurrent interval winds. Tornado wind loading is applied to structures using procedures paralleling those for extrene winds with additional criteria resulting from the atmospheric pressure change accompanying tornadoes and tornado missile inipact effects. Tornado loading for the 48 contiguous United States is specified for twomore » major zones separated by the Continental Divide. A cross reference listing items related to Atomic Energy Commission Safety Analysis Report format is provided. Development supporting tornado criteria is included. (auth)« less

The reliability of wind power systems in the UK

NASA Astrophysics Data System (ADS)

Newton, K.

A methodology has been developed to evaluate the performance of geographically distributed wind power systems. Results are presented for three widely separated sites based on measured meteorological data obtained over a 17-yr period. The effects of including energy storage were investigated and 150-hr storage found to be a good compromise between store capacity and system performance. When used to provide space heating, the system could have reduced the 17-yr peak demand from conventional sources (smoothed by the storage and geographical separation of sites) by an amount comparable to the mean output of the wind-system, whether or not turbines at the three sites were interconnected by the National Grid. In contrast, the fuel saving capability of the system was found to be comparatively insensitive either to storage period or geographical separation of sites; the system would have been capable of providing up to 90 percent of the total requirement. Results are also given for individual sites to indicate the possible performance of district heating schemes or domestic systems.

Proceedings of the vertical axis wind turbine (VAWT) design technology seminar for industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnston, S.F. Jr.

1980-08-01

The objective of the Vertical Axis Wind Turbine (VAWT) Program at Sandia National Laboratories is to develop technology that results in economical, industry-produced, and commercially marketable wind energy systems. The purpose of the VAWT Design Technology Seminar or Industry was to provide for the exchange of the current state-of-the-art and predictions for future VAWT technology. Emphasis was placed on technology transfer on Sandia's technical developments and on defining the available analytic and design tools. Separate abstracts are included for presented papers.

The formation of a cold-core eddy in the East Australian Current

NASA Astrophysics Data System (ADS)

Macdonald, H. S.; Roughan, M.; Baird, M. E.; Wilkin, J.

2016-02-01

Cold-core eddies (CCEs) frequently form in western boundary currents and can affect continental shelf processes. It is not always clear, however, if baroclinic or barotropic instabilities contribute more to their formation. The Regional Ocean Modelling System (ROMS) is used to investigate the ocean state during the formation of a CCE in the East Australian Current (EAC) during October 2009. The observed eddy initially appeared as a small billow (approx. 50 km in length) that perturbed the landward edge of the EAC. The billow grew into a mesoscale CCE (approx. 100 km in diameter), diverting the EAC around it. A ROMS simulation with a realistic wind field reproduced a similar eddy. This eddy formed from negative vorticity waters found on the continental shelf south of the EAC separation point. A sensitivity analysis is performed whereby the impact of 3 different wind forcing scenarios, upwelling, downwelling, and no winds, are investigated. A CCE formed in all wind scenarios despite the wind induced changes in hydrographic conditions in the continental shelf and slope waters. As such, the source of energy for eddy formation did not come from the interactions of wind with the continental shelf waters. Analysis of strain and energy transformation confirms this by showing that the prevailing source of CCE energy was kinetic energy of the offshore EAC. These results clearly link the formation of the CCE to the swift flowing EAC and barotropic instabilities.

Use of pultruded reinforced plastics in energy generation and energy related applications

NASA Astrophysics Data System (ADS)

Anderson, R.

Applications of pultrusion-formed fiber-reinforced plastics (FRP) in the wind, oil, and coal derived energy industries are reviewed. FRP is noted to be a viable alternative to wood, aluminum, and steel for reasons of availability, price, and weight. Attention is given to the development of FRP wind turbine blades for the DOE 8 kW low cost, high reliability wind turbine program. The blades feature a NACA 23112 profile with a 15 in. chord on the system which was tested at Rocky Flats, CO. Fabricating the blades involved a plus and minus 45 deg roving orientation, a heavy fiber-glass nose piece to assure blade strength, and a separately manufactured foam core. Additional uses for FRP products have been found in the structural members of coal stack scrubbers using a vinyl ester resin in a fire retardant formulation, and as low cost, light weight sucker rods for deep well oil drilling.

The Wind Forecast Improvement Project (WFIP). A Public/Private Partnership for Improving Short Term Wind Energy Forecasts and Quantifying the Benefits of Utility Operations -- the Northern Study Area

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finley, Cathy

2014-04-30

This report contains the results from research aimed at improving short-range (0-6 hour) hub-height wind forecasts in the NOAA weather forecast models through additional data assimilation and model physics improvements for use in wind energy forecasting. Additional meteorological observing platforms including wind profilers, sodars, and surface stations were deployed for this study by NOAA and DOE, and additional meteorological data at or near wind turbine hub height were provided by South Dakota State University and WindLogics/NextEra Energy Resources over a large geographical area in the U.S. Northern Plains for assimilation into NOAA research weather forecast models. The resulting improvements inmore » wind energy forecasts based on the research weather forecast models (with the additional data assimilation and model physics improvements) were examined in many different ways and compared with wind energy forecasts based on the current operational weather forecast models to quantify the forecast improvements important to power grid system operators and wind plant owners/operators participating in energy markets. Two operational weather forecast models (OP_RUC, OP_RAP) and two research weather forecast models (ESRL_RAP, HRRR) were used as the base wind forecasts for generating several different wind power forecasts for the NextEra Energy wind plants in the study area. Power forecasts were generated from the wind forecasts in a variety of ways, from very simple to quite sophisticated, as they might be used by a wide range of both general users and commercial wind energy forecast vendors. The error characteristics of each of these types of forecasts were examined and quantified using bulk error statistics for both the local wind plant and the system aggregate forecasts. The wind power forecast accuracy was also evaluated separately for high-impact wind energy ramp events. The overall bulk error statistics calculated over the first six hours of the forecasts at both the individual wind plant and at the system-wide aggregate level over the one year study period showed that the research weather model-based power forecasts (all types) had lower overall error rates than the current operational weather model-based power forecasts, both at the individual wind plant level and at the system aggregate level. The bulk error statistics of the various model-based power forecasts were also calculated by season and model runtime/forecast hour as power system operations are more sensitive to wind energy forecast errors during certain times of year and certain times of day. The results showed that there were significant differences in seasonal forecast errors between the various model-based power forecasts. The results from the analysis of the various wind power forecast errors by model runtime and forecast hour showed that the forecast errors were largest during the times of day that have increased significance to power system operators (the overnight hours and the morning/evening boundary layer transition periods), but the research weather model-based power forecasts showed improvement over the operational weather model-based power forecasts at these times.« less

Relationship between wave energy and free energy from pickup ions in the Comet Halley environment

NASA Technical Reports Server (NTRS)

Huddleston, D. E.; Johnstone, A. D.

1992-01-01

The free energy available from the implanted heavy ion population at Comet Halley is calculated by assuming that the initial unstable velocity space ring distribution of the ions evolves toward a bispherical shell. Ultimately this free energy adds to the turbulence in the solar wind. Upstream and downstream free energies are obtained separately for the conditions observed along the Giotto spacecraft trajectory. The results indicate that the waves are mostly upstream propagating in the solar wind frame. The total free energy density always exceeds the measured wave energy density because, as expected in the nonlinear process of ion scattering, the available energy is not all immediately released. An estimate of the amount which has been released can be obtained from the measured oxygen ion distributions and again it exceeds that observed. The theoretical analysis is extended to calculate the k spectrum of the cometary-ion-generated turbulence.

The Ultimate Flow Controlled Wind Turbine Blade Airfoil

NASA Astrophysics Data System (ADS)

Seifert, Avraham; Dolgopyat, Danny; Friedland, Ori; Shig, Lior

2015-11-01

Active flow control is being studied as an enabling technology to enhance and maintain high efficiency of wind turbine blades also with contaminated surface and unsteady winds as well as at off-design operating conditions. The study is focused on a 25% thick airfoil (DU91-W2-250) suitable for the mid blade radius location. Initially a clean airfoil was fabricated and tested, as well as compared to XFoil predictions. From these experiments, the evolution of the separation location was identified. Five locations for installing active flow control actuators are available on this airfoil. It uses both Piezo fluidic (``Synthetic jets'') and the Suction and Oscillatory Blowing (SaOB) actuators. Then we evaluate both actuation concepts overall energy efficiency and efficacy in controlling boundary layer separation. Since efficient actuation is to be found at low amplitudes when placed close to separation location, distributed actuation is used. Following the completion of the baseline studies the study has focused on the airfoil instrumentation and extensive wind tunnel testing over a Reynolds number range of 0.2 to 1.5 Million. Sample results will be presented and outline for continued study will be discussed.

Plume meander and dispersion in a stable boundary layer

NASA Astrophysics Data System (ADS)

Hiscox, April L.; Miller, David R.; Nappo, Carmen J.

2010-11-01

Continuous lidar measurements of elevated plume dispersion and corresponding micrometeorology data are analyzed to establish the relationship between plume behavior and nocturnal boundary layer dynamics. Contrasting nights of data from the JORNADA field campaign in the New Mexico desert are analyzed. The aerosol lidar measurements were used to separate the plume diffusion (plume spread) from plume meander (displacement). Mutiresolution decomposition was used to separate the turbulence scale (<90 s) from the submesoscale (>90 s). Durations of turbulent kinetic energy stationarity and the wind steadiness were used to characterize the local scale and submesoscale turbulence. Plume meander, driven by submesoscale wind motions, was responsible for most of the total horizontal plume dispersion in weak and variable winds and strong stability. This proportion was reduced in high winds (i.e., >4 m s-1), weakly stable conditions but remained the dominant dispersion mechanism. The remainder of the plume dispersion in all cases was accounted for by internal spread of the plume, which is a small eddy diffusion process driven by turbulence. Turbulence stationarity and the wind steadiness are demonstrated to be closely related to plume diffusion and plume meander, respectively.

Energy conversion through mass loading of escaping ionospheric ions for different Kp values

NASA Astrophysics Data System (ADS)

Yamauchi, Masatoshi; Slapak, Rikard

2018-01-01

By conserving momentum during the mixing of fast solar wind flow and slow planetary ion flow in an inelastic way, mass loading converts kinetic energy to other forms - e.g. first to electrical energy through charge separation and then to thermal energy (randomness) through gyromotion of the newly born cold ions for the comet and Mars cases. Here, we consider the Earth's exterior cusp and plasma mantle, where the ionospheric origin escaping ions with finite temperatures are loaded into the decelerated solar wind flow. Due to direct connectivity to the ionosphere through the geomagnetic field, a large part of this electrical energy is consumed to maintain field-aligned currents (FACs) toward the ionosphere, in a similar manner as the solar wind-driven ionospheric convection in the open geomagnetic field region. We show that the energy extraction rate by the mass loading of escaping ions (ΔK) is sufficient to explain the cusp FACs, and that ΔK depends only on the solar wind velocity accessing the mass-loading region (usw) and the total mass flux of the escaping ions into this region (mloadFload), as ΔK ˜ -mloadFloadu2sw/4. The expected distribution of the separated charges by this process also predicts the observed flowing directions of the cusp FACs for different interplanetary magnetic field (IMF) orientations if we include the deflection of the solar wind flow directions in the exterior cusp. Using empirical relations of u0 ∝ Kp + 1.2 and Fload ∝ exp(0.45Kp) for Kp = 1-7, where u0 is the solar wind velocity upstream of the bow shock, ΔK becomes a simple function of Kp as log10(ΔK) = 0.2 ṡ Kp + 2 ṡ log10(Kp + 1.2) + constant. The major contribution of this nearly linear increase is the Fload term, i.e. positive feedback between the increase of ion escaping rate Fload through the increased energy consumption in the ionosphere for high Kp, and subsequent extraction of more kinetic energy ΔK from the solar wind to the current system by the increased Fload. Since Fload significantly increases for increased flux of extreme ultraviolet (EUV) radiation, high EUV flux may significantly enhance this positive feedback. Therefore, the ion escape rate and the energy extraction by mass loading during ancient Earth, when the Sun is believed to have emitted much higher EUV flux than at present, could have been even higher than the currently available highest values based on Kp = 9. This raises a possibility that the ion escape has substantially contributed to the evolution of the Earth's atmosphere.

Analysis of the balancing of the wind and solar energy resources in Andalusia (Southern Spain)

NASA Astrophysics Data System (ADS)

Santos-Alamillos, F. J.; Pozo-Vazquez, D.; Lara-Fanego, V.; Ruiz-Arias, J. A.; Hernandez-Alvaro, J.; Tova-Pescador, J.

2010-09-01

A higher penetration of the renewable energy in the electric system in the future will be conditioned to a reduction of the uncertainty of the yield. A way to obtain this goal is to analyze the balancing between the productions of different sources of renewable energy, trying to combine these productions. In this work we analyze, from a meteorological point of view, the balancing between wind and solar energy resources in Andalusia (southern Iberian Peninsula). To this end, wind speed and global radiation data corresponding to an one year integration of the Weather Research and Forecasting (WRF) Numerical Weather Prediction (NWP) model were analyzed. Two method of analysis were used: a point correlation analysis and a Canonical Correlation Analysis (CCA). Results from these analyses allow obtaining, eventually, areas of local and distributed balancing between the wind and solar energy resources. The analysis was carried out separately for the different seasons of the year. Results showed, overall, a considerable balancing effect between the wind and solar resources in the mountain areas of the interior of the region, along the coast of the central part of the region and, specially, in the coastal area near the Gibraltar strait. Nevertheless, considerable differences were found between the seasons of the year, which may lead to compensating effects. Autumn proved to be the season with the most significant results.

Variability of interconnected wind plants: correlation length and its dependence on variability time scale

DOE PAGES

St. Martin, Clara M.; Lundquist, Julie K.; Handschy, Mark A.

2015-04-02

The variability in wind-generated electricity complicates the integration of this electricity into the electrical grid. This challenge steepens as the percentage of renewably-generated electricity on the grid grows, but variability can be reduced by exploiting geographic diversity: correlations between wind farms decrease as the separation between wind farms increases. However, how far is far enough to reduce variability? Grid management requires balancing production on various timescales, and so consideration of correlations reflective of those timescales can guide the appropriate spatial scales of geographic diversity grid integration. To answer 'how far is far enough,' we investigate the universal behavior of geographic diversity by exploring wind-speed correlations using three extensive datasets spanning continents, durations and time resolution. First, one year of five-minute wind power generation data from 29 wind farms span 1270 km across Southeastern Australia (Australian Energy Market Operator). Second, 45 years of hourly 10 m wind-speeds from 117 stations span 5000 km across Canada (National Climate Data Archive of Environment Canada). Finally, four years of five-minute wind-speeds from 14 meteorological towers span 350 km of the Northwestern US (Bonneville Power Administration). After removing diurnal cycles and seasonal trends from all datasets, we investigate dependence of correlation length on time scale by digitally high-pass filtering the data on 0.25–2000 h timescales and calculating correlations between sites for each high-pass filter cut-off. Correlations fall to zero with increasing station separation distance, but the characteristic correlation length varies with the high-pass filter applied: the higher the cut-off frequency, the smaller the station separation required to achieve de-correlation. Remarkable similarities between these three datasets reveal behavior that, if universal, could be particularly useful for grid management. For high-pass filter time constants shorter than about τ = 38 h, all datasets exhibit a correlation lengthmore » $$\\xi $$ that falls at least as fast as $${{\\tau }^{-1}}$$ . Since the inter-site separation needed for statistical independence falls for shorter time scales, higher-rate fluctuations can be effectively smoothed by aggregating wind plants over areas smaller than otherwise estimated.« less

Variability of interconnected wind plants: correlation length and its dependence on variability time scale

NASA Astrophysics Data System (ADS)

St. Martin, Clara M.; Lundquist, Julie K.; Handschy, Mark A.

2015-04-01

The variability in wind-generated electricity complicates the integration of this electricity into the electrical grid. This challenge steepens as the percentage of renewably-generated electricity on the grid grows, but variability can be reduced by exploiting geographic diversity: correlations between wind farms decrease as the separation between wind farms increases. But how far is far enough to reduce variability? Grid management requires balancing production on various timescales, and so consideration of correlations reflective of those timescales can guide the appropriate spatial scales of geographic diversity grid integration. To answer ‘how far is far enough,’ we investigate the universal behavior of geographic diversity by exploring wind-speed correlations using three extensive datasets spanning continents, durations and time resolution. First, one year of five-minute wind power generation data from 29 wind farms span 1270 km across Southeastern Australia (Australian Energy Market Operator). Second, 45 years of hourly 10 m wind-speeds from 117 stations span 5000 km across Canada (National Climate Data Archive of Environment Canada). Finally, four years of five-minute wind-speeds from 14 meteorological towers span 350 km of the Northwestern US (Bonneville Power Administration). After removing diurnal cycles and seasonal trends from all datasets, we investigate dependence of correlation length on time scale by digitally high-pass filtering the data on 0.25-2000 h timescales and calculating correlations between sites for each high-pass filter cut-off. Correlations fall to zero with increasing station separation distance, but the characteristic correlation length varies with the high-pass filter applied: the higher the cut-off frequency, the smaller the station separation required to achieve de-correlation. Remarkable similarities between these three datasets reveal behavior that, if universal, could be particularly useful for grid management. For high-pass filter time constants shorter than about τ = 38 h, all datasets exhibit a correlation length ξ that falls at least as fast as {{τ }-1} . Since the inter-site separation needed for statistical independence falls for shorter time scales, higher-rate fluctuations can be effectively smoothed by aggregating wind plants over areas smaller than otherwise estimated.

A review of wind turbine-oriented active flow control strategies

NASA Astrophysics Data System (ADS)

Aubrun, Sandrine; Leroy, Annie; Devinant, Philippe

2017-10-01

To reduce the levelized cost of energy, the energy production, robustness and lifespan of horizontal axis wind turbines (HAWTs) have to be improved to ensure optimal energy production and operational availability during periods longer than 15-20 years. HAWTs are subject to unsteady wind loads that generate combinations of unsteady mechanical loads with characteristic time scales from seconds to minutes. This can be reduced by controlling the aerodynamic performance of the wind turbine rotors in real time to compensate the overloads. Mitigating load fluctuations and optimizing the aerodynamic performance at higher time scales need the development of fast-response active flow control (AFC) strategies located as close as possible to the torque generation, i.e., directly on the blades. The most conventional actuators currently used in HAWTs are mechanical flaps/tabs (similar to aeronautical accessories), but some more innovative concepts based on fluidic and plasma actuators are very promising since they are devoid of mechanical parts, have a fast response and can be driven in unsteady modes to influence natural instabilities of the flow. In this context, the present paper aims at giving a state-of-the-art review of current research in wind turbine-oriented flow control strategies applied at the blade scale. It provides an overview of research conducted in the last decade dealing with the actuators and devices devoted to developing AFC on rotor blades, focusing on the flow phenomena that they cause and that can lead to aerodynamic load increase or decrease. After providing some general background on wind turbine blade aerodynamics and on the atmospheric flows in which HAWTs operate, the review focuses on flow separation control and circulation control mainly through experimental investigations. It is followed by a discussion about the overall limitations of current studies in the wind energy context, with a focus on a few studies that attempt to provide a global efficiency assessment and wind energy-oriented energy balance.

Proceedings: Second Annual Pacific Northwest Alternative and Renewable Energy Resources Conference.

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1980-01-01

Papers presented at the conference are published in this volume. The purpose of the conference was to solicit regional cooperation in the promoting of near-term development of such alternative and renewable energy resources in the Pacific Northwest as: cogeneration; biomass; wind; small hydro; solar end-use applications; and geothermal direct heat utilization. Separate abstracts of selected papers were prepared for inclusion in the Energy Data Base.

A numerical analysis to evaluate Betz's Law for vertical axis wind turbines

NASA Astrophysics Data System (ADS)

Thönnißen, F.; Marnett, M.; Roidl, B.; Schröder, W.

2016-09-01

The upper limit for the energy conversion rate of horizontal axis wind turbines (HAWT) is known as the Betz limit. Often this limit is also applied to vertical axis wind turbines (VAWT). However, a literature review reveals that early analytical and recent numerical approaches predicted values for the maximum power output of VAWTs close to or even higher than the Betz limit. Thus, it can be questioned whether the application of Betz's Law to VAWTs is justified. To answer this question, the current approach combines a free vortex model with a 2D inviscid panel code to represent the flow field of a generic VAWT. To ensure the validity of the model, an active blade pitch control system is used to avoid flow separation. An optimal pitch curve avoiding flow separation is determined for one specific turbine configuration by applying an evolutionary algorithm. The analysis yields a net power output that is slightly (≈6%) above the Betz limit. Besides the numerical result of an increased energy conversion rate, especially the identification of two physical power increasing mechanisms shows, that the application of Betz's Law to VAWTs is not justified.

Spectral scaling laws of solar wind fluctuations at 1 AU: Part 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Podesta, John J.

2013-06-13

In-situ measurements of solar wind fluctuations at 1 AU show that the reduced energy spectrum, equal to the sum of the reduced kinetic plus magnetic energy spectra, is characterized by a power-law scaling k{sup -{alpha}} in the inertial range with an average spectral exponent {alpha} Asymptotically-Equal-To 3/2, a result confirmed by independent analyses using data from different spacecraft. Magnetic field and electron density spectra at kinetic scales {rho}{sup -1}{sub i} < k < {rho}{sup -1}{sub e} both have a spectral index of approximately 2.7. These and other recent observations of spectral scaling laws in the solar wind using single spacecraftmore » measurements are briefly reviewed. The first part of this review, Part 1, is contained in a separate paper in these proceedings.« less

Surface drifter derived circulation in the northern and middle Adriatic Sea: Response to wind regime and season

USGS Publications Warehouse

Ursella, L.; Poulain, P.-M.; Signell, R.P.

2007-01-01

More than 120 satellite-tracked drifters were deployed in the northern and middle Adriatic (NMA) Sea between September 2002 and November 2003, with the purpose of studying the surface circulation at mesoscale to seasonal scale in relation to wind forcing, river runoff, and bottom topography. Pseudo-Eulerian and Lagrangian statistics were calculated from the low-pass-filtered drifter velocity data between September 2002 and December 2003. The structure of the mean circulation is determined with unprecedented high horizontal resolution by the new data. In particular, mean currents, velocity variance, and kinetic energy levels are shown to be maximal in the Western Adriatic Current (WAC). Separating data into seasons, we found that the mean kinetic energy is maximal in fall, with high values also in winter, while it is significantly weaker in summer. High-resolution Local Area Model Italy winds were used to relate the drifter velocities to the wind fields. The surface currents appear to be significantly influenced by the winds. The mean flow during the northeasterly bora regime shows an intensification of the across-basin recirculating currents. In addition, the WAC is strongly intensified both in intensity and in its offshore lateral extension. In the southeasterly sirocco regime, northward flow without recirculation dominates in the eastern half of the basin, while during northwesterly maestro the WAC is enhanced. Separating the data into low and high Po River discharge rates for low-wind conditions shows that the WAC and the velocity fluctuations in front of the Po delta are stronger for high Po River runoff. Lagrangian covariance, diffusivity, and integral time and space scales are larger in the along-basin direction and are maximal in the southern portion of the WAC. Copyright 2006 by the American Geophysical Union.

Numerical simulation of transitional flow on a wind turbine airfoil with RANS-based transition model

NASA Astrophysics Data System (ADS)

Zhang, Ye; Sun, Zhengzhong; van Zuijlen, Alexander; van Bussel, Gerard

2017-09-01

This paper presents a numerical investigation of transitional flow on the wind turbine airfoil DU91-W2-250 with chord-based Reynolds number Rec = 1.0 × 106. The Reynolds-averaged Navier-Stokes based transition model using laminar kinetic energy concept, namely the k - kL - ω model, is employed to resolve the boundary layer transition. Some ambiguities for this model are discussed and it is further implemented into OpenFOAM-2.1.1. The k - kL - ω model is first validated through the chosen wind turbine airfoil at the angle of attack (AoA) of 6.24° against wind tunnel measurement, where lift and drag coefficients, surface pressure distribution and transition location are compared. In order to reveal the transitional flow on the airfoil, the mean boundary layer profiles in three zones, namely the laminar, transitional and fully turbulent regimes, are investigated. Observation of flow at the transition location identifies the laminar separation bubble. The AoA effect on boundary layer transition over wind turbine airfoil is also studied. Increasing the AoA from -3° to 10°, the laminar separation bubble moves upstream and reduces in size, which is in close agreement with wind tunnel measurement.

Development of a 5.5 m diameter vertical axis wind turbine, phase 3

NASA Astrophysics Data System (ADS)

Dekitsch, A.; Etzler, C. C.; Fritzsche, A.; Lorch, G.; Mueller, W.; Rogalla, K.; Schmelzle, J.; Schuhwerk, W.; Vollan, A.; Welte, D.

1982-06-01

In continuation of development of a 5.5 m diameter vertical axis windmill that consists in conception, building, and wind tunnel testing, a Darrieus rotor windpowered generator feeding an isolated network under different wind velocity conditions and with optimal energy conversion efficiency was designed built, and field tested. The three-bladed Darrieus rotor tested in the wind tunnel was equiped with two variable pitch Savonius rotors 2 m in diameter. By means of separate measures of the aerodynamic factors and the energy consumption, effect of revisions and optimizations on different elements was assessed. Pitch adjustement of the Savonius blades, lubrication of speed reducer, rotor speed at cut-in of generator field excitation, time constant of field excitation, stability conditions, switch points of ohmic resistors which combined with a small electric battery simulated a larger isolated network connected with a large storage battery, were investigated. Fundamentals for the economic series production of windpowered generators with Darrieus rotors for the control and the electric conversion system are presented.

Rollover of Apparent Wave Attenuation in Ice Covered Seas

NASA Astrophysics Data System (ADS)

Li, Jingkai; Kohout, Alison L.; Doble, Martin J.; Wadhams, Peter; Guan, Changlong; Shen, Hayley H.

2017-11-01

Wave attenuation from two field experiments in the ice-covered Southern Ocean is examined. Instead of monotonically increasing with shorter waves, the measured apparent attenuation rate peaks at an intermediate wave period. This "rollover" phenomenon has been postulated as the result of wind input and nonlinear energy transfer between wave frequencies. Using WAVEWATCH III®, we first validate the model results with available buoy data, then use the model data to analyze the apparent wave attenuation. With the choice of source parameterizations used in this study, it is shown that rollover of the apparent attenuation exists when wind input and nonlinear transfer are present, independent of the different wave attenuation models used. The period of rollover increases with increasing distance between buoys. Furthermore, the apparent attenuation for shorter waves drops with increasing separation between buoys or increasing wind input. These phenomena are direct consequences of the wind input and nonlinear energy transfer, which offset the damping caused by the intervening ice.

Recent Insights into the Nature of Turbulence in the Solar Wind

NASA Technical Reports Server (NTRS)

Goldstein, Melvun L.

2008-01-01

During the past several years, studies of solar wind turbulence using data from Cluster and other spacecraft, and results from new numerical simulations, have revealed new aspects of solar wind turbulence. I will try to highlight some of that research. At the shortest length scales and highest frequencies, there is renewed interest in determining how the turbulence dissipates, e.g., whether by kinetic Alfven waves or whistler turbulence. Finding observational evidence for exponential damping of solar wind fluctuations has proven challenging. New studies using a combination of flux gate and search coil magnetometer data from Cluster have extended this search (in the spacecraft frame of reference) to more than 10 Hertz. New models and simulations are also being used to study the dissipation. A detailed study of fluctuations in the magnetosheath suggests that turbulent dissipation could be occurring at very thin current sheets as had been suggested by two-dimensional MHD simulations more than 20 years ago. Data from the four Cluster spacecraft, now at their maximum separation of 10,000 km provide new opportunities to investigate the symmetry properties, scale lengths, and the relative proportion of magnetic energy in parallel and perpendicular wave numbers of solar wind turbulence. By utilizing well-calibrated electron data, it has been possible to take advantage of the tetrahedral separation of Cluster in the solar wind near apogee to measure directly the compressibility and vorticity of the solar wind plasma.

A wind turbine hybrid simulation framework considering aeroelastic effects

NASA Astrophysics Data System (ADS)

Song, Wei; Su, Weihua

2015-04-01

In performing an effective structural analysis for wind turbine, the simulation of turbine aerodynamic loads is of great importance. The interaction between the wake flow and the blades may impact turbine blades loading condition, energy yield and operational behavior. Direct experimental measurement of wind flow field and wind profiles around wind turbines is very helpful to support the wind turbine design. However, with the growth of the size of wind turbines for higher energy output, it is not convenient to obtain all the desired data in wind-tunnel and field tests. In this paper, firstly the modeling of dynamic responses of large-span wind turbine blades will consider nonlinear aeroelastic effects. A strain-based geometrically nonlinear beam formulation will be used for the basic structural dynamic modeling, which will be coupled with unsteady aerodynamic equations and rigid-body rotations of the rotor. Full wind turbines can be modeled by using the multi-connected beams. Then, a hybrid simulation experimental framework is proposed to potentially address this issue. The aerodynamic-dominant components, such as the turbine blades and rotor, are simulated as numerical components using the nonlinear aeroelastic model; while the turbine tower, where the collapse of failure may occur under high level of wind load, is simulated separately as the physical component. With the proposed framework, dynamic behavior of NREL's 5MW wind turbine blades will be studied and correlated with available numerical data. The current work will be the basis of the authors' further studies on flow control and hazard mitigation on wind turbine blades and towers.

Quantification of the Energy Dissipated by Alfven Waves in a Polar Coronal Hole

NASA Astrophysics Data System (ADS)

Hahn, M.; Savin, D. W.

2013-12-01

We present a measurement of the energy carried and dissipated by Alfven waves in a polar coronal hole. Alfven waves have been proposed as the energy source that heats the corona and drives the solar wind. Previous work has shown that line widths decrease with height in coronal holes, which is a signature of wave damping, but have been unable to quantify the energy lost by the waves. This is because line widths depend on both the non-thermal velocity vnt and the ion temperature Ti. We have implemented a means to separate the Ti and vnt contributions using the observation that, at low heights, the waves are undamped and the ion temperatures do not change with height. This enables us to determine the amount of energy carried by the waves at low heights, which is proportional to vnt. We find the initial energy flux density present was 6.7×0.7×10^5 erg cm^-2 s^-1, which is sufficient to heat the coronal hole and accelerate the solar wind during the 2007 - 2009 solar minimum. Additionally, we find that about 85% of this energy is dissipated below 1.5 R_sun, sufficiently low that thermal conduction can transport the energy throughout the coronal hole, heating it and driving the fast solar wind. The remaining energy is roughly consistent with what models show is needed to provide the extended heating above the sonic point for the fast solar wind. We have also studied Ti, which we found to be in the range of 1 - 2 MK, depending on the ion species.

Flow separation on wind turbines blades

NASA Astrophysics Data System (ADS)

Corten, G. P.

2001-01-01

In the year 2000, 15GW of wind power was installed throughout the world, producing 100PJ of energy annually. This contributes to the total electricity demand by only 0.2%. Both the installed power and the generated energy are increasing by 30% per year world-wide. If the airflow over wind turbine blades could be controlled fully, the generation efficiency and thus the energy production would increase by 9%. Power Control To avoid damage to wind turbines, they are cut out above 10 Beaufort (25 m/s) on the wind speed scale. A turbine could be designed in such a way that it converts as much power as possible in all wind speeds, but then it would have to be to heavy. The high costs of such a design would not be compensated by the extra production in high winds, since such winds are rare. Therefore turbines usually reach maximum power at a much lower wind speed: the rated wind speed, which occurs at about 6 Beaufort (12.5 m/s). Above this rated speed, the power intake is kept constant by a control mechanism. Two different mechanisms are commonly used. Active pitch control, where the blades pitch to vane if the turbine maximum is exceeded or, passive stall control, where the power control is an implicit property of the rotor. Stall Control The flow over airfoils is called "attached" when it flows over the surface from the leading edge to the trailing edge. However, when the angle of attack of the flow exceeds a certain critical angle, the flow does not reach the trailing edge, but leaves the surface at the separation line. Beyond this line the flow direction is reversed, i.e. it flows from the trailing edge backward to the separation line. A blade section extracts much less energy from the flow when it separates. This property is used for stall control. Stall controlled rotors always operate at a constant rotation speed. The angle of attack of the flow incident to the blades is determined by the blade speed and the wind speed. Since the latter is variable, it determines the angle of attack. The art of designing stall rotors is to make the separated area on the blades extend in such a way, that the extracted power remains precisely constant, independent of the wind speed, while the power in the wind at cut-out exceeds the maximum power of the turbine by a factor of 8. Since the stall behaviour is influenced by many parameters, this demand cannot be easily met. However, if it can be met, the advantage of stall control is its passive operation, which is reliable and cheap. Problem Definition In practical application, stall control is not very accurate and many stall-controlled turbines do not meet their specifications. Deviations of the design-power in the order of tens of percent are regular. In the nineties, the aerodynamic research on these deviations focussed on: profile aerodynamics, computational fluid dynamics, rotational effects on separation and pressure measurements on test turbines. However, this did not adequately solve the actual problems with stall turbines. In this thesis, we therefore formulated the following as the essential question: "Does the separated blade area really extend with the wind speed, as we predict?" To find the answer a measurement technique was required, which 1) was applicable on large commercial wind turbines, 2) could follow the dynamic changes of the stall pattern, 3) was not influenced by the centrifugal force and 4) did not disturb the flow. Such a technique was not available, therefore we decided to develop it. Stall Flag Method For this method, a few hundred indicators are fixed to the rotor blades in a special pattern. These indicators, called "stall flags" are patented by the Netherlands Energy Research Foundation (ECN). They have a retro-reflective area which, depending on the flow direction, is or is not covered. A powerful light source in the field up to 500m behind the turbine illuminates the swept rotor area. The uncovered reflectors reflect the light to the source, where a digital video camera records the dynamic stall patterns. The images are analysed by image processing software that we developed. The program extracts the stall pattern, the blade azimuth angles and the rotor speed from the stall flags. It also measures the yaw error and the wind speed from the optical signals of other sensors, which are recorded simultaneously. We subsequently characterise the statistical stall behaviour from the sequences of thousands of analysed images. For example, the delay in the stall angle by vortex generators can be measured within 1° of accuracy from the stall flag signals. Properties of the Stall Flag The new indicators are compared to the classic tufts. Stall flags are pressure driven while tufts are driven by frictional drag, which means that they have more drag. The self-excited motion of tufts, due to the Kelvin-Helmholtz instability, complicates the interpretation and gives more drag. We designed stall flags in such a way that this instability is avoided. An experiment with a 65cm diameter propeller confirms the independence of stall flags from the centrifugal force and that stall flags respond quickly to changes in the flow. We developed an optical model of the method to find an optimum set-up. With the present system, we can take measurements on turbines of all actual diameters. The stall flag responds to separated flow with an optical signal. The contrast of this signal exceeds that of tuft-signals by a factor of at least 1000. To detect the stall flag signal we need a factor of 25 fewer pixels of the CCD chip than is necessary for tufts. Stall flags applied on fast moving objects may show light tracks due to motion blur, which in fact yields even more information. In the case of tuft visualisations, even a slight motion blur is fatal. Principal Results In dealing with the fundamental theory of wind turbines, we found a new aspect of the conversion efficiency of a wind turbine, which also concerns the stall behaviour. Another new aspect concerns the effects of rotation on stall. By using the stall flag method, we were able to clear up two practical problems that seriously threatened the performance of stall turbines. These topics will be described briefly. 1. Inherent Heat Generation The classic result for an actuator disk representing a wind turbine is that the power extracted equals the kinetic power transferred. This is a consequence of disregarding the flow around the disk. When this flow is included, we need to introduce a heat generation term in the energy balance. This has the practical consequence that an actuator disk at the Lanchester-Betz limit transfers 50% more kinetic energy than it extracts. This surplus is dissipated in heat. Using this new argument, together with a classic argument on induction, we see no reason to introduce the concept of edge-forces on the tips of the rotor blades (Van Kuik, 1991). We rather recommend following the ideas of Lanchester (1915) on the edge of the actuator disk and on the wind speed at the disc. We analyse the concept induction, and show that correcting for the aspect ratio, for induced drag and application of Blade Element Momentum Theory all have the same significance for a wind turbine. Such corrections are sometimes made twice (Viterna & Corrigan, 1981). 2. Rotational Effects on Flow Separation In designing wind turbine rotors, one uses the aerodynamic characteristics measured in the wind tunnel on fixed aerodynamic profiles. These characteristics are corrected for the effects of rotation and subsequently used for wind turbine rotors. Such a correction was developed by Snel (1990-1999). This correction is based on boundary layer theory, the validity of which we question in regard to separated flow. We estimated the effects of rotation on flow separation by arguing that the separation layer is thick so the velocity gradients are small and viscosity can be neglected. We add the argument that the chord-wise speed and its derivative normal to the wall is zero at the separation line, which causes the terms with the chord-wise speed or accelerations to disappear. The conclusion is that the chord-wise pressure gradient balances the Coriolis force. By doing so we obtain a simple set of equations that can be solved analytically. Subsequently, our model predicts that the convective term with the radial velocity (vrvr/r) is dominant in the equation for the r-direction, precisely the term that was neglected in Snel's analysis. 3. Multiple Power Levels Several large commercial wind turbines demonstrate drops in maximum power levels up to 45%, under apparently equal conditions. Earlier studies attempting to explain this effect by technical malfunctioning, aerodynamic instabilities and blade contamination effects estimated with computational fluid dynamics, have not yet yielded a plausible result. We formulated many hypotheses, three of which were useful. By taking stall flag measurements and making two other crucial experiments, we could confirm one of those three hypotheses: the insect hypothesis. Insects only fly in low wind, impacting upon the blades at specific locations. In these conditions, the insectual remains are located at positions where roughness has little influence on the profile performance, so that the power is not affected. In high winds however, the flow around the blades has changed. As a result, the positions at which the insects have impacted at low winds are very sensitive to contamination. So the contamination level changes at low wind when insects fly and this level determines the power in high winds when insects do not fly. As a consequence we get discrete power levels in high winds. The other two hypotheses, which did not cause the multiple power levels for the case we studied, gave rise to two new insights. First, we expect the power to depend on the wind direction at sites where the shape of the terrain concentrates the wind. In this case the power level of all turbine types, including pitch regulated ones, will be affected. Second, we infer heuristically that the stalled area on wind turbine blades will adapt continuously to wind variations. Therefore, the occurrence of strong bi-stable stall-hysteresis, which most blade sections demonstrate in the wind tunnel, is lost. This has been confirmed by taking special stall flag measurements. 4. Deviation of Specifications The maximum power of stall controlled wind turbines often shows large systematic deviations from the design. We took stall flag measurements on a rotor, the maximum power of which was 30% too high, so that the turbine had to be cut out far below the designed cut-out wind speed. We immediately observed the blade areas with deviating stall behaviour. Some areas that should have stalled did not and caused the excessive power. We adapted those areas by shifting the vortex generators. In this way we obtained a power curve that met the design much more closely and we realised a production increase of 8%.

Supernova ejecta with a relativistic wind from a central compact object: a unified picture for extraordinary supernovae

NASA Astrophysics Data System (ADS)

Suzuki, Akihiro; Maeda, Keiichi

2017-04-01

The hydrodynamical interaction between freely expanding supernova ejecta and a relativistic wind injected from the central region is studied in analytic and numerical ways. As a result of the collision between the ejecta and the wind, a geometrically thin shell surrounding a hot bubble forms and expands in the ejecta. We use a self-similar solution to describe the early dynamical evolution of the shell and carry out a two-dimensional special relativistic hydrodynamic simulation to follow further evolution. The Rayleigh-Taylor instability inevitably develops at the contact surface separating the shocked wind and ejecta, leading to the complete destruction of the shell and the leakage of hot gas from the hot bubble. The leaking hot materials immediately catch up with the outermost layer of the supernova ejecta and thus different layers of the ejecta are mixed. We present the spatial profiles of hydrodynamical variables and the kinetic energy distributions of the ejecta. We stop the energy injection when a total energy of 1052 erg, which is 10 times larger than the initial kinetic energy of the supernova ejecta, is deposited into the ejecta and follow the subsequent evolution. From the results of our simulations, we consider expected emission from supernova ejecta powered by the energy injection at the centre and discuss the possibility that superluminous supernovae and broad-lined Ic supernovae could be produced by similar mechanisms.

A preliminary theoretical study of double blade two-dimensional aerodynamics for applications to vertical axis wind turbines

NASA Astrophysics Data System (ADS)

Weibust, E.

1981-04-01

A NASA model for computing the subsonic, viscous, attached flow around multielement airfoils was used to determine the amount of energy lost when using double blades rather than single ones. The resulting tangential force for the double or single blade configuration used as a criterion is found. Radial spacing, toe-in toe-out angle and tangential displacement (stagger) were varied to see how tagential force is affected. The greatest tangential force values are found to be achieved for maximum allowable radial spacing, which is determined by structural considerations, and is assumed to be on the order of 1.5 c. At this rather large distance, stagger as well as toe-in toe-out angle only gives slight improvements as long as the flow separation effects (stall region) are not considered. A large part of the energy is captured at relatively high wind speeds when the flow on the blades is partly separated (stalled).

Concurrent Harvesting of Ambient Energy by Hybrid Nanogenerators for Wearable Self-Powered Systems and Active Remote Sensing.

PubMed

Zheng, Haiwu; Zi, Yunlong; He, Xu; Guo, Hengyu; Lai, Ying-Chih; Wang, Jie; Zhang, Steven L; Wu, Changsheng; Cheng, Gang; Wang, Zhong Lin

2018-05-02

Harvesting energy available from ambient environment is highly desirable for powering personal electronics and health applications. Due to natural process and human activities, steam can be produced by boilers, human perspiration, and the wind exists ubiquitously. In the outdoor environment, these two phenomena usually exist at the same place, which contain heat and mechanical energies simultaneously. However, previous studies have isolated them as separate sources of energy to harvest and hence failed to utilize them effectively. Herein, we present unique hybrid nanogenerators for individually/simultaneously harvesting thermal energy from water vapors and mechanical energy from intermittent wind blowing from the bottom side, which consist of a wind-driven triboelectric nanogenerator (TENG) and pyroelectric-piezoelectric nanogenerators (PPENGs). The output power of the PPENG and the TENG can be up to about 184.32 μW and 4.74 mW, respectively, indicating the TENG plays the dominant role. Our hybrid nanogenerators could provide different applications such as to power digital watch and enable self-powered sensing with wireless transmission. The device could also be further integrated into a face mask for potentially wearable applications. This work not only provides a promising approach for renewable energy harvesting but also enriches potential applications for self-powered systems and wireless sensors.

A Numerical Study of Wind-Turbine Wakes for Three Atmospheric Stability Conditions

NASA Astrophysics Data System (ADS)

Xie, Shengbai; Archer, Cristina L.

2017-10-01

The effects of atmospheric stability on wind-turbine wakes are studied via large-eddy simulations. Three stability conditions are considered: stable, neutral, and unstable, with the same geostrophic wind speed aloft and the same Coriolis frequency. Both a single 5-MW turbine and a wind farm of five turbines are studied. The single-turbine wake is strongly correlated with stability, in terms of velocity deficit, turbulence kinetic energy (TKE) and temperature distribution. Because of the Coriolis effect, the wake shape deviates from a Gaussian distribution. For the wind-farm simulations, the separation of the core region and outer region is clear for the stable and neutral cases, but less distinct for the unstable case. The unstable case exhibits strong horizontal variations in wind speed. Local accelerations such as related to aisle jets are also observed, whose features depend on stability. The added TKE in the wind farm increases with stability. The highest power extraction and lowest power deficit are observed for the unstable case.

Gradient-Based Optimization of Wind Farms with Different Turbine Heights: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stanley, Andrew P. J.; Thomas, Jared; Ning, Andrew

Turbine wakes reduce power production in a wind farm. Current wind farms are generally built with turbines that are all the same height, but if wind farms included turbines with different tower heights, the cost of energy (COE) may be reduced. We used gradient-based optimization to demonstrate a method to optimize wind farms with varied hub heights. Our study includes a modified version of the FLORIS wake model that accommodates three-dimensional wakes integrated with a tower structural model. Our purpose was to design a process to minimize the COE of a wind farm through layout optimization and varying turbine hubmore » heights. Results indicate that when a farm is optimized for layout and height with two separate height groups, COE can be lowered by as much as 5%-9%, compared to a similar layout and height optimization where all the towers are the same. The COE has the best improvement in farms with high turbine density and a low wind shear exponent.« less

Gradient-Based Optimization of Wind Farms with Different Turbine Heights

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stanley, Andrew P. J.; Thomas, Jared; Ning, Andrew

Turbine wakes reduce power production in a wind farm. Current wind farms are generally built with turbines that are all the same height, but if wind farms included turbines with different tower heights, the cost of energy (COE) may be reduced. We used gradient-based optimization to demonstrate a method to optimize wind farms with varied hub heights. Our study includes a modified version of the FLORIS wake model that accommodates three-dimensional wakes integrated with a tower structural model. Our purpose was to design a process to minimize the COE of a wind farm through layout optimization and varying turbine hubmore » heights. Results indicate that when a farm is optimized for layout and height with two separate height groups, COE can be lowered by as much as 5%-9%, compared to a similar layout and height optimization where all the towers are the same. The COE has the best improvement in farms with high turbine density and a low wind shear exponent.« less

Wind Forced Variability in Eddy Formation, Eddy Shedding, and the Separation of the East Australian Current

NASA Astrophysics Data System (ADS)

Bull, Christopher Y. S.; Kiss, Andrew E.; Jourdain, Nicolas C.; England, Matthew H.; van Sebille, Erik

2017-12-01

The East Australian Current (EAC), like many other subtropical western boundary currents, is believed to be penetrating further poleward in recent decades. Previous observational and model studies have used steady state dynamics to relate changes in the westerly winds to changes in the separation behavior of the EAC. As yet, little work has been undertaken on the impact of forcing variability on the EAC and Tasman Sea circulation. Here using an eddy-permitting regional ocean model, we present a suite of simulations forced by the same time-mean fields, but with different atmospheric and remote ocean variability. These eddy-permitting results demonstrate the nonlinear response of the EAC to variable, nonstationary inhomogeneous forcing. These simulations show an EAC with high intrinsic variability and stochastic eddy shedding. We show that wind stress variability on time scales shorter than 56 days leads to increases in eddy shedding rates and southward eddy propagation, producing an increased transport and southward reach of the mean EAC extension. We adopt an energetics framework that shows the EAC extension changes to be coincident with an increase in offshore, upstream eddy variance (via increased barotropic instability) and increase in subsurface mean kinetic energy along the length of the EAC. The response of EAC separation to regional variable wind stress has important implications for both past and future climate change studies.

Experimental study of separator effect and shift angle on crossflow wind turbine performance

NASA Astrophysics Data System (ADS)

Fahrudin, Tjahjana, Dominicus Danardono Dwi Prija; Santoso, Budi

2018-02-01

This paper present experimental test results of separator and shift angle influence on Crossflow vertical axis wind turbine. Modification by using a separator and shift angle is expected to improve the thrust on the blade so as to improve the efficiency. The design of the wind turbine is tested at different wind speeds. There are 2 variations of crossflow turbine design which will be analyzed using an experimental test scheme that is, 3 stage crossflow and 2 stage crossflow with the shift angle. Maximum power coefficient obtained as Cpmax = 0.13 at wind speed 4.05 m/s for 1 separator and Cpmax = 0.12 for 12° shear angle of wind speed 4.05 m/s. In this study, power characteristics of the crossflow rotor with separator and shift angle have been tested. The experimental data was collected by variation of 2 separator and shift angle 0°, 6°, 12° and wind speed 3.01 - 4.85 m/s.

Use of meteorological information in the risk analysis of a mixed wind farm and solar

NASA Astrophysics Data System (ADS)

Mengelkamp, H.-T.; Bendel, D.

2010-09-01

Use of meteorological information in the risk analysis of a mixed wind farm and solar power plant portfolio H.-T. Mengelkamp*,** , D. Bendel** *GKSS Research Center Geesthacht GmbH **anemos Gesellschaft für Umweltmeteorologie mbH The renewable energy industry has rapidly developed during the last two decades and so have the needs for high quality comprehensive meteorological services. It is, however, only recently that international financial institutions bundle wind farms and solar power plants and offer shares in these aggregate portfolios. The monetary value of a mixed wind farm and solar power plant portfolio is determined by legal and technical aspects, the expected annual energy production of each wind farm and solar power plant and the associated uncertainty of the energy yield estimation or the investment risk. Building an aggregate portfolio will reduce the overall uncertainty through diversification in contrast to the single wind farm/solar power plant energy yield uncertainty. This is similar to equity funds based on a variety of companies or products. Meteorological aspects contribute to the diversification in various ways. There is the uncertainty in the estimation of the expected long-term mean energy production of the wind and solar power plants. Different components of uncertainty have to be considered depending on whether the power plant is already in operation or in the planning phase. The uncertainty related to a wind farm in the planning phase comprises the methodology of the wind potential estimation and the uncertainty of the site specific wind turbine power curve as well as the uncertainty of the wind farm effect calculation. The uncertainty related to a solar power plant in the pre-operational phase comprises the uncertainty of the radiation data base and that of the performance curve. The long-term mean annual energy yield of operational wind farms and solar power plants is estimated on the basis of the actual energy production and it's relation to a climatologically stable long-term reference period. These components of uncertainty are of technical nature and based on subjective estimations rather than on a statistically sound data analysis. And then there is the temporal and spatial variability of the wind speed and radiation. Their influence on the overall risk is determined by the regional distribution of the power plants. These uncertainty components are calculated on the basis of wind speed observations and simulations and satellite derived radiation data. The respective volatility (temporal variability) is calculated from the site specific time series and the influence on the portfolio through regional correlation. For an exemplary portfolio comprising fourteen wind farms and eight solar power plants the annual mean energy production to be expected is calculated, the different components of uncertainty are estimated for each single wind farm and solar power plant and for the portfolio as a whole. The reduction in uncertainty (or risk) through bundling the wind farms and the solar power plants (the portfolio effect) is calculated by Markowitz' Modern Portfolio Theory. This theory is applied separately for the wind farm and the solar power plant bundle and for the combination of both. The combination of wind and photovoltaic assets clearly shows potential for a risk reduction. Even assets with a comparably low expected return can lead to a significant risk reduction depending on their individual characteristics.

Estimation of Separation Buffers for Wind-Prediction Error in an Airborne Separation Assistance System

NASA Technical Reports Server (NTRS)

Consiglio, Maria C.; Hoadley, Sherwood T.; Allen, B. Danette

2009-01-01

Wind prediction errors are known to affect the performance of automated air traffic management tools that rely on aircraft trajectory predictions. In particular, automated separation assurance tools, planned as part of the NextGen concept of operations, must be designed to account and compensate for the impact of wind prediction errors and other system uncertainties. In this paper we describe a high fidelity batch simulation study designed to estimate the separation distance required to compensate for the effects of wind-prediction errors throughout increasing traffic density on an airborne separation assistance system. These experimental runs are part of the Safety Performance of Airborne Separation experiment suite that examines the safety implications of prediction errors and system uncertainties on airborne separation assurance systems. In this experiment, wind-prediction errors were varied between zero and forty knots while traffic density was increased several times current traffic levels. In order to accurately measure the full unmitigated impact of wind-prediction errors, no uncertainty buffers were added to the separation minima. The goal of the study was to measure the impact of wind-prediction errors in order to estimate the additional separation buffers necessary to preserve separation and to provide a baseline for future analyses. Buffer estimations from this study will be used and verified in upcoming safety evaluation experiments under similar simulation conditions. Results suggest that the strategic airborne separation functions exercised in this experiment can sustain wind prediction errors up to 40kts at current day air traffic density with no additional separation distance buffer and at eight times the current day with no more than a 60% increase in separation distance buffer.

Estimating Tropical Cyclone Surface Wind Field Parameters with the CYGNSS Constellation

NASA Astrophysics Data System (ADS)

Morris, M.; Ruf, C. S.

2016-12-01

A variety of parameters can be used to describe the wind field of a tropical cyclone (TC). Of particular interest to the TC forecasting and research community are the maximum sustained wind speed (VMAX), radius of maximum wind (RMW), 34-, 50-, and 64-kt wind radii, and integrated kinetic energy (IKE). The RMW is the distance separating the storm center and the VMAX position. IKE integrates the square of surface wind speed over the entire storm. These wind field parameters can be estimated from observations made by the Cyclone Global Navigation Satellite System (CYGNSS) constellation. The CYGNSS constellation consists of eight small satellites in a 35-degree inclination circular orbit. These satellites will be operating in standard science mode by the 2017 Atlantic TC season. CYGNSS will provide estimates of ocean surface wind speed under all precipitating conditions with high temporal and spatial sampling in the tropics. TC wind field data products can be derived from the level-2 CYGNSS wind speed product. CYGNSS-based TC wind field science data products are developed and tested in this paper. Performance of these products is validated using a mission simulator prelaunch.

High Resolution Observations of Escaping Ions in the Martian Magnetotail

NASA Astrophysics Data System (ADS)

Halekas, J. S.; Raman, C.; Brain, D.; DiBraccio, G. A.; Harada, Y.; McFadden, J. P.; Mitchell, D. L.; Connerney, J. E. P.; Jakosky, B. M.

2016-12-01

Ions escape from the Martian upper atmosphere via a number of channels, including the central plasmasheet of the magnetotail. Mars Express observations show that the heavy ions O+ and O2+ escaping through the central tail often have approximately the same energy, suggesting acceleration in a quasi-static electric field, which has been interpreted as a Hall electric field. The Solar Wind Ion Analyzer (SWIA) on MAVEN was designed to measure the upstream solar wind. However, during orbit segments with appropriate spacecraft attitude, SWIA can also make high resolution measurements of escaping ions in the tail. During the prime mission, these observations were only returned sporadically, during periods of intense escaping fluxes that fortuitously triggered a mode switch. Now, in the extended mission, we return high resolution observations from SWIA routinely. Some of these high resolution measurements reveal slight differences in both the direction and energy of escaping O+ and O2+ ions, which may help determine the acceleration process(es). We investigate the location and solar wind conditions for which the escaping ions separate in energy and angle and the systematics of their energies and flow vectors, and discuss the implications for ion acceleration and the overall picture of Martian atmospheric escape.

Nanotechnologies for efficient solar and wind energy harvesting and storage

NASA Astrophysics Data System (ADS)

Eldada, Louay A.

2010-08-01

We describe nanotechnologies used to improve the efficient harvest of energy from the Sun and the wind, and the efficient storage of energy in secondary batteries and ultracapacitors, for use in a variety of applications including smart grids, electric vehicles, and portable electronics. We demonstrate high-quality nanostructured copper indium gallium selenide (CIGS) thin films for photovoltaic (PV) applications. The self-assembly of nanoscale p-n junction networks creates n-type networks that act as preferential electron pathways, and p-type networks that act as preferential hole pathways, allowing positive and negative charges to travel to the contacts in physically separated paths, reducing charge recombination. We also describe PV nanotechnologies used to enhance light trapping, photon absorption, charge generation, charge transport, and current collection. Furthermore, we describe nanotechnologies used to improve the efficiency of power-generating wind turbines. These technologies include nanoparticle-containing lubricants that reduce the friction generated from the rotation of the turbines, nanocoatings for de-icing and self-cleaning technologies, and advanced nanocomposites that provide lighter and stronger wind blades. Finally, we describe nanotechnologies used in advanced secondary batteries and ultracapacitors. Nanostructured powder-based and carbon-nanotube-based cathodes and anodes with ultra-high surface areas boost the energy and power densities in secondary batteries, including lithium-ion and sodium-sulfur batteries. Nanostructured carbon materials are also controlled on a molecular level to offer large surface areas for the electrodes of ultracapacitors, allowing to store and supply large bursts of energy needed in some applications.

Using Large-Eddy Simulations to Define Spectral and Coherence Characteristics of the Hurricane Boundary Layer for Wind-Energy Applications

NASA Astrophysics Data System (ADS)

Worsnop, Rochelle P.; Bryan, George H.; Lundquist, Julie K.; Zhang, Jun A.

2017-10-01

Offshore wind-energy development is planned for regions where hurricanes commonly occur, such as the USA Atlantic Coast. Even the most robust wind-turbine design (IEC Class I) may be unable to withstand a Category-2 hurricane (hub-height wind speeds >50 m s^{-1}). Characteristics of the hurricane boundary layer that affect the structural integrity of turbines, especially in major hurricanes, are poorly understood, primarily due to a lack of adequate observations that span typical turbine heights (<200 m above sea level). To provide these data, we use large-eddy simulations to produce wind profiles of an idealized Category-5 hurricane at high spatial (10 m) and temporal (0.1 s) resolution. By comparison with unique flight-level observations from a field project, we find that a relatively simple configuration of the Cloud Model I model accurately represents the properties of Hurricane Isabel (2003) in terms of mean wind speeds, wind-speed variances, and power spectra. Comparisons of power spectra and coherence curves derived from our hurricane simulations to those used in current turbine design standards suggest that adjustments to these standards may be needed to capture characteristics of turbulence seen within the simulated hurricane boundary layer. To enable improved design standards for wind turbines to withstand hurricanes, we suggest modifications to account for shifts in peak power to higher frequencies and greater spectral coherence at large separations.

Using Large-Eddy Simulations to Define Spectral and Coherence Characteristics of the Hurricane Boundary Layer for Wind-Energy Applications

DOE PAGES

Worsnop, Rochelle P.; Bryan, George H.; Lundquist, Julie K.; ...

2017-06-08

Offshore wind-energy development is planned for regions where hurricanes commonly occur, such as the USA Atlantic Coast. Even the most robust wind-turbine design (IEC Class I) may be unable to withstand a Category-2 hurricane (hub-height wind speeds >50 m s -1). Characteristics of the hurricane boundary layer that affect the structural integrity of turbines, especially in major hurricanes, are poorly understood, primarily due to a lack of adequate observations that span typical turbine heights (<200 m above sea level). To provide these data, we use large-eddy simulations to produce wind profiles of an idealized Category-5 hurricane at high spatial (10more » m) and temporal (0.1 s) resolution. By comparison with unique flight-level observations from a field project, we find that a relatively simple configuration of the Cloud Model I model accurately represents the properties of Hurricane Isabel (2003) in terms of mean wind speeds, wind-speed variances, and power spectra. Comparisons of power spectra and coherence curves derived from our hurricane simulations to those used in current turbine design standards suggest that adjustments to these standards may be needed to capture characteristics of turbulence seen within the simulated hurricane boundary layer. To enable improved design standards for wind turbines to withstand hurricanes, we suggest modifications to account for shifts in peak power to higher frequencies and greater spectral coherence at large separations.« less

Using Large-Eddy Simulations to Define Spectral and Coherence Characteristics of the Hurricane Boundary Layer for Wind-Energy Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Worsnop, Rochelle P.; Bryan, George H.; Lundquist, Julie K.

Offshore wind-energy development is planned for regions where hurricanes commonly occur, such as the USA Atlantic Coast. Even the most robust wind-turbine design (IEC Class I) may be unable to withstand a Category-2 hurricane (hub-height wind speeds >50 m s -1). Characteristics of the hurricane boundary layer that affect the structural integrity of turbines, especially in major hurricanes, are poorly understood, primarily due to a lack of adequate observations that span typical turbine heights (<200 m above sea level). To provide these data, we use large-eddy simulations to produce wind profiles of an idealized Category-5 hurricane at high spatial (10more » m) and temporal (0.1 s) resolution. By comparison with unique flight-level observations from a field project, we find that a relatively simple configuration of the Cloud Model I model accurately represents the properties of Hurricane Isabel (2003) in terms of mean wind speeds, wind-speed variances, and power spectra. Comparisons of power spectra and coherence curves derived from our hurricane simulations to those used in current turbine design standards suggest that adjustments to these standards may be needed to capture characteristics of turbulence seen within the simulated hurricane boundary layer. To enable improved design standards for wind turbines to withstand hurricanes, we suggest modifications to account for shifts in peak power to higher frequencies and greater spectral coherence at large separations.« less

Cost Benefit Analysis of the Installation of a Wind Turbine on a Naval Ship

DTIC Science & Technology

2010-09-01

the ship is going to perform its mission. This area is known in advance and, according to data from meteorological stations, wind power potential and...the wind speed and the point of separation are revealed. Separation occurs about 50 degrees of the bow [1]. Separation and turbulence, however...positioned away from and before the separation point. 4 In summary, a wind turbine should be installed at the upper deck at the bow, before and as

The Development of a Finite Volume Method for Modeling Sound in Coastal Ocean Environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Long, Wen; Yang, Zhaoqing; Copping, Andrea E.

: As the rapid growth of marine renewable energy and off-shore wind energy, there have been concerns that the noises generated from construction and operation of the devices may interfere marine animals’ communication. In this research, a underwater sound model is developed to simulate sound prorogation generated by marine-hydrokinetic energy (MHK) devices or offshore wind (OSW) energy platforms. Finite volume and finite difference methods are developed to solve the 3D Helmholtz equation of sound propagation in the coastal environment. For finite volume method, the grid system consists of triangular grids in horizontal plane and sigma-layers in vertical dimension. A 3Dmore » sparse matrix solver with complex coefficients is formed for solving the resulting acoustic pressure field. The Complex Shifted Laplacian Preconditioner (CSLP) method is applied to efficiently solve the matrix system iteratively with MPI parallelization using a high performance cluster. The sound model is then coupled with the Finite Volume Community Ocean Model (FVCOM) for simulating sound propagation generated by human activities in a range-dependent setting, such as offshore wind energy platform constructions and tidal stream turbines. As a proof of concept, initial validation of the finite difference solver is presented for two coastal wedge problems. Validation of finite volume method will be reported separately.« less

Modeling and Optimization of Coordinative Operation of Hydro-wind-photovoltaic Considering Power Generation and Output Fluctuation

NASA Astrophysics Data System (ADS)

Wang, Xianxun; Mei, Yadong

2017-04-01

Coordinative operation of hydro-wind-photovoltaic is the solution of mitigating the conflict of power generation and output fluctuation of new energy and conquering the bottleneck of new energy development. Due to the deficiencies of characterizing output fluctuation, depicting grid construction and disposal of power abandon, the research of coordinative mechanism is influenced. In this paper, the multi-object and multi-hierarchy model of coordinative operation of hydro-wind-photovoltaic is built with the aim of maximizing power generation and minimizing output fluctuation and the constraints of topotaxy of power grid and balanced disposal of power abandon. In the case study, the comparison of uncoordinative and coordinative operation is carried out with the perspectives of power generation, power abandon and output fluctuation. By comparison from power generation, power abandon and output fluctuation between separate operation and coordinative operation of multi-power, the coordinative mechanism is studied. Compared with running solely, coordinative operation of hydro-wind-photovoltaic can gain the compensation benefits. Peak-alternation operation reduces the power abandon significantly and maximizes resource utilization effectively by compensating regulation of hydropower. The Pareto frontier of power generation and output fluctuation is obtained through multiple-objective optimization. It clarifies the relationship of mutual influence between these two objects. When coordinative operation is taken, output fluctuation can be markedly reduced at the cost of a slight decline of power generation. The power abandon also drops sharply compared with operating separately. Applying multi-objective optimization method to optimize the coordinate operation, Pareto optimal solution set of power generation and output fluctuation is achieved.

78 FR 2382 - Combined Notice of Filings #2

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-11

...: Blackwell Wind, LLC, CPV Cimarron Renewable Energy Company, LLC, Elk City Wind, LLC, Elk City II Wind, LLC, Ensign Wind, LLC, FPL Energy Cowboy Wind, LLC, FPL Energy Oklahoma Wind, LLC, FPL Energy Sooner Wind, LLC, Gray County Wind Energy, LLC, High Majestic Wind Energy Center, LLC, High Majestic Wind II, LLC, Minco...

Making windpower an important part of a national energy plan

NASA Astrophysics Data System (ADS)

Finlayson, A. N.

1981-01-01

The design characteristics of the Finlayson Windcatcher wind turbine are outlined. The unit geometry consists of two vertical axis cylindrical vane arrays mounted very close to each other and rotating in opposite directions. The two rotors are supported top and bottom by anti-friction bearings mounted at the ends of arms which are attached to a single support pillar. Because the rotor axes are downwind of the support pillar axis, they are free to swing in the horizontal plane, remaining automatically downwind without the need for a separate guide vane. There is not gyroscopic effect of the rotors to hinder rotation in wind direction. A 1-2 kW net electrical output in a 30 mph wind is estimated.

Operational Impacts of Wind Energy Resources in the Bonneville Power Administration Control Area - Phase I Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makarov, Yuri V.; Lu, Shuai

2008-07-15

This report presents a methodology developed to study the future impact of wind on BPA power system load following and regulation requirements. The methodology uses historical data and stochastic processes to simulate the load balancing processes in the BPA power system, by mimicking the actual power system operations. Therefore, the results are close to reality, yet the study based on this methodology is convenient to conduct. Compared with the proposed methodology, existing methodologies for doing similar analysis include dispatch model simulation and standard deviation evaluation on load and wind data. Dispatch model simulation is constrained by the design of themore » dispatch program, and standard deviation evaluation is artificial in separating the load following and regulation requirements, both of which usually do not reflect actual operational practice. The methodology used in this study provides not only capacity requirement information, it also analyzes the ramp rate requirements for system load following and regulation processes. The ramp rate data can be used to evaluate generator response/maneuverability requirements, which is another necessary capability of the generation fleet for the smooth integration of wind energy. The study results are presented in an innovative way such that the increased generation capacity or ramp requirements are compared for two different years, across 24 hours a day. Therefore, the impact of different levels of wind energy on generation requirements at different times can be easily visualized.« less

Solar wind energy input during prolonged, intense northward interplanetary magnetic fields: A new coupling function

NASA Astrophysics Data System (ADS)

Du, A. M.; Tsurutani, B. T.; Sun, W.

2011-12-01

Sudden energy release (ER) events in the midnight sector auroral zone during intense (B > 10 nT), long-duration (T > 3 h), northward (N = Bz > 0 nT) IMF magnetic clouds (MCs) during solar cycle 23 (SC23) have been examined in detail. The MCs with northward-then-southward (NS) IMFs were analyzed separately from MCs with southward-then-northward (SN) configurations. It is found that there is a lack of ER/substorms during the N field intervals of NS clouds. In sharp contrast, ER events do occur during the N field portions of SN MCs. From the above two results it is reasonable to conclude that the latter ER events represent residual energy remaining from the preceding S portions of the SN MCs. We derive a new solar wind-magnetosphere coupling function during northward IMFs: ENIMF = α N-1/12 V7/3 B1/2 + β V |Dstmin|. The first term on the right-hand side of the equation represents the energy input via “viscous interaction,” and the second term indicates the residual energy stored in the magnetotail. It is empirically found that the magnetotail/magnetosphere/ionosphere can store energy for a maximum of ˜4 h before it has dissipated away. This concept is defining one for ER/substorm energy storage. Our scenario indicates that the rate of solar wind energy injection into the magnetotail/magnetosphere/ionosphere for storage determines the potential form of energy release into the magnetosphere/ionosphere. This may be more important to understand solar wind-magnetosphere coupling than the dissipation mechanism itself (in understanding the form of the release). The concept of short-term energy storage is also applied for the solar case. It is argued that it may be necessary to identify the rate of energy input into solar magnetic loop systems to be able to predict the occurrence of solar flares.

Unraveling the Mysteries of Turbulence Transport in a Wind Farm

DOE PAGES

Jha, Pankaj K.; Duque, Earl P. N.; Bashioum, Jessica L.; ...

2015-06-26

A true physical understanding of the mysteries involved in the recovery process of the wake momentum deficit, downstream of utility-scale wind turbines in the atmosphere, has not been obtained to date. Field data are not acquired at sufficient spatial and temporal resolutions to dissect some of the mysteries of wake turbulence. It is here that the actuator line method has evolved to become the technology standard in the wind energy community. This work presents the actuator line method embedded into an Open source Field Operation and Manipulation (OpenFOAM) large-eddy simulation solver and applies it to two small wind farms, themore » first one consisting of an array of two National Renewable Energy Laboratory 5 Megawatt (NREL 5-MW) turbines separated by seven rotor diameters in neutral and unstable atmospheric boundary-layer flow and the second one consisting of five NREL 5-MW wind turbines in unstable atmospheric conditions arranged in two staggered arrays of two and three turbines, respectively. Detailed statistics involving power spectral density (PSD) of turbine power along with standard deviations reveal the effects of atmospheric turbulence and its space and time scales. In conclusion, high-resolution surface data extracts provide new insight into the complex recovery process of the wake momentum deficit governed by turbulence transport phenomena.« less

Unraveling the Mysteries of Turbulence Transport in a Wind Farm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jha, Pankaj K.; Duque, Earl P. N.; Bashioum, Jessica L.

A true physical understanding of the mysteries involved in the recovery process of the wake momentum deficit, downstream of utility-scale wind turbines in the atmosphere, has not been obtained to date. Field data are not acquired at sufficient spatial and temporal resolutions to dissect some of the mysteries of wake turbulence. It is here that the actuator line method has evolved to become the technology standard in the wind energy community. This work presents the actuator line method embedded into an Open source Field Operation and Manipulation (OpenFOAM) large-eddy simulation solver and applies it to two small wind farms, themore » first one consisting of an array of two National Renewable Energy Laboratory 5 Megawatt (NREL 5-MW) turbines separated by seven rotor diameters in neutral and unstable atmospheric boundary-layer flow and the second one consisting of five NREL 5-MW wind turbines in unstable atmospheric conditions arranged in two staggered arrays of two and three turbines, respectively. Detailed statistics involving power spectral density (PSD) of turbine power along with standard deviations reveal the effects of atmospheric turbulence and its space and time scales. In conclusion, high-resolution surface data extracts provide new insight into the complex recovery process of the wake momentum deficit governed by turbulence transport phenomena.« less

Small UAS-Based Wind Feature Identification System Part 1: Integration and Validation

PubMed Central

Rodriguez Salazar, Leopoldo; Cobano, Jose A.; Ollero, Anibal

2016-01-01

This paper presents a system for identification of wind features, such as gusts and wind shear. These are of particular interest in the context of energy-efficient navigation of Small Unmanned Aerial Systems (UAS). The proposed system generates real-time wind vector estimates and a novel algorithm to generate wind field predictions. Estimations are based on the integration of an off-the-shelf navigation system and airspeed readings in a so-called direct approach. Wind predictions use atmospheric models to characterize the wind field with different statistical analyses. During the prediction stage, the system is able to incorporate, in a big-data approach, wind measurements from previous flights in order to enhance the approximations. Wind estimates are classified and fitted into a Weibull probability density function. A Genetic Algorithm (GA) is utilized to determine the shaping and scale parameters of the distribution, which are employed to determine the most probable wind speed at a certain position. The system uses this information to characterize a wind shear or a discrete gust and also utilizes a Gaussian Process regression to characterize continuous gusts. The knowledge of the wind features is crucial for computing energy-efficient trajectories with low cost and payload. Therefore, the system provides a solution that does not require any additional sensors. The system architecture presents a modular decentralized approach, in which the main parts of the system are separated in modules and the exchange of information is managed by a communication handler to enhance upgradeability and maintainability. Validation is done providing preliminary results of both simulations and Software-In-The-Loop testing. Telemetry data collected from real flights, performed in the Seville Metropolitan Area in Andalusia (Spain), was used for testing. Results show that wind estimation and predictions can be calculated at 1 Hz and a wind map can be updated at 0.4 Hz. Predictions show a convergence time with a 95% confidence interval of approximately 30 s. PMID:28025531

Small UAS-Based Wind Feature Identification System Part 1: Integration and Validation.

PubMed

Rodriguez Salazar, Leopoldo; Cobano, Jose A; Ollero, Anibal

2016-12-23

This paper presents a system for identification of wind features, such as gusts and wind shear. These are of particular interest in the context of energy-efficient navigation of Small Unmanned Aerial Systems (UAS). The proposed system generates real-time wind vector estimates and a novel algorithm to generate wind field predictions. Estimations are based on the integration of an off-the-shelf navigation system and airspeed readings in a so-called direct approach. Wind predictions use atmospheric models to characterize the wind field with different statistical analyses. During the prediction stage, the system is able to incorporate, in a big-data approach, wind measurements from previous flights in order to enhance the approximations. Wind estimates are classified and fitted into a Weibull probability density function. A Genetic Algorithm (GA) is utilized to determine the shaping and scale parameters of the distribution, which are employed to determine the most probable wind speed at a certain position. The system uses this information to characterize a wind shear or a discrete gust and also utilizes a Gaussian Process regression to characterize continuous gusts. The knowledge of the wind features is crucial for computing energy-efficient trajectories with low cost and payload. Therefore, the system provides a solution that does not require any additional sensors. The system architecture presents a modular decentralized approach, in which the main parts of the system are separated in modules and the exchange of information is managed by a communication handler to enhance upgradeability and maintainability. Validation is done providing preliminary results of both simulations and Software-In-The-Loop testing. Telemetry data collected from real flights, performed in the Seville Metropolitan Area in Andalusia (Spain), was used for testing. Results show that wind estimation and predictions can be calculated at 1 Hz and a wind map can be updated at 0.4 Hz . Predictions show a convergence time with a 95% confidence interval of approximately 30 s .

Remote sensing signatures of oceanic whitecap at different wavelengths

NASA Astrophysics Data System (ADS)

Anguelova, M. D.; Dowgiallo, D. J.; Smith, G. B.; Means, S. L.; Savelyev, I.; Frick, G. M.; Snow, C. M.; Schindall, J. A.; Bobak, J. P.

2012-12-01

Oceanic whitecaps are the most direct surface expression of breaking wind waves in the ocean. Whitecap fraction quantifies the breaking events and is thus a suitable forcing variable for parameterizing and predicting various air-sea interaction processes. To this end, we have compiled a database of whitecap fraction W from satellites-borne microwave radiometric observations. These observations provide the total W including foam generated during active breaking of wind-driven waves and residual foam left behind by these breaking waves. However, the whitecap fraction associated with the actively breaking waves WA is needed for dynamic air-sea processes in the upper ocean such as turbulent mixing, gas exchange, ocean ambient noise, and spray-mediated intensification of tropical storms. To parameterize such processes, a database of WA separate from W is needed. We pursue this separation of WA from W by combining the Phillips concept of breaking wave statistics which connects WA with the energy dissipation rate of breaking waves and parametric estimates of energy dissipation from wave spectra measured from buoys. We seek additional physical understanding of, and experimental support for, this separation with a multi-instrumental field campaign. The instrumentation deployed includes a suite of sensors recording the whitecaps and breaking waves on the surface over wide range of the electromagnetic spectrum: visible (video cameras), infrared (IR camera), and microwave (radiometers at two frequencies, 10 GHz and 37 GHz). An acoustic array with three nested-aperture array at frequencies up to 2.4 kHz and aerosol/particle counter provide data for the bubbles generated beneath and sea spray produced above the whitecaps. We also deployed a transmitter horn to collect data useful to asses Radio Frequency Interference (RFI), which affects the collection and accuracy of satellite-based data. Various auxiliary data such as wind speed, air temperature, humidity, wave field, and water temperature profile characterize the experimental conditions. The goal of this field campaign is to provide experimental data for determining WA and W independently from the Phillips concept for energy dissipation. In these measurements, we rely on the good separation between WA and W in the IR region of the electromagnetic spectrum. We use the IR data to identify a separation criterion which then can be applied to time series of microwave and acoustic data. Obtaining WA via this separation criterion and comparing the results with those from the Phillips concept, we will have additional possibility to constrain WA obtained using energy dissipation. The measurements are made in April-May, 2012, on the Floating Instrument Platform (FLIP) drifting along the coast of California from Monterey Bay south toward Point Conception. We describe the experiment, characterize the study site, and present first data collected during this campaign.

Surface flow visualization of separated flows on the forebody of an F-18 aircraft and wind-tunnel model

NASA Technical Reports Server (NTRS)

Fisher, David F.; Richwine, David M.; Banks, Daniel W.

1988-01-01

A method of in-flight surface flow visualization similar to wind-tunnel-model oil flows is described for cases where photo-chase planes or onboard photography are not practical. This method, used on an F-18 aircraft in flight at high angles of attack, clearly showed surface flow streamlines in the fuselage forebody. Vortex separation and reattachment lines were identified with this method and documented using postflight photography. Surface flow angles measured at the 90 and 270 degrees meridians show excellent agreement with the wind tunnel data for a pointed tangent ogive with an aspect ratio of 3.5. The separation and reattachment line locations were qualitatively similar to the F-18 wind-tunnel-model oil flows but neither the laminar separation bubble nor the boundary-layer transition on the wind tunnel model were evident in the flight surface flows. The separation and reattachment line locations were in fair agreement with the wind tunnel data for the 3.5 ogive. The elliptical forebody shape of the F-18 caused the primary separation lines to move toward the leeward meridian. Little effect of angle of attack on the separation locations was noted for the range reported.

Computational studies of the effects of active and passive circulation enhancement concepts on wind turbine performance

NASA Astrophysics Data System (ADS)

Tongchitpakdee, Chanin

With the advantage of modern high speed computers, there has been an increased interest in the use of first-principles based computational approaches for the aerodynamic modeling of horizontal axis wind turbine (HAWT). Since these approaches are based on the laws of conservation (mass, momentum, and energy), they can capture much of the physics in great detail. The ability to accurately predict the airloads and power output can greatly aid the designers in tailoring the aerodynamic and aeroelastic features of the configuration. First-principles based analyses are also valuable for developing active means (e.g., circulation control), and passive means (e.g., Gurney flaps) of reducing unsteady blade loads, mitigating stall, and for efficient capture of wind energy leading to more electrical power generation. In this present study, the aerodynamic performance of a wind turbine rotor equipped with circulation enhancement technology (trailing edge blowing or Gurney flaps) is investigated using a three-dimensional unsteady viscous flow analysis. The National Renewable Energy Laboratory (NREL) Phase VI horizontal axis wind turbine is chosen as the baseline configuration. Prior to its use in exploring these concepts, the flow solver is validated with the experimental data for the baseline case under yawed flow conditions. Results presented include radial distribution of normal and tangential forces, shaft torque, root flap moment, surface pressure distributions at selected radial locations, and power output. Results show that good agreement has been for a range of wind speeds and yaw angles, where the flow is attached. At high wind speeds, however, where the flow is fully separated, it was found that the fundamental assumptions behind this present methodology breaks down for the baseline turbulence model (Spalart-Allmaras model), giving less accurate results. With the implementation of advanced turbulence model, Spalart-Allmaras Detached Eddy Simulation (SA-DES), the accuracy of the results at high wind speeds are improved. Results of circulation enhancement concepts show that, at low wind speed (attached flow) conditions, a Coanda jet at the trailing edge of the rotor blade is effective at increasing circulation resulting in an increase of lift and the chordwise thrust force. This leads to an increased amount of net power generation compared to the baseline configuration for moderate blowing coefficients. The effects of jet slot height and pulsed jet are also investigated in this study. A passive Gurney flap was found to increase the bound circulation and produce increased power in a manner similar to the Coanda jet. At high wind speed where the flow is separated, both the Coanda jet and Gurney flap become ineffective. Results of leading edge blowing indicate that a leading edge blowing jet is found to be beneficial in increasing power generation at high wind speeds. The effect of Gurney flap angle is also studied. Gurney flap angle has significant influence in power generation. Higher power output is obtained at higher flap angles.

Plasma plume MHD power generator and method

DOEpatents

Hammer, James H.

1993-01-01

Highly-conducting plasma plumes are ejected across the interplanetary magnetic field from a situs that is moving relative to the solar wind, such as a spacecraft or an astral body, such as the moon, having no magnetosphere that excludes the solar wind. Discrete plasma plumes are generated by plasma guns at the situs extending in opposite directions to one another and at an angle, preferably orthogonal, to the magnetic field direction of the solar wind plasma. The opposed plumes are separately electrically connected to their source by a low impedance connection. The relative movement between the plasma plumes and the solar wind plasma creates a voltage drop across the plumes which is tapped by placing the desired electrical load between the electrical connections of the plumes to their sources. A portion of the energy produced may be used in generating the plasma plumes for sustained operation.

A parameter study of the two-fluid solar wind

NASA Technical Reports Server (NTRS)

Sandbaek, Ornulf; Leer, Egil; Holzer, Thomas E.

1992-01-01

A two-fluid model of the solar wind was introduced by Sturrock and Hartle (1966) and Hartle and Sturrock (1968). In these studies the proton energy equation was integrated neglecting the heat conductive term. Later several authors solved the equations for the two-fluid solar wind model keeping the proton heat conductive term. Methods where the equations are integrated simultaneously outward and inward from the critical point were used. The equations were also integrated inward from a large heliocentric distance. These methods have been applied to cases with low coronal base electron densities and high base temperatures. In this paper we present a method of integrating the two-fluid solar wind equations using an iteration procedure where the equations are integrated separately and the proton flux is kept constant during the integrations. The technique is applicable for a wide range of coronal base densities and temperatures. The method is used to carry out a parameter study of the two-fluid solar wind.

Interaction Between the Atmospheric Boundary Layer and Wind Energy: From Continental-Scale to Turbine-Scale

NASA Astrophysics Data System (ADS)

St. Martin, Clara Mae

Wind turbines and groups of wind turbines, or "wind plants", interact with the complex and heterogeneous boundary layer of the atmosphere. We define the boundary layer as the portion of the atmosphere directly influenced by the surface, and this layer exhibits variability on a range of temporal and spatial scales. While early developments in wind energy could ignore some of this variability, recent work demonstrates that improved understanding of atmosphere-turbine interactions leads to the discovery of new ways to approach turbine technology development as well as processes such as performance validation and turbine operations. This interaction with the atmosphere occurs at several spatial and temporal scales from continental-scale to turbine-scale. Understanding atmospheric variability over continental-scales and across plants can facilitate reliance on wind energy as a baseload energy source on the electrical grid. On turbine scales, understanding the atmosphere's contribution to the variability in power production can improve the accuracy of power production estimates as we continue to implement more wind energy onto the grid. Wind speed and directional variability within a plant will affect wind turbine wakes within the plants and among neighboring plants, and a deeper knowledge of these variations can help mitigate effects of wakes and possibly even allow the manipulation of these wakes for increased production. Herein, I present the extent of my PhD work, in which I studied outstanding questions at these scales at the intersections of wind energy and atmospheric science. My work consists of four distinct projects. At the coarsest scales, I analyze the separation between wind plant sites needed for statistical independence in order to reduce variability for grid-integration of wind. At lower wind speeds, periods of unstable and more turbulent conditions produce more power than periods of stable and less turbulent conditions, while at wind speeds closer to rated wind speed, periods of unstable and more turbulent conditions produce less power than periods of stable and less turbulent conditions. Using these new, stability- and turbulence-specific power curves to calculate annual energy production (AEP) estimates results in smaller AEPs than if calculated using no stability and turbulence filters, which could have implications for manufacturers and operators. In my third project, I address the problem of expensive power production validation. Rather than erecting towers to provide upwind wind measurements, I explore the utility of using nacelle-mounted anemometers for power curve verification studies. I calculate empirical nacelle transfer functions (NTFs) with upwind tower and turbine measurements. The fifth-order and second-order NTFs show a linear relationship between upwind wind speed and nacelle wind speed at wind speeds less than about 9 m s-1 , but this relationship becomes non-linear at wind speeds higher than about 9 m s-1. The use of NTFs results in AEPs within 1 % of an AEP using upwind wind speeds. Additionally, during periods of unstable conditions as well as during more turbulent conditions, the nacelle-mounted anemometer underestimates the upwind wind speed more than during periods of stable conditions and less turbulence conditions at some wind speed bins below rated speed. Finally, in my fourth project, I consider spatial scales on the order of a wind plant. Using power production data from over 300 turbines from four neighboring wind farms in the western US along with simulations using the Weather Research and Forecasting model's Wind Farm Parameterization (WRF-WFP), I investigate the advantage of using the WFP to simulate wakes. During this case, winds from the west and north-northwest range from about 5 to 11 m s-1. A down-ramp occurs in this case study, which WRF predicts too early. The early prediction of the down-ramp likely affects the error in WRF-predicted power, the results of which show exaggerated wake effects. While these projects span a range of spatio-temporal scales, a unifying theme is the important aspect of atmospheric variation on wind power production, wind power production estimates, and means for facilitating the integration of wind-generated electricity into power grids. Future work, such as universal NTFs for sites with similar characteristics, NTFs for waked turbines, or the deployment of lidars on turbine nacelles for operation purposes, should continue to study the mutually-important interconnections between these two fields. (Abstract shortened by ProQuest.).

Dissipation in the Baltic proper during winter stratification

NASA Astrophysics Data System (ADS)

Lass, Hans Ulrich; Prandke, Hartmut; Liljebladh, Bengt

2003-06-01

Profiles of dissipation rates and stratification between 10 and 120 m depth were measured with a loosely tethered profiler over a 9-day winter period in the Gotland Basin of the Baltic Sea. Supplementary measurements of current profiles were made with moored ADCPs. Temporal and spatial patterns of the stratification were observed by means of towed CTD. Shallow freshwater lenses in the surface mixed layer, mesoscale eddies, inertial oscillations, and inertial waves as part of the internal wave spectrum provided the marine physical environment for the small-scale turbulence. Two well-separated turbulence regimes were detected. The turbulence in the surface mixed layer was well correlated with the wind. The majority of the energy flux from the wind to the turbulent kinetic energy was dissipated within the surface mixed layer. A minor part of this flux was consumed by changes of the potential energy of the fresh water lenses. The penetration depth Hpen of the wind-driven turbulence into the weakly stratified surface mixed layer depended on the local wind speed (W10) as Hpen = cW103/2 Active erosion of the Baltic halocline by wind-driven turbulence is expected for wind speeds greater than 14 m/s. The turbulence in the strongly stratified interior of the water column was quite independent of the meteorological forcing at the sea surface. The integrated production of turbulent kinetic energy exceeded the energy loss of inertial oscillations in the surface layer suggesting additional energy sources which might have been provided by inertial wave radiation during geostrophic adjustment of coastal jets and mesoscale eddies. The averaged dissipation rate profile in the stratified part of the water column, best fitted by ɛ ∝ EN, was different from the scaling of the dissipation in the thermocline of the ocean [, 1986]. The diapycnical mixing coefficient (Kv) was best fit by Kv = a0/N according to [1987] with a0 ≈ 0.87 × 10-7 m2/s2. The diapycnal diffusivity estimated from the dissipation rate was lower than those estimated by the bulk method.

Hybrid RANS-LES using high order numerical methods

NASA Astrophysics Data System (ADS)

Henry de Frahan, Marc; Yellapantula, Shashank; Vijayakumar, Ganesh; Knaus, Robert; Sprague, Michael

2017-11-01

Understanding the impact of wind turbine wake dynamics on downstream turbines is particularly important for the design of efficient wind farms. Due to their tractable computational cost, hybrid RANS/LES models are an attractive framework for simulating separation flows such as the wake dynamics behind a wind turbine. High-order numerical methods can be computationally efficient and provide increased accuracy in simulating complex flows. In the context of LES, high-order numerical methods have shown some success in predictions of turbulent flows. However, the specifics of hybrid RANS-LES models, including the transition region between both modeling frameworks, pose unique challenges for high-order numerical methods. In this work, we study the effect of increasing the order of accuracy of the numerical scheme in simulations of canonical turbulent flows using RANS, LES, and hybrid RANS-LES models. We describe the interactions between filtering, model transition, and order of accuracy and their effect on turbulence quantities such as kinetic energy spectra, boundary layer evolution, and dissipation rate. This work was funded by the U.S. Department of Energy, Exascale Computing Project, under Contract No. DE-AC36-08-GO28308 with the National Renewable Energy Laboratory.

Statistical analysis of dispersion relations in turbulent solar wind fluctuations using Cluster data

NASA Astrophysics Data System (ADS)

Perschke, C.; Narita, Y.

2012-12-01

Multi-spacecraft measurements enable us to resolve three-dimensional spatial structures without assuming Taylor's frozen-in-flow hypothesis. This is very useful to study frequency-wave vector diagram in solar wind turbulence through direct determination of three-dimensional wave vectors. The existence and evolution of dispersion relation and its role in fully-developed plasma turbulence have been drawing attention of physicists, in particular, if solar wind turbulence represents kinetic Alfvén or whistler mode as the carrier of spectral energy among different scales through wave-wave interactions. We investigate solar wind intervals of Cluster data for various flow velocities with a high-resolution wave vector analysis method, Multi-point Signal Resonator technique, at the tetrahedral separation about 100 km. Magnetic field data and ion data are used to determine the frequency- wave vector diagrams in the co-moving frame of the solar wind. We find primarily perpendicular wave vectors in solar wind turbulence which justify the earlier discussions about kinetic Alfvén or whistler wave. The frequency- wave vector diagrams confirm (a) wave vector anisotropy and (b) scattering in frequencies.

Effect of wind turbine wakes on summer-time wind profiles in the US Great Plains

NASA Astrophysics Data System (ADS)

Rhodes, M. E.; Lundquist, J. K.; Aitken, M.

2011-12-01

Wind energy is steadily becoming a significant source of grid electricity in the United States, and the Midwestern United States provides one of the nation's richest wind resources. This study examines the effect of wind turbine wakes on the wind profile in central Iowa. Data were collected using a coherent Doppler LiDAR system located approximately 2.5 rotor diameters north of a row of modern multi-MW wind turbine generators. The prevailing wind direction was from the South allowing the LiDAR to capture wind turbine wake properties; however, a number of periods existed where the LiDAR captured undisturbed flow. The LiDAR system reliably obtained readings up to 200 m above ground level (AGL), spanning the entire rotor disk (~40 m to 120 m AGL) which far surpasses the information provided by traditional wind resource assessment instrumentation. We extract several relevant parameters from the lidar data including: horizontal wind speed, vertical velocity, horizontal turbulence intensity, wind shear, and turbulent kinetic energy (TKE). Each time period at a particular LiDAR measurement height was labeled "wake" or "undisturbed" based on the wind direction at that height. Wake and undisturbed data were averaged separately to create a time-height cross-section averaged day for each parameter. Significant differences between wake and undisturbed data emerge. During the day, wake conditions experience larger values of TKE within the altitudes of the turbine rotor disk while TKE values above the rotor disk are similar between waked and undisturbed conditions. Furthermore, the morning transition of TKE in the atmospheric boundary layer commences earlier during wake conditions than in undisturbed conditions, and the evening decay of TKE persists longer during wake conditions. Waked wind shear is consistently greater than undisturbed periods at the edges of the wind turbine rotor disk (40m & 120m AGL), but especially so during the night where wind shear values during wake conditions are three times larger than in undisturbed conditions. Waked conditions show an increased rate of nocturnal subsidence over that of undisturbed conditions, likely due to the momentum deficit as a result of energy extraction by the turbine. Turbulent intensity shows increased levels and longevity in the waked rotor region when compared to the undisturbed conditions. The presentation will present these differences between waked and undisturbed conditions, and compare these observations to the phenomena accounted for in traditional wind turbine wake models.

Intercomparison of state-of-the-art models for wind energy resources with mesoscale models:

NASA Astrophysics Data System (ADS)

Olsen, Bjarke Tobias; Hahmann, Andrea N.; Sempreviva, Anna Maria; Badger, Jake; Joergensen, Hans E.

2016-04-01

1. Introduction Mesoscale models are increasingly being used to estimate wind conditions to identify perspective areas and sites where to develop wind farm projects. Mesoscale models are functional for giving information over extensive areas with various terrain complexities where measurements are scarce and measurement campaigns costly. Several mesoscale models and families of models are being used, and each often contains thousands of setup options. Since long-term integrations are expensive and tedious to carry out, only limited comparisons exist. To remedy this problem and for evaluating the capabilities of mesoscale models to estimate site wind conditions, a tailored benchmarking study has been co-organized by the European Wind Energy Association (EWEA) and the European Energy Research Alliance Joint Programme Wind Energy (EERA JP WIND). EWEA hosted results and ensured that participants were anonymous. The blind evaluation was performed at the Wind Energy Department of the Technical University of Denmark (DTU) with the following objectives: (1) To highlight common issues on mesoscale modelling of wind conditions on sites with different characteristics, and (2) To identify gaps and strengths of models and understand the root conditions for further evaluating uncertainties. 2. Approach Three experimental sites were selected: FINO 3 (offshore, GE), Høvsore (coastal, DK), and Cabauw (land-based, NL), and three other sites without observations based on . The three mast sites were chosen because the availability of concurrent suitable time series of vertical profiles of winds speed and other surface parameters. The participants were asked to provide hourly time series of wind speed, wind direction, temperature, etc., at various vertical heights for a complete year. The methodology used to derive the time series was left to the choice of the participants, but they were asked for a brief description of their model and many other parameters (e.g., horizontal and vertical resolution, model parameterizations, surface roughness length) that could be used to group the various models and interpret the results of the intercomparison. 3. Main body abstract Twenty separate entries were received by the deadline of 31 March 2015. They included simulations done with various versions of the Weather Research and Forecast (WRF) model, but also of six other well-known mesoscale models. The various entries represent an excellent sample of the various models used in by the wind energy industry today. The analysis of the submitted time series included comparison to observations, summarized with well-known measures such as biases, RMSE, correlations, and of sector-wise statistics, e.g. frequency and Weibull A and k. The comparison also includes the observed and modeled temporal spectra. The various statistics were grouped as a function of the various models, their spatial resolution, forcing data, and the various integration methods. Many statistics have been computed and will be presented in addition to those shown in the Helsinki presentation. 4. Conclusions The analysis of the time series from twenty entries has shown to be an invaluable source of information about state of the art in wind modeling with mesoscale models. Biases between the simulated and observed wind speeds at hub heights (80-100 m AGL) from the various models are around ±1.0 m/s and fairly independent of the site and do not seem to be directly related to the model horizontal resolution used in the modeling. As probably expected, the wind speeds from the simulations using the various version of the WRF model cluster close to each other, especially in their description of the wind profile.

Laboratory investigation and direct numerical simulation of wind effect on steep surface waves

NASA Astrophysics Data System (ADS)

Troitskaya, Yuliya; Sergeev, Daniil; Druzhinin, Oleg; Ermakova, Olga

2015-04-01

The small scale ocean-atmosphere interaction at the water-air interface is one of the most important factors determining the processes of heat, mass, and energy exchange in the boundary layers of both geospheres. Another important aspect of the air-sea interaction is excitation of surface waves. One of the most debated open questions of wave modeling is concerned with the wind input in the wave field, especially for the case of steep and breaking waves. Two physical mechanisms are suggested to describe the excitation of finite amplitude waves. The first one is based on the treatment of the wind-wave interaction in quasi-linear approximation in the frameworks of semi-empirical models of turbulence of the low atmospheric boundary layer. An alternative mechanism is associated with separation of wind flow at the crests of the surface waves. The "separating" and "non-separating" mechanisms of wave generation lead to different dependences of the wind growth rate on the wave steepness: the latter predicts a decrease in the increment with wave steepness, and the former - an increase. In this paper the mechanism of the wind-wave interaction is investigated basing on physical and numerical experiments. In the physical experiment, turbulent airflow over waves was studied using the video-PIV method, based on the application of high-speed video photography. Alternatively to the classical PIV technique this approach provides the statistical ensembles of realizations of instantaneous velocity fields. Experiments were performed in a round wind-wave channel at Institute of Applied Physics, Russian Academy of Sciences. A fan generated the airflow with the centerline velocity 4 m/s. The surface waves were generated by a programmed wave-maker at the frequency of 2.5 Hz with the amplitudes of 0.65 cm, 1.4 cm, and 2 cm. The working area (27.4 × 10.7 cm2) was at a distance of 3 m from the fan. To perform the measurements of the instantaneous velocity fields, spherical polyamide particles 20 μm in diameter were injected into the airflow. The images of the illuminated particles were photographed with a digital CCD video camera at a rate of 1000 frames per second. For the each given parameters of wind and waves, a statistical ensemble of 30 movies with duration from 200 to 600 ms was obtained. Individual flow realizations manifested the typical features of flow separation, while the average vector velocity fields obtained by the phase averaging of the individual vector fields were smooth and slightly asymmetrical, with the minimum of the horizontal velocity near the water surface shifted to the leeward side of the wave profile, but do not demonstrate the features of flow separation. The wave-induced pressure perturbations, averaged over the turbulent fluctuations, were retrieved from the measured velocity fields, using the Reynolds equations. It ensures sufficient accuracy for study of the dependence of the wave increment on the wave amplitude. The dependences of the wave growth rate on the wave steepness are weakly decreasing, serving as indirect proof of the non-separated character of flow over waves. Also direct numerical simulation of the airflow over finite amplitude periodic surface wave was performed. In the experiments the primitive 3-dimensional fluid mechanics equations were solved in the airflow over curved water boundary for the following parameters: the Reynolds number Re=15000, the wave steepness ka=0-0.2, the parameter c/u*=0-10 (where u* is the friction velocity and c is the wave celerity). Similar to the physical experiment the instant realizations of the velocity field demonstrate flow separation at the crests of the waves, but the ensemble averaged velocity fields had typical structures similar to those excising in shear flows near critical levels, where the phase velocity of the disturbance coincides with the flow velocity. The wind growth rate determined by the ensemble averaged wave-induced pressure component in phase of the wave slope was retrieved from the DNS results. Similar to the physical experiment the wave growth rate weakly decreased with the wave steepness. The results of physical and numerical experiments were compared with the calculations within the theoretical model of a turbulent boundary layer based on the system of Reynolds equations with the first-order closing hypothesis. Within the model the wind-wave interaction is considered within the quasi-linear approximation and the mean airflow over waves within the model is treated as a non-separated. The calculations within the model represents well profiles of the mean wind velocity, turbulent stress, amplitude and phase of the main harmonics of the wave-induced velocity components and also wave-induced pressure fluctuations and wind wave growth rate obtained both in the physical experiment and DNS. Applicability of the non-separating quasi-linear theory for description of average fields in the airflow over steep and even breaking waves, when the effect of separation is manifested in the instantaneous flow images, can possibly be explained qualitatively by the strongly non-stationary character of the separation process with the typical time being much less than the wave period, and by the small scale of flow heterogeneity in the area of separation. In such a situation small-scale vortices produced within the separation bubble affect the mean flow and wind-induced disturbances as eddy viscosity. Then, the flow turbulence affects the averaged fields as a very viscous fluid, where the effective Reynolds number for the average fields determined by the eddy viscosity was small even for steep waves. It follows from this assumption that strongly nonlinear effects, such as flow separations should not be expected in the flow averaged over turbulent fluctuations, and the main harmonics of the wave-induced disturbances of the averaged flow, which determine the energy flux to surface waves, can be described in the weakly-nonlinear approximation. This paper was supported by a grant from the Government of the Russian Federation under Contract no. 11.G34.31.0048; the European Research Council Advanced Grant, FP7-IDEAS, 227915; RFBF grant 13-05-00865-а, 13-05-12093-ofi-m,15-05-91767.

77 FR 27223 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-09

..., LLC, ESI Vansycle Partners, L.P., Florida Power & Light Co., FPL Energy Burleigh County Wind, LLC, FPL Energy Cabazon Wind, LLC, FPL Energy Cape, LLC, FPL Energy Cowboy Wind, LLC, FPL Energy Green Power Wind..., Garden Wind, LLC, Gray County Wind Energy, LLC, Hatch Solar Energy Center I, LLC, Hawkeye Power Partners...

75 FR 47301 - Cedro Hill Wind LLC; Butler Ridge Wind Energy Center, LLC; High Majestic Wind Energy Center, LLC...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-05

...- 000; EG10-34-000; EG10-34-000; EG10-35-000; EG10-36-000; EG10-37-000; EG10-38-000] Cedro Hill Wind LLC; Butler Ridge Wind Energy Center, LLC; High Majestic Wind Energy Center, LLC; Wessington Wind Energy Center, LLC; Juniper Canyon Wind Power LLC; Loraine Windpark Project, LLC; White Oak Energy LLC; Meadow...

Quiet-Time Suprathermal ( 0.1-1.5 keV) Electrons in the Solar Wind

NASA Astrophysics Data System (ADS)

Wang, L.; Tao, J.; Zong, Q.; Li, G.; Salem, C. S.; Wimmer-Schweingruber, R. F.; He, J.; Tu, C.; Bale, S. D.

2016-12-01

We present a statistical survey of the energy spectrum of solar wind suprathermal (˜0.1-1.5 keV) electrons measured by the WIND/3DP instrument at 1 AU during quiet times at the minimum and maximum of solar cycles 23 and 24. After separating (beaming) strahl electrons from (isotropic) halo electrons according to their different behaviors in the angular distribution, we fit the observed energy spectrum of both strahl and halo electrons at ˜0.1-1.5 keV to a Kappa distribution function with an index κ and effective temperature Teff. We also calculate the number density n and average energy Eavg of strahl and halo electrons by integrating the electron measurements between ˜0.1 and 1.5 keV. We find a strong positive correlation between κ and Teff for both strahl and halo electrons, and a strong positive correlation between the strahl n and halo n, likely reflecting the nature of the generation of these suprathermal electrons. In both solar cycles, κ is larger at solar minimum than at solar maximum for both strahl and halo electrons. The halo κ is generally smaller than the strahl κ (except during the solar minimum of cycle 23). The strahl n is larger at solar maximum, but the halo n shows no difference between solar minimum and maximum. Both the strahl n and halo n have no clear association with the solar wind core population, but the density ratio between the strahl and halo roughly anti-correlates (correlates) with the solar wind density (velocity).

Quiet-time Suprathermal (~0.1-1.5 keV) Electrons in the Solar Wind

NASA Astrophysics Data System (ADS)

Tao, Jiawei; Wang, Linghua; Zong, Qiugang; Li, Gang; Salem, Chadi S.; Wimmer-Schweingruber, Robert F.; He, Jiansen; Tu, Chuanyi; Bale, Stuart D.

2016-03-01

We present a statistical survey of the energy spectrum of solar wind suprathermal (˜0.1-1.5 keV) electrons measured by the WIND 3DP instrument at 1 AU during quiet times at the minimum and maximum of solar cycles 23 and 24. After separating (beaming) strahl electrons from (isotropic) halo electrons according to their different behaviors in the angular distribution, we fit the observed energy spectrum of both strahl and halo electrons at ˜0.1-1.5 keV to a Kappa distribution function with an index κ and effective temperature Teff. We also calculate the number density n and average energy Eavg of strahl and halo electrons by integrating the electron measurements between ˜0.1 and 1.5 keV. We find a strong positive correlation between κ and Teff for both strahl and halo electrons, and a strong positive correlation between the strahl n and halo n, likely reflecting the nature of the generation of these suprathermal electrons. In both solar cycles, κ is larger at solar minimum than at solar maximum for both strahl and halo electrons. The halo κ is generally smaller than the strahl κ (except during the solar minimum of cycle 23). The strahl n is larger at solar maximum, but the halo n shows no difference between solar minimum and maximum. Both the strahl n and halo n have no clear association with the solar wind core population, but the density ratio between the strahl and halo roughly anti-correlates (correlates) with the solar wind density (velocity).

A rotating superconducting solenoid for 100 kWh energy storage. [in space

NASA Technical Reports Server (NTRS)

Waynert, J.; Eyssa, Y. M.; Mcintosh, G. E.; Feng, Z.

1985-01-01

Two concentric superconducting solenoids, one rotating, the other stationary are analyzed for energy storage in space. Energy is transferred from the rotating mass through a shaft coupled to a motor-generator. The inner windings interact with the magnetic field of the outer solenoid to cancel the centrifugal and self-field forces of the flywheel rim. Current is induced in the inner solenoid thus requiring no separate power supply, while the current in the outer solenoid must vary with the angular velocity of the flywheel. The effect of the gap and scaling laws are developed. The efficiency in energy per unit mass is marginally attractive.

77 FR 67356 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-09

..., LLC, FPL Energy Oklahoma Wind, LLC, FPL Energy Sooner Wind, LLC, Minco Wind Interconnection Services, LLC, Minco Wind, LLC, Minco Wind II, LLC, NextEra Energy Power Marketing, LLC. Description... Energy Center, LLC, Crystal Lake Wind, LLC, Crystal Lake Wind II, LLC, Crystal Lake Wind III, LLC, Day...

Solar Wind 0.1-1 keV Electrons in the Corotating Interaction Regions

NASA Astrophysics Data System (ADS)

Wang, L.; Tao, J.; Li, G.; Wimmer-Schweingruber, R. F.; Jian, L. K.; He, J.; Tu, C.; Tian, H.; Bale, S. D.

2017-12-01

Here we present a statistical study of the 0.1-1 keV suprathermal electrons in the undisturbed and compressed slow/fast solar wind, for the 71 corotating interaction regions (CIRs) with good measurements from the WIND 3DP and MFI instruments from 1995 to 1997. For each of these CIRs, we separate the strahl and halo electrons based on their different behaviors in pitch angle distributions in the undisturbed and compressed solar wind. We fit both the strahl and halo energy spectra to a kappa function with an index κ index and effective temperature Teff, and calculate the pitch-angle width at half-maximum (PAHM) of the strahl population. We also integrate the electron measurements between 0.1 and 1.0 keV to obtain the number density n and average energy Eavg for the strahl and halo populations. We find that for both the strahl and halo populations within and around these CIRs, the fitted κ index strongly correlates with Teff, similar to the quiet-time solar wind (Tao et al., ApJ, 2016). The number density of both the strahl and halo shows a strong positive correlation with the electron core temperature. The strahl number density ns is correlated with the magnitude of interplanetary magnetic field, and the strahl PAHM width is anti-correlated with the solar wind speed. These results suggest that the origin of strahl electrons from the solar corona is likely related to the electron core temperature and magnetic field strength, while the production of halo electrons in the interplanetary medium could depend on the solar wind velocity.

Turbulence Impact on Wind Turbines: Experimental Investigations on a Wind Turbine Model

NASA Astrophysics Data System (ADS)

Al-Abadi, A.; Kim, Y. J.; Ertunç, Ö.; Delgado, A.

2016-09-01

Experimental investigations have been conducted by exposing an efficient wind turbine model to different turbulence levels in a wind tunnel. Nearly isotropic turbulence is generated by using two static squared grids: fine and coarse one. In addition, the distance between the wind-turbine and the grid is adjusted. Hence, as the turbulence decays in the flow direction, the wind-turbine is exposed to turbulence with various energy and length scale content. The developments of turbulence scales in the flow direction at various Reynolds numbers and the grid mesh size are measured. Those measurements are conducted with hot-wire anemometry in the absence of the wind-turbine. Detailed measurements and analysis of the upstream and downstream velocities, turbulence intensity and spectrum distributions are done. Performance measurements are conducted with and without turbulence grids and the results are compared. Performance measurements are conducted with an experimental setup that allow measuring of torque, rotational speed from the electrical parameters. The study shows the higher the turbulence level, the higher the power coefficient. This is due to many reasons. First, is the interaction of turbulence scales with the blade surface boundary layer, which in turn delay the stall. Thus, suppressing the boundary layer and preventing it from separation and hence enhancing the aerodynamics characteristics of the blade. In addition, higher turbulence helps in damping the tip vortices. Thus, reduces the tip losses. Adding winglets to the blade tip will reduce the tip vortex. Further investigations of the near and far wake-surrounding intersection are performed to understand the energy exchange and the free stream entrainment that help in retrieving the velocity.

Evaluation model of wind energy resources and utilization efficiency of wind farm

NASA Astrophysics Data System (ADS)

Ma, Jie

2018-04-01

Due to the large amount of abandoned winds in wind farms, the establishment of a wind farm evaluation model is particularly important for the future development of wind farms In this essay, consider the wind farm's wind energy situation, Wind Energy Resource Model (WERM) and Wind Energy Utilization Efficiency Model(WEUEM) are established to conduct a comprehensive assessment of the wind farm. Wind Energy Resource Model (WERM) contains average wind speed, average wind power density and turbulence intensity, which assessed wind energy resources together. Based on our model, combined with the actual measurement data of a wind farm, calculate the indicators using the model, and the results are in line with the actual situation. We can plan the future development of the wind farm based on this result. Thus, the proposed establishment approach of wind farm assessment model has application value.

Vortex detection through pressure measurements

NASA Astrophysics Data System (ADS)

Bhide, Aditi

Vortex Generators (VGs) are known to hinder boundary layer separation, a frequently unwanted phenomenon when it comes to external flows over aircraft wings, on-ground vehicles or internal flows within pipes, diffusers and turbomachinery. Boundary layer separation leads to loss of lift, higher drag and subsequently, energy losses. The vortices generated inhibit boundary layer separation. This thesis is an effort to discern the strength and location of these generated vortices using an array of VGs over a flat plate. Such information may be useful in the future in active control systems for streamwise vortices, which have been proposed to relaminarize turbulent boundary layers. Flow over flat plates, simulated using wind tunnel experiments, is studied for pressure variation using an array of pressure ports mounted over the plate and connected to suitable pressure sensors. Pressure coefficient and Velocity maps are generated using the data obtained from the Kirsten Wind Tunnel data acquisition system. These represent the nature of the flow field over the plate and are used to locate the vortices and determine their strength. It was found that the vortices can be detected using this method and their strength and location can be estimated.

Dissipation of Turbulence in the Solar Wind

NASA Technical Reports Server (NTRS)

Goldstein, Melvyn L.

2010-01-01

I will describe the first three-dimensional (3-D) dispersion relations and wavenumber spectra of magnetic turbulence in the solar wind at sub-proton scales. The analysis takes advantage of the short separations of the Cluster spacecraft (d/sim approx.200 km) to apply the {it k}-filtering technique to the frequency range where the transition to sub-proton scales occurs. The dispersion diagrams show unambiguously that the cascade is carried by highly oblique Kinetic Alfven Wave with \\omega\\leq 0.1\\omega_{ci} in the plasma rest frame down to k_\\perp\\rho_i \\sim 2. The wavenumber spectra in the direction perpendicular to the mean magnetic field consists of two ranges of scales separated by a breakpoint in the interval [0.4,1] k_\\perp \\rho_i. Above the breakpoint, the spectra follow the Kolmogorov scaling k_\\perp^{-1.7}, consistent with existing theoretical predictions. Below the breakpoint, the spectra steepen to \\sim k_\\perp^{-4.5}. We conjecture that the turbulence undergoes a {\\it transition-range}, where part of energy is dissipated into proton heating via Landau damping, and the remaining energy cascades down to electron scales where electron Landau damping may predominate.

77 FR 48138 - Topaz Solar Farms LLC; High Plains Ranch II, LLC; Bethel Wind Energy LLC; Rippey Wind Energy LLC...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-13

... Ranch II, LLC; Bethel Wind Energy LLC; Rippey Wind Energy LLC; Pacific Wind, LLC; Colorado Highlands Wind, LLC; Shooting Star Wind Project, LLC; Notice of Effectiveness of Exempt Wholesale Generator or...

NASA presentation. [wind energy conversion systems planning

NASA Technical Reports Server (NTRS)

Thomas, R. L.

1973-01-01

The development of a wind energy system is outlined that supplies reliable energy at a cost competitive with other energy systems. A government directed industry program with strong university support is recommended that includes meteorological studies to estimate wind energy potentials and determines favorable regions and sites for wind power installations. Key phases of the overall program are wind energy conversion systems, meteorological wind studies, energy storage systems, and environmental impact studies. Performance testing with a prototype wind energy conversion and storage system is projected for Fiscal 1977.

Wind energy systems

NASA Technical Reports Server (NTRS)

Stewart, H. J.

1978-01-01

A discussion on wind energy systems involved with the DOE wind energy program is presented. Some of the problems associated with wind energy systems are discussed. The cost, efficiency, and structural design of wind energy systems are analyzed.

Wind energy development in the United States: Can state-level policies promote efficient development of wind energy capacity?

NASA Astrophysics Data System (ADS)

Goldstein, Blair S.

In the absence of strong U.S. federal renewable energy policies, state governments have taken the lead in passing legislation to promote wind energy. Studies have shown that many of these policies, including Renewable Portfolio Standards (RPS), have aided in the development of wind energy capacity nationwide. This paper seeks to analyze whether these state-level policies have led to an efficient development of U.S. wind energy. For the purposes of this paper, wind energy development is considered efficient if competitive markets enable wind capacity to be built in the most cost effective manner, allowing states to trade wind energy between high wind potential states and low wind potential states. This concept is operationalized by analyzing how state policies that incentivize the in-state development of wind energy impact where wind capacity is developed. A multivariate regression model examining wind capacity in the 48 contiguous United States that had some wind capacity between 1999 and 2008 found these in-state policies are associated with increased wind capacity, controlling for states' wind potential. The results suggest that state-level policies are distorting where wind is developed. These findings support the enactment of a more comprehensive federal energy policy, such as a national RPS, a cap-and-trade program, or a targeted federal transmission policy. These federal policies could spur national markets that would result in the more efficient development of U.S. wind energy.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baranowski, Ruth; Oteri, Frank; Baring-Gould, Ian

The wind industry and the U.S. Department of Energy (DOE) are addressing technical challenges to increasing wind energy's contribution to the national grid (such as reducing turbine costs and increasing energy production and reliability), and they recognize that public acceptance issues can be challenges for wind energy deployment. Wind project development decisions are best made using unbiased information about the benefits and impacts of wind energy. In 2014, DOE established six wind Regional Resource Centers (RRCs) to provide information about wind energy, focusing on regional qualities. This document summarizes the status and drivers for U.S. wind energy development on regionalmore » and state levels. It is intended to be a companion to DOE's 2014 Distributed Wind Market Report, 2014 Wind Technologies Market Report, and 2014 Offshore Wind Market and Economic Analysis that provide assessments of the national wind markets for each of these technologies.« less

IEA Wind Task 26 - Multi-national Case Study of the Financial Cost of Wind Energy; Work Package 1 Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwabe, P.; Lensink, S.; Hand, M.

2011-03-01

The lifetime cost of wind energy is comprised of a number of components including the investment cost, operation and maintenance costs, financing costs, and annual energy production. Accurate representation of these cost streams is critical in estimating a wind plant's cost of energy. Some of these cost streams will vary over the life of a given project. From the outset of project development, investors in wind energy have relatively certain knowledge of the plant's lifetime cost of wind energy. This is because a wind energy project's installed costs and mean wind speed are known early on, and wind generation generallymore » has low variable operation and maintenance costs, zero fuel cost, and no carbon emissions cost. Despite these inherent characteristics, there are wide variations in the cost of wind energy internationally, which is the focus of this report. Using a multinational case-study approach, this work seeks to understand the sources of wind energy cost differences among seven countries under International Energy Agency (IEA) Wind Task 26 - Cost of Wind Energy. The participating countries in this study include Denmark, Germany, the Netherlands, Spain, Sweden, Switzerland, and the United States. Due to data availability, onshore wind energy is the primary focus of this study, though a small sample of reported offshore cost data is also included.« less

76 FR 69252 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-08

..., Butler Ridge Wind Energy Center, LLC, Calhoun Power Company I, LLC, Crystal Lake Wind, LLC, Crystal Lake... Partnership, Elk City Wind, LLC, Elk City II Wind, LLC, ESI Vansycle Partners, L.P., Florida Power & Light Co... Cowboy Wind, LLC, FPL Energy Green Power Wind, LLC, FPL Energy Hancock County Wind, LLC, FPL Energy...

Wind Energy Resource Atlas of Sri Lanka and the Maldives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elliott, D.; Schwartz, M.; Scott, G.

2003-08-01

The Wind Energy Resource Atlas of Sri Lanka and the Maldives, produced by the National Renewable Energy Laboratory's (NREL's) wind resource group identifies the wind characteristics and distribution of the wind resource in Sri Lanka and the Maldives. The detailed wind resource maps and other information contained in the atlas facilitate the identification of prospective areas for use of wind energy technologies, both for utility-scale power generation and off-grid wind energy applications.

Wind cannot be Directed but Sails can be Adjusted for Malaysian Renewable Energy Progress

NASA Astrophysics Data System (ADS)

Palanichamy, C.; Nasir, Meseret; Veeramani, S.

2015-04-01

Wind energy has been the promising energy technology since 1980s in terms of percentage of yearly growth of installed capacity. However the progress of wind energy has not been evenly distributed around the world. Particularly, in South East Asian countries like Malaysia and Singapore, though the Governments are keen on promoting wind energy technology, it is not well practiced due to the low wind speeds. Owing to the recent advancements in wind turbine designs, even Malaysia is well suited for wind energy by proper choice of wind turbines. As evidence, this paper presents successful wind turbines with simulated study outcomes to encourage wind power developments in Malaysia.

Wind energy potential analysis in Al-Fattaih-Darnah

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tjahjana, Dominicus Danardono Dwi Prija, E-mail: danar1405@gmail.com; Salem, Abdelkarim Ali, E-mail: keemsalem@gmail.com; Himawanto, Dwi Aries, E-mail: dwiarieshimawanto@gmail.com

2016-03-29

In this paper the wind energy potential in Al-Fattaih-Darnah, Libya, had been studied. Wind energy is very attractive because it can provide a clean and renewable energy. Due mostly to the uncertainty caused by the chaotic characteristics of wind near the earth’s surface, wind energy characteristic need to be investigated carefully in order to get consistent power generation. This investigation was based on one year wind data measured in 2003. As a result of the analysis, wind speed profile and wind energy potential have been developed. The wind energy potential of the location is looked very promising to generate electricity.more » The annual wind speed of the site is 8.21 m/s and the wind speed carrying maximum energy is 7.97 m/s. The annual power density of the site is classified into class 3. The Polaris P50-500 wind turbine can produce 768.39 M Wh/year and has capacity factor of 17.54%.« less

Analysis of wind energy generation possibilities with various rotor types at disadvantageous wind condition zones

NASA Astrophysics Data System (ADS)

Bieniek, Andrzej

2017-10-01

The paper describe possibilities of energy generation using various rotor types but especially with multi-blade wind engine operates in the areas with unfavourable wind condition. The paper presents also wind energy conversion estimation results presented based on proposed solution of multi-blade wind turbine of outer diameter of 4 m. Based on the wind distribution histogram from the disadvantage wind condition zones (city of Basel) and taking into account design and estimated operating indexes of the considered wind engine rotor an annual energy generation was estimated. Also theoretical energy generation using various types of wind turbines operates at disadvantage wind conditions zones were estimated and compared. The conducted analysis shows that introduction of multi-blade wind rotor instead of the most popular 3- blades or vertical axis rotors results of about 5% better energy generation. Simultaneously there are energy production also at very disadvantages wind condition at wind speed lower then 4 m s-1. Based on considered construction of multi-blade wind engine the rise of rotor mounting height from 10 to 30 m results with more then 300 % better results in terms of electric energy generation.

Energy 101: Wind Turbines - 2014 Update

ScienceCinema

None

2018-05-11

See how wind turbines generate clean electricity from the power of wind. The video highlights the basic principles at work in wind turbines, and illustrates how the various components work to capture and convert wind energy to electricity. This updated version also includes information on the Energy Department's efforts to advance offshore wind power. Offshore wind energy footage courtesy of Vestas.

Wind Energy Conference, Boulder, Colo., April 9-11, 1980, Technical Papers

NASA Astrophysics Data System (ADS)

1980-03-01

Papers are presented concerning the technology, and economics of wind energy conversion systems. Specific topics include the aerodynamic analysis of the Darrieus rotor, the numerical calculation of the flow near horizontal-axis wind turbine rotors, the calculation of dynamic wind turbine rotor loads, markets for wind energy systems, an oscillating-wing windmill, wind tunnel tests of wind rotors, wind turbine generator wakes, the application of a multi-speed electrical generator to wind turbines, the feasibility of wind-powered systems for dairy farms, and wind characteristics over uniform and complex terrain. Attention is also given to performance tests of the DOE/NASA MOD-1 2000-kW wind turbine generator, the assessment of utility-related test data, offshore wind energy conversion systems, and the optimization of wind energy utilization economics through load management.

2016 State of Wind Development in the United States by Region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baranowski, Ruth; Oteri, Frank; Baring-Gould, Ian

Significant expansion of wind energy development will be required to achieve the scenarios outlined in the U.S. Department of Energy's (DOE)'s Wind Vision: 20% wind energy by 2030 and 35% wind energy by 2050. Wind energy currently provides nearly 5% of the nation's electricity but has the potential to provide much more. The wind industry and the DOE's Wind Energy Technologies Office are addressing technical wind energy challenges, such as reducing turbine costs and increasing energy production and reliability. The Office recognizes that public acceptance of wind energy can be challenging, depending on the proximity of proposed wind farms tomore » local populations. Informed decision makers and communities equipped with unbiased information about the benefits and impacts of wind energy development are better prepared to navigate the sometimes contentious development process. In 2014, DOE established six Regional Resource Centers (RRCs) across the United States to communicate unbiased, credible information about wind energy to stakeholders through regional networks. The RRCs provide ready access to this information to familiarize the public with wind energy; raise awareness about potential benefits and issues; and disseminate data on siting considerations such as turbine sound and wildlife habitat protection. This document summarizes the status and drivers for U.S. wind energy development during 2016. RRC leaders provided a report of wind energy development in their regions, which was combined with findings from National Renewable Energy Laboratory (NREL) researchers to provide an account of the state of the regions, as well as updates on developments in individual states. NREL researchers and state partners added updates for all states that are not directly supported by an RRC. Accounts for each region include updates on renewable portfolio standards, the Clean Power Plan, workforce development, manufacturing and economic development, and individual state updates for installed wind capacity, ongoing policy developments, planned projects and their status, transmission progress reports, etc. This report also highlights the efforts of the RRCs to engage stakeholders in their individual regions.« less

78 FR 9904 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-12

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Combined Notice of Filings 1 Take notice..., LLC, Bayswater Peaking Facility, LLC, Blackwell Wind, LLC, Butler Ridge Wind Energy Center, LLC, Cimarron Wind Energy, LLC, Crystal Lake Wind, LLC, Crystal Lake Wind II, LLC, Crystal Lake Wind III, LLC...

Solar wind ∼0.1-1.5 keV electrons at quiet times

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tao, Jiawei; Wang, Linghua, E-mail: wanglhwang@gmail.com; Zong, Qiugang

2016-03-25

We present a statistical survey of the energy spectrum of solar wind suprathermal (∼0.1-1.5 keV) electrons measured by the WIND 3-D Plasma & Energetic Particle (3DP) instrument at 1 AU during quiet times at the minimum and maximum of solar cycles 23 and 24. Firstly, we separate strahl (beaming) electrons and halo (isotropic) electrons based on their features in pitch angle distributions. Secondly, we fit the observed energy spectrum of both the strahl and halo electrons at ∼0.1-1.5 keV to a Kappa distribution function with an index κ, effective temperature T{sub eff} and density n{sub 0}. We also integrate themore » the measurements over ∼0.1-1.5 keV to obtain the average electron energy E{sub avg} of the strahl and halo. We find a strong positive correlation between κ and T{sub eff} for both the strahl and halo, possibly reflecting the nature of the generation of these suprathermal electrons. Among the 245 selected samples, ∼68% have the halo κ smaller than the strahl κ, while ∼50% have the halo E{sub h} larger than the strahl E{sub s}.« less

76 FR 545 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-05

....; Northern Colorado Wind Energy, LLC; NextEra Energy Power Marketing, LLC; Logan Wind Energy LLC; Peetz Table Wind Energy, LLC; FPL Energy Wyoming, LLC; FPL Energy New Mexico Wind, LLC; FPL Energy Vansycle LLC... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Combined Notice of Filings 1 December 28...

76 FR 78641 - Cedar Creek Wind Energy, LLC, Milford Wind Corridor Phase I, LLC; Notice of Filing

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-19

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. RC11-1-002; Docket No. RC11-2-002] Cedar Creek Wind Energy, LLC, Milford Wind Corridor Phase I, LLC; Notice of Filing Take...) June 16, 2011 Order.\\1\\ \\1\\ Cedar Creek Wind Energy, LLC and Milford Wind Corridor Phase I, LLC, 135...

Wind for Schools: A Wind Powering America Project

ERIC Educational Resources Information Center

US Department of Energy, 2007

2007-01-01

The U.S. Department of Energy's (DOE's) Wind Powering America program (based at the National Renewable Energy Laboratory) sponsors the Wind for Schools Project to raise awareness in rural America about the benefits of wind energy while simultaneously educating college seniors regarding wind energy applications. The three primary project goals of…

Solar wind conditions leading to efficient radiation belt electron acceleration: A superposed epoch analysis

DOE PAGES

Li, W.; Thorne, R. M.; Bortnik, J.; ...

2015-09-07

In this study by determining preferential solar wind conditions leading to efficient radiation belt electron acceleration is crucial for predicting radiation belt electron dynamics. Using Van Allen Probes electron observations (>1 MeV) from 2012 to 2015, we identify a number of efficient and inefficient acceleration events separately to perform a superposed epoch analysis of the corresponding solar wind parameters and geomagnetic indices. By directly comparing efficient and inefficient acceleration events, we clearly show that prolonged southward Bz, high solar wind speed, and low dynamic pressure are critical for electron acceleration to >1 MeV energies in the heart of the outermore » radiation belt. We also evaluate chorus wave evolution using the superposed epoch analysis for the identified efficient and inefficient acceleration events and find that chorus wave intensity is much stronger and lasts longer during efficient electron acceleration events, supporting the scenario that chorus waves play a key role in MeV electron acceleration.« less

The Influence of Soil Moisture and Wind on Rainfall Distribution and Intensity in Florida

NASA Technical Reports Server (NTRS)

Baker, R. David; Lynn, Barry H.; Boone, Aaron; Tao, Wei-Kuo

1998-01-01

Land surface processes play a key role in water and energy budgets of the hydrological cycle. For example, the distribution of soil moisture will affect sensible and latent heat fluxes, which in turn may dramatically influence the location and intensity of precipitation. However, mean wind conditions also strongly influence the distribution of precipitation. The relative importance of soil moisture and wind on rainfall location and intensity remains uncertain. Here, we examine the influence of soil moisture distribution and wind distribution on precipitation in the Florida peninsula using the 3-D Goddard Cumulus Ensemble (GCE) cloud model Coupled with the Parameterization for Land-Atmosphere-Cloud Exchange (PLACE) land surface model. This study utilizes data collected on 27 July 1991 in central Florida during the Convection and Precipitation Electrification Experiment (CaPE). The idealized numerical experiments consider a block of land (the Florida peninsula) bordered on the east and on the west by ocean. The initial soil moisture distribution is derived from an offline PLACE simulation, and the initial environmental wind profile is determined from the CaPE sounding network. Using the factor separation technique, the precise contribution of soil moisture and wind to rainfall distribution and intensity is determined.

The effect of humidity on ionic wind velocity in ambient air

NASA Astrophysics Data System (ADS)

Chen, She; Nobelen, J. C. P. Y.; Nijdam, S.

2016-09-01

Due to the evolution of portable electronics and LED lightning system, advances in air cooling technologies must also keep pace. Active cooling by ionic wind, which is usually generated by corona discharge, can greatly reduce the noise and lifetime issues compared to the mechanical fans. The wind is induced when a gas discharge is formed, and neutral molecules gain their energy by the momentum transfer of ion-neutral collisions. However, there is few discussion about the effect of gas composition such as humidity on the wind generation and the physical mechanism is not clear. In the experiment, a positive 5-20 kV DC voltage is applied to the needle-cylinder electrodes with separation of 20 mm. The ionic wind velocity is measured by hot wire anemometry. As the relative humidity (RH) in the ambient air increases, the velocity is found to be severely inhibited. The current is also measured between the cylinder electrode and earth. The results show that the DC component of corona current decreases when RH increases. Since both the discharge current and the ion mobility are reduced when RH increases, their combined effects determine the ionic wind velocity. This work is supported by STW project 13651.

Wind Vision: A New Era for Wind Power in the United States (Highlights); U.S. Department of Energy (DOE), NREL (National Renewable Energy Laboratory)

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2015-03-01

This is a four-part Wind Vision project, consisting of Wind Vision Highlights, Executive Summary, a Full Report, and Appendix. The U.S. Department of Energy (DOE) Wind Program, in close cooperation with the wind industry, led a comprehensive analysis to evaluate future pathways for the wind industry. The Wind Vision report updates and expands upon the DOE's 2008 report, 20% Wind Energy by 2030, and defines the societal, environmental, and economic benefits of wind power in a scenario with wind energy supplying 10% of national end-use electricity demand by 2020, 20% by 2030, and 35% by 2050.

Wind Vision: A New Era for Wind Power in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

U.S. Department of Energy

With more than 4.5% of the nation's electricity supplied by wind energy today, the Department of Energy has collaborated with industry, environmental organizations, academic institutions, and national laboratories to develop a renewed Wind Vision, documenting the contributions of wind to date and envisioning a future where wind continues to provide key contributions to the nation’s energy portfolio. Building on and updating the 2008 20% Wind Energy by 2030 report, the new Wind Vision Report quantifies the economic, environmental, and social benefits of a robust wind energy future and the actions that wind stakeholders can take to make it a reality.

Development and Application of Advanced Weather Prediction Technologies for the Wind Energy Industry (Invited)

NASA Astrophysics Data System (ADS)

Mahoney, W. P.; Wiener, G.; Liu, Y.; Myers, W.; Johnson, D.

2010-12-01

Wind energy decision makers are required to make critical judgments on a daily basis with regard to energy generation, distribution, demand, storage, and integration. Accurate knowledge of the present and future state of the atmosphere is vital in making these decisions. As wind energy portfolios expand, this forecast problem is taking on new urgency because wind forecast inaccuracies frequently lead to substantial economic losses and constrain the national expansion of renewable energy. Improved weather prediction and precise spatial analysis of small-scale weather events are crucial for renewable energy management. In early 2009, the National Center for Atmospheric Research (NCAR) began a collaborative project with Xcel Energy Services, Inc. to perform research and develop technologies to improve Xcel Energy's ability to increase the amount of wind energy in their generation portfolio. The agreement and scope of work was designed to provide highly detailed, localized wind energy forecasts to enable Xcel Energy to more efficiently integrate electricity generated from wind into the power grid. The wind prediction technologies are designed to help Xcel Energy operators make critical decisions about powering down traditional coal and natural gas-powered plants when sufficient wind energy is predicted. The wind prediction technologies have been designed to cover Xcel Energy wind resources spanning a region from Wisconsin to New Mexico. The goal of the project is not only to improve Xcel Energy’s wind energy prediction capabilities, but also to make technological advancements in wind and wind energy prediction, expand our knowledge of boundary layer meteorology, and share the results across the renewable energy industry. To generate wind energy forecasts, NCAR is incorporating observations of current atmospheric conditions from a variety of sources including satellites, aircraft, weather radars, ground-based weather stations, wind profilers, and even wind sensors on individual wind turbines. The information is utilized by several technologies including: a) the Weather Research and Forecasting (WRF) model, which generates finely detailed simulations of future atmospheric conditions, b) the Real-Time Four-Dimensional Data Assimilation System (RTFDDA), which performs continuous data assimilation providing the WRF model with continuous updates of the initial atmospheric state, 3) the Dynamic Integrated Forecast System (DICast®), which statistically optimizes the forecasts using all predictors, and 4) a suite of wind-to-power algorithms that convert wind speed to power for a wide range of wind farms with varying real-time data availability capabilities. In addition to these core wind energy prediction capabilities, NCAR implemented a high-resolution (10 km grid increment) 30-member ensemble RTFDDA prediction system that provides information on the expected range of wind power over a 72-hour forecast period covering Xcel Energy’s service areas. This talk will include descriptions of these capabilities and report on several topics including initial results of next-day forecasts and nowcasts of wind energy ramp events, influence of local observations on forecast skill, and overall lessons learned to date.

78 FR 28842 - Searchlight Wind Energy Project Record of Decision (DOE/EIS-0413)

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-16

... wind turbine generators (WTGs). The proposed Project includes a wind energy facility and a 230-kV... DEPARTMENT OF ENERGY Western Area Power Administration Searchlight Wind Energy Project Record of...), received a request from Searchlight Wind Energy, LLC (Searchlight) to interconnect its proposed Searchlight...

78 FR 91 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-02

... Cabazon Wind, LLC, FPL Energy Green Power Wind, LLC, FPL Energy Montezuma Wind, LLC, FPL Energy New Mexico... Interconnect, LLC, Peetz Table Wind Energy, LLC, NextEra Energy Power Marketing, LLC. Description: NextEra.... Docket Numbers: ER11-3959-003. Applicants: Post Rock Wind Power Project, LLC. Description: Notice of Non...

Wind Power Career Chat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2011-01-01

This document will teach students about careers in the wind energy industry. Wind energy, both land-based and offshore, is expected to provide thousands of new jobs in the next several decades. Wind energy companies are growing rapidly to meet America's demand for clean, renewable, and domestic energy. These companies need skilled professionals. Wind power careers will require educated people from a variety of areas. Trained and qualified workers manufacture, construct, operate, and manage wind energy facilities. The nation will also need skilled researchers, scientists, and engineers to plan and develop the next generation of wind energy technologies.

Wind Energy Workforce Development: A Roadmap to a Wind Energy Educational Infrastructure (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, I.

2011-05-01

Wind Powering America national technical director Ian Baring-Gould made this presentation about workforce development in the wind energy industry to an audience at the American Wind Energy Association's annual WINDPOWER conference in Anaheim. The presentation outlines job projections from the 20% Wind Energy by 2030 report and steps to take at all levels of educational institutions to meet those projections.

Hawaii energy strategy project 3: Renewable energy resource assessment and development program

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-11-01

RLA Consulting (RLA) has been retained by the State of Hawaii Department of Business, Economic Development and Tourism (DBEDT) to conduct a Renewable Energy Resource Assessment and Development Program. This three-phase program is part of the Hawaii Energy Strategy (HES), which is a multi-faceted program intended to produce an integrated energy strategy for the State of Hawaii. The purpose of Phase 1 of the project, Development of a Renewable Energy Resource Assessment Plan, is to better define the most promising potential renewable energy projects and to establish the most suitable locations for project development in the state. In order tomore » accomplish this goal, RLA has identified constraints and requirements for renewable energy projects from six different renewable energy resources: wind, solar, biomass, hydro, wave, and ocean thermal. These criteria were applied to areas with sufficient resource for commercial development and the results of Phase 1 are lists of projects with the most promising development potential for each of the technologies under consideration. Consideration of geothermal energy was added to this investigation under a separate contract with DBEDT. In addition to the project lists, a monitoring plan was developed with recommended locations and a data collection methodology for obtaining additional wind and solar data. This report summarizes the results of Phase 1. 11 figs., 22 tabs.« less

Wind power: The new energy policy 1

NASA Astrophysics Data System (ADS)

1991-10-01

Increasing use of renewable energy sources is an important aspect of the new energy policy of the State government of Schleswig-Holstein. Technical and industrial innovation are involved. By expanding and developing these regionally available inexhaustible energy sources to generate electricity and heat, we are contributing to environmental protection and helping to reduce adverse affects on the climate. We are also taking our limited resources into account and expanding energy generation in a logical manner. Wind energy is the most attractive renewable energy source for Schleswig-Holstein because our State is well known for its strong winds and constant fresh breeze. For this reason the State government has made expansion of wind energy one of its primary areas of emphasis. The goals of our promotion measures includes ongoing technical and engineering development of wind energy facilities, increasing the level of use of the wind, and increasing the percentage of wind energy used for power generation. This brochure is intended to demonstrate the significance and possibilities of wind energy for our State, to outline the legal requirements for erecting wind energy facilities, and to explain the many promotion measures. It represents a favorable breeze for wind.

2015 Key Wind Program and National Laboratory Accomplishments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Office of Energy Efficiency and Renewable Energy

The U.S. Department of Energy (DOE) Wind Program is committed to helping the nation secure cost-competitive sources of renewable energy through the development and deployment of innovative wind power technologies. By investing in improvements to wind plant design, technology development, and operation as well as developing tools to identify the highest quality wind resources, the Wind Program serves as a leader in making wind energy technologies more competitive with traditional sources of energy and a larger part of our nation’s renewable energy portfolio.

Wind potential assessment in urban area of Surakarta city

NASA Astrophysics Data System (ADS)

Tjahjana, Dominicus Danardono Dwi Prija; Halomoan, Arnold Thamrin; Wibowo, Andreas; Himawanto, Dwi Aries; Wicaksono, Yoga Arob

2018-02-01

Wind energy is one of the promising energy resource in urban area that has not been deeply explored in Indonesia. Generally the wind velocity in Indonesia is relatively low, however on the roof top of the high rise building in urban area the wind velocity is high enough to be converted for supporting the energy needs of the building. In this research a feasibility study of wind energy in urban area of Surakarta was done. The analysis of the wind energy potential on the height of 50 m was done by using Weibull distribution. The wind data based on the daily wind speed taken from 2011-2015. From the result of the wind speed analysis, a wind map in Surakarta was developed for helping to determine the places that have good potential in wind energy. The result showed that in five years the city of Surakarta had mean energy density (ED) of 139.43 W/m2, yearly energy available (EI) of 1221.4 kWh/m2/year, the most frequent wind velocity (VFmax) of 4.79 m/s, and the velocity contributing the maximum energy (VEmax) of 6.97 m/s. The direction of the wind was mostly from south, with frequency of 38%. The south and west area of the city had higher wind velocity than the other parts of the city. Also in those areas there are many high rise buildings, which are appropriate for installation of small wind turbine on the roof top (building mounted wind turbine/ BMWT).

Wind Energy Workforce Development & Jobs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tegen, Suzanne

The United States needs a skilled and qualified wind energy workforce to produce domestic clean power. To assist with wind energy workforce development, the U.S. Department of Energy (DOE) and National Renewable Energy Laboratory are engaged with several efforts.This presentation by Suzanne Tegen describes these efforts, including a wind industry survey, DOE's Wind Career Map, the DOE Wind Vision report, and an in-depth discussion of the Jobs & Economic Development Impacts Model.

Flexible reserve markets for wind integration

NASA Astrophysics Data System (ADS)

Fernandez, Alisha R.

The increased interconnection of variable generation has motivated the use of improved forecasting to more accurately predict future production with the purpose to lower total system costs for balancing when the expected output exceeds or falls short of the actual output. Forecasts are imperfect, and the forecast errors associated with utility-scale generation from variable generators need new balancing capabilities that cannot be handled by existing ancillary services. Our work focuses on strategies for integrating large amounts of wind generation under the flex reserve market, a market that would called upon for short-term energy services during an under or oversupply of wind generation to maintain electric grid reliability. The flex reserve market would be utilized for time intervals that fall in-between the current ancillary services markets that would be longer than second-to-second energy services for maintaining system frequency and shorter than reserve capacity services that are called upon for several minutes up to an hour during an unexpected contingency on the grid. In our work, the wind operator would access the flex reserve market as an energy service to correct for unanticipated forecast errors, akin to paying the generators participating in the market to increase generation during a shortfall or paying the other generators to decrease generation during an excess of wind generation. Such a market does not currently exist in the Mid-Atlantic United States. The Pennsylvania-New Jersey-Maryland Interconnection (PJM) is the Mid-Atlantic electric grid case study that was used to examine if a flex reserve market can be utilized for integrating large capacities of wind generation in a lowcost manner for those providing, purchasing and dispatching these short-term balancing services. The following work consists of three studies. The first examines the ability of a hydroelectric facility to provide short-term forecast error balancing services via a flex reserve market, identifying the operational constraints that inhibit a multi-purpose dam facility to meet the desired flexible energy demand. The second study transitions from the hydroelectric facility as the decision maker providing flex reserve services to the wind plant as the decision maker purchasing these services. In this second study, methods for allocating the costs of flex reserve services under different wind policy scenarios are explored that aggregate farms into different groupings to identify the least-cost strategy for balancing the costs of hourly day-ahead forecast errors. The least-cost strategy may be different for an individual wind plant and for the system operator, noting that the least-cost strategy is highly sensitive to cost allocation and aggregation schemes. The latter may also cause cross-subsidies in the cost for balancing wind forecast errors among the different wind farms. The third study builds from the second, with the objective to quantify the amount of flex reserves needed for balancing future forecast errors using a probabilistic approach (quantile regression) to estimating future forecast errors. The results further examine the usefulness of separate flexible markets PJM could use for balancing oversupply and undersupply events, similar to the regulation up and down markets used in Europe. These three studies provide the following results and insights to large-scale wind integration using actual PJM wind farm data that describe the markets and generators within PJM. • Chapter 2 provides an in-depth analysis of the valuable, yet highly-constrained, energy services multi-purpose hydroelectric facilities can provide, though the opportunity cost for providing these services can result in large deviations from the reservoir policies with minimal revenue gain in comparison to dedicating the whole of dam capacity to providing day-ahead, baseload generation. • Chapter 3 quantifies the system-wide efficiency gains and the distributive effects of PJM's decision to act as a single balancing authority, which means that it procures ancillary services across its entire footprint simultaneously. This can be contrasted to Midwest Independent System Operator (MISO), which has several balancing authorities operating under its footprint. • Chapter 4 uses probabilistic methods to estimate the uncertainty in the forecast errors and the quantity of energy needed to balance these forecast errors at a certain percentile. Current practice is to use a point forecast that describes the conditional expectation of the dependent variable at each time step. The approach here uses quantile regression to describe the relationship between independent variable and the conditional quantiles (equivalently the percentiles) of the dependent variable. An estimate of the conditional density is performed, which contains information about the covariate relationship of the sign of the forecast errors (negative for too much wind generation and positive for too little wind generation) and the wind power forecast. This additional knowledge may be implemented in the decision process to more accurately schedule day-ahead wind generation bids and provide an example for using separate markets for balancing an oversupply and undersupply of generation. Such methods are currently used for coordinating large footprints of wind generation in Europe.

Spatial correlation of atmospheric wind at scales relevant for large scale wind turbines

NASA Astrophysics Data System (ADS)

Bardal, L. M.; Sætran, L. R.

2016-09-01

Wind measurements a short distance upstream of a wind turbine can provide input for a feedforward wind turbine controller. Since the turbulent wind field will be different at the point/plane of measurement and the rotor plane the degree of correlation between wind speed at two points in space both in the longitudinal and lateral direction should be evaluated. This study uses a 2D array of mast mounted anemometers to evaluate cross-correlation of longitudinal wind speed. The degree of correlation is found to increase with height and decrease with atmospheric stability. The correlation is furthermore considerably larger for longitudinal separation than for lateral separation. The integral length scale of turbulence is also considered.

Investigation on wind energy-compressed air power system.

PubMed

Jia, Guang-Zheng; Wang, Xuan-Yin; Wu, Gen-Mao

2004-03-01

Wind energy is a pollution free and renewable resource widely distributed over China. Aimed at protecting the environment and enlarging application of wind energy, a new approach to application of wind energy by using compressed air power to some extent instead of electricity put forward. This includes: explaining the working principles and characteristics of the wind energy-compressed air power system; discussing the compatibility of wind energy and compressor capacity; presenting the theoretical model and computational simulation of the system. The obtained compressor capacity vs wind power relationship in certain wind velocity range can be helpful in the designing of the wind power-compressed air system. Results of investigations on the application of high-pressure compressed air for pressure reduction led to conclusion that pressure reduction with expander is better than the throttle regulator in energy saving.

76 FR 2903 - Interconnection of the Proposed Hyde County Wind Energy Center Project (DOE/EIS-0461), and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-18

... Wind Energy Center Project (DOE/EIS-0461), and Proposed Crowned Ridge Wind Energy Center Project (DOE... to prepare environmental impact statements (EISs) for the Hyde County Wind Energy Center Project and the Crowned Ridge Wind Energy Center Project in the Federal Register on November 30, 2010. Both...

Wind energy developments in the 20th century

NASA Technical Reports Server (NTRS)

Vargo, D. J.

1974-01-01

Wind turbine systems of the past are reviewed and wind energy is reexamined as a future source of power. Various phases and objectives of the Wind Energy Program are discussed. Conclusions indicate that wind generated energy must be considered economically competitive with other power production methods.

NWTC Aerodynamics Studies Improve Energy Capture and Lower Costs of Wind-Generated Electricity

DOE Office of Scientific and Technical Information (OSTI.GOV)

2015-08-01

Researchers at the National Wind Technology Center (NWTC) at the National Renewable Energy Laboratory (NREL) have expanded wind turbine aerodynamic research from blade and rotor aerodynamics to wind plant and atmospheric inflow effects. The energy capture from wind plants is dependent on all of these aerodynamic interactions. Research at the NWTC is crucial to understanding how wind turbines function in large, multiple-row wind plants. These conditions impact the cumulative fatigue damage of turbine structural components that ultimately effect the useful lifetime of wind turbines. This work also is essential for understanding and maximizing turbine and wind plant energy production. Bothmore » turbine lifetime and wind plant energy production are key determinants of the cost of wind-generated electricity.« less

SOLAR WIND TURBULENCE FROM MHD TO SUB-ION SCALES: HIGH-RESOLUTION HYBRID SIMULATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Franci, Luca; Verdini, Andrea; Landi, Simone

2015-05-10

We present results from a high-resolution and large-scale hybrid (fluid electrons and particle-in-cell protons) two-dimensional numerical simulation of decaying turbulence. Two distinct spectral regions (separated by a smooth break at proton scales) develop with clear power-law scaling, each one occupying about a decade in wavenumbers. The simulation results simultaneously exhibit several properties of the observed solar wind fluctuations: spectral indices of the magnetic, kinetic, and residual energy spectra in the magnetohydrodynamic (MHD) inertial range along with a flattening of the electric field spectrum, an increase in magnetic compressibility, and a strong coupling of the cascade with the density and themore » parallel component of the magnetic fluctuations at sub-proton scales. Our findings support the interpretation that in the solar wind, large-scale MHD fluctuations naturally evolve beyond proton scales into a turbulent regime that is governed by the generalized Ohm’s law.« less

Solar Wind Turbulence from MHD to Sub-ion Scales: High-resolution Hybrid Simulations

NASA Astrophysics Data System (ADS)

Franci, Luca; Verdini, Andrea; Matteini, Lorenzo; Landi, Simone; Hellinger, Petr

2015-05-01

We present results from a high-resolution and large-scale hybrid (fluid electrons and particle-in-cell protons) two-dimensional numerical simulation of decaying turbulence. Two distinct spectral regions (separated by a smooth break at proton scales) develop with clear power-law scaling, each one occupying about a decade in wavenumbers. The simulation results simultaneously exhibit several properties of the observed solar wind fluctuations: spectral indices of the magnetic, kinetic, and residual energy spectra in the magnetohydrodynamic (MHD) inertial range along with a flattening of the electric field spectrum, an increase in magnetic compressibility, and a strong coupling of the cascade with the density and the parallel component of the magnetic fluctuations at sub-proton scales. Our findings support the interpretation that in the solar wind, large-scale MHD fluctuations naturally evolve beyond proton scales into a turbulent regime that is governed by the generalized Ohm’s law.

Plans and status of the NASA-Lewis Research Center wind energy project

NASA Technical Reports Server (NTRS)

Thomas, R.; Puthoff, R.; Savino, J.; Johnson, W.

1975-01-01

Wind energy is investigated as a source of energy. The wind energy program that is managed by the NASA-Lewis Research Center is described. The Lewis Research Center's Wind Power Office, its organization, plans, and status are discussed. Major elements of the wind power project included are: an experimental 100 kW wind-turbine generator; first generation industry-built and user-operated wind turbine generators; and supporting research and technology tasks.

Thermospheric nighttime wind and temperature analysis from some 2014 stormy nights monitored at Oukaimeden Observatory by RENOIR instrument

NASA Astrophysics Data System (ADS)

Bounhir, Aziza; Benkhaldoun, Zouhair; Kaab, Mohamed; Makela, Jonathan J.; Harding, Brian; Fisher, Daniel J.; Lagheryeb, Amine; Khalifa, Malki; Lazrek, Mohamed; Daassou, Ahmed

2015-08-01

In this paper we report on the thermospheric winds and temperatures over Oukaimeden Observatory in Morocco in some stormy nights during the year 2014. These results are based on Fabry-Perot interferometer (FPI) measurements of Doppler shifts and Doppler broadenings of the 630.0nm spectral emission and pertain to the lower thermosphere region, near 250km altitude. This FPI is a part of RENOIR experiment installed thanks to scientific cooperation program with university of Illinois Urbana (USA).The storm energy input modify the global circulation in the thermosphere resulting in significant changes in the ionospheric plasma properties. Thermospheric and ionospheric storms are closely connected.We first set up the climatological behavior of the thermospheric winds and temperature during quiet nights. These results will be presented in this session in a separate abstract (M. Kaab & Z. Benkhaldoun et al) . Then we investigate the departure of the winds and the temperatures from their climatological behavior during some magnetic storms. The winds present many features. We can notice westward winds and an enhancement of the equatorward winds with sometimes an appearance of a poleward component. We also notice a significant increase of the temperature that last several hours. By looking trough the geomagnetic indices we investigate the delay of thermospheric storm time in our region and its effects on the winds and temperature patterns.

Preliminary results of the large experimental wind turbine phase of the national wind energy program

NASA Technical Reports Server (NTRS)

Thomas, R. L.; Sholes, J. E.

1975-01-01

A major phase of the wind energy program is the development of reliable wind turbines for supplying cost-competitive electrical energy. This paper discusses the preliminary results of two projects in this phase of the program. First an experimental 100 kW wind turbine design and its status are reviewed. Also discussed are the results of two parallel design studies for determining the configurations and power levels for wind turbines with minimum energy costs. These studies show wind energy costs of 7 to 1.5 c/kWH for wind turbines produced in quantities of 100 to 1000 a year and located at sites having average winds of 12 to 18 mph.

Wind energy potential assessment to estimate performance of selected wind turbine in northern coastal region of Semarang-Indonesia

NASA Astrophysics Data System (ADS)

Premono, B. S.; Tjahjana, D. D. D. P.; Hadi, S.

2017-01-01

The aims of this paper are to investigate the characteristic of the wind speed and wind energy potential in the northern coastal region of Semarang, Central Java, Indonesia. The wind data was gained from Meteorological Station of Semarang, with ten-min average time series wind data for one year period, at the height of 10 m. Weibull distribution has been used to determine the wind power density and wind energy density of the site. It was shown that the value of the two parameters, shape parameter k, and scale parameter c, were 3.37 and 5.61 m/s, respectively. The annual mean wind speed and wind speed carrying the maximum energy were 5.32 m/s and 6.45 m/s, respectively. Further, the annual energy density at the site was found at a value of 103.87 W/m2, and based on Pacific North-west Laboratory (PNL) wind power classification, at the height of 10 m, the value of annual energy density is classified into class 2. The commercial wind turbine is chosen to simulate the wind energy potential of the site. The POLARIS P25-100 is most suitable to the site. It has the capacity factor 29.79% and can produce energy 261 MWh/year.

Tracing Slow Winds from T Tauri Stars via Low Velocity Forbidden Line Emission

NASA Astrophysics Data System (ADS)

Simon, Molly; Pascucci, Ilaria; Edwards, Suzan; Feng, Wanda; Rigliaco, Elisabetta; Gorti, Uma; Hollenbach, David J.; Tuttle Keane, James

2016-06-01

Protoplanetary disks are a natural result of star formation, and they provide the material from which planets form. The evolutional and eventual dispersal of protoplanetary disks play critical roles in determining the final architecture of planetary systems. Models of protoplanetary disk evolution suggest that viscous accretion of disk gas onto the central star and photoevaporation driven by high-energy photons from the central star are the main mechanisms that drive disk dispersal. Understanding when photoevaporation begins to dominate over viscous accretion is critically important for models of planet formation and planetary migration. Using Keck/HIRES (resolution of ~ 7 km/s) we analyze three low excitation forbidden lines ([O I] 6300 Å, [O I] 5577 Å, and [S II] 6731 Å) previously determined to trace winds (including photoevaporative winds). These winds can be separated into two components, a high velocity component (HVC) with blueshifts between ~30 - 150 km/s, and a low velocity component (LVC) with blueshifts on the order of ~5 km/s (Hartigan et al. 1995). We selected a sample of 32 pre-main sequence T Tauri stars in the Taurus-Auriga star-forming region (plus TW Hya) with disks that span a range of evolutionary stages. We focus on the origin of the LVC specifically, which we are able to separate into a broad component (BC) and a narrow component (NC) due to the high resolution of our optical spectra. We focus our analysis on the [O I] 6300 Å emission feature, which is detected in 30/33 of our targets. Interestingly, we find wind diagnostics consistent with photoevaporation for only 21% of our sample. We can, however, conclude that a specific component of the LVC is tracing a magnetohydrodynamic (MHD) wind rather than a photoevaporative wind. We will present the details behind these findings and the implications they have for planet formation more generally.

Crossed, Small-Deflection Energy Analyzer for Wind/Temperature Spectrometer

NASA Technical Reports Server (NTRS)

Herrero, Federico A.; Finne, Theodore T.

2010-01-01

Determination of neutral winds and ion drifts in low-Earth-orbit missions requires measurements of the angular and energy distributions of the flux of neutrals and ions entering the satellite from the ram direction. The magnitude and direction of the neutral-wind (or ion-drift) determine the location of the maximum in the angular distribution of the flux. Knowledge of the angle of maximum flux with respect to satellite coordinates (pointing) is essential to determine the wind (or ion-drift) vector. The crossed Small-Deflection Energy Analyzer (SDEA) spectrometer (see Figure 1) occupies minimal volume and consumes minimal power. Designed for upper atmosphere/ionosphere investigations at Earth altitudes above 100 km, the spectrometer operates by detecting the angular and energy distributions of neutral atoms/molecules and ions in two mutually perpendicular planes. In this configuration, the two detection planes actually cross at the spectrometer center. It is possible to merge two SDEAs so they share a common optical axis and alternate measurements between two perpendicular planes, and reduce the number of ion sources from two to one. This minimizes the volume and footprint significantly and reduces the ion source power by a factor of two. The area of the entrance aperture affects the number of ions detected/second and also determines the energy resolution. Thermionic emitters require heater power of about 100 mW to produce 1 mA of electron beam current. Typically, electron energy is about 100 eV and requires a 100-V supply for electron acceleration to supply an additional 100 mW of power. Thus, ion source power is at most 200 mW. If two ion sources were to be used, the ion source power would be, at most, 400 mW. Detector power, deflection voltage power, and microcontroller and other functions require less than 150 mW. A WTS (wind/ temperature spectrometer) with two separate optical axes would consume about 650 mW, while the crossed SDEA described here consumes about 350 mW. The entrance aperture has a diameter of 0.004 in. (0.10 mm) to provide the required energy resolution between 0.05 and 0.15. This design (see Figure 2) provides a WTS occupying a volume less than 40 cm(sup 3), on a footprint of diameter about 1.5 in. (38 mm). The Crossed SDEA offers many advantages in the measurements of neutral wind and ion drifts in the Earth's thermosphere. As such, it will be useful in future commercial satellites dedicated to monitoring the ionosphere with a view to improving the integrity and predictability of GPS operations.

Simulation of the Atmospheric Boundary Layer for Wind Energy Applications

NASA Astrophysics Data System (ADS)

Marjanovic, Nikola

Energy production from wind is an increasingly important component of overall global power generation, and will likely continue to gain an even greater share of electricity production as world governments attempt to mitigate climate change and wind energy production costs decrease. Wind energy generation depends on wind speed, which is greatly influenced by local and synoptic environmental forcings. Synoptic forcing, such as a cold frontal passage, exists on a large spatial scale while local forcing manifests itself on a much smaller scale and could result from topographic effects or land-surface heat fluxes. Synoptic forcing, if strong enough, may suppress the effects of generally weaker local forcing. At the even smaller scale of a wind farm, upstream turbines generate wakes that decrease the wind speed and increase the atmospheric turbulence at the downwind turbines, thereby reducing power production and increasing fatigue loading that may damage turbine components, respectively. Simulation of atmospheric processes that span a considerable range of spatial and temporal scales is essential to improve wind energy forecasting, wind turbine siting, turbine maintenance scheduling, and wind turbine design. Mesoscale atmospheric models predict atmospheric conditions using observed data, for a wide range of meteorological applications across scales from thousands of kilometers to hundreds of meters. Mesoscale models include parameterizations for the major atmospheric physical processes that modulate wind speed and turbulence dynamics, such as cloud evolution and surface-atmosphere interactions. The Weather Research and Forecasting (WRF) model is used in this dissertation to investigate the effects of model parameters on wind energy forecasting. WRF is used for case study simulations at two West Coast North American wind farms, one with simple and one with complex terrain, during both synoptically and locally-driven weather events. The model's performance with different grid nesting configurations, turbulence closures, and grid resolutions is evaluated by comparison to observation data. Improvement to simulation results from the use of more computationally expensive high resolution simulations is only found for the complex terrain simulation during the locally-driven event. Physical parameters, such as soil moisture, have a large effect on locally-forced events, and prognostic turbulence kinetic energy (TKE) schemes are found to perform better than non-local eddy viscosity turbulence closure schemes. Mesoscale models, however, do not resolve turbulence directly, which is important at finer grid resolutions capable of resolving wind turbine components and their interactions with atmospheric turbulence. Large-eddy simulation (LES) is a numerical approach that resolves the largest scales of turbulence directly by separating large-scale, energetically important eddies from smaller scales with the application of a spatial filter. LES allows higher fidelity representation of the wind speed and turbulence intensity at the scale of a wind turbine which parameterizations have difficulty representing. Use of high-resolution LES enables the implementation of more sophisticated wind turbine parameterizations to create a robust model for wind energy applications using grid spacing small enough to resolve individual elements of a turbine such as its rotor blades or rotation area. Generalized actuator disk (GAD) and line (GAL) parameterizations are integrated into WRF to complement its real-world weather modeling capabilities and better represent wind turbine airflow interactions, including wake effects. The GAD parameterization represents the wind turbine as a two-dimensional disk resulting from the rotation of the turbine blades. Forces on the atmosphere are computed along each blade and distributed over rotating, annular rings intersecting the disk. While typical LES resolution (10-20 m) is normally sufficient to resolve the GAD, the GAL parameterization requires significantly higher resolution (1-3 m) as it does not distribute the forces from the blades over annular elements, but applies them along lines representing individual blades. In this dissertation, the GAL is implemented into WRF and evaluated against the GAD parameterization from two field campaigns that measured the inflow and near-wake regions of a single turbine. The data-sets are chosen to allow validation under the weakly convective and weakly stable conditions characterizing most turbine operations. The parameterizations are evaluated with respect to their ability to represent wake wind speed, variance, and vorticity by comparing fine-resolution GAD and GAL simulations along with coarse-resolution GAD simulations. Coarse-resolution GAD simulations produce aggregated wake characteristics similar to both GAD and GAL simulations (saving on computational cost), while the GAL parameterization enables resolution of near wake physics (such as vorticity shedding and wake expansion) for high fidelity applications. (Abstract shortened by ProQuest.).

77 FR 14010 - Rocky Ridge Wind Project, LLC, Blackwell Wind, LLC, CPV Cimarron Renewable Energy Company, LLC...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-08

..., EG12-18-000, EG12-19-000, EG12- 20-000, EG12-21-000, EG12-22-000, EG12-23-000] Rocky Ridge Wind Project, LLC, Blackwell Wind, LLC, CPV Cimarron Renewable Energy Company, LLC, Minco Wind Interconnection Services, LLC, Shiloh III Lessee, LLC, California Ridge Wind Energy LLC, Perrin Ranch Wind, LLC, Erie Wind...

Solar Wind Energy Input during Prolonged, Intense Northward Interplanetary Magnetic Fields: A New Coupling Function

NASA Astrophysics Data System (ADS)

Du, A. M.; Tsurutani, B. T.; Sun, W.

2012-04-01

Sudden energy release (ER) events in the midnight sector at auroral zone latitudes during intense (B > 10 nT), long-duration (T > 3 hr), northward (Bz > 0 nT = N) IMF magnetic clouds (MCs) during solar cycle 23 (SC23) have been examined in detail. The MCs with northward-then-southward (NS) IMFs were analyzed separately from MCs with southward-then-northward (SN) configurations. It is found that there is a lack of substorms during the N field intervals of NS clouds. In sharp contrast, ER events do occur during the N field portions of SN MCs. From the above two results it is reasonable to conclude that the latter ER events represent residual energy remaining from the preceding S portions of the SN MCs. We derive a new solar wind-magnetosphere coupling function during northward IMFs: ENIMF = α N-1/12V 7/3B1/2 + β V |Dstmin|. The first term on the right-hand side of the equation represents the energy input via "viscous interaction", and the second term indicates the residual energy stored in the magnetotail. It is empirically found that the magnetosphere/magnetotail can store energy for a maximum of ~ 4 hrs before it has dissipated away. This concept is defining one for ER/substorm energy storage. Our scenario indicates that the rate of solar wind energy injection into the magnetosphere/magnetotail determines the form of energy release into the magnetosphere/ionosphere. This may be more important than the dissipation mechanism itself (in understanding the form of the release). The concept of short-term energy storage is applied for the solar case. It is argued that it may be necessary to identify the rate of energy input into solar magnetic loop systems to be able to predict the occurrence of solar flares.

Wind energy developments in the 20th century

NASA Technical Reports Server (NTRS)

Vargo, D. J.

1974-01-01

Wind turbine systems for generating electrical power have been tested in many countries. Representative examples of turbines which have produced from 100 to 1250 kW are described. The advantages of wind energy consist of its being a nondepleting, nonpolluting, and free fuel source. Its disadvantages relate to the variability of wind and the high installation cost per kilowatt of capacity of wind turbines when compared to other methods of electric-power generation. High fuel costs and potential resource scarcity have led to a five-year joint NASA-NSF program to study wind energy. The program will study wind energy conversion and storage systems with respect to cost effectiveness, and will attempt to estimate national wind-energy potential and develop techniques for generator site selection. The studies concern a small-systems (50-250 kW) project, a megawatt-systems (500-3000 kW) project, supporting research and technology, and energy storage. Preliminary economic analyses indicate that wind-energy conversion can be competitive in high-average-wind areas.

Wind Energy Resource Atlas of the Dominican Republic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elliott, D.; Schwartz, M.; George, R.

2001-10-01

The Wind Energy Resource Atlas of the Dominican Republic identifies the wind characteristics and the distribution of the wind resource in this country. This major project is the first of its kind undertaken for the Dominican Republic. The information contained in the atlas is necessary to facilitate the use of wind energy technologies, both for utility-scale power generation and off-grid wind energy applications. A computerized wind mapping system developed by NREL generated detailed wind resource maps for the entire country. This technique uses Geographic Information Systems (GIS) to produce high-resolution (1-square kilometer) annual average wind resource maps.

Comparative analysis of wind energy production in Oklahoma

NASA Astrophysics Data System (ADS)

Ermilova, Ekaterina Alexeevna

Scope and method of study. In the last decades humanity has realized the necessity of developing alternative energy sources for its efficient economic development and simple survival in the future. During the last 30 years major improvements were made in renewable energy technologies and they started to become competitive with traditional energy sources (fossil fuels), especially with consideration of external costs. Among the renewable energy sources, wind energy is one of the cheapest and fastest growing nowadays. Oklahoma is a very promising site for wind energy development considering its excellent wind resources. Developing wind energy can allow not only electricity production for in-state consumption, but also exporting to other states. The development of wind energy could encourage economic growth with very few adverse impacts on the environment. However, traditional energy sources are still the cheapest and, thus, the introduction of the wind energy in Oklahoma should be critically analyzed from economic, ecological and social points of view. The goal of this study is to conduct analysis of wind energy electricity production in Oklahoma on the four main stages: (1) Investment Analysis from Private Perspective: Calculate present value net benefits for wind energy and traditional energy (natural gas), make sure that both of them are positive. (2) Investment Analysis from Social Perspective: Evaluate present value net private benefits (PVNPB) and present value net social benefit from both projects (PVNSB). (3) Government Subsidy Analysis: recognize the necessity of the subsidies and evaluate the amount of subsidies if any. (4) Investment Analysis from a Geographic Perspective: determine economic feasibility of wind power generation for 77 Oklahoma counties. Findings and conclusions. The final output of the study is the recommendations concerning wind energy development in Oklahoma with consideration of economic efficiency, ecological and social impacts. Study not only analyze possibilities for wind energy development in the state, but make recommendations on the county by county basis with consideration of wind power density, land cost, property tax and infrastructure development in each county.

Development of a Probabilistic Tornado Wind Hazard Model for the Continental United States Volume I: Main Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boissonnade, A; Hossain, Q; Kimball, J

Since the mid-l980's, assessment of the wind and tornado risks at the Department of Energy (DOE) high and moderate hazard facilities has been based on the straight wind/tornado hazard curves given in UCRL-53526 (Coats, 1985). These curves were developed using a methodology that utilized a model, developed by McDonald, for severe winds at sub-tornado wind speeds and a separate model, developed by Fujita, for tornado wind speeds. For DOE sites not covered in UCRL-53526, wind and tornado hazard assessments are based on the criteria outlined in DOE-STD-1023-95 (DOE, 1996), utilizing the methodology in UCRL-53526; Subsequent to the publication of UCRL53526,more » in a study sponsored by the Nuclear Regulatory Commission (NRC), the Pacific Northwest Laboratory developed tornado wind hazard curves for the contiguous United States, NUREG/CR-4461 (Ramsdell, 1986). Because of the different modeling assumptions and underlying data used to develop the tornado wind information, the wind speeds at specified exceedance levels, at a given location, based on the methodology in UCRL-53526, are different than those based on the methodology in NUREG/CR-4461. In 1997, Lawrence Livermore National Laboratory (LLNL) was funded by the DOE to review the current methodologies for characterizing tornado wind hazards and to develop a state-of-the-art wind/tornado characterization methodology based on probabilistic hazard assessment techniques and current historical wind data. This report describes the process of developing the methodology and the database of relevant tornado information needed to implement the methodology. It also presents the tornado wind hazard curves obtained from the application of the method to DOE sites throughout the contiguous United States.« less

Multidisciplinary Design Optimization for Glass-Fiber Epoxy-Matrix Composite 5 MW Horizontal-Axis Wind-Turbine Blades

NASA Astrophysics Data System (ADS)

Grujicic, M.; Arakere, G.; Pandurangan, B.; Sellappan, V.; Vallejo, A.; Ozen, M.

2010-11-01

A multi-disciplinary design-optimization procedure has been introduced and used for the development of cost-effective glass-fiber reinforced epoxy-matrix composite 5 MW horizontal-axis wind-turbine (HAWT) blades. The turbine-blade cost-effectiveness has been defined using the cost of energy (CoE), i.e., a ratio of the three-blade HAWT rotor development/fabrication cost and the associated annual energy production. To assess the annual energy production as a function of the blade design and operating conditions, an aerodynamics-based computational analysis had to be employed. As far as the turbine blade cost is concerned, it is assessed for a given aerodynamic design by separately computing the blade mass and the associated blade-mass/size-dependent production cost. For each aerodynamic design analyzed, a structural finite element-based and a post-processing life-cycle assessment analyses were employed in order to determine a minimal blade mass which ensures that the functional requirements pertaining to the quasi-static strength of the blade, fatigue-controlled blade durability and blade stiffness are satisfied. To determine the turbine-blade production cost (for the currently prevailing fabrication process, the wet lay-up) available data regarding the industry manufacturing experience were combined with the attendant blade mass, surface area, and the duration of the assumed production run. The work clearly revealed the challenges associated with simultaneously satisfying the strength, durability and stiffness requirements while maintaining a high level of wind-energy capture efficiency and a lower production cost.

75 FR 81637 - Commercial Lease for the Cape Wind Energy Project

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-28

... Commercial Lease for the Cape Wind Energy Project AGENCY: Bureau of Ocean Energy Management, Regulation and... Renewable Energy Development on the Outer Continental Shelf (``OCS'') for the Cape Wind Energy Project... requirements of 30 CFR 285.231. The Lease is for the Cape Wind Energy Project (``Project'') which grants Cape...

Atlas de Recursos Eólicos del Estado de Oaxaca (The Spanish version of Wind Energy Resource Atlas of Oaxaca) (in Spanish)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elliott, D.; Schwartz, M.; Scott, G.

The Oaxaca Wind Resource Atlas, produced by the National Renewable Energy Laboratory's (NREL's) wind resource group, is the result of an extensive mapping study for the Mexican State of Oaxaca. This atlas identifies the wind characteristics and distribution of the wind resource in Oaxaca. The detailed wind resource maps and other information contained in the atlas facilitate the identification of prospective areas for use of wind energy technologies, both for utility-scale power generation and off-grid wind energy applications.

76 FR 36532 - Iberdrola Renewables, Inc., PacifiCorp, NextEra Energy Resources, LLC, Invenergy Wind North...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-22

... Renewables, Inc., PacifiCorp, NextEra Energy Resources, LLC, Invenergy Wind North America LLC, Horizon Wind...), Iberdrola Renewables, Inc., PacifiCorp, NextEra Energy Resources, LLC, Invenergy Wind North America LLC, and Horizon Wind Energy LLC (Complainants) filed a formal complaint against Bonneville Power Administration...

Experimental testing of axial induction based control strategies for wake control and wind farm optimization

NASA Astrophysics Data System (ADS)

Bartl, J.; Sætran, L.

2016-09-01

In state-of-the-art wind farms each turbine is controlled individually aiming for optimum turbine power not considering wake effects on downstream turbines. Wind farm control concepts aim for optimizing the overall power output of the farm taking wake interactions between the individual turbines into account. This experimental wind tunnel study investigates axial induction based control concepts. It is examined how the total array efficiency of two in-line model turbines is affected when the upstream turbine's tip speed ratio (λcontrol) or blade pitch angle (β-control) is modified. The focus is particularly directed on how the wake flow behind the upstream rotor is affected when its axial induction is reduced in order to leave more kinetic energy in the wake to be recovered by a downstream turbine. It is shown that the radial distribution of kinetic energy in the wake area can be controlled by modifying the upstream turbine's tip speed ratio. By pitching out the upstream turbine's blades, however, the available kinetic energy in the wake is increased at an equal rate over the entire blade span. Furthermore, the total array efficiency of the two turbine setup is mapped depending on the upstream turbines tip speed ratio and pitch angle. For a small turbine separation distance of x/D=3 the downstream turbine is able to recover the major part of the power lost on the upstream turbine. However, no significant increase in the two-turbine array efficiency is achieved by altering the upstream turbine's operation point away from its optimum.

An Analysis of the Use of Energy Audits, Solar Panels, and Wind Turbines to Reduce Energy Consumption from Non Renewable Energy Sources

DTIC Science & Technology

2015-04-15

the Use of Energy Audits, Solar Panels, and Wind Turbines to Reduce Energy Consumption from Non Renewable Energy Sources Energy is a National...Park, NC 27709-2211 Energy Audits, Energy Conservation, Renewable Energy, Solar Energy, Wind Turbine Use, Energy Consumption REPORT DOCUMENTATION PAGE 11...in non peer-reviewed journals: An Analysis of the Use of Energy Audits, Solar Panels, and Wind Turbines to Reduce Energy Consumption from Non

DOE/NREL supported wind energy activities in Alaska

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drouilhet, S.

1997-12-01

This paper describes three wind energy projects implemented in Alaska. The first, a sustainable technology energy partnerships (STEP) wind energy deployment project in Kotzebue will install 6 AOC 15/50 wind turbines and connect to the existing village diesel grid, consisting of approximately 1 MW average load. It seeks to develop solutions to the problems of arctic wind energy installations (transport, foundations, erection, operation, and maintenance), to establish a wind turbine test site, and to establish the Kotzebue Electric Association as a training and deployment center for wind/diesel technology in rural Alaska. The second project, a large village medium-penetration wind/diesel system,more » also in Kotzebue, will install a 1-2 MW windfarm, which will supplement the AOC turbines of the STEP project. The program will investigate the impact of medium penetration wind energy on power quality and system stability. The third project, the Alaska high-penetration wind/diesel village power pilot project in Wales will install a high penetration (80-100%) wind/diesel system in a remote Alaskan village. The system will include about 180 kW installed wind capacity, meeting an average village load of about 60 kW. This program will provide a model for high penetration wind retrofits to village diesel power systems and build the capability in Alaska to operate, maintain, and replicate wind/diesel technology. The program will also address problems of: effective use of excess wind energy; reliable diesel-off operation; and the role of energy storage.« less

Wind Tunnel Modeling Of Wind Flow Over Complex Terrain

NASA Astrophysics Data System (ADS)

Banks, D.; Cochran, B.

2010-12-01

This presentation will describe the finding of an atmospheric boundary layer (ABL) wind tunnel study conducted as part of the Bolund Experiment. This experiment was sponsored by Risø DTU (National Laboratory for Sustainable Energy, Technical University of Denmark) during the fall of 2009 to enable a blind comparison of various air flow models in an attempt to validate their performance in predicting airflow over complex terrain. Bohlund hill sits 12 m above the water level at the end of a narrow isthmus. The island features a steep escarpment on one side, over which the airflow can be expected to separate. The island was equipped with several anemometer towers, and the approach flow over the water was well characterized. This study was one of only two only physical model studies included in the blind model comparison, the other being a water plume study. The remainder were computational fluid dynamics (CFD) simulations, including both RANS and LES. Physical modeling of air flow over topographical features has been used since the middle of the 20th century, and the methods required are well understood and well documented. Several books have been written describing how to properly perform ABL wind tunnel studies, including ASCE manual of engineering practice 67. Boundary layer wind tunnel tests are the only modelling method deemed acceptable in ASCE 7-10, the most recent edition of the American Society of Civil Engineers standard that provides wind loads for buildings and other structures for buildings codes across the US. Since the 1970’s, most tall structures undergo testing in a boundary layer wind tunnel to accurately determine the wind induced loading. When compared to CFD, the US EPA considers a properly executed wind tunnel study to be equivalent to a CFD model with infinitesimal grid resolution and near infinite memory. One key reason for this widespread acceptance is that properly executed ABL wind tunnel studies will accurately simulate flow separation, vortex shedding, and local turbulence intensity and wind shear values. To achieve accurate results, attention must of course be paid to issues such as ensuring Reynolds number independence, avoiding blockage issues, and properly matching the velocity power spectrum, but once this is done, the laws of fluid mechanics take care of the rest. There will not be an overproduction of turbulent kinetic energy at the top of escarpments, or unacceptable dissipation of inlet turbulence levels. Modern atmospheric boundary layer wind tunnels are also often used to provide validation data for evaluating the performance of CFD model in complex flow environments. Present day computers have further increased the quality and quantity of data that can be economically obtained in a timely manner, for example through wind speed measurement using a computer controlled 3-D measurement positioning system Given this accuracy and widespread acceptance, it is perhaps surprising that ours was the only wind tunnel model in the Bolund blind experiment, an indication of how seldom physical modelling is used when estimating terrain effect for wind farms. In demonstrating how the Bolund test was modeled, this presentation will provide background on wind tunnel testing, including the governing scaling parameters. And we’ll see how our results compared to the full scale tests.

GRASSLAND BIRD DISTRIBUTION AND RAPTOR FLIGHT PATTERNS IN THE COMPETITIVE RENEWABLE ENERGY ZONES OF THE TEXAS PANHANDLE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jansen, Erik

The consistent wind resource in the Great Plains of North America has encouraged the development of wind energy facilities across this region. In the Texas Panhandle, a high quality wind resource is only one factor that has led to the expansion of wind energy development. Other factors include federal tax incentives and the availability of subsidies. Moreover, the State Renewable Portfolio Standards (RPS), mandating production of 10,000 mega-watts of renewable energy in the state by 2025, has contributed to an amicable regulatory and permitting environment (State Energy Conservation Office 2010). Considering the current rate of development, the RPS will bemore » met in coming years (American Wind Energy Association 2011) and the rate of development is likely to continue. To meet increased energy demands in the face of a chronically constrained transmission grid, Texas has developed a comprehensive plan that organizes and prioritizes new transmission systems in high quality wind resource areas called Competitive Renewable Energy Zones (CREZ). The CREZ plan provides developers a solution to transmission constraints and unlocks large areas of undeveloped wind resource areas. In the northern Texas panhandle, there are two CREZs that are classified Class 3 wind (Class 5 is the highest) and range from 862,725 to 1,772,328 ha in size (Public Utility Commission of Texas 2008). Grassland bird populations have declined more than any other bird group in North America (Peterjohn and Sauer 1999, Sauer et al. 2004). Loss of grassland habitat from agricultural development has been the greatest contributor to the decline of grassland bird populations, but development of non-renewable (i.e., oil, coal, and gas) and renewable energy (i.e., wind, solar, biomass, and geothermal) sources have contributed to the decline as well (Pimentel et al. 2002, Maybe and Paul 2007). The effects of wind energy development on declining grassland bird populations has become an area of extensive research, as we attempt to understand and minimize potential impacts of a growing energy sector on declining bird populations. Based on data from post-construction fatality surveys, two grassland bird groups have been the specific focus of research, passerines (songbird guild) and raptors (birds of prey). The effects of wind energy development on these two groups of birds, both of conservation concern, have been examined over the last decade. The primary focus of this research has been on mortality resulting from collision with wind turbines (Kuvlesky et al. 2007). Most studies just quantify post-construction fatality levels (e.g., Erickson et al. 2002) while very few studies provide a comparison of bird populations prior to development through a Before-After-Control-Impact (BACI) study design. Before-After-Control-Impact studies provide powerful evidence of avian/wind energy relationships (Anderson et al. 1999). Despite repeated urgency on conducting these types of studies (Anderson et al. 1999, Madders and Whitfield 2006, Kuvelsky et al. 2007), few have been conducted in North America. Although several European researchers (Larsson 1994, de Lucas et al. 2007) have used BACI designs to examine whether wind facilities modified raptor behavior, there is a scarcity of BACI data relating to North America grassland ecosystems that examine avian-wind energy relationships. There are less than a handful of studies in the entire United States, let alone the southern short grass prairie ecosystem, that incorporate preconstruction data to form the baseline for post-construction impact estimates (Johnson et al. 2000, Erickson et al. 2002). Although declines in grassland bird populations are well-documented (Peterjohn and Sauer 1999, Sauer et al. 2004), the causal mechanisms affecting the decline of grassland birds with increasing wind energy development in the southern short grass prairie are not well-understood (Kuvlesky et al. 2007, Maybe and Paul 2007). Several factors may potentially affect the bird population when wind turbines are constructed in areas with high bird densities (de Lucas et al. 2007). Habitat fragmentation, noise from turbines, physical movement of turbine blades, and increased vehicle traffic have been suggested as causes of decreased density of nesting grassland birds in Minnesota (Leddy et al. 1999), Oklahoma (O’Connell and Piorkowski 2006), and South Dakota (Shaffer and Johnson 2008). Similarly, constructing turbines in areas where bird flight patterns place them at similar heights of turbine blades increases the potential for bird collisions (Johnson et al. 2000, Hoover 2002). Raptor fatalities have been associated with topographic features such as ridges, saddles and rims where birds use updrafts from prevailing winds (Erickson et al. 2000, Johnson et al. 2000, Barrios and Rodriquez 2004, Hoover and Morrison 2005). Thus, wind energy development can result in indirect (e.g., habitat avoidance, decreased nest success) and direct (e.g., collision fatalities) impacts to bird populations (Anderson et al. 1999). Directly quantifying the level of potential impacts (e.g., estimated fatalities/mega-watthour) from wind energy development is beyond the scope of this study. Instead, I aim to quantify density, occupancy and flight behavior for the two bird groups mentioned earlier: obligate grassland songbirds and raptors, respectively, predict where impacts may occur, and provide management recommendations to minimize potential impacts. The United States Department of Energy (DOE), through the Office of Energy Efficiency and Renewable Energy Allocation, contracted Texas Tech University to investigate grassland bird patterns of occurrence in the anticipated CREZ in support of DOE’s 20% Wind Energy by 2030 initiative. In cooperation with Iberdrola Renewables, Inc., studies initiated by Wulff (2010) at Texas Tech University were continued at an area proposed for wind energy development and a separate reference site unassociated with wind energy development. I focused on four primary objectives and this thesis is accordingly organized in four separate chapters that address grassland bird density, grassland bird occupancy, raptor flight patterns, and finally I summarize species diversity and composition. The following chapters use formatting from the Journal of Wildlife Management guidelines (Block et al. 2011) with modifications as required by the Texas Tech University Graduate School. 1) I estimate pre-construction bird density patterns using methods that adjust for imperfect detection. I used a distance sampling protocol that effectively accounts for incomplete detection in the field where birds are present but not detected (Buckland et al. 2001). I improved density estimates with hierarchical distance sampling models, a modeling technique that effectively incorporates the detection process with environmental covariates that further influence bird density (Royle et al. 2004, Royle and Dorazio 2008). Covariates included road density and current oil and gas infrastructure to determine the relationship between existing energy development and bird density patterns. Further, I used remote sensing techniques and vegetation field data to investigate how landcover characteristics influenced bird density patterns. I focused species-specific analyses on obligate grassland birds with >70 detections per season namely grasshopper sparrow (Ammodramus savannarum) and horned lark (Eremophila alpestris). Chapter II focuses on hierarchical models that model and describe relationships between grassland bird density and anthropogenic and landscape features. 2) A large number of bird detections (>70) are needed to estimate density using distance sampling and collection of such quantity are often not feasible, particularly for cryptic species or species that naturally occur at low densities (Buckland et al. 2001). Occupancy models operate with far fewer data and are often used as a surrogate for bird abundance when there are fewer detections (MacKenzie and Nichols 2004). I used occupancy models that allow for the possibility of imperfect detection and species abundance to improve estimates of occurrence probability (Royal 2004). I focused species-specific analyses on grassland birds with few detections: Cassin’s sparrow (Peucaea cassinii), eastern meadowlark (Sturnella magna), and upland sandpiper (Bartramia longicauda). Chapter III uses a multi-season dynamic site occupancy model that incorporates bird abundance to better estimate occurrence probability. 3) When I considered the topographic relief of the study sites, the proposed design of the wind facility and its location within the central U.S. migratory corridor, I expanded the study to investigate raptor abundance and flight behavior (Hoover 2002, Miller 2008). I developed a new survey technique that improved the accuracy of raptor flight height estimates and compared seasonal counts and flight heights at the plateau rim and areas further inland. I used counts and flight behaviors to calculate species-specific collision risk indices for raptors based on topographic features. I focused species-specific analyses on raptors with the highest counts: American kestrel (Falco sparverius), northern harrier (Circus cyaneus), red-tailed hawk (Buteo jamaicensis), Swainson’s hawk (Buteo swainsoni), and turkey vulture (Cathartes aura). Chapter IV describes patterns of seasonal raptor abundance and flight behavior and how topography modulates collision risk with proposed wind energy turbines. 4) Finally, for completeness, in Chapter V I summarize morning point count data for all species and provide estimates of relative composition and species diversity with the Shannon-Wiener Diversity Index (Shannon and Weaver 1949).« less

Wind and Temperature Spectrometry of the Upper Atmosphere in Low-Earth Orbit

NASA Technical Reports Server (NTRS)

Herrero, Federico

2011-01-01

Wind and Temperature Spectrometry (WATS) is a new approach to measure the full wind vector, temperature, and relative densities of major neutral species in the Earth's thermosphere. The method uses an energy-angle spectrometer moving through the tenuous upper atmosphere to measure directly the angular and energy distributions of the air stream that enters the spectrometer. The angular distribution gives the direction of the total velocity of the air entering the spectrometer, and the energy distribution gives the magnitude of the total velocity. The wind velocity vector is uniquely determined since the measured total velocity depends on the wind vector and the orbiting velocity vector. The orbiting spectrometer moves supersonically, Mach 8 or greater, through the air and must point within a few degrees of its orbital velocity vector (the ram direction). Pointing knowledge is critical; for example, pointing errors 0.1 lead to errors of about 10 m/s in the wind. The WATS method may also be applied without modification to measure the ion-drift vector, ion temperature, and relative ion densities of major ionic species in the ionosphere. In such an application it may be called IDTS: Ion-Drift Temperature Spectrometry. A spectrometer-based coordinate system with one axis instantaneously pointing along the ram direction makes it possible to transform the Maxwellian velocity distribution of the air molecules to a Maxwellian energy-angle distribution for the molecular flux entering the spectrometer. This implementation of WATS is called the gas kinetic method (GKM) because it is applied to the case of the Maxwellian distribution. The WATS method follows from the recognition that in a supersonic platform moving at 8,000 m/s, the measurement of small wind velocities in the air on the order of a few 100 m/s and less requires precise knowledge of the angle of incidence of the neutral atoms and molecules. The same is true for the case of ion-drift measurements. WATS also provides a general approach that can obtain non-equilibrium distributions as may exist in the upper regions of the thermosphere, above 500 km and into the exosphere. Finally, WATS serves as a mass spectrometer, with very low mass resolution of roughly 1 part in 3, but easily separating atomic oxygen from molecular nitrogen.

Wind Energy | Climate Neutral Research Campuses | NREL

Science.gov Websites

turbine or wind farm is one of the few technologies that supplies renewable energy at the scale required . Before determining whether a site is suitable for a wind turbine, read the Wind Energy Siting Handbook Community College has installed a wind turbine on site and now offers an Associate Degree in wind energy and

Roadmap of retail electricity market reform in China: assisting in mitigating wind energy curtailment

NASA Astrophysics Data System (ADS)

Yu, Dezhao; Qiu, Huadong; Yuan, Xiang; Li, Yuan; Shao, Changzheng; Lin, You; Ding, Yi

2017-01-01

Among the renewable energies, wind energy has gained the rapidest development in China. Moreover wind power generation has been penetrated into power system in a large scale. However, the high level wind curtailment also indicates a low efficiency of wind energy utilization over the last decade in China. One of the primary constraints on the utilization of wind energy is the lack of an electricity market, in which renewable energies can compete equally with traditional fossil fuel generation. Thus the new round electric power industry reform is essential in China. The reform involves implementing new pricing mechanism, introducing retail-side competition, promoting the consumption of renewable energy. The new round reform can be a promising solution for promoting the development and consumption of wind energy generation in China. Based on proposed reform policies of electric power industry, this paper suggests a roadmap for retail electricity market reform of China, which consists of three stages. Barriers to the efficient utilization of wind energy are also analysed. Finally, this paper introduces several efficient measures for mitigating wind curtailment in each stage of reform.

Transition from geostrophic turbulence to inertia-gravity waves in the atmospheric energy spectrum.

PubMed

Callies, Jörn; Ferrari, Raffaele; Bühler, Oliver

2014-12-02

Midlatitude fluctuations of the atmospheric winds on scales of thousands of kilometers, the most energetic of such fluctuations, are strongly constrained by the Earth's rotation and the atmosphere's stratification. As a result of these constraints, the flow is quasi-2D and energy is trapped at large scales—nonlinear turbulent interactions transfer energy to larger scales, but not to smaller scales. Aircraft observations of wind and temperature near the tropopause indicate that fluctuations at horizontal scales smaller than about 500 km are more energetic than expected from these quasi-2D dynamics. We present an analysis of the observations that indicates that these smaller-scale motions are due to approximately linear inertia-gravity waves, contrary to recent claims that these scales are strongly turbulent. Specifically, the aircraft velocity and temperature measurements are separated into two components: one due to the quasi-2D dynamics and one due to linear inertia-gravity waves. Quasi-2D dynamics dominate at scales larger than 500 km; inertia-gravity waves dominate at scales smaller than 500 km.

Transition from geostrophic turbulence to inertia–gravity waves in the atmospheric energy spectrum

PubMed Central

Callies, Jörn; Ferrari, Raffaele; Bühler, Oliver

2014-01-01

Midlatitude fluctuations of the atmospheric winds on scales of thousands of kilometers, the most energetic of such fluctuations, are strongly constrained by the Earth’s rotation and the atmosphere’s stratification. As a result of these constraints, the flow is quasi-2D and energy is trapped at large scales—nonlinear turbulent interactions transfer energy to larger scales, but not to smaller scales. Aircraft observations of wind and temperature near the tropopause indicate that fluctuations at horizontal scales smaller than about 500 km are more energetic than expected from these quasi-2D dynamics. We present an analysis of the observations that indicates that these smaller-scale motions are due to approximately linear inertia–gravity waves, contrary to recent claims that these scales are strongly turbulent. Specifically, the aircraft velocity and temperature measurements are separated into two components: one due to the quasi-2D dynamics and one due to linear inertia–gravity waves. Quasi-2D dynamics dominate at scales larger than 500 km; inertia–gravity waves dominate at scales smaller than 500 km. PMID:25404349

National Wind Technology Center | NREL

Science.gov Websites

. Wind Energy Research Wind turbine blade Wind energy research at the NWTC allows for validation and verification of large and small components and wind turbine systems. Photo by Dennis Schroeder / NREL 40935 Wind energy research at the NWTC has pioneered wind turbine components, systems, and modeling methods

Artificial Bird Feathers: An Adaptive Wing with High Lift Capability.

NASA Astrophysics Data System (ADS)

Hage, W.; Meyer, R.; Bechert, D. W.

1997-11-01

In Wind tunnel experiments, the operation of the covering feathers of bird wings has been investigated. At incipient flow separation, local flow reversal lifts the feathers and inhibits the spreading of the separation regime towards the leading edge. This mechanism can be utilized by movable flaps on airfoils. The operation of quasi-steady and of vibrating movable flaps is outlined. These devices are self-actuated, require no energy and do not produce parasitic drag. They are compatible with laminar and turbulent airfoils as well as with various conventional flaps on aircraft wings. Laboratory and flight experiments are shown. Ref: AIAA-Paper 97-1960.

Wind for Schools Project Curriculum Brief (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2010-08-01

The U.S. Department of Energy's (DOE's) 20% Wind Energy by 2030 report recommends expanding education to ensure a trained workforce to meet the projected growth of the wind industry and deployment. Although a few U.S. higher education institutions offer wind technology education programs, most are found in community and technical colleges, resulting in a shortage of programs preparing highly skilled graduates for wind industry careers. Further, the United States lags behind Europe (which has more graduate programs in wind technology design and manufacturing) and is in danger of relinquishing the economic benefits of domestic production of wind turbines and relatedmore » components and services to European countries. DOE's Wind Powering America initiative launched the Wind for Schools project to develop a wind energy knowledge base among future leaders of our communities, states, and nation while raising awareness about wind energy's benefits. This fact sheet provides an overview of wind energy curricula as it relates to the Wind for Schools project.« less

78 FR 49496 - Combined Notice of Filings #2

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-14

... LLC, Vantage Wind Energy LLC, Stony Creek Energy LLC, Gratiot County Wind LLC, Gratiot County Wind II LLC, Bishop Hill Energy LLC, Bishop Hill Energy III LLC, California Ridge Wind Energy LLC. Description.... Docket Numbers: ER13-2056-000. Applicants: Southwest Power Pool, Inc. Description: 2198R9 Kansas Power...

The First Bachelor of Science Degree in Wind Energy in the US at Texas Tech University Authors: A. Ruiz Columbié, K. Rozsavolgyi, P. Hughes, D. Farris, A. Swift, R. Walker and M. Baker

NASA Astrophysics Data System (ADS)

Ruiz-Columbie, A.

2010-12-01

This paper presents a new Bachelor of Science Degree in Wind Energy proposal at Texas Tech University (TTU) beginning the spring 2011. It is designed to prepare the students for admission into a graduate program in wind energy, and/or employment as a professional in wind energy. The program integrates the environmental, social, economic, ethical, technical, scientific principles and practical skills the graduates will need in order to success as professionals in their field of expertise. This degree will provide a multidisciplinary education in the wind energy field through the study of subjects as wind meteorology, wind power generation, wind resource assessment, sustainable energy systems, utility systems operations, and fiscal and operational oversight. Students will be prepared to contribute in areas that include planning, development, operations, analysis and supervision of wind energy systems and projects, as well as to continue in graduate studies. Following the Texas Tech Uniform Undergraduate Degree Requirement Act, the major in Wind Energy will include 47 hours of general education courses from the TTU academic core, 18 hours of junior/senior level electives, and 55 hours of coursework in wind energy topics. A minor of 18 hours is also provided at TTU for those students with a different major who might decide to get a higher education in wind energy.

Kansas Wind Energy Consortium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gruenbacher, Don

2015-12-31

This project addresses both fundamental and applied research problems that will help with problems defined by the DOE “20% Wind by 2030 Report”. In particular, this work focuses on increasing the capacity of small or community wind generation capabilities that would be operated in a distributed generation approach. A consortium (KWEC – Kansas Wind Energy Consortium) of researchers from Kansas State University and Wichita State University aims to dramatically increase the penetration of wind energy via distributed wind power generation. We believe distributed generation through wind power will play a critical role in the ability to reach and extend themore » renewable energy production targets set by the Department of Energy. KWEC aims to find technical and economic solutions to enable widespread implementation of distributed renewable energy resources that would apply to wind.« less

Effects of Blade Boundary Layer Transition and Daytime Atmospheric Turbulence on Wind Turbine Performance Analyzed with Blade-Resolved Simulation and Field Data

NASA Astrophysics Data System (ADS)

Nandi, Tarak Nath

Relevant to utility scale wind turbine functioning and reliability, the present work focuses on enhancing our understanding of wind turbine responses from interactions between energy-dominant daytime atmospheric turbulence eddies and rotating blades of a GE 1.5 MW wind turbine using a unique data set from a GE field experiment and computer simulations at two levels of fidelity. Previous studies have shown that the stability state of the lower troposphere has a major impact on the coherent structure of the turbulence eddies, with corresponding differences in wind turbine loading response. In this study, time-resolved aerodynamic data measured locally at the leading edge and trailing edge of three outer blade sections on a GE 1.5 MW wind turbine blade and high-frequency SCADA generator power data from a daytime field campaign are combined with computer simulations that mimic the GE wind turbine within a numerically generated atmospheric boundary layer (ABL) flow field which is a close approximation of the atmospheric turbulence experienced by the wind turbine in the field campaign. By combining the experimental and numerical data sets, this study describes the time-response characteristics of the local loadings on the blade sections in response to nonsteady nonuniform energetic atmospheric turbulence eddies within a daytime ABL which have spatial scale commensurate with that of the turbine blade length. This study is the first of its kind where actuator line and blade boundary layer resolved CFD studies of a wind turbine field campaign are performed with the motivation to validate the numerical predictions with the experimental data set, and emphasis is given on understanding the influence of the laminar to turbulent transition process on the blade loadings. The experimental and actuator line method data sets identify three important response time scales quantified at the blade location: advective passage of energy-dominant eddies (≈25 - 50 s), blade rotation (1P, ≈3 s) and sub-1P scale (< 1 s) response to internal eddy structure. Large amplitude short-time ramp-like and oscillatory load fluctuations result in response to temporal changes in velocity vector inclination in the airfoil plane, modulated by eddy passage at longer time scales. Generator power is found to respond strongly to large-eddy wind modulations. The experimental data show that internal dynamics of blade boundary layer near the trailing edge is temporally modulated by the nonsteady external ABL flow that was measured at the leading edge, as well as blade generated turbulence motions. A blade boundary layer resolved CFD study of a GE 1.5MW wind turbine blade is carried out using a hybrid URANS/LES framework to quantify the influence of transition on the blade boundary layer dynamics and subsequent loadings, and also to predict the velocity magnitude data set measured by the trailing edge rakes in the experiment. A URANS based transition model is used as the near-wall model, and its ability to predict nonsteady boundary layer dynamics is assessed for flow over an oscillating airfoil exhibiting varying extents of nonsteady behavior. The CFD study shows that, at rated conditions, the transition and separation locations on the blade surface can be quite dynamic, but the transitional flow has negligible influence on the determination of the separation location and the overall pressure distribution at various blade sections, and subsequently the power output. But this conclusion should be accepted with caution for wind turbines running in off-design conditions (e.g. with significant yaw error, off-design pitch or rapid changes in pitch), where massive separation and dynamic stall may occur. Analysis of the near-blade flow field shows strong three dimensional flow in the inboard regions, which can possibly weaken the chordwise flow in the relatively outboard regions and make them more prone to separation. The trailing edge velocity profiles show qualitative resemblance with some specific cycles observed in the field experiment. The factors leading to the observed differences from the experimental data are also mentioned.

Investigation on installation of offshore wind turbines

NASA Astrophysics Data System (ADS)

Wang, Wei; Bai, Yong

2010-06-01

Wind power has made rapid progress and should gain significance as an energy resource, given growing interest in renewable energy and clean energy. Offshore wind energy resources have attracted significant attention, as, compared with land-based wind energy resources, offshore wind energy resources are more promising candidates for development. Sea winds are generally stronger and more reliable and with improvements in technology, the sea has become a hot spot for new designs and installation methods for wind turbines. In the present paper, based on experience building offshore wind farms, recommended foundation styles have been examined. Furthermore, wave effects have been investigated. The split installation and overall installation have been illustrated. Methods appropriate when installing a small number of turbines as well as those useful when installing large numbers of turbines were analyzed. This investigation of installation methods for wind turbines should provide practical technical guidance for their installation.

Lidar-Enhanced Wind Turbine Control: Past, Present, and Future

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scholbrock, Andrew; Fleming, Paul; Schlipf, David

The main challenges in harvesting energy from the wind arise from the unknown incoming turbulent wind field. Balancing the competing interests of reduction in structural loads and increasing energy production is the goal of a wind turbine controller to reduce the cost of producing wind energy. Conventional wind turbines use feedback methods to optimize these goals, reacting to wind disturbances after they have already impacted the wind turbine. Lidar sensors offer a means to provide additional inputs to a wind turbine controller, enabling new techniques to improve control methods, allowing a controller to actuate a wind turbine in anticipation ofmore » an incoming wind disturbance. This paper will look at the development of lidar-enhanced controls and how they have been used for various turbine load reductions with pitch actuation, as well as increased energy production with improved yaw control. Ongoing work will also be discussed to show that combining pitch and torque control using feedforward nonlinear model predictive control can lead to both reduced loads and increased energy production. Future work is also proposed on extending individual wind turbine controls to the wind plant level and determining how lidars can be used for control methods to further lower the cost of wind energy by minimizing wake impacts in a wind farm.« less

Orion GN&C Detection and Mitigation of Parachute Pendulosity

NASA Technical Reports Server (NTRS)

Kane, Mark A.; Wacker, Roger

2016-01-01

New techniques being employed by Orion guidance, navigation, and control (GN&C) using a reaction control system (RCS) under parachutes are described. Pendulosity refers to a pendulum-oscillatory mode that can occur during descent under main parachutes and that has been observed during Orion parachute drop tests. The pendulum mode reduces the ability of GN&C to maneuver the suspended vehicle resulting in undesirable increases to structural loads at touchdown. Parachute redesign efforts have been unsuccessful in reducing the pendulous behavior necessitating GN&C mitigation options. An observer has been developed to estimate the pendulum motion as well as the underlying wind velocity vector. Using this knowledge, the control system maneuvers the vehicle using two separate strategies determined by wind velocity magnitude and pendulum energy thresholds; at high wind velocities the vehicle is aligned with the wind direction and for cases with lower wind velocities and large pendulum amplitudes the vehicle is aligned such that it is perpendicular to the swing plane. Pendulum damping techniques using RCS thrusters are discussed but have not been selected for use onboard the Orion spacecraft. The techniques discussed in this paper will be flown on Exploration Mission 1 (EM-1).

A Study of the Effects of Large Scale Gust Generation in a Small Scale Atmospheric Wind Tunnel: Application to Micro Aerial Vehicles

NASA Astrophysics Data System (ADS)

Roadman, Jason; Mohseni, Kamran

2009-11-01

Modern technology operating in the atmospheric boundary layer could benefit from more accurate wind tunnel testing. While scaled atmospheric boundary layer tunnels have been well developed, tunnels replicating portions of the turbulence of the atmospheric boundary layer at full scale are a comparatively new concept. Testing at full-scale Reynolds numbers with full-scale turbulence in an ``atmospheric wind tunnel'' is sought. Many programs could utilize such a tool including that of Micro Aerial Vehicles (MAVs) and other unmanned aircraft, the wind energy industry, fuel efficient vehicles, and the study of bird and insect fight. The construction of an active ``gust generator'' for a new atmospheric tunnel is reviewed and the turbulence it generates is measured utilizing single and cross hot wires. Results from this grid are compared to atmospheric turbulence and it is shown that various gust strengths can be produced corresponding to days ranging from calm to quite gusty. An initial test is performed in the atmospheric wind tunnel whereby the effects of various turbulence conditions on transition and separation on the upper surface of a MAV wing is investigated using oil flow visualization.

Experimental investigation of flow over two-dimensional multiple hill models.

PubMed

Li, Qing'an; Maeda, Takao; Kamada, Yasunari; Yamada, Keisuke

2017-12-31

The aim of this study is to investigate the flow field characteristics in ABL (Atmospheric Boundary Layer) flow over multiple hills and valleys in two-dimensional models under neutral conditions. Active turbulence grids and boundary layer generation frame were used to simulate the natural winds in wind tunnel experiments. As a result, the mean wind velocity, the velocity vector diagram and turbulence intensity around the hills were investigated by using a PIV (Particle Image Velocimetry) system. From the measurement results, it was known that the average velocity was increased along the upstream slope of upside hill, and then separated at the top of the hills, the acceleration region of U/U ref >1 was generated at the downstream of the hill. Meanwhile, a large clockwise circulation flow was generated between the two hill models. Moreover, the turbulence intensity showed small value in the circulation flow regions. Compared to 1H model, the turbulence intensity in the mainstream direction showed larger value than that in the vertical direction. This paper provided a better understanding of the wind energy distribution on the terrain for proper selection of suitable sites for installing wind farms in the ABL. Copyright © 2017 Elsevier B.V. All rights reserved.

IEA Wind Task 26. Wind Technology, Cost, and Performance Trends in Denmark, Germany, Ireland, Norway, the European Union, and the United States: 2007–2012

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vitina, Aisma; Lüers, Silke; Wallasch, Anna-Kathrin

The International Energy Agency Implementing Agreement for cooperation in Research, Development, and Deployment of Wind Energy Systems (IEA Wind) Task 26—The Cost of Wind Energy represents an international collaboration dedicated to exploring past, present and future cost of wind energy. This report provides an overview of recent trends in wind plant technology, cost, and performance in those countries that are currently represented by participating organizations in IEA Wind Task 26: Denmark, Germany, Ireland, Norway, and the United States as well as the European Union.

Computational studies of horizontal axis wind turbines in high wind speed condition using advanced turbulence models

NASA Astrophysics Data System (ADS)

Benjanirat, Sarun

Next generation horizontal-axis wind turbines (HAWTs) will operate at very high wind speeds. Existing engineering approaches for modeling the flow phenomena are based on blade element theory, and cannot adequately account for 3-D separated, unsteady flow effects. Therefore, researchers around the world are beginning to model these flows using first principles-based computational fluid dynamics (CFD) approaches. In this study, an existing first principles-based Navier-Stokes approach is being enhanced to model HAWTs at high wind speeds. The enhancements include improved grid topology, implicit time-marching algorithms, and advanced turbulence models. The advanced turbulence models include the Spalart-Allmaras one-equation model, k-epsilon, k-o and Shear Stress Transport (k-o-SST) models. These models are also integrated with detached eddy simulation (DES) models. Results are presented for a range of wind speeds, for a configuration termed National Renewable Energy Laboratory Phase VI rotor, tested at NASA Ames Research Center. Grid sensitivity studies are also presented. Additionally, effects of existing transition models on the predictions are assessed. Data presented include power/torque production, radial distribution of normal and tangential pressure forces, root bending moments, and surface pressure fields. Good agreement was obtained between the predictions and experiments for most of the conditions, particularly with the Spalart-Allmaras-DES model.

Contribution of wind energy to the energy balance of a combined solar and wind energy system. Part 1: System description, data acquisition and system performance

NASA Astrophysics Data System (ADS)

Ferger, R.; Machens, U.

1985-05-01

A one-family house was equipped with a combined solar and wind energy system plus a night storage heater to measure the seasonal complementary contribution of wind and solar energy to energy demand. Project implementation, problems encountered and modifications to the initial system are described. Meteorological and operational data and house consumption data were recorded on computer-based measuring system. Data on the combined effects of and interdependence between solar collector and wind energy converter are discussed.

Environmentally conscious alternative energy production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kutz, M.

This fourth volume of the series describes and compares the environmental and economic impacts of renewable and conventional power generation technologies. Chapter heading are: Economic comparisons of power generation technologies (Todd Nemec); Solar energy applications (Jan F. Kreider); Fuel cells (Matthew W. Mench); Geothermal resources and technology: an introduction (Peter D. Blair); Wind power generation (Todd Nemec); Cogeneration (Jerald Caton); Hydrogen energy (Elias K. Stefanakos, Yogi Goswami, S.S. Srinivasan, and J.T. Wolan); Clean power generation from coal (Prabir Basu and James Butler); and Using waste heat from power plants (Herbert A. Ingley). The chapter on clean coal power generation frommore » coal has been abstracted separately on the Coal Abstracts database. 2 apps.« less

Wind Turbine Wakes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelley, Christopher Lee; Maniaci, David Charles; Resor, Brian R.

2015-10-01

The total energy produced by a wind farm depends on the complex interaction of many wind turbines operating in proximity with the turbulent atmosphere. Sometimes, the unsteady forces associated with wind negatively influence power production, causing damage and increasing the cost of producing energy associated with wind power. Wakes and the motion of air generated by rotating blades need to be better understood. Predicting wakes and other wind forces could lead to more effective wind turbine designs and farm layouts, thereby reducing the cost of energy, allowing the United States to increase the installed capacity of wind energy. The Windmore » Energy Technologies Department at Sandia has collaborated with the University of Minnesota to simulate the interaction of multiple wind turbines. By combining the validated, large-eddy simulation code with Sandia’s HPC capability, this consortium has improved its ability to predict unsteady forces and the electrical power generated by an array of wind turbines. The array of wind turbines simulated were specifically those at the Sandia Scaled Wind Farm Testbed (SWiFT) site which aided the design of new wind turbine blades being manufactured as part of the National Rotor Testbed project with the Department of Energy.« less

Power from the Wind

ERIC Educational Resources Information Center

Roman, Harry T.

2004-01-01

Wind energy is the fastest-growing renewable energy source in the world. Over the last 20 years, the wind industry has done a very good job of engineering machines, improving materials, and economies of production, and making this energy source a reality. Like all renewable energy forms, wind energy's successful application is site specific. Also,…

76 FR 490 - Marking Meteorological Evaluation Towers

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-05

... of energy generation. Wind energy, converted into electrical energy by wind turbines, is widely... turbine or wind farm, companies erect METs. These towers are used to gather wind data necessary for site... if the targeted area represents a potential location for the installation of wind turbines...

77 FR 31839 - Wind and Water Power Program

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-30

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy Wind and Water Power Program... projects. The 2012 Wind and Water Power Program, Wind Power Peer Review Meeting will review wind technology development and market acceleration and deployment projects from the Program's research and development...

Wind energy utilization: A bibliography

NASA Technical Reports Server (NTRS)

1975-01-01

Bibliography cites documents published to and including 1974 with abstracts and references, and is indexed by topic, author, organization, title, and keywords. Topics include: Wind Energy Potential and Economic Feasibility, Utilization, Wind Power Plants and Generators, Wind Machines, Wind Data and Properties, Energy Storage, and related topics.

National Offshore Wind Energy Grid Interconnection Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daniel, John P.; Liu, Shu; Ibanez, Eduardo

2014-07-30

The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States. A total of 54GW of offshore wind was assumed to be the target for the analyses conducted. A variety of issues are considered including: the anticipated staging of offshore wind; the offshore wind resource availability; offshore wind energy power production profiles; offshore wind variability; present and potential technologies for collection and delivery of offshore wind energy to the onshore grid; potential impacts to existing utility systemsmore » most likely to receive large amounts of offshore wind; and regulatory influences on offshore wind development. The technologies considered the reliability of various high-voltage ac (HVAC) and high-voltage dc (HVDC) technology options and configurations. The utility system impacts of GW-scale integration of offshore wind are considered from an operational steady-state perspective and from a regional and national production cost perspective.« less

Status of wind-energy conversion

NASA Technical Reports Server (NTRS)

Thomas, R. L.; Savino, J. M.

1973-01-01

The utilization of wind energy is technically feasible as evidenced by the many past demonstrations of wind generators. The cost of energy from the wind has been high compared to fossil fuel systems; a sustained development effort is needed to obtain economical systems. The variability of the wind makes it an unreliable source on a short term basis. However, the effects of this variability can be reduced by storage systems or connecting wind generators to: (1) fossil fuel systems; (2) hydroelectric systems; or (3) dispersing them throughout a large grid network. Wind energy appears to have the potential to meet a significant amount of our energy needs.

Wind and Wildlife in the Northern Great Plains: Identifying Low-Impact Areas for Wind Development

PubMed Central

Fargione, Joseph; Kiesecker, Joseph; Slaats, M. Jan; Olimb, Sarah

2012-01-01

Wind energy offers the potential to reduce carbon emissions while increasing energy independence and bolstering economic development. However, wind energy has a larger land footprint per Gigawatt (GW) than most other forms of energy production and has known and predicted adverse effects on wildlife. The Northern Great Plains (NGP) is home both to some of the world’s best wind resources and to remaining temperate grasslands, the most converted and least protected ecological system on the planet. Thus, appropriate siting and mitigation of wind development is particularly important in this region. Steering energy development to disturbed lands with low wildlife value rather than placing new developments within large and intact habitats would reduce impacts to wildlife. Goals for wind energy development in the NGP are roughly 30 GW of nameplate capacity by 2030. Our analyses demonstrate that there are large areas where wind development would likely have few additional impacts on wildlife. We estimate there are ∼1,056 GW of potential wind energy available across the NGP on areas likely to have low-impact for biodiversity, over 35 times development goals. New policies and approaches will be required to guide wind energy development to low-impact areas. PMID:22848505

Wind and wildlife in the Northern Great Plains: identifying low-impact areas for wind development.

PubMed

Fargione, Joseph; Kiesecker, Joseph; Slaats, M Jan; Olimb, Sarah

2012-01-01

Wind energy offers the potential to reduce carbon emissions while increasing energy independence and bolstering economic development. However, wind energy has a larger land footprint per Gigawatt (GW) than most other forms of energy production and has known and predicted adverse effects on wildlife. The Northern Great Plains (NGP) is home both to some of the world's best wind resources and to remaining temperate grasslands, the most converted and least protected ecological system on the planet. Thus, appropriate siting and mitigation of wind development is particularly important in this region. Steering energy development to disturbed lands with low wildlife value rather than placing new developments within large and intact habitats would reduce impacts to wildlife. Goals for wind energy development in the NGP are roughly 30 GW of nameplate capacity by 2030. Our analyses demonstrate that there are large areas where wind development would likely have few additional impacts on wildlife. We estimate there are ∼1,056 GW of potential wind energy available across the NGP on areas likely to have low-impact for biodiversity, over 35 times development goals. New policies and approaches will be required to guide wind energy development to low-impact areas.

The power of runoff

NASA Astrophysics Data System (ADS)

Wörman, A.; Lindström, G.; Riml, J.

2017-05-01

Although the potential energy of surface water is a small part of Earth's energy budget, this highly variable physical property is a key component in the terrestrial hydrologic cycle empowering geomorphological and hydrological processes throughout the hydrosphere. By downscaling of the daily hydrometeorological data acquired in Sweden over the last half-century this study quantifies the spatial and temporal distribution of the dominating energy components in terrestrial hydrology, including the frictional resistance in surface water and groundwater as well as hydropower. The energy consumed in groundwater circulation was found to be 34.6 TWh/y or a heat production of approximately 13% of the geothermal heat flux. Significant climate driven, periodic fluctuations in the power of runoff, stream flows and groundwater circulation were revealed that have not previously been documented. We found that the runoff power ranged from 173 to 260 TWh/y even when averaged over the entire surface of Sweden in a five-year moving window. We separated short-term fluctuations in runoff due to precipitation filtered through the watershed from longer-term seasonal and climate driven modes. Strong climate driven correlations between the power of runoff and climate indices, wind and solar intensity were found over periods of 3.6 and 8 years. The high covariance that we found between the potential energy of surface water and wind energy implies significant challenges for the combination of these renewable energy sources.

78 FR 18580 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-27

.... Applicants: Ashtabula Wind, LLC, Ashtabula Wind II, LLC, Ashtabula Wind III, LLC, Backbone Mountain Windpower LLC, Badger Windpower, LLC, Baldwin Wind, LLC, Bayswater Peaking Facility, LLC, Blackwell Wind, LLC, Butler Ridge Wind Energy Center, LLC, Cimarron Wind Energy, LLC, Crystal Lake Wind, LLC, Crystal Lake...

Numerical Investigations of an Optimized Airfoil with a Rotary Cylinder

NASA Astrophysics Data System (ADS)

Gada, Komal; Rahai, Hamid

2015-11-01

Numerical Investigations of an optimized thin airfoil with a rotary cylinder as a control device for reducing separation and improving lift to drag ratio have been performed. Our previous investigations have used geometrical optimization for development of an optimized airfoil with increased torque for applications in a vertical axis wind turbine. The improved performance was due to contributions of lift to torque at low angles of attack. The current investigations have been focused on using the optimized airfoil for micro-uav applications with an active flow control device, a rotary cylinder, to further control flow separation, especially during wind gust conditions. The airfoil has a chord length of 19.66 cm and a width of 25 cm with 0.254 cm thickness. Previous investigations have shown flow separation at approximately 85% chord length at moderate angles of attack. Thus the rotary cylinder with a 0.254 cm diameter was placed slightly downstream of the location of flow separation. The free stream mean velocity was 10 m/sec. and investigations have been performed at different cylinder's rotations with corresponding tangential velocities higher than, equal to and less than the free stream velocity. Results have shown more than 10% improvement in lift to drag ratio when the tangential velocity is near the free stream mean velocity. Graduate Assistant, Center for Energy and Environmental Research and Services (CEERS), College of Engineering, California State University, Long Beach.

76 FR 41510 - Draft Environmental Impact Statement and Habitat Conservation Plan for Commercial Wind Energy...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-14

...] Draft Environmental Impact Statement and Habitat Conservation Plan for Commercial Wind Energy... regional- level construction, operation, and maintenance associated with multiple commercial wind energy...; Attention: Laila Lienesch; Facsimile: 505/248-6922 (Attention: Laila Lienesch); E-Mail: WindEnergy...

Wind Vision: Updating the DOE 20% Wind Energy by 2030 Report (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, E. I.

The 20% Wind Energy by 2030 report was developed as part of the Advanced Energy Initiative. Published in 2008, the report was largely based on information collected and analyzed in 2006. Much has changed since then, including shifts in technology, markets, and policy. The industry needs a new, clear, vision for wind power that is shared among stakeholders from the U.S. government, industry, academia, and NGO communities. At WINDPOWER 2013, the U.S. Department of Energy, in partnership with the American Wind Energy Association and the Wind Energy Foundation, launched a project to update the 20% report with new objectives. Thismore » conference poster outlines the elements of the new Wind Vision.« less

IEA Wind Task 26: The Past and Future Cost of Wind Energy, Work Package 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lantz, E.; Wiser, R.; Hand, M.

2012-05-01

Over the past 30 years, wind power has become a mainstream source of electricity generation around the world. However, the future of wind power will depend a great deal on the ability of the industry to continue to achieve cost of energy reductions. In this summary report, developed as part of the International Energy Agency Wind Implementing Agreement Task 26, titled 'The Cost of Wind Energy,' we provide a review of historical costs, evaluate near-term market trends, review the methods used to estimate long-term cost trajectories, and summarize the range of costs projected for onshore wind energy across an arraymore » of forward-looking studies and scenarios. We also highlight the influence of high-level market variables on both past and future wind energy costs.« less

Large-scale anisotropy in stably stratified rotating flows

DOE PAGES

Marino, R.; Mininni, P. D.; Rosenberg, D. L.; ...

2014-08-28

We present results from direct numerical simulations of the Boussinesq equations in the presence of rotation and/or stratification, both in the vertical direction. The runs are forced isotropically and randomly at small scales and have spatial resolutions of up tomore » $1024^3$ grid points and Reynolds numbers of $$\\approx 1000$$. We first show that solutions with negative energy flux and inverse cascades develop in rotating turbulence, whether or not stratification is present. However, the purely stratified case is characterized instead by an early-time, highly anisotropic transfer to large scales with almost zero net isotropic energy flux. This is consistent with previous studies that observed the development of vertically sheared horizontal winds, although only at substantially later times. However, and unlike previous works, when sufficient scale separation is allowed between the forcing scale and the domain size, the total energy displays a perpendicular (horizontal) spectrum with power law behavior compatible with $$\\sim k_\\perp^{-5/3}$$, including in the absence of rotation. In this latter purely stratified case, such a spectrum is the result of a direct cascade of the energy contained in the large-scale horizontal wind, as is evidenced by a strong positive flux of energy in the parallel direction at all scales including the largest resolved scales.« less

Mammalian mesocarnivore visitation at tortoise burrows in a wind farm

USGS Publications Warehouse

Agha, Mickey; Smith, Amanda L.; Lovich, Jeffrey E.; Delaney, David F.; Ennen, Joshua R.; Briggs, Jessica R.; Fleckenstein, Leo J.; Tennant, Laura A.; Puffer, Shellie R.; Walde, Andrew D.; Arundel, Terry; Price, Steven J.; Todd, Brian D.

2017-01-01

There is little information on predator–prey interactions in wind energy landscapes in North America, especially among terrestrial vertebrates. Here, we evaluated how proximity to roads and wind turbines affect mesocarnivore visitation with desert tortoises (Gopherus agassizii) and their burrows in a wind energy landscape. In 2013, we placed motion-sensor cameras facing the entrances of 46 active desert tortoise burrows in a 5.2-km2 wind energy facility near Palm Springs, California, USA. Cameras recorded images of 35 species of reptiles, mammals, and birds. Counts for 4 species of mesocarnivores at desert tortoise burrows increased closer to dirt roads, and decreased closer to wind turbines. Our results suggest that anthropogenic infrastructure associated with wind energy facilities could influence the general behavior of mammalian predators and their prey. Further investigation of proximate mechanisms that underlie road and wind turbine effects (i.e., ground vibrations, sound emission, and traffic volume) and on wind energy facility spatial designs (i.e., road and wind turbine configuration) could prove useful for better understanding wildlife responses to wind energy development. © 2017 The Wildlife Society.

How important is getting the land surface energy exchange correct in WRF for wind energy forecasting?

NASA Astrophysics Data System (ADS)

Wharton, S.; Simpson, M.; Osuna, J. L.; Newman, J. F.; Biraud, S.

2013-12-01

Wind power forecasting is plagued with difficulties in accurately predicting the occurrence and intensity of atmospheric conditions at the heights spanned by industrial-scale turbines (~ 40 to 200 m above ground level). Better simulation of the relevant physics would enable operational practices such as integration of large fractions of wind power into power grids, scheduling maintenance on wind energy facilities, and deciding design criteria based on complex loads for next-generation turbines and siting. Accurately simulating the surface energy processes in numerical models may be critically important for wind energy forecasting as energy exchange at the surface strongly drives atmospheric mixing (i.e., stability) in the lower layers of the planetary boundary layer (PBL), which in turn largely determines wind shear and turbulence at heights found in the turbine rotor-disk. We hypothesize that simulating accurate a surface-atmosphere energy coupling should lead to more accurate predictions of wind speed and turbulence at heights within the turbine rotor-disk. Here, we tested 10 different land surface model configurations in the Weather Research and Forecasting (WRF) model including Noah, Noah-MP, SSiB, Pleim-Xiu, RUC, and others to evaluate (1) the accuracy of simulated surface energy fluxes to flux tower measurements, (2) the accuracy of forecasted wind speeds to observations at rotor-disk heights, and (3) the sensitivity of forecasting hub-height rotor disk wind speed to the choice of land surface model. WRF was run for four, two-week periods covering both summer and winter periods over the Southern Great Plains ARM site in Oklahoma. Continuous measurements of surface energy fluxes and lidar-based wind speed, direction and turbulence were also available. The SGP ARM site provided an ideal location for this evaluation as it centrally located in the wind-rich Great Plains and multi-MW wind farms are rapidly expanding in the area. We found significant differences in simulated wind speeds at rotor-disk heights from WRF which indicated, in part, the sensitivity of lower PBL winds to surface energy exchange. We also found significant differences in energy partitioning between sensible heat and latent energy depending on choice of land surface model. Overall, the most consistent, accurate model results were produced using Noah-MP. Noah-MP was most accurate at simulating energy fluxes and wind shear. Hub-height wind speed, however, was predicted with most accuracy with Pleim-Xiu. This suggests that simulating wind shear in the surface layer is consistent with accurately simulating surface energy exchange while the exact magnitudes of wind speed may be more strongly influenced by the PBL dynamics. As the nation is working towards a 20% wind energy goal by 2030, increasing the accuracy of wind forecasting at rotor-disk heights becomes more important considering that utilities require wind farms to estimate their power generation 24 to 36 hours ahead and face penalties for inaccuracies in those forecasts.

Onshore-offshore wind energy resource evaluation based on synergetic use of multiple satellite data and meteorological stations in Jiangsu Province, China

NASA Astrophysics Data System (ADS)

Wei, Xianglin; Duan, Yuewei; Liu, Yongxue; Jin, Song; Sun, Chao

2018-05-01

The demand for efficient and cost-effective renewable energy is increasing as traditional sources of energy such as oil, coal, and natural gas, can no longer satisfy growing global energy demands. Among renewable energies, wind energy is the most prominent due to its low, manageable impacts on the local environment. Based on meteorological data from 2006 to 2014 and multi-source satellite data (i.e., Advanced Scatterometer, Quick Scatterometer, and Windsat) from 1999 to 2015, an assessment of the onshore and offshore wind energy potential in Jiangsu Province was performed by calculating the average wind speed, average wind direction, wind power density, and annual energy production (AEP). Results show that Jiangsu has abundant wind energy resources, which increase from inland to coastal areas. In onshore areas, wind power density is predominantly less than 200 W/m2, while in offshore areas, wind power density is concentrates in the range of 328-500 W/m2. Onshore areas comprise more than 13,573.24 km2, mainly located in eastern coastal regions with good wind farm potential. The total wind power capacity in onshore areas could be as much as 2.06 x 105 GWh. Meanwhile, offshore wind power generation in Jiangsu Province is calculated to reach 2 x 106 GWh, which is approximately four times the electricity demand of the entire Jiangsu Province. This study validates the effective application of Advanced Scatterometer, Quick Scatterometer, and Windsat data to coastal wind energy monitoring in Jiangsu. Moreover, the methodology used in this study can be effectively applied to other similar coastal zones.

Wind energy in electric power production, preliminary study

NASA Astrophysics Data System (ADS)

Lento, R.; Peltola, E.

1984-01-01

The wind speed conditions in Finland have been studied with the aid of the existing statistics of the Finnish Meteorological Institute. With the aid of the statistics estimates on the available wind energy were also made. Eight hundred wind power plants, 1.5 MW each, on the windiest west coast would produce about 2 TWh energy per year. Far more information on the temporal, geographical and vertical distribution of the wind speed than the present statistics included is needed when the available wind energy is estimated, when wind power plants are dimensioned optimally, and when suitable locations are chosen for them. The investment costs of a wind power plant increase when the height of the tower or the diameter of the rotor is increased, but the energy production increases, too. Thus, overdimensioning the wind power plant in view of energy needs or the wind conditions caused extra costs. The cost of energy produced by wind power can not yet compete with conventional energy, but the situation changes to the advantage of wind energy, if the real price of the plants decreases (among other things due to large series production and increasing experience), or if the real price of fuels rises. The inconvinience on the environment caused by the wind power plants is considered insignificant. The noise caused by the plant attenuates rapidly with distance. No harmful effects to birds and other animals caused by the wind power plants have been observed in the studies made abroad. Parts of the plant getting loose during an accident, or ice forming on the blades are estimated to fly even from a large plant only a few hundred meters.

76 FR 76333 - Notification for Airborne Wind Energy Systems (AWES)

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-07

...-1279; Notice No. 11-07] Notification for Airborne Wind Energy Systems (AWES) AGENCY: Federal Aviation... CFR) part 77, ``Safe, Efficient Use and Preservation of the Navigable Airspace,'' to airborne wind energy systems (AWES). In addition, this notice requests information from airborne wind energy system...

Advanced Performance Hydraulic Wind Energy

NASA Technical Reports Server (NTRS)

Jones, Jack A.; Bruce, Allan; Lam, Adrienne S.

2013-01-01

The Jet Propulsion Laboratory, California Institute of Technology, has developed a novel advanced hydraulic wind energy design, which has up to 23% performance improvement over conventional wind turbine and conventional hydraulic wind energy systems with 5 m/sec winds. It also has significant cost advantages with levelized costs equal to coal (after carbon tax rebate). The design is equally applicable to tidal energy systems and has passed preliminary laboratory proof-of-performance tests, as funded by the Department of Energy.

Scope of wind energy in Bangladesh and simulation analysis of three different horizontal axis wind turbine blade shapes

NASA Astrophysics Data System (ADS)

Khan, Md. Arif-Ul Islam; Das, Swapnil; Dey, Saikat

2017-12-01

: Economic growth and energy demand are intertwined. Therefore, one of the most important concerns of the government and in the world is the need for energy security. Currently, the world relies on coal, crude oil and natural gas for energy generati on. However, the energy crisis together with climate change and depletion of oil have become major concerns to all countries. Therefore, alternative energy resources such as wind energy attracted interest from both public and private sectors to invest in energy generation from this source extensively. Both Vertical and Horizontal axis wind turbine can be used for this purpose. But, Horizontal axis is the most promising between them due to its efficiency and low expense. Bangladesh being a tropical country does have a lot of wind flow at different seasons of the year. However, there are some windy locations in which wind energy projects could be feasible. In this project a detailed review of the current st ate-of-art for wind turbine blade design is presented including theoretical maximum efficiency, Horizontal Axis Wind Turbine (HAWT) blade design, simulation power and COP values for different blade material. By studying previously collected data on the wind resources available in B angladesh at present and by analyzing this data, this paper will discuss the scope of wind energy in Bangladesh.

Mesoscale Air-Sea Interactions along the Gulf Stream: An Eddy-Resolving and Convection-Permitting Coupled Regional Climate Model Study

NASA Astrophysics Data System (ADS)

Hsieh, J. S.; Chang, P.; Saravanan, R.

2017-12-01

Frontal and mesoscale air-sea interactions along the Gulf Stream (GS) during boreal winter are investigated using an eddy-resolving and convection-permitting coupled regional climate model with atmospheric grid resolutions varying from meso-β (27-km) to -r (9-km and 3-km nest) scales in WRF and a 9-km ocean model (ROMS) that explicitly resolves the ocean mesoscale eddies across the North Atlantic basin. The mesoscale wavenumber energy spectra for the simulated surface wind stress and SST demonstrate good agreement with the observed spectra calculated from the observational QuikSCAT and AMSR-E datasets, suggesting that the model well captures the energy cascade of the mesoscale eddies in both the atmosphere and the ocean. Intercomparison among different resolution simulations indicates that after three months of integration the simulated GS path tends to overshoot beyond the separation point in the 27-km WRF coupled experiments than the observed climatological path of the GS, whereas the 3-km nested and 9-km WRF coupled simulations realistically simulate GS separation. The GS overshoot in 27-km WRF coupled simulations is accompanied with a significant SST warming bias to the north of the GS extension. Such biases are associated with the deficiency of wind stress-SST coupling strengths simulated by the coupled model with a coarser resolution in WRF. It is found that the model at 27-km grid spacing can approximately simulate 72% (62%) of the observed mean coupling strength between surface wind stress curl (divergence) and crosswind (downwind) SST gradient while by increasing the WRF resolutions to 9 km or 3 km the coupled model can much better capture the observed coupling strengths.

77 FR 29633 - Alta Wind VII, LLC, Alta Wind IX, LLC, Alta Wind X, LLC, Alta Wind XI, LLC, Alta Wind XII, LLC...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-18

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL12-68-000] Alta Wind VII, LLC, Alta Wind IX, LLC, Alta Wind X, LLC, Alta Wind XI, LLC, Alta Wind XII, LLC, Alta Wind XIII, LLC, Alta Wind XIV, LLC, Alta Wind XV, LLC, Alta Windpower Development, LLC, TGP Development Company, LLC...

75 FR 23263 - Alta Wind I, LLC; Alta Wind II, LLC; Alta Wind III, LLC; Alta Wind IV, LLC; Alta Wind V, LLC...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-03

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL10-62-000] Alta Wind I, LLC; Alta Wind II, LLC; Alta Wind III, LLC; Alta Wind IV, LLC; Alta Wind V, LLC; Alta Wind VI, LLC; Alta Wind VII, LLC; Alta Wind VIII, LLC; Alta Windpower Development, LLC; TGP Development Company, LLC...

Highly reliable wind-rolling triboelectric nanogenerator operating in a wide wind speed range

PubMed Central

Yong, Hyungseok; Chung, Jihoon; Choi, Dukhyun; Jung, Daewoong; Cho, Minhaeng; Lee, Sangmin

2016-01-01

Triboelectric nanogenerators are aspiring energy harvesting methods that generate electricity from the triboelectric effect and electrostatic induction. This study demonstrates the harvesting of wind energy by a wind-rolling triboelectric nanogenerator (WR-TENG). The WR-TENG generates electricity from wind as a lightweight dielectric sphere rotates along the vortex whistle substrate. Increasing the kinetic energy of a dielectric converted from the wind energy is a key factor in fabricating an efficient WR-TENG. Computation fluid dynamics (CFD) analysis is introduced to estimate the precise movements of wind flow and to create a vortex flow by adjusting the parameters of the vortex whistle shape to optimize the design parameters to increase the kinetic energy conversion rate. WR-TENG can be utilized as both a self-powered wind velocity sensor and a wind energy harvester. A single unit of WR-TENG produces open-circuit voltage of 11.2 V and closed-circuit current of 1.86 μA. Additionally, findings reveal that the electrical power is enhanced through multiple electrode patterns in a single device and by increasing the number of dielectric spheres inside WR-TENG. The wind-rolling TENG is a novel approach for a sustainable wind-driven TENG that is sensitive and reliable to wind flows to harvest wasted wind energy in the near future. PMID:27653976

78 FR 15737 - Incidental Take Permit Amendment and Supplemental Environmental Assessment for Wind Energy...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-12

...] Incidental Take Permit Amendment and Supplemental Environmental Assessment for Wind Energy Development... of a revised habitat conservation plan (revised HCP) and accompanying documents for wind energy development by San Francisco Wind Farm LLC (formerly WindMar R.E.) (Permittee). The revised HCP analyzes take...

Philippines Wind Energy Resource Atlas Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elliott, D.

2000-11-29

This paper describes the creation of a comprehensive wind energy resource atlas for the Philippines. The atlas was created to facilitate the rapid identification of good wind resource areas and understanding of the salient wind characteristics. Detailed wind resource maps were generated for the entire country using an advanced wind mapping technique and innovative assessment methods recently developed at the National Renewable Energy Laboratory.

Wind Powering America Podcasts, Wind Powering America (WPA)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2012-04-01

Wind Powering America and the National Association of Farm Broadcasters produce a series of radio interviews featuring experts discussing wind energy topics. The interviews are aimed at a rural stakeholder audience and are available as podcasts. On the Wind Powering America website, you can access past interviews on topics such as: Keys to Local Wind Energy Development Success, What to Know about Installing a Wind Energy System on Your Farm, and Wind Energy Development Can Revitalize Rural America. This postcard is a marketing piece that stakeholders can provide to interested parties; it will guide them to this online resource formore » podcast episodes.« less

Preliminary results of the large experimental wind turbine phase of the national wind energy program

NASA Technical Reports Server (NTRS)

Thomas, R. L.; Sholes, T.; Sholes, J. E.

1975-01-01

The preliminary results of two projects in the development phase of reliable wind turbines designed to supply cost-competitive electrical energy were discussed. An experimental 100 kW wind turbine design and its status are first reviewed. The results of two parallel design studies for determining the configurations and power levels for wind turbines with minimum energy costs are also discussed. These studies predict wind energy costs of 1.5 to 7 cents per kW-h for wind turbines produced in quantities of 100 to 1000 per year and located at sites having average winds of 12 to 18 mph.

77 FR 19683 - Proposed Information Collection; Land-Based Wind Energy Guidelines

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-02

...-FF09F20000] Proposed Information Collection; Land-Based Wind Energy Guidelines AGENCY: Fish and Wildlife..., on an emergency basis, our request to collect information associated with the Land- Based Wind Energy... proposed wind energy facilities may have on wildlife and their habitat. OMB approved our request and...

76 FR 47353 - Final Directives for Forest Service Wind Energy Special Use Authorizations, Forest Service Manual...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-04

... siting wind energy turbines, evaluating a variety of resource interests, and addressing issues... power guidelines produced by the Wind Energy Turbines Guidelines Advisory Committee, which consists of... recognizes that recommendations from the Wind Energy Turbines Guidelines Advisory Committee will be used to...

A Vision for Systems Engineering Applied to Wind Energy (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Felker, F.; Dykes, K.

2015-01-01

This presentation was given at the Third Wind Energy Systems Engineering Workshop on January 14, 2015. Topics covered include the importance of systems engineering, a vision for systems engineering as applied to wind energy, and application of systems engineering approaches to wind energy research and development.

Design of multi-energy Helds coupling testing system of vertical axis wind power system

NASA Astrophysics Data System (ADS)

Chen, Q.; Yang, Z. X.; Li, G. S.; Song, L.; Ma, C.

2016-08-01

The conversion efficiency of wind energy is the focus of researches and concerns as one of the renewable energy. The present methods of enhancing the conversion efficiency are mostly improving the wind rotor structure, optimizing the generator parameters and energy storage controller and so on. Because the conversion process involves in energy conversion of multi-energy fields such as wind energy, mechanical energy and electrical energy, the coupling effect between them will influence the overall conversion efficiency. In this paper, using system integration analysis technology, a testing system based on multi-energy field coupling (MEFC) of vertical axis wind power system is proposed. When the maximum efficiency of wind rotor is satisfied, it can match to the generator function parameters according to the output performance of wind rotor. The voltage controller can transform the unstable electric power to the battery on the basis of optimizing the parameters such as charging times, charging voltage. Through the communication connection and regulation of the upper computer system (UCS), it can make the coupling parameters configure to an optimal state, and it improves the overall conversion efficiency. This method can test the whole wind turbine (WT) performance systematically and evaluate the design parameters effectively. It not only provides a testing method for system structure design and parameter optimization of wind rotor, generator and voltage controller, but also provides a new testing method for the whole performance optimization of vertical axis wind energy conversion system (WECS).

Energy harvesting for self-powered aerostructure actuation

NASA Astrophysics Data System (ADS)

Bryant, Matthew; Pizzonia, Matthew; Mehallow, Michael; Garcia, Ephrahim

2014-04-01

This paper proposes and experimentally investigates applying piezoelectric energy harvesting devices driven by flow induced vibrations to create self-powered actuation of aerostructure surfaces such as tabs, flaps, spoilers, or morphing devices. Recently, we have investigated flow-induced vibrations and limit cycle oscillations due to aeroelastic flutter phenomena in piezoelectric structures as a mechanism to harvest energy from an ambient fluid flow. We will describe how our experimental investigations in a wind tunnel have demonstrated that this harvested energy can be stored and used on-demand to actuate a control surface such as a trailing edge flap in the airflow. This actuated control surface could take the form of a separate and discrete actuated flap, or could constitute rotating or deflecting the oscillating energy harvester itself to produce a non-zero mean angle of attack. Such a rotation of the energy harvester and the associated change in aerodynamic force is shown to influence the operating wind speed range of the device, its limit cycle oscillation (LCO) amplitude, and its harvested power output; hence creating a coupling between the device's performance as an energy harvester and as a control surface. Finally, the induced changes in the lift, pitching moment, and drag acting on a wing model are quantified and compared for a control surface equipped with an oscillating energy harvester and a traditional, static control surface of the same geometry. The results show that when operated in small amplitude LCO the energy harvester adds negligible aerodynamic drag.

Wind Power Today and Tomorrow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Wind Power Today and Tomorrow is an annual publication that provides an overview of the wind research conducted under the U.S. Department of Energy's Wind and Hydropower Technologies Program. The purpose of Wind Power Today and Tomorrow is to show how DOE supports wind turbine research and deployment in hopes of furthering the advancement of wind technologies that produce clean, low-cost, reliable energy. Content objectives include: educate readers about the advantages and potential for widespread deployment of wind energy; explain the program's objectives and goals; describe the program's accomplishments in research and application; examine the barriers to widespread deployment; describemore » the benefits of continued research and development; facilitate technology transfer; and attract cooperative wind energy projects with industry. This 2003 edition of the program overview also includes discussions about wind industry growth in 2003, how DOE is taking advantage of low wind speed region s through advancing technology, and distributed applications for small wind turbines.« less

Introducing WISDEM:An Integrated System Modeling for Wind Turbines and Plant (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dykes, K.; Graf, P.; Scott, G.

2015-01-01

The National Wind Technology Center wind energy systems engineering initiative has developed an analysis platform to leverage its research capabilities toward integrating wind energy engineering and cost models across wind plants. This Wind-Plant Integrated System Design & Engineering Model (WISDEM) platform captures the important interactions between various subsystems to achieve a better National Wind Technology Center wind energy systems engineering initiative has developed an analysis platform to leverage its research capabilities toward integrating wind energy engineering and cost models across wind plants. This Wind-Plant Integrated System Design & Engineering Model (WISDEM) platform captures the important interactions between various subsystems tomore » achieve a better understanding of how to improve system-level performance and achieve system-level cost reductions. This work illustrates a few case studies with WISDEM that focus on the design and analysis of wind turbines and plants at different system levels.« less

Lessons learned from Ontario wind energy disputes

NASA Astrophysics Data System (ADS)

Fast, Stewart; Mabee, Warren; Baxter, Jamie; Christidis, Tanya; Driver, Liz; Hill, Stephen; McMurtry, J. J.; Tomkow, Melody

2016-02-01

Issues concerning the social acceptance of wind energy are major challenges for policy-makers, communities and wind developers. They also impact the legitimacy of societal decisions to pursue wind energy. Here we set out to identify and assess the factors that lead to wind energy disputes in Ontario, Canada, a region of the world that has experienced a rapid increase in the development of wind energy. Based on our expertise as a group comprising social scientists, a community representative and a wind industry advocate engaged in the Ontario wind energy situation, we explore and suggest recommendations based on four key factors: socially mediated health concerns, the distribution of financial benefits, lack of meaningful engagement and failure to treat landscape concerns seriously. Ontario's recent change from a feed-in-tariff-based renewable electricity procurement process to a competitive bid process, albeit with more attention to community engagement, will only partially address these concerns.

The Unitary Plan Wind Tunnel(UPWT) Test 1891 Space Launch System

NASA Image and Video Library

2014-10-15

Stage Separation Test of the Space Launch System(SLS) in the Langley Unitary Plan Wind Tunnel (UPWT). The model used High Pressure air blown through the solid rocket boosters. (SRB) to simulate the booster separation motors (BSM) firing.

The Unitary Plan Wind Tunnel(UPWT) Test 1891 Space Launch System

NASA Image and Video Library

2014-10-14

Stage Separation Test of the Space Launch System(SLS) in the Langley Unitary Plan Wind Tunnel (UPWT). The model used High Pressure air blown through the solid rocket boosters. (SRB) to simulate the booster separation motors (BSM) firing.

Status of wind-energy conversion

NASA Technical Reports Server (NTRS)

Thomas, R. L.; Savino, J. M.

1973-01-01

The utilization of wind energy is technically feasible as evidenced by the many past demonstrations of wind generators. The cost of energy from the wind has been high compared to fossil fuel systems. A sustained development effort is needed to obtain economical systems. The variability of the wind makes it an unreliable source on a short-term basis. However, the effects of this variability can be reduced by storage systems or connecting wind generators to fossil fuel systems, hydroelectric systems, or dispersing them throughout a large grid network. The NSF and NASA-Lewis Research Center have sponsored programs for the utilization of wind energy.

Wind turbines acoustic measurements

NASA Astrophysics Data System (ADS)

Trematerra, Amelia; Iannace, Gino

2017-07-01

The importance of wind turbines has increased over the last few years throughout the European Community. The European energy policy guidelines state that for the year 2020 20% of all energy must be produced by alternative energy sources. Wind turbines are an important type of energy production without petrol. A wind speed in a range from 2.5 m/s to 25.0 m/s is needed. One of the obstacles to the widespread diffusion of wind turbine is noise generation. This work presents some noise measurements of wind turbines in the South of Italy, and discusses the noise problems for the people living near wind farms.

A documentation of two- and three-dimensional shock-separated turbulent boundary layers

NASA Technical Reports Server (NTRS)

Brown, J. D.; Brown, J. L.; Kussoy, M. I.

1988-01-01

A shock-related separation of a turbulent boundary layer has been studied and documented. The flow was that of an axisymmetric turbulent boundary layer over a 5.02-cm-diam cylinder that was aligned with the wind tunnel axis. The boundary layer was compressed by a 30 deg half-angle conical flare, with the cone axis inclined at an angle alpha to the cylinder axis. Nominal test conditions were P sub tau equals 1.7 atm and M sub infinity equals 2.85. Measurements were confined to the upper-symmetry, phi equals 0 deg, plane. Data are presented for the cases of alpha equal to 0. 5. and 10 deg and include mean surface pressures, streamwise and normal mean velocities, kinematic turbulent stresses and kinetic energies, as well as reverse-flow intermittencies. All data are given in tabular form; pressures, streamwise velocities, turbulent shear stresses, and kinetic energies are also presented graphically.

Connecting Communities to Wind Resources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, Edward I

2017-08-18

WINDExchange is the platform for the U.S. Department of Energy's (DOE's) Wind Energy Technologies Office to disseminate credible wind energy information on a national level. Stakeholder engagement and outreach activities are designed to enable well-informed decisions about appropriate wind energy deployment. WINDExchange focuses on wind energy outreach at the national level while managing and supporting similar regional efforts through the implementation of DOE Regional Resource Centers (RRCs). This fact sheet provides an overview of DOE's WINDExchange initiative and the RRCs. Examples of RRC activities are provided.

Sri Lanka Wind Farm Analysis and Site Selection Assistance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, M.; Vilhauer, R.

2003-08-01

The United States Department of Energy (DOE), through the National Renewable Energy Laboratory (NREL), has been working in partnership with the U.S. Agency for International Development (USAID) in an on-going process to quantify the Sri Lanka wind energy potential and foster wind energy development. Work to date includes completion of the NREL wind atlas for Sri Lanka. In addition, the Ceylon Electricity Board (CEB) has conducted a wind resource assessment of several areas of the country and has successfully completed and is currently operating a 3-MW pilot wind project. A review of the work completed to date indicates that additionalmore » activities are necessary to provide Sri Lanka with the tools necessary to identify the best wind energy development opportunities. In addition, there is a need to identify key policy, regulatory, business and infrastructure issues that affect wind energy development and to recommend steps to encourage and support wind power development and investment.« less

Assessing climate change impacts on the near-term stability of the wind energy resource over the United States

PubMed Central

Pryor, S. C.; Barthelmie, R. J.

2011-01-01

The energy sector comprises approximately two-thirds of global total greenhouse gas emissions. For this and other reasons, renewable energy resources including wind power are being increasingly harnessed to provide electricity generation potential with negligible emissions of carbon dioxide. The wind energy resource is naturally a function of the climate system because the “fuel” is the incident wind speed and thus is determined by the atmospheric circulation. Some recent articles have reported historical declines in measured near-surface wind speeds, leading some to question the continued viability of the wind energy industry. Here we briefly articulate the challenges inherent in accurately quantifying and attributing historical tendencies and making robust projections of likely future wind resources. We then analyze simulations from the current generation of regional climate models and show, at least for the next 50 years, the wind resource in the regions of greatest wind energy penetration will not move beyond the historical envelope of variability. Thus this work suggests that the wind energy industry can, and will, continue to make a contribution to electricity provision in these regions for at least the next several decades. PMID:21536905

Assessing climate change impacts on the near-term stability of the wind energy resource over the United States.

PubMed

Pryor, S C; Barthelmie, R J

2011-05-17

The energy sector comprises approximately two-thirds of global total greenhouse gas emissions. For this and other reasons, renewable energy resources including wind power are being increasingly harnessed to provide electricity generation potential with negligible emissions of carbon dioxide. The wind energy resource is naturally a function of the climate system because the "fuel" is the incident wind speed and thus is determined by the atmospheric circulation. Some recent articles have reported historical declines in measured near-surface wind speeds, leading some to question the continued viability of the wind energy industry. Here we briefly articulate the challenges inherent in accurately quantifying and attributing historical tendencies and making robust projections of likely future wind resources. We then analyze simulations from the current generation of regional climate models and show, at least for the next 50 years, the wind resource in the regions of greatest wind energy penetration will not move beyond the historical envelope of variability. Thus this work suggests that the wind energy industry can, and will, continue to make a contribution to electricity provision in these regions for at least the next several decades.

International Collaboration on Offshore Wind Energy Under IEA Annex XXIII

DOE Office of Scientific and Technical Information (OSTI.GOV)

Musial, W.; Butterfield, S.; Lemming, J.

This paper defines the purpose of IEA Annex XXIII, the International Collaboration on Offshore Wind Energy. This international collaboration through the International Energy Agency (IEA) is an efficient forum from which to advance the technical and environmental experiences collected from existing offshore wind energy projects, as well as the research necessary to advance future technology for deep-water wind energy technology.

75 FR 76453 - Top of the World Wind Energy, LLC; Kit Carson Windpower, LLC; Chestnut Flats Wind, LLC; Minco...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-08

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket Nos. EG10-65-000; EG10-66-000; EG10-67-000; EG10-68-000; EG10- 69-000; EG10-70-000; EG10-71-000] Top of the World Wind Energy, LLC; Kit Carson Windpower, LLC; Chestnut Flats Wind, LLC; Minco Wind, LLC; Arizona Solar One LLC; Criterion...

Assessment of the visual landscape impact and dominance of wind tubines in Austria using weighted viewshed maps

NASA Astrophysics Data System (ADS)

Schauppenlehner, Thomas; Salak, Boris; Scherhaufer, Patrick; Höltinger, Stefan; Schmidt, Johannes

2017-04-01

Due to efficiency reasons and broadly availability of wind, wind energy is in focus of strategies regarding the expansion of renewable energy and energy transition policies. Nevertheless, the dimensions of the wind turbines and rotating dynamics have a significant impact on the landscape scenery and recreation as well as tourism activities. This often leads to local opposition against wind energy projects and is a major criterion regarding the acceptance of wind energy. In the project TransWind, the social acceptance of wind energy is surveyed on the basis of different development scenarios for Austria. Therefore, a GIS-based viewshed indicator was developed to assess the visual impact of different development scenarios as well as the current situation using weighted - regarding distance, amount and masking - viewshed analysis. This weighted viewshed maps for Austria allows a comprehensive evaluation of existing and potential wind energy sites regarding dominance and visual impact and can contribute to the spatial development process of wind energy site. Different regions can be compared and repowering strategies can be evaluated. Due to the large project area, data resolutions, generalized assumptions (e.g. tree heights) and missing data (e.g. solitary trees, small hedges) at local level further analysis are necessary but it supports the assessment of large-scale development scenarios can be identified.

Large wind turbines: A utility option for the generation of electricity

NASA Technical Reports Server (NTRS)

Robbins, W. H.; Thomas, R. L.; Baldwin, D. H.

1980-01-01

The wind resource is such that wind energy generation has the potential to save 6-7 quads of energy nationally. Thus, the Federal Government is sponsoring and encouraging the development of cost effective and reliable wind turbines. One element of the Federal Wind Energy Programs, Large Horizontal Axis Wind Turbine Development, is managed by the NASA Lewis Research Center for the Department of Energy. There are several ongoing wind system development projects oriented primarily toward utility application within this program element. In addition, a comprehensive technology program supporting the wind turbine development projects is being conducted. An overview is presented of the NASA activities with emphasis on application of large wind turbines for generation of electricity by utility systems.

Impact of AGN and nebular emission on the estimation of stellar properties of galaxies

NASA Astrophysics Data System (ADS)

Cardoso, Leandro Saul Machado

The aim of this PhD thesis is to apply tools from stochastic modeling to wind power, speed and direction data, in order to reproduce their empirically observed statistical features. In particular, the wind energy conversion process is modeled as a Langevin process, which allows to describe its dynamics with only two coefficients, namely the drift and the diffusion coefficients. Both coefficients can be directly derived from collected time-series and this so-called Langevin method has proved to be successful in several cases. However, the application to empirical data subjected to measurement noise sources in general and the case of wind turbines in particular poses several challenges and this thesis proposes methods to tackle them. To apply the Langevin method it is necessary to have data that is both stationary and Markovian, which is typically not the case. Moreover, the available time-series are often short and have missing data points, which affects the estimation of the coefficients. This thesis proposes a new methodology to overcome these issues by modeling the original data with a Markov chain prior to the Langevin analysis. The latter is then performed on data synthesized from the Markov chain model of wind data. Moreover, it is shown that the Langevin method can be applied to low sample rate wind data, namely 10-minute average data. The method is then extended in two different directions. First, to tackle non-stationary data sets. Wind data often exhibits daily patterns due to the solar cycle and this thesis proposes a method to consider these daily patterns in the analysis of the timeseries. For that, a cyclic Markov model is developed for the data synthesis step and subsequently, for each time of the day, a separate Langevin analysis of the wind energy conversion system is performed. Second, to resolve the dynamical stochastic process in the case it is spoiled by measurement noise. When working with measurement data a challenge can be posed by the quality of the data in itself. Often measurement devices add noise to the time-series that is different from the intrinsic noise of the underlying stochastic process and can even be time-correlated. This spoiled data, analyzed with the Langevin method leads to distorted drift and diffusion coefficients. This thesis proposes a direct, parameter-free way to extract the Langevin coefficients as well as the parameters of the measurement noise from spoiled data. Put in a more general context, the method allows to disentangle two superposed independent stochastic processes. Finally, since a characteristic of wind energy that motivates this stochastic modeling framework is the fluctuating nature of wind itself, several issues raise when it comes to reserve commitment or bidding on the liberalized energy market. This thesis proposes a measure to quantify the risk-returnratio that is associated to wind power production conditioned to a wind park state. The proposed state of the wind park takes into account data from all wind turbines constituting the park and also their correlations at different time lags. None

Stochastic Analysis of Wind Energy for Wind Pump Irrigation in Coastal Andhra Pradesh, India

NASA Astrophysics Data System (ADS)

Raju, M. M.; Kumar, A.; Bisht, D.; Rao, D. B.

2014-09-01

The rapid escalation in the prices of oil and gas as well as increasing demand for energy has attracted the attention of scientists and researchers to explore the possibility of generating and utilizing the alternative and renewable sources of wind energy in the long coastal belt of India with considerable wind energy resources. A detailed analysis of wind potential is a prerequisite to harvest the wind energy resources efficiently. Keeping this in view, the present study was undertaken to analyze the wind energy potential to assess feasibility of the wind-pump operated irrigation system in the coastal region of Andhra Pradesh, India, where high ground water table conditions are available. The stochastic analysis of wind speed data were tested to fit a probability distribution, which describes the wind energy potential in the region. The normal and Weibull probability distributions were tested; and on the basis of Chi square test, the Weibull distribution gave better results. Hence, it was concluded that the Weibull probability distribution may be used to stochastically describe the annual wind speed data of coastal Andhra Pradesh with better accuracy. The size as well as the complete irrigation system with mass curve analysis was determined to satisfy various daily irrigation demands at different risk levels.

Wind/water energy converter

NASA Technical Reports Server (NTRS)

Paulkovich, J.

1979-01-01

Device will convert wind, water, tidal or wave energy into electrical or mechanical energy. Is comprised of windmill-like paddles or blades synchronously geared to orient themselves to wind direction for optimum energy extraction.

Impact of wind farms with energy storage on transient stability

NASA Astrophysics Data System (ADS)

Bowman, Douglas Allen

Today's energy infrastructure will need to rapidly expand in terms of reliability and flexibility due to aging infrastructure, changing energy market conditions, projected load increases, and system reliability requirements. Over the few decades, several states in the U.S. are now requiring an increase in wind penetration. These requirements will have impacts on grid reliability given the inherent intermittency of wind generation and much research has been completed on the impact of wind on grid reliability. Energy storage has been proposed as a tool to provide greater levels of reliability; however, little research has occurred in the area of wind with storage and its impact on stability given different possible scenarios. This thesis addresses the impact of wind farm penetration on transient stability when energy storage is added. The results show that battery energy storage located at the wind energy site can improve the stability response of the system.

Quantifying variability in fast and slow solar wind: From turbulence to extremes

NASA Astrophysics Data System (ADS)

Tindale, E.; Chapman, S. C.; Moloney, N.; Watkins, N. W.

2017-12-01

Fast and slow solar wind exhibit variability across a wide range of spatiotemporal scales, with evolving turbulence producing fluctuations on sub-hour timescales and the irregular solar cycle modulating the system over many years. Here, we apply the data quantile-quantile (DQQ) method [Tindale and Chapman 2016, 2017] to over 20 years of Wind data, to study the time evolution of the statistical distribution of plasma parameters in fast and slow solar wind. This model-independent method allows us to simultaneously explore the evolution of fluctuations across all scales. We find a two-part functional form for the statistical distributions of the interplanetary magnetic field (IMF) magnitude and its components, with each region of the distribution evolving separately over the solar cycle. Up to a value of 8nT, turbulent fluctuations dominate the distribution of the IMF, generating the approximately lognormal shape found by Burlaga [2001]. The mean of this core-turbulence region tracks solar cycle activity, while its variance remains constant, independent of the fast or slow state of the solar wind. However, when we test the lognormality of this core-turbulence component over time, we find the model provides a poor description of the data at solar maximum, where sharp peaks in the distribution dominate over the lognormal shape. At IMF values higher than 8nT, we find a separate, extremal distribution component, whose moments are sensitive to solar cycle phase, the peak activity of the cycle and the solar wind state. We further investigate these `extremal' values using burst analysis, where a burst is defined as a continuous period of exceedance over a predefined threshold. This form of extreme value statistics allows us to study the stochastic process underlying the time series, potentially supporting a probabilistic forecast of high-energy events. Tindale, E., and S.C. Chapman (2016), Geophys. Res. Lett., 43(11) Tindale, E., and S.C. Chapman (2017), submitted Burlaga, L.F. (2001), J. Geophys. Res., 106(A8)

National Offshore Wind Strategy: Facilitating the Development of the Offshore Wind Industry in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patrick Gilman; Maurer, Ben; Feinberg, Luke

2016-09-01

The U.S. Department of Energy, through its Wind Energy Technologies Office, and U.S. Department of the Interior, through its Bureau of Ocean Energy Management, have jointly produced this updated national strategy to facilitate the responsible development of offshore wind energy in the United States.

76 FR 40390 - Notice of Availability of a Draft Land Use Plan Amendment, Environmental Impact Statement and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-08

..., 474 megawatt (MW) wind energy project including 158 wind turbine generators, a substation... Environmental Impact Report for the Pattern Energy Group Ocotillo Express Wind Energy Project, Imperial County... Statement (EIS) and Draft Environmental Impact Report (EIR) for the Ocotillo Express Wind Energy Project...

Final Report: An Undergraduate Minor in Wind Energy at Iowa State University

DOE Office of Scientific and Technical Information (OSTI.GOV)

James McCalley

This report describes an undergraduate minor program in wind energy that has been developed at Iowa State University. The minor program targets engineering and meteorology students and was developed to provide interested students with focused technical expertise in wind energy science and engineering, to increase their employability and ultimate effectiveness in this growing industry. The report describes the requirements of the minor program and courses that fulfill those requirements. Five new courses directly addressing wind energy have been developed. Topical descriptions for these five courses are provided in this report. Six industry experts in various aspects of wind energy sciencemore » and engineering reviewed the wind energy minor program and provided detailed comments on the program structure, the content of the courses, and the employability in the wind energy industry of students who complete the program. The general consensus is that the program is well structured, the course content is highly relevant, and students who complete it will be highly employable in the wind energy industry. The detailed comments of the reviewers are included in the report.« less

A review of damage detection methods for wind turbine blades

NASA Astrophysics Data System (ADS)

Li, Dongsheng; Ho, Siu-Chun M.; Song, Gangbing; Ren, Liang; Li, Hongnan

2015-03-01

Wind energy is one of the most important renewable energy sources and many countries are predicted to increase wind energy portion of their whole national energy supply to about twenty percent in the next decade. One potential obstacle in the use of wind turbines to harvest wind energy is the maintenance of the wind turbine blades. The blades are a crucial and costly part of a wind turbine and over their service life can suffer from factors such as material degradation and fatigue, which can limit their effectiveness and safety. Thus, the ability to detect damage in wind turbine blades is of great significance for planning maintenance and continued operation of the wind turbine. This paper presents a review of recent research and development in the field of damage detection for wind turbine blades. Specifically, this paper reviews frequently employed sensors including fiber optic and piezoelectric sensors, and four promising damage detection methods, namely, transmittance function, wave propagation, impedance and vibration based methods. As a note towards the future development trend for wind turbine sensing systems, the necessity for wireless sensing and energy harvesting is briefly presented. Finally, existing problems and promising research efforts for online damage detection of turbine blades are discussed.

The influence of spatially and temporally high-resolution wind forcing on the power input to near-inertial waves in the ocean

NASA Astrophysics Data System (ADS)

Rimac, Antonija; von Storch, Jin-Song; Eden, Carsten

2013-04-01

The estimated power required to sustain global general circulation in the ocean is about 2 TW. This power is supplied with wind stress and tides. Energy spectrum shows pronounced maxima at near-inertial frequency. Near-inertial waves excited by high-frequency winds represent an important source for deep ocean mixing since they can propagate into the deep ocean and dissipate far away from the generation sites. The energy input by winds to near-inertial waves has been studied mostly using slab ocean models and wind stress forcing with coarse temporal resolution (e.g. 6-hourly). Slab ocean models lack the ability to reproduce fundamental aspects of kinetic energy balance and systematically overestimate the wind work. Also, slab ocean models do not account the energy used for the mixed layer deepening or the energy radiating downward into the deep ocean. Coarse temporal resolution of the wind forcing strongly underestimates the near-inertial energy. To overcome this difficulty we use an eddy permitting ocean model with high-frequency wind forcing. We establish the following model setup: We use the Max Planck Institute Ocean Model (MPIOM) on a tripolar grid with 45 km horizontal resolution and 40 vertical levels. We run the model with wind forcings that vary in horizontal and temporal resolution. We use high-resolution (1-hourly with 35 km horizontal resolution) and low-resolution winds (6-hourly with 250 km horizontal resolution). We address the following questions: Is the kinetic energy of near-inertial waves enhanced when high-resolution wind forcings are used? If so, is this due to higher level of overall wind variability or higher spatial or temporal resolution of wind forcing? How large is the power of near-inertial waves generated by winds? Our results show that near-inertial waves are enhanced and the near-inertial kinetic energy is two times higher (in the storm track regions 3.5 times higher) when high-resolution winds are used. Filtering high-resolution winds in space and time, the near-inertial kinetic energy reduces. The reduction is faster when a temporal filter is used suggesting that the high-frequency wind forcing is more efficient in generating near-inertial wave energy than the small-scale wind forcing. Using low-resolution wind forcing the wind generated power to near-inertial waves is 0.55 TW. When we use high-resolution wind forcing the result is 1.6 TW meaning that the result increases by 300%.

Win-Win for Wind and Wildlife: A Vision to Facilitate Sustainable Development

PubMed Central

Kiesecker, Joseph M.; Evans, Jeffrey S.; Fargione, Joe; Doherty, Kevin; Foresman, Kerry R.; Kunz, Thomas H.; Naugle, Dave; Nibbelink, Nathan P.; Niemuth, Neal D.

2011-01-01

Wind energy offers the potential to reduce carbon emissions while increasing energy independence and bolstering economic development. However, wind energy has a larger land footprint per Gigawatt (GW) than most other forms of energy production, making appropriate siting and mitigation particularly important. Species that require large unfragmented habitats and those known to avoid vertical structures are particularly at risk from wind development. Developing energy on disturbed lands rather than placing new developments within large and intact habitats would reduce cumulative impacts to wildlife. The U.S. Department of Energy estimates that it will take 241 GW of terrestrial based wind development on approximately 5 million hectares to reach 20% electricity production for the U.S. by 2030. We estimate there are ∼7,700 GW of potential wind energy available across the U.S., with ∼3,500 GW on disturbed lands. In addition, a disturbance-focused development strategy would avert the development of ∼2.3 million hectares of undisturbed lands while generating the same amount of energy as development based solely on maximizing wind potential. Wind subsidies targeted at favoring low-impact developments and creating avoidance and mitigation requirements that raise the costs for projects impacting sensitive lands could improve public value for both wind energy and biodiversity conservation. PMID:21533285

Win-win for wind and wildlife: a vision to facilitate sustainable development.

PubMed

Kiesecker, Joseph M; Evans, Jeffrey S; Fargione, Joe; Doherty, Kevin; Foresman, Kerry R; Kunz, Thomas H; Naugle, Dave; Nibbelink, Nathan P; Niemuth, Neal D

2011-04-13

Wind energy offers the potential to reduce carbon emissions while increasing energy independence and bolstering economic development. However, wind energy has a larger land footprint per Gigawatt (GW) than most other forms of energy production, making appropriate siting and mitigation particularly important. Species that require large unfragmented habitats and those known to avoid vertical structures are particularly at risk from wind development. Developing energy on disturbed lands rather than placing new developments within large and intact habitats would reduce cumulative impacts to wildlife. The U.S. Department of Energy estimates that it will take 241 GW of terrestrial based wind development on approximately 5 million hectares to reach 20% electricity production for the U.S. by 2030. We estimate there are ∼7,700 GW of potential wind energy available across the U.S., with ∼3,500 GW on disturbed lands. In addition, a disturbance-focused development strategy would avert the development of ∼2.3 million hectares of undisturbed lands while generating the same amount of energy as development based solely on maximizing wind potential. Wind subsidies targeted at favoring low-impact developments and creating avoidance and mitigation requirements that raise the costs for projects impacting sensitive lands could improve public value for both wind energy and biodiversity conservation.

International energy outlook 1998

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1998-04-01

The International Energy Outlook 1998 (IEO98) presents an assessment by the Energy Information Administration (EIA) of the outlook for international energy markets through 2020. Projections in IEO98 are displaced according to six basic country groupings. The industrialized region includes projections for four individual countries -- the United States, Canada, Mexico, and Japan -- along with the subgroups Western Europe and Australasia (defined as Australia, New Zealand, and the US Territories). The developing countries are represented by four separate regional subgroups: developing Asia, Africa, Middle East, and Central and South America. China and India are represented in developing Asia. New tomore » this year`s report, country-level projections are provided for Brazil -- which is represented in Central and South America. Eastern Europe and the former Soviet Union (EE/FSU) are considered as a separate country grouping. The report begins with a review of world trends in energy demand. Regional consumption projections for oil, natural gas, coal, nuclear power, and renewable energy (hydroelectricity, geothermal, wind, solar, and other renewables) are presented in five fuel chapters, with a review of the current status of each fuel on a worldwide basis. Summary tables of the IEO98 projections for world energy consumption, carbon emissions, oil production, and nuclear power generating capacity are provided in Appendix A. 88 figs., 77 tabs.« less

Gaseous isotope separation using solar wind phenomena.

PubMed

Wang, C G

1980-12-01

A large evacuated drum-like chamber fitted with supersonic nozzles in the center, with the chamber and the nozzles corotating, can separate gaseous fluids according to their molecular weights. The principle of separation is essentially the same as that of the solar wind propagation, in which components of the plasma fluid are separated due to their difference in the time-of-flight. The process can inherently be very efficient, serving as a pump as well as a separator, and producing well over 10(5) separative work units (kg/year) for the hydrogen/deuterium mixture at high-velocity flows.

Determination of Extrapolation Distance With Pressure Signatures Measured at Two to Twenty Span Lengths From Two Low-Boom Models

NASA Technical Reports Server (NTRS)

Mack, Robert J.; Kuhn, Neil S.

2006-01-01

A study was performed to determine a limiting separation distance for the extrapolation of pressure signatures from cruise altitude to the ground. The study was performed at two wind-tunnel facilities with two research low-boom wind-tunnel models designed to generate ground pressure signatures with "flattop" shapes. Data acquired at the first wind-tunnel facility showed that pressure signatures had not achieved the desired low-boom features for extrapolation purposes at separation distances of 2 to 5 span lengths. However, data acquired at the second wind-tunnel facility at separation distances of 5 to 20 span lengths indicated the "limiting extrapolation distance" had been achieved so pressure signatures could be extrapolated with existing codes to obtain credible predictions of ground overpressures.

CWEX (Crop/Wind-Energy Experiment): Measurements of the interaction between crop agriculture and wind power

NASA Astrophysics Data System (ADS)

Rajewski, Daniel Andrew

The current expansion of wind farms in the U.S. Midwest promotes an alternative renewable energy portfolio to conventional energy sources derived from fossil fuels. The construction of wind turbines and large wind farms within several millions of cropland acres creates a unique interaction between two unlike energy sources: electric generation by wind and bio-fuel production derived from crop grain and plant tissues. Wind turbines produce power by extracting mean wind speed and converting a portion of the flow to turbulence downstream of each rotor. Turbine-scale turbulence modifies fluxes of momentum, heat, moisture, and other gaseous constituents (e.g. carbon dioxide) between the crop canopy and the atmospheric boundary layer. Conversely, crop surfaces and tillage elements produce drag on the hub-height wind resource, and the release of sensible and latent heat flux from the canopy or soil influences the wind speed profile. The Crop-Wind Energy Experiment (CWEX) measured momentum, energy, and CO2 fluxes at several locations within the leading line of turbines in a large operational wind farm, and overall turbines promote canopy mixing of wind speed, temperature, moisture, and carbon dioxide in both the day and night. Turbine-generated perturbations of these fluxes are dependent on several factors influencing the turbine operation (e.g. wind speed, wind direction, stability, orientation of surrounding turbines within a wind park) and the cropland surface (e.g. crop type and cultivar, planting density, chemical application, and soil composition and drainage qualities). Additional strategies are proposed for optimizing the synergy between crop and wind power.

Offshore Wind Energy Resource Assessment for Alaska

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doubrawa Moreira, Paula; Scott, George N.; Musial, Walter D.

This report quantifies Alaska's offshore wind resource capacity while focusing on its unique nature. It is a supplement to the existing U.S. Offshore Wind Resource Assessment, which evaluated the offshore wind resource for all other U.S. states. Together, these reports provide the foundation for the nation's offshore wind value proposition. Both studies were developed by the National Renewable Energy Laboratory. The analysis presented herein represents the first quantitative evidence of the offshore wind energy potential of Alaska. The technical offshore wind resource area in Alaska is larger than the technical offshore resource area of all other coastal U.S. states combined.more » Despite the abundant wind resource available, significant challenges inhibit large-scale offshore wind deployment in Alaska, such as the remoteness of the resource, its distance from load centers, and the wealth of land available for onshore wind development. Throughout this report, the energy landscape of Alaska is reviewed and a resource assessment analysis is performed in terms of gross and technical offshore capacity and energy potential.« less

PC index as a proxy of the solar wind energy that entered into the magnetosphere: 2. Relation to the interplanetary electric field E KL before substorm onset

NASA Astrophysics Data System (ADS)

Troshichev, O. A.; Sormakov, D. A.

2015-10-01

This paper (the second of a series) presents the results of statistical investigation of relationship between the interplanetary electric field E KL and the Polar Cap (PC) index in case of magnetic substorms (1998-2001), which have been analyzed in Troshichev et al. (J. Geophys. Res. Space Physics, 119, 2014). The PC index is directly related to the E KL field variations on interval preceding the substorm sudden onset (SO): correlation R > 0.5 is typical of more than 90 % of isolated substorms, 80 % of expanded substorms, and 99 % of events with coordinated E KL and PC jumps. The low or negative correlation observing in ~10 % of examined substorms suggests that the solar wind flow measured by the Advanced Composition Explorer (ACE) spacecraft in the Lagrange point L1 did not encounter the magnetosphere in these cases. Examination of the delay times Δ T in the response of PC index to E KL variations provides the following results: (1) delay times do not depend on separate solar wind parameters, such as solar wind speed V X and interplanetary magnetic field (IMF) B Z component, contrary to general conviction, (2) the Δ T value is best controlled by the E KL field growth rate (d E KL/dt), (3) the lower Δ T limit (5-7 min is attained under conditions of the higher E KL growth rate, and (4) the PC index provides the possibility to verify the solar wind flow transportation time from ACE position (where the solar wind speed is estimated) to magnetosphere. These results, in combination with data testifying that the substorm onsets are related to the PC precursors, demonstrate that the PC index is an adequate ground-based indicator of the solar wind energy incoming into the magnetosphere.

Planetary Atmosphere Dynamics and Radiative Transfer

NASA Technical Reports Server (NTRS)

Atkinson, David H.

1996-01-01

This research program has dealt with two projects in the field of planetary atmosphere dynamics and radiative energy transfer, one theoretical and one experimental. The first project, in radiative energy transfer, incorporated the capability to isolate and quantify the contribution of individual atmospheric components to the Venus radiative balance and thermal structure to greatly improve the current understanding of the radiative processes occurring within the Venus atmosphere. This is possible by varying the mixing ratios of each gas species, and the location, number density and aerosol size distributions of the clouds. This project was a continuation of the work initiated under a 1992 University Consortium Agreement. Under the just completed grant, work has continued on the use of a convolution-based algorithm that provided the capability to calculate the k coefficients of a gas mixture at different temperatures, pressures and spectral intervals from the separate k-distributions of the individual gas species. The second primary goal of this research dealt with the Doppler wind retrieval for the Successful Galileo Jupiter probe mission in December, 1995. In anticipation of the arrival of Galileo at Jupiter, software development continued to read the radioscience and probe/orbiter trajectory data provided by the Galileo project and required for Jupiter zonal wind measurements. Sample experiment radioscience data records and probe/orbiter trajectory data files provided by the Galileo Radioscience and Navigation teams at the Jet Propulsion Laboratory, respectively, were used for the first phase of the software development. The software to read the necessary data records was completed in 1995. The procedure by which the wind retrieval takes place begins with initial consistency checks of the raw data, preliminary data reductions, wind recoveries, iterative reconstruction of the probe descent profile, and refined wind recoveries. At each stage of the wind recovery consistency is checked and maintained between the orbiter navigational data, the radioscience data, and the probe descent profile derived by the Atmospheric Instrument Team. Preliminary results show that the zonal winds at Jupiter increase with depth to approximately 150 m/s.

QUIET-TIME SUPRATHERMAL (∼0.1–1.5 keV) ELECTRONS IN THE SOLAR WIND

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tao, Jiawei; Wang, Linghua; Zong, Qiugang

2016-03-20

We present a statistical survey of the energy spectrum of solar wind suprathermal (∼0.1–1.5 keV) electrons measured by the WIND 3DP instrument at 1 AU during quiet times at the minimum and maximum of solar cycles 23 and 24. After separating (beaming) strahl electrons from (isotropic) halo electrons according to their different behaviors in the angular distribution, we fit the observed energy spectrum of both strahl and halo electrons at ∼0.1–1.5 keV to a Kappa distribution function with an index κ and effective temperature T{sub eff}. We also calculate the number density n and average energy E{sub avg} of strahl andmore » halo electrons by integrating the electron measurements between ∼0.1 and 1.5 keV. We find a strong positive correlation between κ and T{sub eff} for both strahl and halo electrons, and a strong positive correlation between the strahl n and halo n, likely reflecting the nature of the generation of these suprathermal electrons. In both solar cycles, κ is larger at solar minimum than at solar maximum for both strahl and halo electrons. The halo κ is generally smaller than the strahl κ (except during the solar minimum of cycle 23). The strahl n is larger at solar maximum, but the halo n shows no difference between solar minimum and maximum. Both the strahl n and halo n have no clear association with the solar wind core population, but the density ratio between the strahl and halo roughly anti-correlates (correlates) with the solar wind density (velocity)« less

Tail Shape Design of Boat Wind Turbines

NASA Astrophysics Data System (ADS)

Singamsitty, Venkatesh

Wind energy is a standout among the most generally utilized sustainable power source assets. A great deal of research and improvements have been happening in the wind energy field. Wind turbines are mechanical devices that convert kinetic energy into electrical power. Boat wind turbines are for the small-scale generation of electric power. In order to catch wind energy effectively, boat wind turbines need to face wind direction. Tails are used in boat wind turbines to alter the wind turbine direction and receive the variation of the incoming direction of wind. Tails are used to change the performance of boat wind turbines in an effective way. They are required to generate a quick and steady response as per change in wind direction. Tails can have various shapes, and their effects on boat wind turbines are different. However, the effects of tail shapes on the performance of boat wind turbines are not thoroughly studied yet. In this thesis, five tail shapes were studied. Their effects on boat wind turbines were investigated. The power extracted by the turbines from the air and the force acting on the boat wind turbine tail were analyzed. The results of this thesis provide a guideline of tail shape design for boat wind turbines.

Establishment of a National Wind Energy Center at University of Houston

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Su Su

The DOE-supported project objectives are to: establish a national wind energy center (NWEC) at University of Houston and conduct research to address critical science and engineering issues for the development of future large MW-scale wind energy production systems, especially offshore wind turbines. The goals of the project are to: (1) establish a sound scientific/technical knowledge base of solutions to critical science and engineering issues for developing future MW-scale large wind energy production systems, (2) develop a state-of-the-art wind rotor blade research facility at the University of Houston, and (3) through multi-disciplinary research, introducing technology innovations on advanced wind-turbine materials, processing/manufacturingmore » technology, design and simulation, testing and reliability assessment methods related to future wind turbine systems for cost-effective production of offshore wind energy. To achieve the goals of the project, the following technical tasks were planned and executed during the period from April 15, 2010 to October 31, 2014 at the University of Houston: (1) Basic research on large offshore wind turbine systems (2) Applied research on innovative wind turbine rotors for large offshore wind energy systems (3) Integration of offshore wind-turbine design, advanced materials and manufacturing technologies (4) Integrity and reliability of large offshore wind turbine blades and scaled model testing (5) Education and training of graduate and undergraduate students and post- doctoral researchers (6) Development of a national offshore wind turbine blade research facility The research program addresses both basic science and engineering of current and future large wind turbine systems, especially offshore wind turbines, for MW-scale power generation. The results of the research advance current understanding of many important scientific issues and provide technical information for solving future large wind turbines with advanced design, composite materials, integrated manufacturing, and structural reliability and integrity. The educational program have trained many graduate and undergraduate students and post-doctoral level researchers to learn critical science and engineering of wind energy production systems through graduate-level courses and research, and participating in various projects in center’s large multi-disciplinary research. These students and researchers are now employed by the wind industry, national labs and universities to support the US and international wind energy industry. The national offshore wind turbine blade research facility developed in the project has been used to support the technical and training tasks planned in the program to accomplish their goals, and it is a national asset which is available for used by domestic and international researchers in the wind energy arena.« less

Wind-energy Science, Technology and Research (WindSTAR) Consortium: Curriculum, Workforce Development, and Education Plan Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manwell, James

2013-03-19

The purpose of the project is to modify and expand the current wind energy curriculum at the University of Massachusetts Amherst and to develop plans to expand the graduate program to a national scale. The expansion plans include the foundational steps to establish the American Academy of Wind Energy (AAWE). The AAWE is intended to be a cooperative organization of wind energy research, development, and deployment institutes and universities across North America, whose mission will be to develop and execute joint RD&D projects and to organize high-level science and education in wind energy

Sustainable electrical energy storage through the ferrocene/ferrocenium redox reaction in aprotic electrolyte.

PubMed

Zhao, Yu; Ding, Yu; Song, Jie; Li, Gang; Dong, Guangbin; Goodenough, John B; Yu, Guihua

2014-10-06

The large-scale, cost-effective storage of electrical energy obtained from the growing deployment of wind and solar power is critically needed for the integration into the grid of these renewable energy sources. Rechargeable batteries having a redox-flow cathode represent a viable solution for either a Li-ion or a Na-ion battery provided a suitable low-cost redox molecule soluble in an aprotic electrolyte can be identified that is stable for repeated cycling and does not cross the separator membrane to the anode. Here we demonstrate an environmentally friendly, low-cost ferrocene/ferrocenium molecular redox couple that shows about 95% energy efficiency and about 90% capacity retention after 250 full charge/discharge cycles. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Introduction Wind farms in complex terrains: an introduction

PubMed Central

Alfredsson, P. H.; Segalini, A.

2017-01-01

Wind energy is one of the fastest growing sources of sustainable energy production. As more wind turbines are coming into operation, the best locations are already becoming occupied by turbines, and wind-farm developers have to look for new and still available areas—locations that may not be ideal such as complex terrain landscapes. In these locations, turbulence and wind shear are higher, and in general wind conditions are harder to predict. Also, the modelling of the wakes behind the turbines is more complicated, which makes energy-yield estimates more uncertain than under ideal conditions. This theme issue includes 10 research papers devoted to various fluid-mechanics aspects of using wind energy in complex terrains and illustrates recent progress and future developments in this important field. This article is part of the themed issue ‘Wind energy in complex terrains’. PMID:28265020

The Crab Pulsar and Relativistic Wind

NASA Astrophysics Data System (ADS)

Coroniti, F. V.

2017-12-01

The possibility that the Crab pulsar produces a separated ion-dominated and pair-plasma-dominated, magnetically striped relativistic wind is assessed by rough estimates of the polar cap acceleration of the ion and electron primary beams, the pair production of secondary electrons and positrons, and a simple model of the near-magnetosphere-wind zone. For simplicity, only the orthogonal rotator is considered. Below (above) the rotational equator, ions (electrons) are accelerated in a thin sheath, of order (much less than) the width of the polar cap, to Lorentz factor {γ }i≈ (5{--}10)× {10}7({γ }e≈ {10}7). The accelerating parallel electric field is shorted out by ion-photon (curvature synchrotron) pair production. With strong, but fairly reasonable, assumptions, a set of general magnetic geometry relativistic wind equations is derived and shown to reduce to conservation relations that are similar to those of the wind from a magnetic monopole. The strength of the field-aligned currents carried by the primary beams is determined by the wind’s Alfvén critical point condition to be about eight times the Goldreich-Julian value. A simple model for the transition from the dipole region wind to the asymptotic monopole wind zone is developed. The asymptotic ratio of Poynting flux to ion (pair plasma) kinetic energy flux—the wind {σ }w∞ -parameter—is found to be of order {σ }w∞ ≈ 1/2({10}4). The far wind zone is likely to be complex, with the ion-dominated and pair-plasma-dominated magnetic stripes merging, and the oppositely directed azimuthal magnetic fields annihilating.

PC index as a proxy of the solar wind energy that entered into the magnetosphere and energy accumulated in the magnetosphere

NASA Astrophysics Data System (ADS)

Troshichev, Oleg; Sormakov, Dmitry

The PC index has been approved by the International Association of Geomagnetism and Aeronomy (Merida, Mexico, 2013) as a new international index of magnetic activity. Application of the PC index as a proxy of a solar wind energy that entered into the magnetosphere determines a principal distinction of the PC index from AL and Dst indices, which are regarded as characteristics of the energy that realized in magnetosphere in form of substorms and magnetic storms. This conclusion is based on results of analysis of relationships between the polar cap magnetic activity (PC-index) and parameters of the solar wind, on the one hand, relationships between changes of PC and development of magnetospheric substorms (AL-index) and magnetic storms (Dst-index), on the other hand. In this study the relationships between the PC and Dst indices in course of more than 200 magnetic storms observed in epoch of solar maximum (1998-2004) have been examined for different classes of storms separated by their kind and intensity. Results of statistical analysis demonstrate that depression of geomagnetic field starts to develop as soon as PC index steadily excess the threshold level ~1.5 mV/m; the storm intensity (DstMIN) follows, with delay ~ 1 hour, the maximum of PC in course of the storm. Main features of magnetic storms are determined, irrespective of their class and intensity, by the accumulated-mean PC value (PCAM): storm is developed as long as PCAM increases, comes to maximal intensity when PCAM attains the maximum, and starts to decay as soon as PCAM value displays decline. The run of “anomalous” magnetic storm on January 21-22, 2005, lasting many hours (with intensity of ≈ -100 nT) under conditions of northward or close to zero BZ component, is perfectly governed by behavior of the accumulated-mean PCAM index and, therefore, this storm should be regarded as an ordinary phenomenon. The conclusion is made that the PC index provides the unique on-line information on solar wind energy that entered into magnetosphere and PCAM index provides information on energy that accumulated in the magnetosphere.

Wind Alliance for the Sustainable Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Camacho, Damarys Gonzalez

2012-09-30

The Puerto Rico Energy Affairs Administration (PREAA) is actively engaged in the implementation of existing public policy for the conservation of energy and promotion of renewable energy to reduce consumer’s costs and reduce environmental impact. Puerto Rico is an island in where no own reserves of gas, oil or coal exists. This severe dependence in on foreign oil is reflected in the higher cost of electricity in Puerto Rico, which is significantly higher than most of the United States. Therefore, public energy policy of Puerto Rico places emphasis on diversification of energy sources and the use of renewable energy technologies.more » The Wind energy Alliance for the Sustainable Development project focused on the formation of a wind energy working group to educate and promote wind energy technologies; at the same time the evaluating the viability of wind energy in Puerto Rico. The educational outreach was performed through a series of wind energy workshops where interested parties such as, installers, sellers, engineers, general public even opposing groups participate from the activities.« less

The Feasibility of Wind and Solar Energy Application for Oil and Gas Offshore Platform

NASA Astrophysics Data System (ADS)

Tiong, Y. K.; Zahari, M. A.; Wong, S. F.; Dol, S. S.

2015-04-01

Renewable energy is an energy which is freely available in nature such as winds and solar energy. It plays a critical role in greening the energy sector as these sources of energy produce little or no pollution to environment. This paper will focus on capability of renewable energy (wind and solar) in generating power for offshore application. Data of wind speeds and solar irradiation that are available around SHELL Sabah Water Platform for every 10 minutes, 24 hours a day, for a period of one year are provided by SHELL Sarawak Sdn. Bhd. The suitable wind turbine and photovoltaic panel that are able to give a high output and higher reliability during operation period are selected by using the tabulated data. The highest power output generated using single wind energy application is equal to 492 kW while for solar energy application is equal to 20 kW. Using the calculated data, the feasibility of renewable energy is then determined based on the platform energy demand.

Integration of permanent magnet synchronous generator wind turbines into power grid

NASA Astrophysics Data System (ADS)

Abedini, Asghar

The world is seeing an ever-increasing demand for electrical energy. The future growth of electrical power generation needs to be a mix of technologies including fossil fuels, hydro, nuclear, wind, and solar. The federal and state energy agencies have taken several proactive steps to increase the share of renewable energy in the total generated electrical power. In 2005, 11.1% of the total 1060 GW electricity generation capacity was from Renewable Energy Sources (RES) in the US. The power capacity portfolio included 9.2% from hydroelectric, 0.87% from wind, and 0.7% from biomass. Other renewable power capacity included 2.8 GW of geothermal, 0.4 GW of solar thermal, and 0.2 GW of solar PV. Although the share of renewable energy sources is small compared with the total power capacity, they are experiencing a high and steady growth. The US is leading the world in wind energy growth with a 27% increase in 2006 and a projected 26% increase in 2007, according to the American Wind Energy Association (AWEA). The US Department of Energy benchmarked a goal to meet 5% of the nation's energy need by launching the Wind Powering America (WPA) program. Although renewable energy sources have many benefits, their utilization in the electrical grid does not come without cost. The higher penetration of RES has introduced many technical and non-technical challenges, including power quality, reliability, safety and protection, load management, grid interconnections and control, new regulations, and grid operation economics. RES such as wind and PV are also intermittent in nature. The energy from these sources is available as long as there is wind or sunlight. However, these are energies that are abundant in the world and the power generated from these sources is pollution free. Due to high price of foundation of wind farms, employing variable speed wind turbines to maximize the extracted energy from blowing wind is more beneficial. On the other hand, since wind power is intermittent, integrating energy storage systems with wind farms has attracted a lot of attention. These two subjects are addressed in this dissertation in detail. Permanent Magnet Synchronous Generators (PMSG) are used in variable speed wind turbines. In this thesis, the dynamic of the PMSG is investigated and a power electronic converter is designed to integrate the wind turbine to the grid. The risks of PMSG wind turbines such as low voltage ride through and short circuits, are assessed and the methods of mitigating the risks are discussed. In the second section of the thesis, various methods of smoothing wind turbine output power are explained and compared. Two novel methods of output power smoothing are analyzed: Rotor inertia and Super capacitors. The advantages and disadvantages of each method are explained and the dynamic model of each method is developed. The performance of the system is evaluated by simulating the wind turbine system in each method. The concepts of the methods of smoothing wind power can be implemented in other types of wind turbines such as Doubly Fed Induction Generator (DFIG) wind turbines.

Wind energy: A renewable energy option

NASA Technical Reports Server (NTRS)

Zimmerman, J. S.

1977-01-01

Wind turbine generator research programs administered by the Energy Research and Development Administration are examined. The design and operation of turbine demonstration models are described. Wind assessments were made to determine the feasibility of using wind generated power for various parts of the country.

RENEWABLE RESOURCES EVALUATION

EPA Science Inventory

The role of wind energy and solar photovoltaics (PV) in producing grid connected electricity and reducing CO2 emissions in the U.S. will be evaluated. Growth in the wind energy is booming , and wind is the World's fastest growing source of energy. Growth in wind turbine sales...

2016 Offshore Wind Energy Resource Assessment for the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Musial, Walt; Heimiller, Donna; Beiter, Philipp

2016-09-01

This report, the 2016 Offshore Wind Energy Resource Assessment for the United States, was developed by the National Renewable Energy Laboratory, and updates a previous national resource assessment study, and refines and reaffirms that the available wind resource is sufficient for offshore wind to be a large-scale contributor to the nation's electric energy supply.

76 FR 64941 - Notice of Cancellation of Environmental Impact Statement for the Proposed Hyde County Wind Energy...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-19

... Environmental Impact Statement for the Proposed Hyde County Wind Energy Center Project, Hyde County, SD AGENCY... design, construct, operate, and maintain a 150-megawatt Hyde County Wind Energy Center Project (Project... terminated the NEPA process for NextEra's proposed Hyde County Wind Energy Center Project with the...

Application of Satellite Data to Develop Wind Potential Model: A Case Study of Pakistan Coastal Belt

NASA Astrophysics Data System (ADS)

Nayyar, Z. A.; Zaigham, N. A.

2010-12-01

Since the independence in 1947, the Pakistan relies on the conventional resources for the generation of electricity. Since the local production of fossil fuel is not sufficient to fulfill the growing need of the country, the major economic burden involves huge import of petroleum products. In such a situation, the renewable energy resources are imperative in view to substantiate the economic burden. Wind energy resource is one of them, which is freely available and environmental friendly in nature. Pakistan is the late starter in the field of wind energy technology mainly because of the unavailability of the baseline wind data. As such, the adequate wind modeling and identification of the potential areas are imperative for the development of wind energy technology in the country. Present research study is carried out, based on the available satellite-collected wind data, to establish the rational wind potential model(s) of lower Indus Plains and Sindh coastal areas of Pakistan. The results of the present study reveals interesting pattern of the wind energy potential demarcating the higher wind energy resource zones and indicating hot spots for the future wind-farm installations. This paper describes the use of available satellite-collected wind data in the demarcation and modeling of wind potential along the lower Indus coastal belt and the methodology could be replicated on other parts of Pakistan and/or other counties.

77 FR 3468 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-24

... Energy LLC, Hardee Power Partners Limited, Judith Gap Energy LLC, Invenergy TN LLC, Wolverine Creek... Energy V LLC, Vantage Wind Energy LLC, Beech Ridge Energy LLC, Gratiot County Wind LLC, Stony Creek Energy LLC, Gratiot County Wind II LLC. Description: Notification of Change in Facts Under Market-Based...

Considerations of solar wind dynamics in mapping of Jupiter's auroral features to magnetospheric sources

NASA Astrophysics Data System (ADS)

Gyalay, S.; Vogt, M.; Withers, P.

2015-12-01

Previous studies have mapped locations from the magnetic equator to the ionosphere in order to understand how auroral features relate to magnetospheric sources. Vogt et al. (2011) in particular mapped equatorial regions to the ionosphere by using a method of flux equivalence—requiring that the magnetic flux in a specified region at the equator is equal to the magnetic flux in the region to which it maps in the ionosphere. This is preferred to methods relying on tracing field lines from global Jovian magnetic field models, which are inaccurate beyond 30 Jupiter radii from the planet. That previous study produced a two-dimensional model—accounting for changes with radial distance and local time—of the normal component of the magnetic field in the equatorial region. However, this two-dimensional fit—which aggregated all equatorial data from Pioneer 10, Pioneer 11, Voyager 1, Voyager 2, Ulysses, and Galileo—did not account for temporal variability resulting from changing solar wind conditions. Building off of that project, this study aims to map the Jovian aurora to the magnetosphere for two separate cases: with a nominal magnetosphere, and with a magnetosphere compressed by high solar wind dynamic pressure. Using the Michigan Solar Wind Model (mSWiM) to predict the solar wind conditions upstream of Jupiter, intervals of high solar wind dynamic pressure were separated from intervals of low solar wind dynamic pressure—thus creating two datasets of magnetometer measurements to be used for two separate 2D fits, and two separate mappings.

Wind Energy Modeling and Simulation | Wind | NREL

Science.gov Websites

Wind Energy Modeling and Simulation Wind Turbine Modeling and Simulation Wind turbines are unique wind turbines. It enables the analysis of a range of wind turbine configurations, including: Two- or (SOWFA) employs computational fluid dynamics to allow users to investigate wind turbine and wind power

Evaluation of Proposed Solutions to Global Warming, Air Pollution, and Energy Security

NASA Astrophysics Data System (ADS)

Jacobson, M. Z.

2008-12-01

This study reviews and ranks major proposed solutions to global warming, air pollution mortality, and energy security while considering other impacts of the proposed solutions, such as on water supply, land use, wildlife, resource availability, thermal pollution, water chemical pollution, nuclear proliferation, and undernutrition. Nine electric power sources and two liquid fuel options are considered. The electricity sources include solar-photovoltaics (PV), concentrated solar power (CSP), wind, geothermal, hydroelectric, wave, tidal, nuclear, and coal with carbon capture and storage (CCS) technology. The liquid fuel options include corn-E85 and cellulosic E85. To place the electric and liquid fuel sources on an equal footing, we examine their comparative abilities to address the problems mentioned by powering new-technology vehicles, including battery-electric vehicles (BEVs), hydrogen fuel cell vehicles (HFCVs), and flex-fuel vehicles run on E85. Twelve combinations of energy source-vehicle type are considered. Upon ranking and weighting each combination with respect to each of 11 impact categories, four clear divisions of ranking, or tiers, emerge. Tier 1 (highest-ranked) includes wind-BEVs and wind-HFCVs. Tier 2 includes CSP-BEVs, geothermal-BEVs, PV-BEVs, tidal-BEVs, and wave-BEVs. Tier 3 includes hydro-BEVs, nuclear-BEVs, and CCS-BEVs. Tier 4 includes corn- and cellulosic-E85. Wind-BEVs ranked first in six out of 11 categories, including the two most important, mortality and climate damage reduction. Although HFCVs are less efficient than BEVs, wind- HFCVs ranked second among all combinations. Tier 2 options provide significant benefits and are recommended. Tier 3 options are less desirable. However, hydroelectricity, which was ranked ahead of coal- CCS and nuclear with respect to climate and health, is an excellent load balancer, thus strongly recommended. The Tier-4 combinations (cellulosic- and corn-E85) were ranked lowest overall and with respect to climate, air pollution, land use, wildlife damage, and chemical waste. Cellulosic-E85 ranked lower than corn-E85 overall, primarily due to its potentially larger land footprint based on recent data and its higher upstream air pollution emissions than corn-E85. Whereas cellulosic-E85 may cause the greatest average human mortality, nuclear-BEVs cause the greatest upper-limit mortality risk due to the expansion of plutonium separation and uranium enrichment in nuclear energy facilities worldwide. Wind-BEVs and CSP-BEVs cause the least mortality. The footprint area of wind-BEVs is 2-6 orders of magnitude less than that of any other option. Because of their low footprint and pollution, wind-BEVs cause the least wildlife loss. The largest consumer of water is corn-E85. The smallest are wind-, tidal-, and wave-BEVs. In sum, use of wind, CSP, geothermal, tidal, PV, wave, and hydro to power electricity for BEVs and HFCVs and for general use in the residential, industrial, and commercial sectors will result in the most benefit among the options considered. The combination of these technologies should be advanced as a solution to global warming, air pollution, and energy security. Coal-CCS and nuclear offer less benefit, and the biofuel options provide little or no benefit and greater negative impacts.

The resilience of Australian wind energy to climate change

NASA Astrophysics Data System (ADS)

Evans, Jason P.; Kay, Merlinde; Prasad, Abhnil; Pitman, Andy

2018-02-01

The Paris Agreement limits global average temperature rise to 2 °C and commits to pursuing efforts in limiting warming to 1.5 °C above pre-industrial levels. This will require rapid reductions in the emissions of greenhouse gases and the eventual decarbonisation of the global economy. Wind energy is an established technology to help achieve emissions reductions, with a cumulative global installed capacity of ~486 GW (2016). Focusing on Australia, we assess the future economic viability of wind energy using a 12-member ensemble of high-resolution regional climate simulations forced by Coupled Model Intercomparison Project (CMIP) output. We examine both near future (around 2030) and far future (around 2070) changes. Extractable wind power changes vary across the continent, though the most spatially coherent change is a small but significant decrease across southern regions. The cost of future wind energy generation, measured via the Levelised Cost of Energy (LCOE), increases negligibly in the future in regions with significant existing installed capacity. Technological developments in wind energy generation more than compensate for projected small reductions in wind, decreasing the LCOE by around 30%. These developments ensure viability for existing wind farms, and enhance the economic viability of proposed wind farms in Western Australian and Tasmania. Wind energy is therefore a resilient source of electricity over most of Australia and technological innovation entering the market will open new regions for energy production in the future.

Climate information for the wind energy industry in the Mediterranean Region

NASA Astrophysics Data System (ADS)

Calmanti, Sandro; Davis, Melanie; Schmidt, Peter; Dell'Aquila, Alessandro

2013-04-01

According to the World Wind Energy Association the total wind generation capacity worldwide has come close to cover 3% of the world's electricity demand in 2011. Thanks to the enormous resource potential and the relatively low costs of construction and maintenance of wind power plants, the wind energy sector will remain one of the most attractive renewable energy investment options. Studies reveal that climate variability and change pose a new challenge to the entire renewable energy sector, and in particular for wind energy. Stakeholders in the wind energy sector mainly use, if available, site-specific historical climate information to assess wind resources at a given project site. So far, this is the only source of information that investors (e.g., banks) are keen to accept for decisions concerning the financing of wind energy projects. However, one possible wind energy risk at the seasonal scale is the volatility of earnings from year to year investment. The most significant risk is therefore that not enough units of energy (or megawatt hours) can be generated from the project to capture energy sales to pay down debt in any given quarter or year. On the longer time scale the risk is that a project's energy yields fall short of their estimated levels, resulting in revenues that consistently come in below their projection, over the life of the project. The nature of the risk exposure determines considerable interest in wind scenarios, as a potential component of both the planning and operational phase of a renewable energy project. Fundamentally, by using climate projections, the assumption of stationary wind regimes can be compared to other scenarios where large scale changes in atmospheric circulation patterns may affect local wind regimes. In the framework of CLIM-RUN EU FP7 project, climate experts are exploring the potential of seasonal to decadal climate forecast techniques (time-frame 2012-2040) and regional climate scenarios (time horizon 2040+) over the Mediterranean Region as a tool for assessing the impact of changes in climate patterns on the energy output of wind power plants. Subsequently, we will give here a brief overview of these techniques as well as first results related to wind projections for different sites across the Mediterranean Region. We will highlight that regional climate models have a large potential for enhancing the quality of climate projections in the presence of complex orography and in the proximity of coastal areas.

Wind for Schools Affiliate Programs: Wind and Hydropower Technologies Program (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2009-12-01

The U.S. Department of Energy's (DOE's) Wind for Schools program is designed to raise awareness about the benefits of wind energy while simultaneously developing a wind energy knowledge base in future leaders of our communities, states, and nation. To accommodate the many stakeholders who are interested in the program, a Wind for Schools affiliate program has been implemented. This document describes the affiliate program and how interested schools may participate.

Performance characteristics of aerodynamically optimum turbines for wind energy generators

NASA Technical Reports Server (NTRS)

Rohrbach, C.; Worobel, R.

1975-01-01

This paper presents a brief discussion of the aerodynamic methodology for wind energy generator turbines, an approach to the design of aerodynamically optimum wind turbines covering a broad range of design parameters, some insight on the effect on performance of nonoptimum blade shapes which may represent lower fabrication costs, the annual wind turbine energy for a family of optimum wind turbines, and areas of needed research. On the basis of the investigation, it is concluded that optimum wind turbines show high performance over a wide range of design velocity ratios; that structural requirements impose constraints on blade geometry; that variable pitch wind turbines provide excellent power regulation and that annual energy output is insensitive to design rpm and solidity of optimum wind turbines.

Final Technical Report. DeepCwind Consortium Research Program. January 15, 2010 - March 31, 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dagher, Habib; Viselli, Anthony; Goupee, Andrew

This is the final technical report for the U.S. Department of Energy-funded program, DE-0002981: DeepCwind Consortium Research Program. The project objective was the partial validation of coupled models and optimization of materials for offshore wind structures. The United States has a great opportunity to harness an indigenous abundant renewable energy resource: offshore wind. In 2010, the National Renewable Energy Laboratory (NREL) estimated there to be over 4,000 GW of potential offshore wind energy found within 50 nautical miles of the US coastlines (Musial and Ram, 2010). The US Energy Information Administration reported the total annual US electric energy generation inmore » 2010 was 4,120 billion kilowatt-hours (equivalent to 470 GW) (US EIA, 2011), slightly more than 10% of the potential offshore wind resource. In addition, deep water offshore wind is the dominant US ocean energy resource available comprising 75% of the total assessed ocean energy resource as compared to wave and tidal resources (Musial, 2008). Through these assessments it is clear offshore wind can be a major contributor to US energy supplies. The caveat to capturing offshore wind along many parts of the US coast is deep water. Nearly 60%, or 2,450 GW, of the estimated US offshore wind resource is located in water depths of 60 m or more (Musial and Ram, 2010). At water depths over 60 m building fixed offshore wind turbine foundations, such as those found in Europe, is likely economically infeasible (Musial et al., 2006). Therefore floating wind turbine technology is seen as the best option for extracting a majority of the US offshore wind energy resource. Volume 1 - Test Site; Volume 2 - Coupled Models; and Volume 3 - Composite Materials« less

Mercury Capsule Separation Tests

NASA Image and Video Library

1960-04-01

Mercury capsule separation from Redstone booster in the Altitude Wind Tunnel (AWT): NASA Lewis conducted full-scale separation tests of the posigrade rockets that were fired after the Redstone rockets burned out. The researchers studied the effect of the posigrade rockets firing on the Redstone booster and retrograde package. This film shows the Mercury capsule being mounted to the Redstone missile model in the Altitude Wind Tunnel. The capsule's engines are fired and it horizontally separates from the Atlas. After firing the capsule swings from an overhead crane.

Wind energy resource modelling in Portugal and its future large-scale alteration due to anthropogenic induced climate changes =

NASA Astrophysics Data System (ADS)

Carvalho, David Joao da Silva

The high dependence of Portugal from foreign energy sources (mainly fossil fuels), together with the international commitments assumed by Portugal and the national strategy in terms of energy policy, as well as resources sustainability and climate change issues, inevitably force Portugal to invest in its energetic self-sufficiency. The 20/20/20 Strategy defined by the European Union defines that in 2020 60% of the total electricity consumption must come from renewable energy sources. Wind energy is currently a major source of electricity generation in Portugal, producing about 23% of the national total electricity consumption in 2013. The National Energy Strategy 2020 (ENE2020), which aims to ensure the national compliance of the European Strategy 20/20/20, states that about half of this 60% target will be provided by wind energy. This work aims to implement and optimise a numerical weather prediction model in the simulation and modelling of the wind energy resource in Portugal, both in offshore and onshore areas. The numerical model optimisation consisted in the determination of which initial and boundary conditions and planetary boundary layer physical parameterizations options provide wind power flux (or energy density), wind speed and direction simulations closest to in situ measured wind data. Specifically for offshore areas, it is also intended to evaluate if the numerical model, once optimised, is able to produce power flux, wind speed and direction simulations more consistent with in situ measured data than wind measurements collected by satellites. This work also aims to study and analyse possible impacts that anthropogenic climate changes may have on the future wind energetic resource in Europe. The results show that the ECMWF reanalysis ERA-Interim are those that, among all the forcing databases currently available to drive numerical weather prediction models, allow wind power flux, wind speed and direction simulations more consistent with in situ wind measurements. It was also found that the Pleim-Xiu and ACM2 planetary boundary layer parameterizations are the ones that showed the best performance in terms of wind power flux, wind speed and direction simulations. This model optimisation allowed a significant reduction of the wind power flux, wind speed and direction simulations errors and, specifically for offshore areas, wind power flux, wind speed and direction simulations more consistent with in situ wind measurements than data obtained from satellites, which is a very valuable and interesting achievement. This work also revealed that future anthropogenic climate changes can negatively impact future European wind energy resource, due to tendencies towards a reduction in future wind speeds especially by the end of the current century and under stronger radiative forcing conditions.

78 FR 17653 - Upper Great Plains Wind Energy Draft Programmatic Environmental Impact Statement (DOE/EIS-0408)

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-22

... infrastructure development, including siting wind turbines, access roads, underground collector lines, overhead... Wildlife Service Upper Great Plains Wind Energy Draft Programmatic Environmental Impact Statement (DOE/EIS... Plains Wind Energy Draft Programmatic Environmental Impact Statement (Draft [[Page 17654

Energy by the Numbers: Collegiate Wind Competition

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2016-05-19

The U.S. Department of Energy Collegiate Wind Competition prepares students from multiple disciplines to enter tomorrow’s wind energy workforce. As part of the competition, undergraduate students build and test a wind turbine, establish a deployment strategy, and develop and deliver a business plan.

Research on the effects of wind power grid to the distribution network of Henan province

NASA Astrophysics Data System (ADS)

Liu, Yunfeng; Zhang, Jian

2018-04-01

With the draining of traditional energy, all parts of nation implement policies to develop new energy to generate electricity under the favorable national policy. The wind has no pollution, Renewable and other advantages. It has become the most popular energy among the new energy power generation. The development of wind power in Henan province started relatively late, but the speed of the development is fast. The wind power of Henan province has broad development prospects. Wind power has the characteristics of volatility and randomness. The wind power access to power grids will cause much influence on the power stability and the power quality of distribution network, and some areas have appeared abandon the wind phenomenon. So the study of wind power access to power grids and find out improvement measures is very urgent. Energy storage has the properties of the space transfer energy can stabilize the operation of power grid and improve the power quality.

Flowfield Comparisons from Three Navier-Stokes Solvers for an Axisymmetric Separate Flow Jet

NASA Technical Reports Server (NTRS)

Koch, L. Danielle; Bridges, James; Khavaran, Abbas

2002-01-01

To meet new noise reduction goals, many concepts to enhance mixing in the exhaust jets of turbofan engines are being studied. Accurate steady state flowfield predictions from state-of-the-art computational fluid dynamics (CFD) solvers are needed as input to the latest noise prediction codes. The main intent of this paper was to ascertain that similar Navier-Stokes solvers run at different sites would yield comparable results for an axisymmetric two-stream nozzle case. Predictions from the WIND and the NPARC codes are compared to previously reported experimental data and results from the CRAFT Navier-Stokes solver. Similar k-epsilon turbulence models were employed in each solver, and identical computational grids were used. Agreement between experimental data and predictions from each code was generally good for mean values. All three codes underpredict the maximum value of turbulent kinetic energy. The predicted locations of the maximum turbulent kinetic energy were farther downstream than seen in the data. A grid study was conducted using the WIND code, and comments about convergence criteria and grid requirements for CFD solutions to be used as input for noise prediction computations are given. Additionally, noise predictions from the MGBK code, using the CFD results from the CRAFT code, NPARC, and WIND as input are compared to data.

Design and performance of a centimetre-scale shrouded wind turbine for energy harvesting

NASA Astrophysics Data System (ADS)

Howey, D. A.; Bansal, A.; Holmes, A. S.

2011-08-01

A miniature shrouded wind turbine aimed at energy harvesting for power delivery to wireless sensors in pipes and ducts is presented. The device has a rotor diameter of 2 cm, with an outer diameter of 3.2 cm, and generates electrical power by means of an axial-flux permanent magnet machine built into the shroud. Fabrication was accomplished using a combination of traditional machining, rapid prototyping, and flexible printed circuit board technology for the generator stator, with jewel bearings providing low friction and start up speed. Prototype devices can operate at air speeds down to 3 m s-1, and deliver between 80 µW and 2.5 mW of electrical power at air speeds in the range 3-7 m s-1. Experimental turbine performance curves, obtained by wind tunnel testing and corrected for bearing losses using data obtained in separate vacuum run-down tests, are compared with the predictions of an elementary blade element momentum (BEM) model. The two show reasonable agreement at low tip speed ratios. However, in experiments where a maximum could be observed, the maximum power coefficient (~9%) is marginally lower than predicted from the BEM model and occurs at a lower than predicted tip speed ratio of around 0.6.

Aqueous cathode for next-generation alkali-ion batteries.

PubMed

Lu, Yuhao; Goodenough, John B; Kim, Youngsik

2011-04-20

The lithium-ion batteries that ushered in the wireless revolution rely on electrode strategies that are being stretched to power electric vehicles. Low-cost, safe electrical-energy storage that enables better use of alternative energy sources (e.g., wind, solar, and nuclear) requires an alternative strategy. We report a demonstration of the feasibility of a battery having a thin, solid alkali-ion electrolyte separating a water-soluble redox couple as the cathode and lithium or sodium in a nonaqueous electrolyte as the anode. The cell operates without a catalyst and has high storage efficiency. The possibility of a flow-through mode for the cathode allows flexibility of the cell design for safe, large-capacity electrical-energy storage at an acceptable cost.

Pickup Ion Effect of the Solar Wind Interaction with the Local Interstellar Medium

DOE PAGES

Pogorelov, N. V.; Bedford, M. C.; Kryukov, I. A.; ...

2016-11-22

Pickup ions are created when interstellar neutral atoms resonantly exchange charge with the solar wind (SW) ions, especially in the supersonic part of the wind, where they carry most of the plasma pressure. Here we present numerical simulation results of the 3D heliospheric interface treating pickup ions as a separate proton fluid. To satisfy the fundamental conservation laws, we solve the system of equations describing the flow of the mixture of electrons, thermal protons, and pickup ions. To find the density and pressure of pickup ions behind the termination shock, we employ simple boundary conditions that take into account themore » \\emph{Voyager} observations that showed that the decrease in the kinetic energy of the mixture at the termination shock predominantly contributed to the increase in the pressure of pickup ions. We show that this model adequately describes the flow of the plasma mixture and results in a noticeable decrease in the heliosheath width.« less

Wind Energy Forecasting: A Collaboration of the National Center for Atmospheric Research (NCAR) and Xcel Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parks, K.; Wan, Y. H.; Wiener, G.

2011-10-01

The focus of this report is the wind forecasting system developed during this contract period with results of performance through the end of 2010. The report is intentionally high-level, with technical details disseminated at various conferences and academic papers. At the end of 2010, Xcel Energy managed the output of 3372 megawatts of installed wind energy. The wind plants span three operating companies1, serving customers in eight states2, and three market structures3. The great majority of the wind energy is contracted through power purchase agreements (PPAs). The remainder is utility owned, Qualifying Facilities (QF), distributed resources (i.e., 'behind the meter'),more » or merchant entities within Xcel Energy's Balancing Authority footprints. Regardless of the contractual or ownership arrangements, the output of the wind energy is balanced by Xcel Energy's generation resources that include fossil, nuclear, and hydro based facilities that are owned or contracted via PPAs. These facilities are committed and dispatched or bid into day-ahead and real-time markets by Xcel Energy's Commercial Operations department. Wind energy complicates the short and long-term planning goals of least-cost, reliable operations. Due to the uncertainty of wind energy production, inherent suboptimal commitment and dispatch associated with imperfect wind forecasts drives up costs. For example, a gas combined cycle unit may be turned on, or committed, in anticipation of low winds. The reality is winds stayed high, forcing this unit and others to run, or be dispatched, to sub-optimal loading positions. In addition, commitment decisions are frequently irreversible due to minimum up and down time constraints. That is, a dispatcher lives with inefficient decisions made in prior periods. In general, uncertainty contributes to conservative operations - committing more units and keeping them on longer than may have been necessary for purposes of maintaining reliability. The downside is costs are higher. In organized electricity markets, units that are committed for reliability reasons are paid their offer price even when prevailing market prices are lower. Often, these uplift charges are allocated to market participants that caused the inefficient dispatch in the first place. Thus, wind energy facilities are burdened with their share of costs proportional to their forecast errors. For Xcel Energy, wind energy uncertainty costs manifest depending on specific market structures. In the Public Service of Colorado (PSCo), inefficient commitment and dispatch caused by wind uncertainty increases fuel costs. Wind resources participating in the Midwest Independent System Operator (MISO) footprint make substantial payments in the real-time markets to true-up their day-ahead positions and are additionally burdened with deviation charges called a Revenue Sufficiency Guarantee (RSG) to cover out of market costs associated with operations. Southwest Public Service (SPS) wind plants cause both commitment inefficiencies and are charged Southwest Power Pool (SPP) imbalance payments due to wind uncertainty and variability. Wind energy forecasting helps mitigate these costs. Wind integration studies for the PSCo and Northern States Power (NSP) operating companies have projected increasing costs as more wind is installed on the system due to forecast error. It follows that reducing forecast error would reduce these costs. This is echoed by large scale studies in neighboring regions and states that have recommended adoption of state-of-the-art wind forecasting tools in day-ahead and real-time planning and operations. Further, Xcel Energy concluded reduction of the normalized mean absolute error by one percent would have reduced costs in 2008 by over $1 million annually in PSCo alone. The value of reducing forecast error prompted Xcel Energy to make substantial investments in wind energy forecasting research and development.« less

Towards a mature offshore wind energy technology - guidelines from the opti-OWECS project

NASA Astrophysics Data System (ADS)

Kühn, M.; Bierbooms, W. A. A. M.; van Bussel, G. J. W.; Cockerill, T. T.; Harrison, R.; Ferguson, M. C.; Göransson, B.; Harland, L. A.; Vugts, J. H.; Wiecherink, R.

1999-01-01

The article reviews the main results of the recent European research project Opti-OWECS (Structural and Economic Optimisation of Bottom-Mounted Offshore Wind Energy Converters'), which has significantly improved the understanding of the requirements for a large-scale utilization of offshore wind energy. An integrated design approach was demonstrated for a 300 MW offshore wind farm at a demanding North Sea site. Several viable solutions were obtained and one was elaborated to include the design of all major components. Simultaneous structural and economic optimization took place during the different design stages. An offshore wind energy converter founded on a soft-soft monopile was tailored with respect to the distinct characteristics of dynamic wind and wave loading. The operation and maintenance behaviour of the wind farm was analysed by Monte Carlo simulations. With an optimized maintenance strategy and suitable hardware a high availability was achieved. Based upon the experience from the structural design, cost models for offshore wind farms were developed and linked to a European database of the offshore wind energy potential. This enabled the first consistent estimate of cost of offshore wind energy for entire European regions.

78 FR 41791 - Combined Notice of Filings #2

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-11

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Combined Notice of Filings 2 Take notice.... Applicants: Sundevil Power Holdings, LLC, Castleton Energy Services, LLC, Castleton Power, LLC. Description...-1971-011. Applicants: Diablo Winds, LLC, FPL Energy Cabazon Wind, LLC, FPL Energy Green Power Wind, LLC...

Wind power live! An interactive exhibit and related programs about wind generated energy at the Science Museum of Minnesota. Final performance report, February 1, 1995--September 30, 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamilton, P.

The final performance report for the Wind Power Live! museum exhibit summarizes the goals and outcomes for the project. Project goals included: (1) help museum visitors understand why wind is being considered as a significant energy source; (2) enable visualization of the dynamics and power output of turbines; (3) exhibit a working wind turbine; (4) showcase wind as a technological success story; (5) consider the environmental costs and benefits of wind energy; (6) examine the economics of wind power, and (7) explain some of the limits to wind power as a commercial energy source. The methods of meeting the projectmore » goals through the museum exhibit are briefly outlined in the report. Goal number three, to introduce a working wind turbine, was dropped from the final project.« less

2017 Publications Demonstrate Advancements in Wind Energy Research

DOE Office of Scientific and Technical Information (OSTI.GOV)

In 2017, wind energy experts at the National Renewable Energy Laboratory (NREL) made significant strides to advance wind energy. Many of these achievements were presented in articles published in scientific and engineering journals and technical reports that detailed research accomplishments in new and progressing wind energy technologies. During fiscal year 2017, NREL wind energy thought leaders shared knowledge and insights through 45 journal articles and 25 technical reports, benefiting academic and national-lab research communities; industry stakeholders; and local, state, and federal decision makers. Such publications serve as important outreach, informing the public of how NREL wind research, analysis, and deploymentmore » activities complement advanced energy growth in the United States and around the world. The publications also illustrate some of the noteworthy outcomes of U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) and Laboratory Directed Research and Development funding, as well as funding and facilities leveraged through strategic partnerships and other collaborations.« less

A methodology for optimization of wind farm allocation under land restrictions: the case of the Canary Islands

NASA Astrophysics Data System (ADS)

Castaño Moraga, C. A.; Suárez Santana, E.; Sabbagh Rodríguez, I.; Nebot Medina, R.; Suárez García, S.; Rodríguez Alvarado, J.; Piernavieja Izquierdo, G.; Ruiz Alzola, J.

2010-09-01

Wind farms authorization and power allocations to private investors promoting wind energy projects requires some planification strategies. This issue is even more important under land restrictions, as it is the case of Canary Islands, where numerous specially protected areas are present for environmental reasons and land is a scarce resource. Aware of this limitation, the Regional Government of Canary Islands designed the requirements of a public tender to grant licences to install new wind farms trying to maximize the energy produced in terms of occupied land. In this paper, we detail the methodology developed by the Canary Islands Institute of Technology (ITC, S.A.) to support the work of the technical staff of the Regional Ministry of Industry, responsible for the evaluation of a competitive tender process for awarding power lincenses to private investors. The maximization of wind energy production per unit of area requires an exhaustive wind profile characterization. To that end, wind speed was statistically characterized by means of a Weibull probability density function, which mainly depends on two parameters: the shape parameter K, which determines the slope of the curve, and the average wind speed v , which is a scale parameter. These two parameters have been evaluated at three different heights (40,60,80 m) over the whole canarian archipelago, as well as the main wind speed direction. These parameters are available from the public data source Wind Energy Map of the Canary Islands [1]. The proposed methodology is based on the calculation of an initially defined Energy Efficiency Basic Index (EEBI), which is a performance criteria that weighs the annual energy production of a wind farm per unit of area. The calculation of this parameter considers wind conditions, windturbine characteristics, geometry of windturbine distribution in the wind farm (position within the row and column of machines), and involves four steps: Estimation of the energy produced by every windturbine as if it were isolated from all the other machines of the wind farm, using its power curve and the statistical characterization of the wind profile at the site. Estimation of energy losses due to affections caused by other windturbine in the same row and missalignment with respect to the main wind speed direction. Estimation of energy losses due to affections induced by windturbines located upstream. EEBI calculation as the ratio between the annual energy production and the area occupied by the wind farm, as a function of wind speed profile and wind turbine characteristics. Computations involved above are modeled under a System Theory characterization

Introduction Wind farms in complex terrains: an introduction.

PubMed

Alfredsson, P H; Segalini, A

2017-04-13

Wind energy is one of the fastest growing sources of sustainable energy production. As more wind turbines are coming into operation, the best locations are already becoming occupied by turbines, and wind-farm developers have to look for new and still available areas-locations that may not be ideal such as complex terrain landscapes. In these locations, turbulence and wind shear are higher, and in general wind conditions are harder to predict. Also, the modelling of the wakes behind the turbines is more complicated, which makes energy-yield estimates more uncertain than under ideal conditions. This theme issue includes 10 research papers devoted to various fluid-mechanics aspects of using wind energy in complex terrains and illustrates recent progress and future developments in this important field.This article is part of the themed issue 'Wind energy in complex terrains'. © 2017 The Author(s).

Wind energy utilization: A bibliography with abstracts - Cumulative volume 1944/1974

NASA Technical Reports Server (NTRS)

1975-01-01

Bibliography, up to 1974 inclusive, of articles and books on utilization of wind power in energy generation. Worldwide literature is surveyed, and short abstracts are provided in many cases. The citations are grouped by subject: (1) general; (2) utilization; (3) wind power plants; (4) wind power generators (rural, synchronous, remote station); (5) wind machines (motors, pumps, turbines, windmills, home-built); (6) wind data and properties; (7) energy storage; and (8) related topics (control and regulation devices, wind measuring devices, blade design and rotors, wind tunnel simulation, aerodynamics). Gross-referencing is aided by indexes of authors, corporate sources, titles, and keywords.

Wind energy applications for municipal water services: Opportunities, situational analyses, and case studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flowers, L.; Miner-Nordstrom, L.

2006-01-01

As communities grow, greater demands are placed on water supplies, wastewater services, and the electricity needed to power the growing water services infrastructure. Water is also a critical resource for thermoelectric power plants. Future population growth in the United States is therefore expected to heighten competition for water resources. Especially in arid U.S. regions, communities may soon face hard choices with respect to water and electric power. Many parts of the United States with increasing water stresses also have significant wind energy resources. Wind power is the fastest-growing electric generation source in the United States and is decreasing in costmore » to be competitive with thermoelectric generation. Wind energy can potentially offer communities in water-stressed areas the option of economically meeting increasing energy needs without increasing demands on valuable water resources. Wind energy can also provide targeted energy production to serve critical local water-system needs. The U.S. Department of Energy (DOE) Wind Energy Technologies Program has been exploring the potential for wind power to meet growing challenges for water supply and treatment. The DOE is currently characterizing the U.S. regions that are most likely to benefit from wind-water applications and is also exploring the associated technical and policy issues associated with bringing wind energy to bear on water resource challenges.« less

Status report of wind energy programs in the Philippines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benavidez, P.J.

1996-12-31

This paper discusses the wind resource assessment activities being undertaken by the National Power Corporation at the extreme northern part of Luzon island. Preliminary results from the 10-month wind data are presented. This will give prospective wind developers all idea oil tile vast resources of wind energy available in the northern part of the country. This paper will also discuss briefly the stand-alone 10 kW wind turbine system that was commissioned early this year and the guidelines being drafted for the entry of new and renewable energy sources in the country`s energy generation mix. 4 figs., 1 tab.

77 FR 5002 - Wind and Water Power Program

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-01

... with offshore wind turbine support structures, will not be accepted. DOE may fund specific technical... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy Wind and Water Power Program...-solicitation public meeting, request for comment. SUMMARY: The Wind and Water Power Program (WWPP) within the U...

76 FR 17120 - Supplemental Notice Requesting Comments

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-28

... Wind VII, LLC Alta Wind VIII, LLC Alta Windpower Development, LLC TGP Development Company, LLC Puget... Creek Wind Energy, LLC RC11-1-000 Milford Wind Corridor Phase I, LLC........ RC11-2-000 SunZia... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Supplemental Notice Requesting Comments...

Wind energy education projects. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ziegler, P.; Conlon, T.R.; Arcadi, T.

Two projects under DOE's Small-Scale Appropriate Energy Technology Grants Program have educated the public in a hands on way about wind energy systems. The first was awarded to Peter Ziegler of Berkeley, California, to design and build a walk-through exhibition structure powered by an adjoining wind-generator. This Wind Energy Pavilion was erected at Fort Funston in the Golden Gate National Recreation Area. It currently serves both as an enclosure for batteries and a variety of monitoring instruments, and as a graphic environment where the public can learn about wind energy. The second project, entitled Wind and Kid Power, involved anmore » educational program for a classroom of first through third grades in the Vallejo, Unified School District. The students studied weather, measured wind speeds and built small models of wind machines. They also built a weather station, and learned to use weather instruments. The grant funds enabled them to actually build and erect a Savonius wind machine at the Loma Vista Farm School.« less

Evaluation of Wind Energy Production in Texas using Geographic Information Systems (GIS)

NASA Astrophysics Data System (ADS)

Ferrer, L. M.

2017-12-01

Texas has the highest installed wind capacity in the United States. The purpose of this research was to estimate the theoretical wind turbine energy production and the utilization ratio of wind turbines in Texas. Windfarm data was combined applying Geographic Information System (GIS) methodology to create an updated GIS wind turbine database, including location and technical specifications. Applying GIS diverse tools, the windfarm data was spatially joined with National Renewable Energy Laboratory (NREL) wind data to calculate the wind speed at each turbine hub. The power output for each turbine at the hub wind speed was evaluated by the GIS system according the respective turbine model power curve. In total over 11,700 turbines are installed in Texas with an estimated energy output of 60 GWh per year and an average utilization ratio of 0.32. This research indicates that applying GIS methodologies will be crucial in the growth of wind energy and efficiency in Texas.

Collected Papers on Wind Turbine Technology

NASA Technical Reports Server (NTRS)

Spera, David A. (Editor)

1995-01-01

R and D projects on electricity generating wind turbines were conducted at the NASA Lewis Research Center from 1973 to 1988. Most projects were sponsored by the U.S. Department of Energy (DOE), a major element of its Federal Wind Energy Program. Another large wind turbine project was by the Bureau of Reclamation of the U.S. Department of Interior (DOI). From 1988 to 1995, NASA wind energy activities have been directed toward the transfer of technology to commercial and academic organizations. As part of these technology transfer activities, previously unpublished manuscripts have been assembled and presented here to share the wind turbine research results with the wind energy community. A variety of wind turbine technology topics are discussed: Wind and wake models; Airfoil properties; Structural analysis and testing; Control systems; Variable speed generators; and acoustic noise. Experimental and theoretical results are discussed.

Test Plan for the Wake Steering Experiment at the Scaled Wind Farm Technology (SWiFT) Facility.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naughton, Brian Thomas

This document is a test plan describing the objectives, configuration, procedures, reporting, roles, and responsibilities for conducting the joint Sandia National Laboratories and National Renewable Energy Laboratory Wake Steering Experiment at the Sandia Scaled Wind Farm Technology (SWiFT) facility near Lubbock, Texas in 2016 and 2017 . The purpose of this document is to ensure the test objectives and procedures are sufficiently detailed such that al l involved personnel are able to contribute to the technical success of the test. This document is not intended to address safety explicitly which is addressed in a separate document listed in the referencesmore » titled Sandia SWiFT Facility Site Operations Manual . Both documents should be reviewed by all test personnel.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shahidehpour, Mohammad

Integrating 20% or more wind energy into the system and transmitting large sums of wind energy over long distances will require a decision making capability that can handle very large scale power systems with tens of thousands of buses and lines. There is a need to explore innovative analytical and implementation solutions for continuing reliable operations with the most economical integration of additional wind energy in power systems. A number of wind integration solution paths involve the adoption of new operating policies, dynamic scheduling of wind power across interties, pooling integration services, and adopting new transmission scheduling practices. Such practicesmore » can be examined by the decision tool developed by this project. This project developed a very efficient decision tool called Wind INtegration Simulator (WINS) and applied WINS to facilitate wind energy integration studies. WINS focused on augmenting the existing power utility capabilities to support collaborative planning, analysis, and wind integration project implementations. WINS also had the capability of simulating energy storage facilities so that feasibility studies of integrated wind energy system applications can be performed for systems with high wind energy penetrations. The development of WINS represents a major expansion of a very efficient decision tool called POwer Market Simulator (POMS), which was developed by IIT and has been used extensively for power system studies for decades. Specifically, WINS provides the following superiorities; (1) An integrated framework is included in WINS for the comprehensive modeling of DC transmission configurations, including mono-pole, bi-pole, tri-pole, back-to-back, and multi-terminal connection, as well as AC/DC converter models including current source converters (CSC) and voltage source converters (VSC); (2) An existing shortcoming of traditional decision tools for wind integration is the limited availability of user interface, i.e., decision results are often text-based demonstrations. WINS includes a powerful visualization tool and user interface capability for transmission analyses, planning, and assessment, which will be of great interest to power market participants, power system planners and operators, and state and federal regulatory entities; and (3) WINS can handle extended transmission models for wind integration studies. WINS models include limitations on transmission flow as well as bus voltage for analyzing power system states. The existing decision tools often consider transmission flow constraints (dc power flow) alone which could result in the over-utilization of existing resources when analyzing wind integration. WINS can be used to assist power market participants including transmission companies, independent system operators, power system operators in vertically integrated utilities, wind energy developers, and regulatory agencies to analyze economics, security, and reliability of various options for wind integration including transmission upgrades and the planning of new transmission facilities. WINS can also be used by industry for the offline training of reliability and operation personnel when analyzing wind integration uncertainties, identifying critical spots in power system operation, analyzing power system vulnerabilities, and providing credible decisions for examining operation and planning options for wind integration. Researches in this project on wind integration included (1) Development of WINS; (2) Transmission Congestion Analysis in the Eastern Interconnection; (3) Analysis of 2030 Large-Scale Wind Energy Integration in the Eastern Interconnection; (4) Large-scale Analysis of 2018 Wind Energy Integration in the Eastern U.S. Interconnection. The research resulted in 33 papers, 9 presentations, 9 PhD degrees, 4 MS degrees, and 7 awards. The education activities in this project on wind energy included (1) Wind Energy Training Facility Development; (2) Wind Energy Course Development.« less

75 FR 68780 - Cedar Creek Wind Energy, LLC; Notice of Filing

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-09

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. RC11-1-000] Cedar Creek Wind Energy, LLC; Notice of Filing November 2, 2010. Take notice that on October 27, 2010, Cedar Creek Wind Energy, LLC (Cedar Creek) filed an appeal with the Federal Energy Regulatory Commission (Commission) of...

75 FR 74037 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-30

...-000. Applicants: FPL Energy Montezuma Wind, LLC. Description: FPL Energy Montezuma Wind, LLC submits tariff filing per 35.12: FPL Energy Montezuma Wind, LLC MBR Application to be effective 11/20/2010. Filed... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Combined Notice of Filings 1 November 22...

76 FR 30934 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-27

.... Applicants: Synergics Roth Rock Wind Energy, LLC, Synergics Roth Rock North Wind Energy, L, Gestamp Eolica S.L. Description: Amendment to Application of Synergics Roth Rock Wind Energy, LLC, et. al. Filed Date... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Combined Notice of Filings 1 Take notice...

75 FR 54602 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-08

... Wind Energy Marketing, LLC. Description: First Wind Energy Marketing, LLC submits tariff filing per 35.12: First Wind Energy Marketing MBR Baseline to be effective 8/ 30/2010. Filed Date: 08/30/2010... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Combined Notice of Filings 1 August 31...

An integrated assessment for wind energy in Lake Michigan coastal counties.

PubMed

Nordman, Erik; VanderMolen, Jon; Gajewski, Betty; Isely, Paul; Fan, Yue; Koches, John; Damm, Sara; Ferguson, Aaron; Schoolmaster, Claire

2015-04-01

The benefits and challenges of onshore and offshore wind energy development were assessed for a 4-county area of coastal Michigan. Economic, social, environmental, and spatial dimensions were considered. The coastal counties have suitable wind resources for energy development, which could contribute toward Michigan's 10% renewable energy standard. Wind energy is cost-effective with contract prices less than the benchmark energy price of a new coal-fired power plant. Constructing a 100 MW wind farm could have a $54.7 million economic impact. A patchwork of township-level zoning ordinances regulates wind energy siting. Voluntary collaborations among adjacent townships standardizing the ordinances could reduce regulatory complexity. A Delphi Inquiry on offshore wind energy in Lake Michigan elicited considerable agreement on its challenges, but little agreement on the benefits to coastal communities. Offshore turbines could be acceptable to the participants if they reduced pollution, benefited coastal communities, involved substantial public participation, and had minimal impact on property values and tourism. The US Coast Guard will take a risk-based approach to evaluating individual offshore developments and has no plans to issue blanket restrictions around the wind farms. Models showed that using wind energy to reach the remainder of the 10% renewable energy standard could reduce SO2 , NOx , and CO2 pollution by 4% to 7%. Turbines are highly likely to impact the area's navigational and defense radar systems but planning and technological upgrades can reduce the impact. The integrated assessment shows that responsible wind energy development can enhance the quality of life by reducing air pollution and associated health problems and enhancing economic development. Policies could reduce the negative impacts to local communities while preserving the benefits to the broader region. © 2015 SETAC.

Wind Energy Finance (WEF): An Online Calculator for Economic Analysis of Wind Projects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2004-02-01

This brochure provides an overview of Wind Energy Finance (WEF), a free online cost of energy calculator developed by the National Renewable Energy Laboratory that provides quick, detailed economic evaluation of potential utility-scale wind energy projects. The brochure lists the features of the tool, the inputs and outputs that a user can expect, visuals of the screens and a Cash Flow Results table, and contact information.

77 FR 61597 - Avalon Wind, LLC; Avalon Wind 2, LLC; Catalina Solar, LLC; Catalina Solar 2, LLC; Pacific Wind...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-10

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL12-109-000] Avalon Wind, LLC; Avalon Wind 2, LLC; Catalina Solar, LLC; Catalina Solar 2, LLC; Pacific Wind Lessee, LLC; Pacific Wind 2, LLC; Valentine Solar, LLC; EDF Renewable Development, Inc.; Notice of Petition for Declaratory...

Careers in Wind Energy

ERIC Educational Resources Information Center

Liming, Drew; Hamilton, James

2011-01-01

As a common form of renewable energy, wind power is generating more than just electricity. It is increasingly generating jobs for workers in many different occupations. Many workers are employed on wind farms: areas where groups of wind turbines produce electricity from wind power. Wind farms are frequently located in the midwestern, western, and…

Field Line Mapping of the Polar Cap Neutral Density Anomaly

NASA Astrophysics Data System (ADS)

Sutton, E. K.; Lin, C. S.; Huang, C. Y.; Cooke, D. L.

2016-12-01

Polar cap neutral density anomaly (PCNDA) events of localized density enhancement with a half size around 700-1000 km had been frequently detected by CHAMP satellite at around 400 km during major magnetic storms with Dst < -100 nT. Density enhancement is probably produced via Joule heating of the thermosphere when a significant amount of energy is deposited in the polar cap. We have identified 12 PCNDA events measured by CHAMP during two major magnetic storms including one initiated by a large solar wind pressure pulse. Their density anomaly locations are found to scatter randomly within the polar circle of 80o magnetic latitude in the geomagnetic coordinate. However after transformed to the Geocentric Solar Wind (GSW) coordinates, their locations become aligned in the direction of solar wind velocity. To better understand the polar cap energy deposition we trace magnetic field lines to the magnetosphere up to 30 earth radii from the ionosphere at 400 km using the data-based Tsyganenko T95 and TS05 magnetic field models. Field line tracing is performed in the GSW coordinate along the CHAMP orbit as well as for the whole polar cap. Each traced magnetic field line is classified into one of the three categories, (1) magnetosphere closed field line (MC) crossing the equatorial plane within 30 earth radii, (2) open field line connected to the magnetopause (MP), or (3) open field line connected to the magnetotail lobe (MT). For nine PCNDA events among the 10 events that we are able to conduct tracing, field lines originated from the density anomaly regions are classified as MT. Only one outlier event in association with a very large IMF BZ is classified as MP. Furthermore the separation angle between the density anomaly peak and the MP-MT field line separation point at 400 km on the X- and Z-axes meridian plane varies from -4o to 16o. Based on these results we speculate that convective electric fields and field aligned currents in the ionosphere might be enhanced near the MP-MT separation point during magnetic storms, resulting in intense localized Joule heating of the thermosphere.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fields, Jason; Tinnesand, Heidi; Baring-Gould, Ian

In support of the U.S. Department of Energy (DOE) Wind and Water Power Technologies Office (WWPTO) goals, researchers from DOE's National Renewable Energy Laboratory (NREL), National Wind Technology Center (NWTC) are investigating the Distributed Wind Resource Assessment (DWRA) process, which includes pre-construction energy estimation as well as turbine site suitability assessment. DWRA can have a direct impact on the Wind Program goals of maximizing stakeholder confidence in turbine performance and safety as well as reducing the levelized cost of energy (LCOE). One of the major components of the LCOE equation is annual energy production. DWRA improvements can maximize the annualmore » energy production, thereby lowering the overall LCOE and improving stakeholder confidence in the distributed wind technology sector by providing more accurate predictions of power production. Over the long term, one of the most significant benefits of a more defined DWRA process could be new turbine designs, tuned to site-specific characteristics that will help the distributed wind industry follow a similar trajectory to the low-wind-speed designs in the utility-scale industry sector. By understanding the wind resource better, the industry could install larger rotors, capture more energy, and as a result, increase deployment while lowering the LCOE. a direct impact on the Wind Program goals of maximizing stakeholder confidence in turbine performance and safety as well as reducing the levelized cost of energy (LCOE). One of the major components of the LCOE equation is annual energy production. DWRA improvements can maximize the annual energy production, thereby lowering the overall LCOE and improving stakeholder confidence in the distributed wind technology sector by providing more accurate predictions of power production. Over the long term, one of the most significant benefits of a more defined DWRA process could be new turbine designs, tuned to site-specific characteristics that will help the distributed wind industry follow a similar trajectory to the low-wind-speed designs in the utility-scale industry sector. By understanding the wind resource better, the industry could install larger rotors, capture more energy, and as a result, increase deployment while lowering the LCOE.« less

The importance of dynamic stall in aerodynamic modeling of the Darrieus rotor

NASA Astrophysics Data System (ADS)

Fraunie, P.; Beguier, C.; Paraschivoiu, I.

The CAARDEX program is defined for analyzing the behavior of Darrieus wind turbines in terms of the Reynolds number, the geometrical characteristics of the wind turbine and the spreading of the stream tubes traversing the rotor volume. It is demonstrated that the maximum power conversion efficiency of the Darrieus rotor is 0.4, with the energy capture being divided at a 4:1 ratio upstream to downstream rotor. The model shows that the velocity induced on the rotor is a function of the specific velocity and solidity, and that previous stream tube theories are valid only at low values of these parameters. CARDAAX treats the rotor disk in terms of horizontal slices of stream tubes modeled separately for the upstream and downstream segments. Account is taken of the velocity profile in the atmospheric boundary layer, which can vary significantly in the case of large wind turbines, i.e., several hundred feet high. When applied to predicting the performance of a 1 kW, 2.6 m diam prototype Darrieus wind turbine in a 10 mps flow, fair agreement is obtained for power capture/wind velocity and cyclic aerodynamic forces. Additional flow visualization data is provided to illustrate the production of turbulence in the form of vortices shed between the blades.

Coaxial Compound Helicopter for Confined Urban Operations

DTIC Science & Technology

2016-01-22

climb or descent power for the aircraft) is obtained from the wind axis drag force and rotor velocity: ! Pp = "XV . The induced power is...speed. The induced and profile power cannot be measured separately in a wind tunnel or flight test, only the sum is available from ! P i + P o = P...XV (if the rotor wind -axis drag force ! X is measured or estimated). Therefore analysis is used to separate induced and profile power. In this

A Combined Energy Management Algorithm for Wind Turbine/Battery Hybrid System

NASA Astrophysics Data System (ADS)

Altin, Necmi; Eyimaya, Süleyman Emre

2018-03-01

From an energy management standpoint, natural phenomena such as solar irradiation and wind speed are uncontrolled variables, so the correlation between the energy generated by renewable energy sources and energy demand cannot always be predicted. For this reason, energy storage systems are used to provide more efficient renewable energy systems. In these systems, energy management systems are used to control the energy storage system and establish a balance between the generated power and the power demand. In addition, especially in wind turbines, rapidly varying wind speeds cause wind power fluctuations, which threaten the power system stability, especially at high power levels. Energy storage systems are also used to mitigate the power fluctuations and sustain the power system's stability. In these systems, another controller which controls the energy storage system power to mitigate power fluctuations is required. These two controllers are different from each other. In this study, a combined energy management algorithm is proposed which can perform both as an energy control system and a power fluctuation mitigation system. The proposed controller is tested with wind energy conversion system modeled in MATLAB/Simulink. Simulation results show that the proposed controller acts as an energy management system while, at the same time, mitigating power fluctuations.

Shifts in wind energy potential following land-use driven vegetation dynamics in complex terrain.

PubMed

Fang, Jiannong; Peringer, Alexander; Stupariu, Mihai-Sorin; Pǎtru-Stupariu, Ileana; Buttler, Alexandre; Golay, Francois; Porté-Agel, Fernando

2018-10-15

Many mountainous regions with high wind energy potential are characterized by multi-scale variabilities of vegetation in both spatial and time dimensions, which strongly affect the spatial distribution of wind resource and its time evolution. To this end, we developed a coupled interdisciplinary modeling framework capable of assessing the shifts in wind energy potential following land-use driven vegetation dynamics in complex mountain terrain. It was applied to a case study area in the Romanian Carpathians. The results show that the overall shifts in wind energy potential following the changes of vegetation pattern due to different land-use policies can be dramatic. This suggests that the planning of wind energy project should be integrated with the land-use planning at a specific site to ensure that the expected energy production of the planned wind farm can be reached over its entire lifetime. Moreover, the changes in the spatial distribution of wind and turbulence under different scenarios of land-use are complex, and they must be taken into account in the micro-siting of wind turbines to maximize wind energy production and minimize fatigue loads (and associated maintenance costs). The proposed new modeling framework offers, for the first time, a powerful tool for assessing long-term variability in local wind energy potential that emerges from land-use change driven vegetation dynamics over complex terrain. Following a previously unexplored pathway of cause-effect relationships, it demonstrates a new linkage of agro- and forest policies in landscape development with an ultimate trade-off between renewable energy production and biodiversity targets. Moreover, it can be extended to study the potential effects of micro-climatic changes associated with wind farms on vegetation development (growth and patterning), which could in turn have a long-term feedback effect on wind resource distribution in mountainous regions. Copyright © 2018 Elsevier B.V. All rights reserved.

Current Sheets in Pulsar Magnetospheres and Winds: Particle Acceleration and Pulsed Gamma Ray Emission

NASA Astrophysics Data System (ADS)

Arons, Jonathan

The research proposed addresses understanding of the origin of non-thermal energy in the Universe, a subject beginning with the discovery of Cosmic Rays and continues, including the study of relativistic compact objects - neutron stars and black holes. Observed Rotation Powered Pulsars (RPPs) have rotational energy loss implying they have TeraGauss magnetic fields and electric potentials as large as 40 PetaVolts. The rotational energy lost is reprocessed into particles which manifest themselves in high energy gamma ray photon emission (GeV to TeV). Observations of pulsars from the FERMI Gamma Ray Observatory, launched into orbit in 2008, have revealed 130 of these stars (and still counting), thus demonstrating the presence of efficient cosmic accelerators within the strongly magnetized regions surrounding the rotating neutron stars. Understanding the physics of these and other Cosmic Accelerators is a major goal of astrophysical research. A new model for particle acceleration in the current sheets separating the closed and open field line regions of pulsars' magnetospheres, and separating regions of opposite magnetization in the relativistic winds emerging from those magnetopsheres, will be developed. The currents established in recent global models of the magnetosphere will be used as input to a magnetic field aligned acceleration model that takes account of the current carrying particles' inertia, generalizing models of the terrestrial aurora to the relativistic regime. The results will be applied to the spectacular new results from the FERMI gamma ray observatory on gamma ray pulsars, to probe the physics of the generation of the relativistic wind that carries rotational energy away from the compact stars, illuminating the whole problem of how compact objects can energize their surroundings. The work to be performed if this proposal is funded involves extending and developing concepts from plasma physics on dissipation of magnetic energy in thin sheets of electric current that separate regions of differing magnetization into the domain of highly relativistic magnetic fields - those with energy density large compared to the rest mass energy of the charged particles - the plasma - caught in that field. The investigators will create theoretical and computational models of the magnetic dissipation - a form of viscous flow in the thin sheets of electric current that form in the magnetized regions around the rotating stars - using Particle in-Cell plasma simulations. These simulations use a large computer to solve the equations of motion of many charged particles - millions to billions in the research that will be pursued - to unravel the dissipation of those fields and the acceleration of beams of particles in the thin sheets. The results will be incorporated into macroscopic MHD models of the magnetic structures around the stars which determine the location and strength of the current sheets, so as to model and analyze the pulsed gamma ray emission seen from hundreds of Rotation Powered Pulsars. The computational models will be assisted by ``pencil and paper'' theoretical modeling designed to motivate and interpret the computer simulations, and connect them to the observations.

Maximum wind energy extraction strategies using power electronic converters

NASA Astrophysics Data System (ADS)

Wang, Quincy Qing

2003-10-01

This thesis focuses on maximum wind energy extraction strategies for achieving the highest energy output of variable speed wind turbine power generation systems. Power electronic converters and controls provide the basic platform to accomplish the research of this thesis in both hardware and software aspects. In order to send wind energy to a utility grid, a variable speed wind turbine requires a power electronic converter to convert a variable voltage variable frequency source into a fixed voltage fixed frequency supply. Generic single-phase and three-phase converter topologies, converter control methods for wind power generation, as well as the developed direct drive generator, are introduced in the thesis for establishing variable-speed wind energy conversion systems. Variable speed wind power generation system modeling and simulation are essential methods both for understanding the system behavior and for developing advanced system control strategies. Wind generation system components, including wind turbine, 1-phase IGBT inverter, 3-phase IGBT inverter, synchronous generator, and rectifier, are modeled in this thesis using MATLAB/SIMULINK. The simulation results have been verified by a commercial simulation software package, PSIM, and confirmed by field test results. Since the dynamic time constants for these individual models are much different, a creative approach has also been developed in this thesis to combine these models for entire wind power generation system simulation. An advanced maximum wind energy extraction strategy relies not only on proper system hardware design, but also on sophisticated software control algorithms. Based on literature review and computer simulation on wind turbine control algorithms, an intelligent maximum wind energy extraction control algorithm is proposed in this thesis. This algorithm has a unique on-line adaptation and optimization capability, which is able to achieve maximum wind energy conversion efficiency through continuously improving the performance of wind power generation systems. This algorithm is independent of wind power generation system characteristics, and does not need wind speed and turbine speed measurements. Therefore, it can be easily implemented into various wind energy generation systems with different turbine inertia and diverse system hardware environments. In addition to the detailed description of the proposed algorithm, computer simulation results are presented in the thesis to demonstrate the advantage of this algorithm. As a final confirmation of the algorithm feasibility, the algorithm has been implemented inside a single-phase IGBT inverter, and tested with a wind simulator system in research laboratory. Test results were found consistent with the simulation results. (Abstract shortened by UMI.)

Wind Resource Assessment of Gujarat (India)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Draxl, C.; Purkayastha, A.; Parker, Z.

India is one of the largest wind energy markets in the world. In 1986 Gujarat was the first Indian state to install a wind power project. In February 2013, the installed wind capacity in Gujarat was 3,093 MW. Due to the uncertainty around existing wind energy assessments in India, this analysis uses the Weather Research and Forecasting (WRF) model to simulate the wind at current hub heights for one year to provide more precise estimates of wind resources in Gujarat. The WRF model allows for accurate simulations of winds near the surface and at heights important for wind energy purposes.more » While previous resource assessments published wind power density, we focus on average wind speeds, which can be converted to wind power densities by the user with methods of their choice. The wind resource estimates in this study show regions with average annual wind speeds of more than 8 m/s.« less

Systems Engineering Workshop 2017 | Wind | NREL

Science.gov Websites

Energy for Wind Systems Today Cost and Value of Wind Power-Implications of Wind Turbine Design, János Aaron Smith, PPI Session II: Uncertainty Impacts on Wind Turbine Design and Performance Mitigation of Wind Turbine Design Load Uncertainties, Anand Natarajan, DTU Wind Energy Uncertainty in the Wind

76 FR 43682 - Shetek Wind Inc. Jeffers South, LLC Allco Renewable Energy Limited v. Midwest Independent...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-21

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL11-53-000] Shetek Wind Inc. Jeffers South, LLC Allco Renewable Energy Limited v. Midwest Independent Transmission System Operator, Inc...), Shetek Wind Inc., Jeffers South, LLC, and Allco Renewable Energy Limited (collectively Complainants...

Global energy regulation in the solar wind-magnetosphere-ionosphere system

NASA Technical Reports Server (NTRS)

Sato, T.

1985-01-01

Some basic concepts which are essential in the understanding of global energy regulation in the solar wind-magnetosphere-ionosphere system are introduced. The importance of line-tying concept is particularly emphasized in connection with the solar wind energy, energy release in the magnetosphere and energy dissipation in the ionosphere.

76 FR 62793 - Combined Notice Of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-11

.... Docket Numbers: ER11-4676-000. Applicants: Puget Sound Energy, Inc. Description: Puget Sound Energy, Inc...: NextEra Energy Montezuma II Wind, LLC. Description: NextEra Energy Montezuma II Wind, LLC submits tariff filing per 35.12: NextEra Energy Montezuma II Wind, LLC Market-Based Rate Tariff to be effective...

The problem of the second wind turbine - a note on a common but flawed wind power estimation method

NASA Astrophysics Data System (ADS)

Gans, F.; Miller, L. M.; Kleidon, A.

2010-06-01

Several recent wind power estimates suggest how this renewable resource can meet all of the current and future global energy demand with little impact on the atmosphere. These estimates are calculated using observed wind speeds in combination with specifications of wind turbine size and density to quantify the extractable wind power. Here we show that this common methodology is flawed because it does not account for energy removal by the turbines that is necessary to ensure the conservation of energy. We will first illustrate the common but flawed methodology using parameters from a recent global quantification of wind power in a simple experimental setup. For a small number of turbines at small scales, the conservation of energy hardly results in a difference when compared to the common method. However, when applied at large to global scales, the ability of radiative gradients to generate a finite amount of kinetic energy needs to be taken into account. Using the same experimental setup, we use the simplest method to ensure the conservation of energy to show a non-negligble decrease in wind velocity after the first turbine that will successively result in lower extraction of the downwind turbines. We then show how the conservation of energy inevitably results in substantially lower estimates of wind power at the global scale. Because conservation of energy is fundamental, we conclude that ultimately environmental constraints set the upper limit for wind power availability at the larger scale rather than detailed engineering specifications of the wind turbine design and placement.

Nonparametric Stochastic Model for Uncertainty Quantifi cation of Short-term Wind Speed Forecasts

NASA Astrophysics Data System (ADS)

AL-Shehhi, A. M.; Chaouch, M.; Ouarda, T.

2014-12-01

Wind energy is increasing in importance as a renewable energy source due to its potential role in reducing carbon emissions. It is a safe, clean, and inexhaustible source of energy. The amount of wind energy generated by wind turbines is closely related to the wind speed. Wind speed forecasting plays a vital role in the wind energy sector in terms of wind turbine optimal operation, wind energy dispatch and scheduling, efficient energy harvesting etc. It is also considered during planning, design, and assessment of any proposed wind project. Therefore, accurate prediction of wind speed carries a particular importance and plays significant roles in the wind industry. Many methods have been proposed in the literature for short-term wind speed forecasting. These methods are usually based on modeling historical fixed time intervals of the wind speed data and using it for future prediction. The methods mainly include statistical models such as ARMA, ARIMA model, physical models for instance numerical weather prediction and artificial Intelligence techniques for example support vector machine and neural networks. In this paper, we are interested in estimating hourly wind speed measures in United Arab Emirates (UAE). More precisely, we predict hourly wind speed using a nonparametric kernel estimation of the regression and volatility functions pertaining to nonlinear autoregressive model with ARCH model, which includes unknown nonlinear regression function and volatility function already discussed in the literature. The unknown nonlinear regression function describe the dependence between the value of the wind speed at time t and its historical data at time t -1, t - 2, … , t - d. This function plays a key role to predict hourly wind speed process. The volatility function, i.e., the conditional variance given the past, measures the risk associated to this prediction. Since the regression and the volatility functions are supposed to be unknown, they are estimated using nonparametric kernel methods. In addition, to the pointwise hourly wind speed forecasts, a confidence interval is also provided which allows to quantify the uncertainty around the forecasts.

A Framework for Statewide Analysis of Site Suitability, Energy Estimation, Life Cycle Costs, Financial Feasibility and Environmental Assessment of Wind Farms: A Case Study of Indiana

NASA Astrophysics Data System (ADS)

Kumar, Indraneel

In the last decade, Midwestern states including Indiana have experienced an unprecedented growth in utility scale wind energy farms. For example, by end of 2013, Indiana had 1.5 GW of wind turbines installed, which could provide electrical energy for as many as half-a-million homes. However, there is no statewide systematic framework available for the evaluation of wind farm impacts on endangered species, required necessary setbacks and proximity standards to infrastructure, and life cycle costs. This research is guided to fill that gap and it addresses the following questions. How much land is suitable for wind farm siting in Indiana given the constraints of environmental, ecological, cultural, settlement, physical infrastructure and wind resource parameters? How much wind energy can be obtained? What are the life cycle costs and economic and financial feasibility? Is wind energy production and development in a state an emission free undertaking? The framework developed in the study is applied to a case study of Indiana. A fuzzy logic based AHP (Analytic Hierarchy Process) spatial site suitability analysis for wind energy is formulated. The magnitude of wind energy that could be sited and installed comprises input for economic and financial feasibility analysis for 20-25 years life cycle of wind turbines in Indiana. Monte Carlo simulation is used to account for uncertainty and nonlinearity in various costs and price parameters. Impacts of incentives and cost variables such as production tax credits, costs of capital, and economies of scale are assessed. Further, an economic input-output (IO) based environmental assessment model is developed for wind energy, where costs from financial feasibility analysis constitute the final demand vectors. This customized model for Indiana is used to assess emissions for criteria air pollutants, hazardous air pollutants and greenhouse gases (GHG) across life cycle events of wind turbines. The findings of the case study include that, Indiana has adequate suitable land area available to locate wind farms with installed capacity between 11 and 51 GW if 100 meters high turbines are used. For a 1.5 MW standard wind turbine, financial feasibility analysis shows that production tax credits and property tax abatements are helpful for financial success in Indiana. Also, the wind energy is not entirely emission free if life cycle events of wind turbine manufacturing, production, installation, construction and decommissioning are considered. The research developed a replicable and integrated framework for statewide life cycle analysis of wind energy production accounting for uncertainty into the analyses. Considering the complexity of life cycle analysis and lack of state specific data on performance of wind turbines and wind farms, this study should be considered an intermediate step.

Flapping wing applied to wind generators

NASA Astrophysics Data System (ADS)

Colidiuc, Alexandra; Galetuse, Stelian; Suatean, Bogdan

2012-11-01

The new conditions at the international level for energy source distributions and the continuous increasing of energy consumption must lead to a new alternative resource with the condition of keeping the environment clean. This paper offers a new approach for a wind generator and is based on the theoretical aerodynamic model. This new model of wind generator helped me to test what influences would be if there will be a bird airfoil instead of a normal wind generator airfoil. The aim is to calculate the efficiency for the new model of wind generator. A representative direction for using the renewable energy is referred to the transformation of wind energy into electrical energy, with the help of wind turbines; the development of such systems lead to new solutions based on high efficiency, reduced costs and suitable to the implementation conditions.

Modeling energy production of solar thermal systems and wind turbines for installation at corn ethanol plants

NASA Astrophysics Data System (ADS)

Ehrke, Elizabeth

Nearly every aspect of human existence relies on energy in some way. Most of this energy is currently derived from fossil fuel resources. Increasing energy demands coupled with environmental and national security concerns have facilitated the move towards renewable energy sources. Biofuels like corn ethanol are one of the ways the U.S. has significantly reduced petroleum consumption. However, the large energy requirement of corn ethanol limits the net benefit of the fuel. Using renewable energy sources to produce ethanol can greatly improve its economic and environmental benefits. The main purpose of this study was to model the useful energy received from a solar thermal array and a wind turbine at various locations to determine the feasibility of applying these technologies at ethanol plants around the country. The model calculates thermal energy received from a solar collector array and electricity generated by a wind turbine utilizing various input data to characterize the equipment. Project cost and energy rate inputs are used to evaluate the profitability of the solar array or wind turbine. The current state of the wind and solar markets were examined to give an accurate representation of the economics of each industry. Eighteen ethanol plant locations were evaluated for the viability of a solar thermal array and/or wind turbine. All ethanol plant locations have long payback periods for solar thermal arrays, but high natural gas prices significantly reduce this timeframe. Government incentives will be necessary for the economic feasibility of solar thermal arrays. Wind turbines can be very profitable for ethanol plants in the Midwest due to large wind resources. The profitability of wind power is sensitive to regional energy prices. However, government incentives for wind power do not significantly change the economic feasibility of a wind turbine. This model can be used by current or future ethanol facilities to investigate or begin the planning process for a solar thermal array or wind turbine. The model is meant to aide in the planning stages of a renewable energy project, and advanced investigation will be needed to move forward with that project.

Wind energy.

PubMed

Leithead, W E

2007-04-15

From its rebirth in the early 1980s, the rate of development of wind energy has been dramatic. Today, other than hydropower, it is the most important of the renewable sources of power. The UK Government and the EU Commission have adopted targets for renewable energy generation of 10 and 12% of consumption, respectively. Much of this, by necessity, must be met by wind energy. The US Department of Energy has set a goal of 6% of electricity supply from wind energy by 2020. For this potential to be fully realized, several aspects, related to public acceptance, and technical issues, related to the expected increase in penetration on the electricity network and the current drive towards larger wind turbines, need to be resolved. Nevertheless, these challenges will be met and wind energy will, very likely, become increasingly important over the next two decades. An overview of the technology is presented.

Wind Energy Program Summary. Volume 2: Research summaries, fiscal year 1988

NASA Astrophysics Data System (ADS)

1989-04-01

Activities by the Federal Wind Energy program since the early 1980s have focused on developing a technology base necessary for industry to demonstrate the viability of wind energy as an alternative energy supply. The Federal Wind Energy Program's research has targeted the sciences of wind turbine dynamics and the development of advanced components and systems. These efforts have resulted in major advancements toward the development and commercialization of wind technology as an alternative energy source. The installation of more than 16,000 wind turbines in California by the end of 1987 provides evidence that commercial use of wind energy technology can be a viable source of electric power. Research in wind turbine sciences has focused on atmospheric fluid dynamics, aerodynamics, and structural dynamics. As outlines in the projects that are described in this document, advancements in atmospheric fluid dynamics have been made through the development and refinement of wind characterization models and wind/rotor interaction prediction codes. Recent gains in aerodynamics can be attributed to a better understanding of airfoil operations, using innovative research approaches such as flow-visualization techniques. Qualitative information and data from laboratory and field tests are being used to document fatigue damage processes. These data are being used to develop new theories and data bases for structural dynamics, and will help to achieve long-term unit life and lower capital and maintenance costs. Material characterization and modeling techniques have been improved to better analyze effects of stress and fatigue on system components.

Conversion of magnetic field energy into kinetic energy in the solar wind

NASA Technical Reports Server (NTRS)

Whang, Y. C.

1972-01-01

The outflow of the solar magnetic field energy (the radial component of the Poynting vector) per steradian is inversely proportional to the solar wind velocity. It is a decreasing function of the heliocentric distance. When the magnetic field effect is included in the one-fluid model of the solar wind, the transformation of magnetic field energy into kinetic energy during the expansion process increases the solar wind velocity at 1 AU by 17 percent.

Where there is a wind, there is a way

NASA Technical Reports Server (NTRS)

Mosher, C. A.

1973-01-01

A shift in USA energy policy from oil or natural gases to thermonuclear fission and solar energy is predicted. A massive diversified energy research and development effort to productively harness the energy in the winds is outlined to develop commercially feasible wind energy conversion systems - considered a form of solar energy - in the near future.

Wind speed time series reconstruction using a hybrid neural genetic approach

NASA Astrophysics Data System (ADS)

Rodriguez, H.; Flores, J. J.; Puig, V.; Morales, L.; Guerra, A.; Calderon, F.

2017-11-01

Currently, electric energy is used in practically all modern human activities. Most of the energy produced came from fossil fuels, making irreversible damage to the environment. Lately, there has been an effort by nations to produce energy using clean methods, such as solar and wind energy, among others. Wind energy is one of the cleanest alternatives. However, the wind speed is not constant, making the planning and operation at electric power systems a difficult activity. Knowing in advance the amount of raw material (wind speed) used for energy production allows us to estimate the energy to be generated by the power plant, helping the maintenance planning, the operational management, optimal operational cost. For these reasons, the forecast of wind speed becomes a necessary task. The forecast process involves the use of past observations from the variable to forecast (wind speed). To measure wind speed, weather stations use devices called anemometers, but due to poor maintenance, connection error, or natural wear, they may present false or missing data. In this work, a hybrid methodology is proposed, and it uses a compact genetic algorithm with an artificial neural network to reconstruct wind speed time series. The proposed methodology reconstructs the time series using a ANN defined by a Compact Genetic Algorithm.

77 FR 76023 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-26

..., UNS Electric, Inc., UniSource Energy Development Company. Description: Triennial Market Power Update... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Combined Notice of Filings 1 Take notice... County Wind Energy, LLC. Description: Gray County Wind and Ensign Wind Shared Facilities Agreement to be...

NSF presentation. [summary on energy conversion research program

NASA Technical Reports Server (NTRS)

Morse, F. H.

1973-01-01

Wind energy conversion research is considered in the framework of the national energy problem. Research and development efforts for the practical application of solar energy -- including wind energy -- as alternative energy supplies are assessed in: (1) Heating and cooling of buildings; (2) photovoltaic energy conversion; (3) solar thermal energy conversion; (4) wind energy conversion; (5) ocean thermal energy conversion; (6) photosynthetic production of organic matter; and (7) conversion of organic matter into fuels.

Potentiality of wind power generation along the Bangladesh coast

NASA Astrophysics Data System (ADS)

Shaikh, Md. Akramuzzaman; Chowdhury, K. M. Azam; Sen, Sukanta; Islam, Mohammad Masudul

2017-12-01

Nowadays Bangladesh is facing the problem with electricity as the production is less comparing to the demand. A significant amount of electricity is consumed in urban areas especially by industries whereas in rural or coastal areas most of the people are not having it. Around 40 millions of people living in the 724 km long coast in Bangladesh. Moreover, it is surprising that throughout the year there is sufficient wind blow in coastal areas by which we can produce a massive amount of electricity. However, day by day the utilization of wind energy is increasing in the world which reduces costs of renewable energy technology, improves efficiency. It would be a good alternative solution instead of dependency on natural gas. Wind energy is mainly potential in coastal and offshore areas with strong wind regimes. Wind energy is vital for ensuring a green energy for the future. The agricultural land of Bangladesh needs the supply of water at right time for better yielding. The installation of windmills will be very much convenient for operating the water supply pumps. This research highlights the possibility of wind energy and describes the necessary steps to implement and develop wind energy sector in Bangladesh by using other's successful ideas. Supportive policies, rules, and decree can be applied to make government, non-government organization, and donor organizations work together to develop wind energy sector in Bangladesh.

Hexcrete Tower for Harvesting Wind Energy at Taller Hub Heights - Budget Period 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sritharan, Sri

Interest in designing taller towers for wind energy production in the United States (U.S.) has been steadily growing. In May 2015, it was revealed that taller towers will make wind energy production a reality in all 50 states, including some states that have nearly zero renewables in their energy portfolio. Facilitating wind energy production feasibility in all 50 states will no doubt contribute to increasing the electricity produced by wind from 4.5% in 2013 to a targeted scenario of 35% by 2050 in the Wind Vision report. This project focuses on the Hexcrete tower concept developed for tall towers usingmore » High Strength Concrete (HSC) and/or Ultra-High Performance Concrete (UHPC). Among other benefits, the Hexcrete concept overcomes transportation and logistical challenges, thus facilitating construction of towers with hub heights of 100-m (328-ft) and higher. The goal of this project is to facilitate widespread deployment of Hexcrete towers for harvesting wind energy at 120 to 140-m (394 to 459-ft) hub heights and reduce the Levelized Cost of Energy (LCOE) of wind energy production in the U.S. The technical scope of the project includes detailed design and optimization of at least three wind turbine towers using the Hexcrete concept together with experimental validation and LCOE analyses and development of a commercialization plan.« less

Final Technical Report Laramie County Community College: Utility-Scale Wind Energy Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Douglas P. Cook

The Utility-Scale Wind Energy Technology U.S. Department of Energy (DOE) grant EE0000538, provided a way ahead for Laramie County Community College (LCCC) to increase educational and training opportunities for students seeking an Associate of Applied Science (AAS) or Associate of Science (AS) degree in Wind Energy Technology. The DOE grant enabled LCCC to program, schedule, and successfully operate multiple wind energy technology cohorts of up to 20-14 students per cohort simultaneously. As of this report, LCCC currently runs four cohorts. In addition, the DOE grant allowed LCCC to procure specialized LABVOLT electronic equipment that directly supports is wind energy technologymore » curriculum.« less

Characterizing a Wind Energy Converter's Wake in distinct ABL Conditions by means of Long-Range Lidar Measurements in the Context of the Perdigão 2017 Experiment

NASA Astrophysics Data System (ADS)

Wildmann, N.; Kigle, S.; Hagen, M.; Gerz, T.

2017-12-01

As the resource wind is increasingly exploited to produce electricity, wind energy converter (WEC) deployment relocates to more complex terrain such as hilltops or mountain ridges. In that context, it is crucial to understand the interaction between the atmospheric boundary layer (ABL) flow and the WEC in order to predict downstream flow characteristics. In the context of the Perdigão 2017 experiment, the German Aerospace Center (DLR) performed full-scale wake measurements on a single WEC of type Enercon E82 with three Leosphere Windcube 200S long-range scanning lidar systems. The experimental setup covers two parallel ridges 1.4 km apart, separated by a 200 m deep valley. The ridges are oriented in NW-SE direction, perpendicular to main wind direction, which is SW. Two of the three scanning lidar systems are positioned downstream of the WEC in line with main wind direction to span a vertical plane, perpendicular to the ridges, with RHI scans. This allows investigating wake events with single or dual-doppler lidar techniques. The third lidar system, which is positioned along the WEC ridge, is used to measure the wake position outside the before mentioned measurement plane. Wake events in three different ABL regimes (neutral, stable and convective) are evaluated with respect to wake position, dispersion, propagation and the wind-speed deficit. It is found that wake position and propagation are strongly influenced by the atmospheric stability, forcing the wake to deviate from hub height, migrating to higher levels for convective regimes. For stable ABL conditions wakes descend into the valley, and are clearly detectable up to at least eight rotor diameters downstream of the WEC. The coplanar scanning strategy furthermore allows to calculate the two-dimensional wind vector in the vertical scanning plane, indicating that vertical wind components with up to 2 ms-1 play an important role in the interaction between ABL flow and WEC. With the help of the third lidar system on the WEC ridge, wake meandering can be quantified. The presentation will provide a thorough analysis of three exemplary measurement days.

Complex Flow: Workshop Report; January 17-18, 2012, University of Colorado, Boulder

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2012-06-01

The Department of Energy's Wind Program organized a two-day workshop designed to examine complex wind flow into and out of the wind farm environment and the resulting impacts on the mechanical workings of individual wind turbines. An improved understanding of these processes will subsequently drive down the risk involved for wind energy developers, financiers, and owner/operators, thus driving down the cost of energy.

Wind for Schools: Developing Education Programs to Train the Next Generation of the Wind Energy Workforce

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, I.; Flowers, L.; Kelly, M.

2009-08-01

This paper provides an overview of the Wind for Schools project elements, including a description of host and collegiate school curricula developed for wind energy and the status of the current projects. The paper also provides focused information on how schools, regions, or countries can become involved or implement similar projects to expand the social acceptance and understanding of wind energy.

SimWIND: A Geospatial Infrastructure Model for Wind Energy Production and Transmission

NASA Astrophysics Data System (ADS)

Middleton, R. S.; Phillips, B. R.; Bielicki, J. M.

2009-12-01

Wind is a clean, enduring energy resource with a capacity to satisfy 20% or more of the electricity needs in the United States. A chief obstacle to realizing this potential is the general paucity of electrical transmission lines between promising wind resources and primary load centers. Successful exploitation of this resource will therefore require carefully planned enhancements to the electric grid. To this end, we present the model SimWIND for self-consistent optimization of the geospatial arrangement and cost of wind energy production and transmission infrastructure. Given a set of wind farm sites that satisfy meteorological viability and stakeholder interest, our model simultaneously determines where and how much electricity to produce, where to build new transmission infrastructure and with what capacity, and where to use existing infrastructure in order to minimize the cost for delivering a given amount of electricity to key markets. Costs and routing of transmission line construction take into account geographic and social factors, as well as connection and delivery expenses (transformers, substations, etc.). We apply our model to Texas and consider how findings complement the 2008 Electric Reliability Council of Texas (ERCOT) Competitive Renewable Energy Zones (CREZ) Transmission Optimization Study. Results suggest that integrated optimization of wind energy infrastructure and cost using SimWIND could play a critical role in wind energy planning efforts.

Factors of Renewable Energy Deployment and Empirical Studies of United States Wind Energy

NASA Astrophysics Data System (ADS)

Can Sener, Serife Elif

Considered essential for countries' development, energy demand is growing worldwide. Unlike conventional sources, the use of renewable energy sources has multiple benefits, including increased energy security, sustainable economic growth, and pollution reduction, in particular greenhouse gas emissions. Nevertheless, there is a considerable difference in the share of renewable energy sources in national energy portfolios. This dissertation contains a series of studies to provide an outlook on the existing renewable energy deployment literature and empirically identify the factors of wind energy generation capacity and wind energy policy diffusion in the U.S. The dissertation begins with a systematic literature review to identify drivers and barriers which could help in understanding the diverging paths of renewable energy deployment for countries. In the analysis, economic, environmental, and social factors are found to be drivers, whereas political, regulatory, technical potential and technological factors are not classified as either a driver or a barrier (i.e., undetermined). Each main category contains several subcategories, among which only national income is found to have a positive impact, whereas all other subcategories are considered undetermined. No significant barriers to the deployment of renewable energy sources are found over the analyzed period. Wind energy deployment within the states related to environmental and economic factors was seldom discussed in the literature. The second study of the dissertation is thus focused on the wind energy deployment in the United States. Wind energy is among the most promising clean energy sources and the United States has led the world in per capita newly installed generation capacity since 2000. In the second study, using a fixed-effects panel data regression analysis, the significance of a number of economic and environmental factors are investigated for 39 states from 2000 to 2015. The results suggested that the increase in economic factors is related to a significant increase in the installed wind energy capacity, whereas, the increase in environmental factors is related to a significant decrease in the installed wind capacity. The final study explores the factors of diffusion of state- and local-level wind energy support policies which are considered fundamental factors of the continuum and development of wind power in the United States. To reveal the internal determinants of state's wind energy policy diffusion, we further narrow the scope and control for the geographical region in the final study. We limit our analysis to seven neighboring Midwestern states, which are located in the center of United States wind energy corridor. Using data from 2008 to 2015, the study investigates the significance of the following internal factors: wind power potential, per capita gross state product, unemployment rate, per capita value of the agriculture sector, number of establishments in agricultural sector, and state government control. Through the addition of interaction terms, the study also considers the behavioral differences in the explanatory variables under Republican and non-Republican state governance. Our findings suggest that the economic development potential and related environmental benefits were the common motivation for state- and local-level policy makers. Lastly, technical terms and agricultural sector presence provides additional motives for the state level diffusion of wind energy policies. The findings of this dissertation are expected to contribute to the understanding of how countries and states might best stimulate and support renewable energy, and in particular wind energy, deployment.

Investigation of wind turbine effects on Evapotranspiration using surface energy balance model based on satellite-derived data

NASA Astrophysics Data System (ADS)

hassanpour Adeh, E.; Higgins, C. W.

2014-12-01

Wind turbines have been introduced as an energy source that does not require a large expenditure of water. However, recent simulation results indicate that wind turbines increase evaporation rates from the nearby land. In this research the effect of wind energy on irrigated agriculture is determined using a Surface Energy Balance Algorithm (SEBAL) on Landsat data spanning a 30 year interval. The analysis allows the characterization of evapotranspiration (ET) before and after wind turbine installations. The time history of ET from Landsat data will be presented for several major wind farms across the US. These data will be used to determine the impact on water demand due to presence of wind turbines.

Separation of Electric Fields Into Potential and Inductive Parts, and Implications for Radial Diffusion

NASA Astrophysics Data System (ADS)

Chan, A. A.; Ilie, R.; Elkington, S. R.; Albert, J.; Huie, W.

2017-12-01

It has been traditional to separate radiation belt radial-diffusion coefficients into two contributions: an "electrostatic" diffusion coefficient, which is assumed to be due to a potential (non-inductive) electric field, and an "electromagnetic" diffusion coefficient , which is assumed to be due to the combined effect of an inductive electric field and the corresponding time-dependent magnetic field. One difficulty in implementing this separation when using magnetospheric fields obtained from measurements, or from MHD simulations, is that only the total electric field is given; the separation of the electric field into potential and inductive parts is not readily available. In this work we separate the electric field using a numerical method based on the Helmholtz decomposition of the total motional electric field calculated by the BATS-R-US MHD code. The inner boundary for the electric potential is based on the Ridley Ionospheric Model solution and we assume floating boundary conditions in the solar wind. Using different idealized solar wind drivers, including a solar wind density that is oscillating at a single frequency or with a broad spectrum of frequencies, we calculate potential and inductive electric fields, electric and magnetic power spectral densities, and corresponding radial diffusion coefficients. Simulations driven by idealized solar wind conditions show a clear separation of the potential and inductive contributions to the power spectral densities and diffusion coefficients. Simulations with more realistic solar wind drivers are underway to better assess the use of electrostatic and electromagnetic diffusion coefficients in understanding ULF wave-particle interactions in Earth's radiation belts.

77 FR 74842 - Sunshine Act Meeting Notice

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-18

... Wind North America LLC, and Horizon Wind Energy LLC v. Bonneville Power Administration. E-3 EL11-44-002 Iberdrola Renewables, Inc., PacifiCorp, NextEra Energy Resources, LLC, Invenergy Wind North America LLC, and Horizon Wind Energy LLC v. Bonneville Power Administration. E-4 RM11-12-000 Availability of E-Tag...

Social Acceptance of Wind: A Brief Overview (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lantz, E.

This presentation discusses concepts and trends in social acceptance of wind energy, profiles recent research findings, and discussions mitigation strategies intended to resolve wind power social acceptance challenges as informed by published research and the experiences of individuals participating in the International Energy Agencies Working Group on Social Acceptance of Wind Energy

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... Environmental Impact Statement for the Proposed Crowned Ridge Wind Energy Center Project, Codington and Grant... to design, construct, operate, and maintain a 150-megawatt Crowned Ridge Wind Energy Center Project... that memorandum, I have terminated the NEPA process for NextEra's proposed Crowned Ridge Wind Energy...

The Current State of Additive Manufacturing in Wind Energy Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mann, Margaret; Palmer, Sierra; Lee, Dominic

Wind power is an inexhaustible form of energy that is being captured throughout the U.S. to power the engine of our economy. A robust, domestic wind industry promises to increase U.S. industry growth and competitiveness, strengthen U.S. energy security independence, and promote domestic manufacturing nationwide. As of 2016, ~82GW of wind capacity had been installed, and wind power now provides more than 5.5% of the nation’s electricity and supports more than 100,000 domestic jobs, including 500 manufacturing facilities in 43 States. To reach the U.S. Department of Energy’s (DOE’s) 2015 Wind Vision study scenario of wind power serving 35% ofmore » the nation's end-use demand by 2050, significant advances are necessary in all areas of wind technologies and market. An area that can greatly impact the cost and rate of innovation in wind technologies is the use of advanced manufacturing, with one of the most promising areas being additive manufacturing (AM). Considering the tremendous promise offered by advanced manufacturing, it is the purpose of this report to identify the use of AM in the production and operation of wind energy systems. The report has been produced as a collaborative effort for the DOE Wind Energy Technology Office (WETO), between Oak Ridge National Laboratory (ORNL) and the National Renewable Energy Laboratory (NREL).« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sotiropoulos, Fotis; Marr, Jeffrey D.G.; Milliren, Christopher

In January 2010, the University of Minnesota, along with academic and industry project partners, began work on a four year project to establish new facilities and research in strategic areas of wind energy necessary to move the nation towards a goal of 20% wind energy by 2030. The project was funded by the U.S. Department of Energy with funds made available through the American Recovery and Reinvestment Act of 2009. $7.9M of funds were provided by DOE and $3.1M was provided through matching funds. The project was organized into three Project Areas. Project Area 1 focused on design and developmentmore » of a utility scale wind energy research facility to support research and innovation. The project commissioned the Eolos Wind Research Field Station in November of 2011. The site, located 20 miles from St. Paul, MN operates a 2.5MW Clipper Liberty C-96 wind turbine, a 130-ft tall sensored meteorological tower and a robust sensor and data acquisition network. The site is operational and will continue to serve as a site for innovation in wind energy for the next 15 years. Project Areas 2 involved research on six distinct research projects critical to the 20% Wind Energy by 2030 goals. The research collaborations involved faculty from two universities, over nine industry partners and two national laboratories. Research outcomes include new knowledge, patents, journal articles, technology advancements, new computational models and establishment of new collaborative relationships between university and industry. Project Area 3 focused on developing educational opportunities in wind energy for engineering and science students. The primary outcome is establishment of a new graduate level course at the University of Minnesota called Wind Engineering Essentials. The seminar style course provides a comprehensive analysis of wind energy technology, economics, and operation. The course is highly successful and will continue to be offered at the University. The vision of U.S. DOE to establish unique, open-access research facilities and creation of university-industry research collaborations in wind energy were achieved through this project. The University of Minnesota, through the establishment of the Eolos Wind Energy Consortium and the Eolos Wind Research Field Station continue to develop new research collaborations with industry partners.« less

Suitability analysis of wind energy development on brownfields, landfills and industrial sites in the city of Chicago

NASA Astrophysics Data System (ADS)

Fyodorova, Valeryia A.

In 2011 renewable energy generated only about 5% of total U.S. electricity and 3% came from wind power. Wind power is the oldest and fastest growing renewable energy, and U.S. Department of Energy (DOE) anticipates that by 2030 the potential of the U.S. to generate wind power will rise up to 20% (National Renewable Energy Laboratory 2008). Currently, the rural areas serve as the primary choice of wind turbine installation because there are less wind obstacles that create wind turbulence, which in turn is disruptive for the proper functioning of the wind turbines, and allows more laminar (streamline) wind flow. However according to various literatures, the installation of wind turbines in rural areas has its drawbacks. The infrastructure is underdeveloped and usually the selected sites require the construction of new roads and transmission lines. The new construction and occasional deforestation lead to soil erosion and environmental degradation. On top of that transporting energy to cities that are the primary consumers of wind energy results in energy transmission loss. Urban areas, on the other hand, have well developed infrastructure, and the installation of turbines on abandoned and contaminated urban lands which are expensive to clean and rehabilitate for other uses would lower installation costs and would have little environmental degradation effect. The objective of this research was to provide a preliminary wind power suitability analysis for installing medium (100 -1000 kW) and large (1000 - 3000 kW) size wind turbines in urban areas, such as city of Chicago. Geographic Information Systems (GIS) and a multi attribute Weighted Linear Combination (WLC) method that is based on the concept of weighted average were primary tools utilized to conduct the analysis. The criteria that were used to select suitable sites were the same criteria used for rural wind farms, such as wind speeds, historic landmarks, avian and wildlife habitat, conservation lands, proximity to airports, roads, and transmission lines. The result of study showed that there is a range of 29 to 81 locations that are potentially feasible for the placement of large and medium-scale wind turbines in city of Chicago. Twenty nine of these sites were found to be most suitable. The study has limitations in that some of the data used were incomplete and some additional variables that needed to be considered, such as, the effects of passing trains on wind turbines and acceptance of urban dwellers of wind turbines in their city. Despite these limitations, the framework of this research can be applied to improve the study for the city of Chicago by considering additional variables and to extend it to other areas of study, and raise awareness of renewable energy, and the possibilities and flexibility of wind energy.

Wind Energy Facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laurie, Carol

2017-02-01

This book takes readers inside the places where daily discoveries shape the next generation of wind power systems. Energy Department laboratory facilities span the United States and offer wind research capabilities to meet industry needs. The facilities described in this book make it possible for industry players to increase reliability, improve efficiency, and reduce the cost of wind energy -- one discovery at a time. Whether you require blade testing or resource characterization, grid integration or high-performance computing, Department of Energy laboratory facilities offer a variety of capabilities to meet your wind research needs.

Wind Energy Facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Office of Energy Efficiency and Renewable Energy

This book takes readers inside the places where daily discoveries shape the next generation of wind power systems. Energy Department laboratory facilities span the United States and offer wind research capabilities to meet industry needs. The facilities described in this book make it possible for industry players to increase reliability, improve efficiency, and reduce the cost of wind energy -- one discovery at a time. Whether you require blade testing or resource characterization, grid integration or high-performance computing, Department of Energy laboratory facilities offer a variety of capabilities to meet your wind research needs.

75 FR 42743 - Synergics Roth Rock North Wind Energy, LLC; Supplemental Notice That Initial Market-Based Rate...

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... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER10-1673-000] Synergics Roth Rock North Wind Energy, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...-referenced proceeding of Synergics Roth Rock North Wind Energy, LLC's application for market- based rate...

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Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-07

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER11-2765-000] Elk Wind Energy, LLC; Supplemental Notice That Initial Market- Based Rate Filing Includes Request for Blanket... proceeding of Elk Wind Energy, LLC's application for market-based rate authority, with an accompanying rate...

77 FR 2286 - Iberdrola Renewables, Inc., PacifiCorp, NextEra Energy Resources, LLC, Invenergy Wind North...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-17

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL11-44-000] Iberdrola Renewables, Inc., PacifiCorp, NextEra Energy Resources, LLC, Invenergy Wind North America LLC, Horizon Wind Energy LLC v. Bonneville Power Administration; Notice of Designation of Certain Commission Personnel as...

77 FR 47625 - Laurel Hill Wind Energy, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-09

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER12-2313-000] Laurel Hill Wind Energy, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request For... Laurel Hill Wind Energy, LLC's application for market-based rate authority, with an accompanying rate...

78 FR 62300 - Prairie Breeze Wind Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-15

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER14-25-000] Prairie Breeze Wind Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket... Breeze Wind Energy LLC's application for market-based rate authority, with an accompanying rate schedule...

77 FR 106 - California Ridge Wind Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-03

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER12-645-000] California Ridge Wind Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for... California Ridge Wind Energy LLC's application for market-based rate authority, with an accompanying rate...

77 FR 41400 - Mehoopany Wind Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-13

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER12-2200-000] Mehoopany Wind Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket... Wind Energy LLC's application for market-based rate authority, with an accompanying rate tariff, noting...

Ion Layer Separation and Equilibrium Zonal Winds in Midlatitude Sporadic E

NASA Technical Reports Server (NTRS)

Earle, G. D.; Kane, T. J.; Pfaff, R. F.; Bounds, S. R.

2000-01-01

In-situ observations of a moderately strong mid-latitude sporadic-E layer show a separation in altitude between distinct sublayers composed of Fe(+), Mg(+), and NO(+). From these observations it is possible to estimate the zonal wind field consistent with diffusive equilibrium near the altitude of the layer. The amplitude of the zonal wind necessary to sustain the layer against diffusive effects is less than 10 meters per second, and the vertical wavelength is less than 10 km.

Mixed H2/H∞ pitch control of wind turbine with a Markovian jump model

NASA Astrophysics Data System (ADS)

Lin, Zhongwei; Liu, Jizhen; Wu, Qiuwei; Niu, Yuguang

2018-01-01

This paper proposes a Markovian jump model and the corresponding H2/H∞ control strategy for the wind turbine driven by the stochastic switching wind speed, which can be used to regulate the generator speed in order to harvest the rated power while reducing the fatigue loads on the mechanical side of wind turbine. Through sampling the low-frequency wind speed data into separate intervals, the stochastic characteristic of the steady wind speed can be represented as a Markov process, while the high-frequency wind speed in the each interval is regarded as the disturbance input. Then, the traditional operating points of wind turbine can be divided into separate subregions correspondingly, where the model parameters and the control mode can be fixed in each mode. Then, the mixed H2/H∞ control problem is discussed for such a class of Markovian jump wind turbine working above the rated wind speed to guarantee both the disturbance rejection and the mechanical loads objectives, which can reduce the power volatility and the generator torque fluctuation of the whole transmission mechanism efficiently. Simulation results for a 2 MW wind turbine show the effectiveness of the proposed method.

GIS-based approach for the evaluation of offshore wind power potential for Gujarat

NASA Astrophysics Data System (ADS)

Patel, Dhrumin; Nagababu, Garlapati; Radadia, Nishil; Parsana, Sohil; Sheth, Mohak; Sheth, Nisarg

2018-05-01

In the current global scenario, India is increasing its focus towards the methods to enrich the benefits of non-renewable energy sources as much as possible due to their key advantage of having low carbon footprint. India has already emerged as a key global player in on-shore wind energy and to achieve its annual wind energy production demand of 50 GWh, avenues other than current options have been researched on. Offshore wind energy has experienced remarkable growth worldwide but has not yet been harnessed sufficiently in India, despite addressing many of environmental and economic concerns. The present study focuses on offshore wind resource assessment on Indian exclusive economic zone (EEZ) around Gujarat region. The geographical information system (GIS) methodology has been used to develop maps of wind speed, power density and capacity factor maps. Further, careful consideration has been accorded for expulsion of marine protected areas, shipping transportation lines, fishing zones, and migratory bird movements. The resultant available area has been considered for annual energy production considering data from Siemens Wind Turbine 3.6. The results obtained shows that offshore wind energy can offset twice the annual energy demand of entire country with a potential energy production of more than 2580 TWh.

Turbulence Simulation of Laboratory Wind-Wave Interaction in High Winds and Upscaling to Ocean Conditions

DTIC Science & Technology

2016-12-22

investigated air-sea fluxes characterized by strong air flow separation over a very steep wave field. We first investigated propagating steep wave...mechanisms for flow separation over rigid surfaces compared with unsteady surfaces with a boundary slip velocity. We investigated passive scalar fluxes. In...turbulent flow over steep stationary roughness, the primary mechanism for momentum flux is via pressure drag resulting from flow separation. However

25 CFR 162.010 - How do I obtain a lease?

Code of Federal Regulations, 2014 CFR

2014-04-01

... subpart E for wind energy evaluation, wind resource, or solar resource leases; and (3) Prospective lessees..., residential, business, wind energy evaluation, wind resource, and solar resource leases will not be advertised...

25 CFR 162.010 - How do I obtain a lease?

Code of Federal Regulations, 2013 CFR

2013-04-01

... subpart E for wind energy evaluation, wind resource, or solar resource leases; and (3) Prospective lessees..., residential, business, wind energy evaluation, wind resource, and solar resource leases will not be advertised...

Wind Power Potential at Abandoned Mines in Korea

NASA Astrophysics Data System (ADS)

jang, M.; Choi, Y.; Park, H.; Go, W.

2013-12-01

This study performed an assessment of wind power potential at abandoned mines in the Kangwon province by analyzing gross energy production, greenhouse gas emission reduction and economic effects estimated from a 600 kW wind turbine. Wind resources maps collected from the renewable energy data center in Korea Institute of Energy Research(KIER) were used to determine the average wind speed, temperature and atmospheric pressure at hub height(50 m) for each abandoned mine. RETScreen software developed by Natural Resources Canada(NRC) was utilized for the energy, emission and financial analyses of wind power systems. Based on the results from 5 representative mining sites, we could know that the average wind speed at hub height is the most critical factor for assessing the wind power potential. Finally, 47 abandoned mines that have the average wind speed faster than 6.5 m/s were analyzed, and top 10 mines were suggested as relatively favorable sites with high wind power potential in the Kangwon province.

Wind Resource Assessment Report: Mille Lacs Indian Reservation, Minnesota

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jimenez, Antonio C.; Robichaud, Robi

The U.S. Environmental Protection Agency (EPA) launched the RE-Powering America's Land initiative to encourage development of renewable energy on potentially contaminated land and mine sites. EPA collaborated with the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL) and the Mille Lacs Band of Chippewa Indians to evaluate the wind resource and examine the feasibility of a wind project at a contaminated site located on the Mille Lacs Indian Reservation in Minnesota. The wind monitoring effort involved the installation of a 60-m met tower and the collection of 18 months of wind data at multiple heights above the ground.more » This report focuses on the wind resource assessment, the estimated energy production of wind turbines, and an assessment of the economic feasibility of a potential wind project sited this site.« less

Lidar-based Research and Innovation at DTU Wind Energy - a Review

NASA Astrophysics Data System (ADS)

Mikkelsen, T.

2014-06-01

As wind turbines during the past decade have increased in size so have the challenges met by the atmospheric boundary-layer meteorologists and the wind energy society to measure and characterize the huge-volume wind fields surpassing and driving them. At the DTU Wind Energy test site "Østerild" for huge wind turbines, the hub-height of a recently installed 8 MW Vestas V164 turbine soars 143 meters up above the ground, and its rotor of amazing 164 meters in diameter make the turbine tips flicker 225 meters into the sky. Following the revolution in photonics-based telecommunication at the turn of the Millennium new fibre-based wind lidar technologies emerged and DTU Wind Energy, at that time embedded within Rise National Laboratory, began in collaboration with researchers from wind lidar companies to measure remote sensed wind profiles and turbulence structures within the atmospheric boundary layer with the emerging, at that time new, all-fibre-based 1.55 μ coherent detection wind lidars. Today, ten years later, DTU Wind Energy routinely deploys ground-based vertical profilers instead of met masts for high-precision measurements of mean wind profiles and turbulence profiles. At the departments test site "Høvsøre" DTU Wind Energy also routinely calibrate and accredit wind lidar manufactures wind lidars. Meanwhile however, new methodologies for power curve assessment based on ground-based and nacelle based lidars have also emerged. For improving the turbines power curve assessments and for advancing their control with feed-forward wind measurements experience has also been gained with wind lidars installed on turbine nacelles and integrated into the turbines rotating spinners. A new mobile research infrastructure WindScanner.dk has also emerged at DTU Wind Energy. Wind and turbulence fields are today scanned from sets of three simultaneously in space and time synchronized scanning lidars. One set consists of three fast scanning continuous-wave based wind lidars (short-range system), and another consisting of three synchronized pulsed wind lidar systems (long-range system). Today, wind lidar profilers and WindScanners are routinely deployed and operated during field tests and measurement campaigns. Lidars have been installed and operated from ground, on offshore platforms, and also as scanning lidars integrated in operating turbines. As a result, wind profiles and also detailed 3D scanning of wind and turbulence fields have been achieved: 1) of the free wind aloft, 2) over complex terrain, 3) at coastal ranges with land-sea interfaces, 4) offshore, 5) in turbine inflow induction zone, and 6) of the complex and turbulent flow fields in the wakes inside wind parks.

Planners to the rescue: spatial planning facilitating the development of offshore wind energy.

PubMed

Jay, Stephen

2010-04-01

The development of offshore wind energy has started to take place surprisingly quickly, especially in North European waters. This has taken the wind energy industry out of the territory of planning systems that usually govern the siting of wind farms on land, and into the world of departmental, sectoral regulation of marine activities. Although this has favoured the expansion of offshore wind energy in some respects, evidence suggests that the practice and principles of spatial planning can make an important contribution to the proper consideration of proposals for offshore wind arrays. This is especially so when a strategic planning process is put in place for marine areas, in which offshore wind is treated as part of the overall configuration of marine interests, so that adjustments can be made in the interests of wind energy. The current process of marine planning in the Netherlands is described as an illustration of this. (c) 2009 Elsevier Ltd. All rights reserved.

Push-pull converter with energy saving circuit for protecting switching transistors from peak power stress

NASA Technical Reports Server (NTRS)

Mclyman, W. T. (Inventor)

1981-01-01

In a push-pull converter, switching transistors are protected from peak power stresses by a separate snubber circuit in parallel with each comprising a capacitor and an inductor in series, and a diode in parallel with the inductor. The diode is connected to conduct current of the same polarity as the base-emitter juction of the transistor so that energy stored in the capacitor while the transistor is switched off, to protect it against peak power stress, discharges through the inductor when the transistor is turned on, and after the capacitor is discharges through the diode. To return this energy to the power supply, or to utilize this energy in some external circuit, the inductor may be replaced by a transformer having its secondary winding connected to the power supply or to the external circuit.

Energy Security: From Deal Killers to Game Changers

NASA Astrophysics Data System (ADS)

Orbach, Raymond L.

2010-03-01

Five ``deal killers'' for achieving energy security will be addressed: 1) Global warming and CO2 emissions from fossil fuel combustion, 2) Intermittent energy sources (wind, solar) and the presence and stability of the grid, 3) Penetration of plant defenses to produce transportation fuels from biomass, 4) Mimicking nature: artificial photosynthesis for solar energy-to-fuels, and 5) Spent fuel from nuclear power reactors. Basic research can lead to ``game changers'' for these five fields: 1) Carbon capture and storage through enhanced oil and gas recovery, 2) Electrical energy storage for base-load electricity through batteries and supercapacitors, 3) Genetic modification of the plant cell wall, and catalytic methods for conversion of plant sugars to fuels, 4) Separation of solar-induced electrons from holes, and catalysis to produce fuels, and 5) Closing the nuclear fuel cycle. The present state for each of these game changers will be summarized, and future research opportunities discussed.

Roadmap to the multidisciplinary design analysis and optimisation of wind energy systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perez-Moreno, S. Sanchez; Zaaijer, M. B.; Bottasso, C. L.

Here, a research agenda is described to further encourage the application of Multidisciplinary Design Analysis and Optimisation (MDAO) methodologies to wind energy systems. As a group of researchers closely collaborating within the International Energy Agency (IEA) Wind Task 37 for Wind Energy Systems Engineering: Integrated Research, Design and Development, we have identified challenges that will be encountered by users building an MDAO framework. This roadmap comprises 17 research questions and activities recognised to belong to three research directions: model fidelity, system scope and workflow architecture. It is foreseen that sensible answers to all these questions will enable to more easilymore » apply MDAO in the wind energy domain. Beyond the agenda, this work also promotes the use of systems engineering to design, analyse and optimise wind turbines and wind farms, to complement existing compartmentalised research and design paradigms.« less

Roadmap to the multidisciplinary design analysis and optimisation of wind energy systems

DOE PAGES

Perez-Moreno, S. Sanchez; Zaaijer, M. B.; Bottasso, C. L.; ...

2016-10-03

Here, a research agenda is described to further encourage the application of Multidisciplinary Design Analysis and Optimisation (MDAO) methodologies to wind energy systems. As a group of researchers closely collaborating within the International Energy Agency (IEA) Wind Task 37 for Wind Energy Systems Engineering: Integrated Research, Design and Development, we have identified challenges that will be encountered by users building an MDAO framework. This roadmap comprises 17 research questions and activities recognised to belong to three research directions: model fidelity, system scope and workflow architecture. It is foreseen that sensible answers to all these questions will enable to more easilymore » apply MDAO in the wind energy domain. Beyond the agenda, this work also promotes the use of systems engineering to design, analyse and optimise wind turbines and wind farms, to complement existing compartmentalised research and design paradigms.« less

The value of compressed air energy storage with wind in transmission-constrained electric power systems

DOE PAGES

Denholm, Paul; Sioshansi, Ramteen

2009-05-05

In this paper, we examine the potential advantages of co-locating wind and energy storage to increase transmission utilization and decrease transmission costs. Co-location of wind and storage decreases transmission requirements, but also decreases the economic value of energy storage compared to locating energy storage at the load. This represents a tradeoff which we examine to estimate the transmission costs required to justify moving storage from load-sited to wind-sited in three different locations in the United States. We examined compressed air energy storage (CAES) in three “wind by wire” scenarios with a variety of transmission and CAES sizes relative to amore » given amount of wind. In the sites and years evaluated, the optimal amount of transmission ranges from 60% to 100% of the wind farm rating, with the optimal amount of CAES equal to 0–35% of the wind farm rating, depending heavily on wind resource, value of electricity in the local market, and the cost of natural gas.« less

Resolving Environmental Effects of Wind Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinclair, Karin C; DeGeorge, Elise M; Copping, Andrea E.

Concerns for potential wildlife impacts resulting from land-based and offshore wind energy have created challenges for wind project development. Research is not always adequately supported, results are neither always readily accessible nor are they satisfactorily disseminated, and so decisions are often made based on the best available information, which may be missing key findings. The potential for high impacts to avian and bat species and marine mammals have been used by wind project opponents to stop, downsize, or severely delay project development. The global nature of the wind industry - combined with the understanding that many affected species cross-national boundaries,more » and in many cases migrate between continents - also points to the need to collaborate on an international level. The International Energy Agency (IEA) Wind Technology Collaborative Programs facilitates coordination on key research issues. IEA Wind Task 34 - WREN: Working Together to Resolve Environmental Effects of Wind Energy-is a collaborative forum to share lessons gained from field research and modeling, including management methods, wildlife monitoring methods, best practices, study results, and successful approaches to mitigating impacts and addressing the cumulative effects of wind energy on wildlife.« less

National Offshore Wind Energy Grid Interconnection Study Full Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daniel, John P.; Liu, Shu; Ibanez, Eduardo

2014-07-30

The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States.

The National Wind Energy Skills Assessment and Preparing for the Future Wind Workforce; NREL (National Renewable Energy Laboratory)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tegen, Suzanne

2015-07-10

A robust workforce is essential to growing domestic wind manufacturing capabilities. This presentation provides an overview of an NREL analysis of wind-focused education at American colleges and universities. The second part of the presentation discusses DOE/NREL workforce-related projects, such as the Wind Career Map, the Collegiate Wind Competition, and the Wind for Schools project.

Quantifying the Benefits of Combining Offshore Wind and Wave Energy

NASA Astrophysics Data System (ADS)

Stoutenburg, E.; Jacobson, M. Z.

2009-12-01

For many locations the offshore wind resource and the wave energy resource are collocated, which suggests a natural synergy if both technologies are combined into one offshore marine renewable energy plant. Initial meteorological assessments of the western coast of the United States suggest only a weak correlation in power levels of wind and wave energy at any given hour associated with the large ocean basin wave dynamics and storm systems of the North Pacific. This finding indicates that combining the two power sources could reduce the variability in electric power output from a combined wind and wave offshore plant. A combined plant is modeled with offshore wind turbines and Pelamis wave energy converters with wind and wave data from meteorological buoys operated by the US National Buoy Data Center off the coast of California, Oregon, and Washington. This study will present results of quantifying the benefits of combining wind and wave energy for the electrical power system to facilitate increased renewable energy penetration to support reductions in greenhouse gas emissions, and air and water pollution associated with conventional fossil fuel power plants.

Effects of 3D Virtual Simulators in the Introductory Wind Energy Course: A Tool for Teaching Engineering Concepts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Do, Phuong T.; Moreland, John R.; Delgado, Catherine

Our research provides an innovative solution for optimizing learning effectiveness and improving postsecondary education through the development of virtual simulators that can be easily used and integrated into existing wind energy curriculum. Two 3D virtual simulators are developed in our laboratory for use in an immersive 3D virtual reality (VR) system or for 3D display on a 2D screen. Our goal is to apply these prototypical simulators to train postsecondary students and professionals in wind energy education; and to offer experiential learning opportunities in 3D modeling, simulation, and visualization. The issue of transferring learned concepts to practical applications is amore » widespread problem in postsecondary education. Related to this issue is a critical demand to educate and train a generation of professionals for the wind energy industry. With initiatives such as the U.S. Department of Energy's “20% Wind Energy by 2030” outlining an exponential increase of wind energy capacity over the coming years, revolutionary educational reform is needed to meet the demand for education in the field of wind energy. These developments and implementation of Virtual Simulators and accompanying curriculum will propel national reforms, meeting the needs of the wind energy industrial movement and addressing broader educational issues that affect a number of disciplines.« less

Effects of 3D Virtual Simulators in the Introductory Wind Energy Course: A Tool for Teaching Engineering Concepts

DOE PAGES

Do, Phuong T.; Moreland, John R.; Delgado, Catherine; ...

2013-01-01

Our research provides an innovative solution for optimizing learning effectiveness and improving postsecondary education through the development of virtual simulators that can be easily used and integrated into existing wind energy curriculum. Two 3D virtual simulators are developed in our laboratory for use in an immersive 3D virtual reality (VR) system or for 3D display on a 2D screen. Our goal is to apply these prototypical simulators to train postsecondary students and professionals in wind energy education; and to offer experiential learning opportunities in 3D modeling, simulation, and visualization. The issue of transferring learned concepts to practical applications is amore » widespread problem in postsecondary education. Related to this issue is a critical demand to educate and train a generation of professionals for the wind energy industry. With initiatives such as the U.S. Department of Energy's “20% Wind Energy by 2030” outlining an exponential increase of wind energy capacity over the coming years, revolutionary educational reform is needed to meet the demand for education in the field of wind energy. These developments and implementation of Virtual Simulators and accompanying curriculum will propel national reforms, meeting the needs of the wind energy industrial movement and addressing broader educational issues that affect a number of disciplines.« less

'Part of the solution': Developing sustainable energy through co-operatives and learning

NASA Astrophysics Data System (ADS)

Duguid, Fiona C. B.

After five years of development, WindShare Co-operative in Toronto, Ontario became the first urban wind turbine in North America and the first co-operatively owned and operated wind turbine in Canada. The development of WindShare Co-operative has spurred the growth of a green energy co-operative sector in Ontario. This study, which included 27 interviews and a focus group with members of WindShare Co-operative, focuses on the roles of community-based green energy co-operatives in advancing sustainable energy development and energy literacy. Sustainable energy development is firmly rooted in the triple bottom line of environmental, social and economic success, and green energy co-operatives can be a way to help achieve those successes. Green energy co-operatives are structures for providing renewable energy generation or energy conservation practices, both of which have important environmental impacts regarding climate change and pollution levels. Co-operative structures are supported by processes that include local ownership, democracy, participation, community organizing, learning and social change. These processes have a significant social impact by creating a venue for people to be directly involved in the energy industry, by involving learning through participation in a community-based organization, and by advancing energy literacy within the membership and the general public. In regards to the economic impacts, green energy co-operatives foster a local economy and local investment opportunities, which have repercussions regarding building expertise within Ontario's green energy and co-operative development future, and more generally, captures members' interest because they have a direct stake in the co-operative. This thesis shows that green energy co-operatives, like WindShare, play an important role in advancing sustainable energy development, energy literacy and the triple bottom line. Members of WindShare expressed resounding feelings of pride, efficacy and understanding of WindShare's role in sustainable energy. WindShare Co-operative provided the structure whereby members felt a part of the solution in terms of sustainable energy development. Policies and practices at all levels of government should encourage the advancement of green energy co-operatives to support Canada's efforts at public involvement in combating climate change and pollution.

A new approach to wind energy: Opportunities and challenges

NASA Astrophysics Data System (ADS)

Dabiri, John O.; Greer, Julia R.; Koseff, Jeffrey R.; Moin, Parviz; Peng, Jifeng

2015-03-01

Despite common characterizations of modern wind energy technology as mature, there remains a persistent disconnect between the vast global wind energy resource—which is 20 times greater than total global power consumption—and the limited penetration of existing wind energy technologies as a means for electricity generation worldwide. We describe an approach to wind energy harvesting that has the potential to resolve this disconnect by geographically distributing wind power generators in a manner that more closely mirrors the physical resource itself. To this end, technology development is focused on large arrays of small wind turbines that can harvest wind energy at low altitudes by using new concepts of biology-inspired engineering. This approach dramatically extends the reach of wind energy, as smaller wind turbines can be installed in many places that larger systems cannot, especially in built environments. Moreover, they have lower visual, acoustic, and radar signatures, and they may pose significantly less risk to birds and bats. These features can be leveraged to attain cultural acceptance and rapid adoption of this new technology, thereby enabling significantly faster achievement of state and national renewable energy targets than with existing technology alone. Favorable economics stem from an orders-of-magnitude reduction in the number of components in a new generation of simple, mass-manufacturable (even 3D-printable), vertical-axis wind turbines. However, this vision can only be achieved by overcoming significant scientific challenges that have limited progress over the past three decades. The following essay summarizes our approach as well as the opportunities and challenges associated with it, with the aim of motivating a concerted effort in basic and applied research in this area.

Dynamic Federalism and Wind Farm Siting

DTIC Science & Technology

2014-05-18

drawbacks, however. Among these, the mechanical and electromagnetic properties of wind turbines pose significant hazards and complications to U.S...have drawbacks, however. Among these, the mechanical and electromagnetic properties of wind turbines pose significant hazards and complications to...benefits. Wind energy conversion systems are no exception. Wind power systems use elevated turbines to capture mechanical energy from the wind

Wind Energy Resource Atlas of the Philippines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elliott, D.; Schwartz, M.; George, R.

2001-03-06

This report contains the results of a wind resource analysis and mapping study for the Philippine archipelago. The study's objective was to identify potential wind resource areas and quantify the value of those resources within those areas. The wind resource maps and other wind resource characteristic information will be used to identify prospective areas for wind-energy applications.

78 FR 62014 - Pioneer Wind Park I, LLC; Notice of Petition for Declaratory Order

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-11

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL14-1-000] Pioneer Wind... Procedure, 18 CFR 385.207(a)(2), Pioneer Wind Park I, LLC (Pioneer Wind) filed a petition for declaratory... execute a Power Purchase Agreement with Pioneer Wind, unless Pioneer Wind agrees to allow PacifiCorp to...

76 FR 77222 - Combined Notice of Filings #2

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-12

... Generator Status of Blackwell Wind, LLC under EG12-17. Filed Date: 12/5/11. Accession Number: 20111205-5060... Creek Wind Energy, LLC, Cedar Creek II, LLC, Flat Ridge Wind Energy, LLC, Fowler Ridge II Wind Farm LLC, Fowler Ridge III Wind Farm LLC, Fowler Ridge Wind Farm LLC, Goshen Phase II, LLC, Long Island Solar Farm...

Wind Energy at NREL's National Wind Technology Center

ScienceCinema

None

2017-12-09

It is a pure, plentiful natural resource. Right now wind is in high demand and it holds the potential to transform the way we power our homes and businesses. NREL is at the forefront of wind energy research and development. NREL's National Wind Technology Center (NWTC) is a world-class facility dedicated to accelerating and deploying wind technology.

75 FR 6020 - Electrical Interconnection of the Lower Snake River Wind Energy Project

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-05

... River Wind Energy Project AGENCY: Bonneville Power Administration (BPA), Department of Energy (DOE... (BPA) has decided to offer Puget Sound Energy Inc., a Large Generator Interconnection Agreement for... and Columbia counties, Washington. To interconnect the Wind Project, BPA will construct a new...

Wind deployment in the United States: states, resources, policy, and discourse.

PubMed

Wilson, Elizabeth J; Stephens, Jennie C

2009-12-15

A transformation in the way the United States produces and uses energy is needed to achieve greenhouse gas reduction targets for climate change mitigation. Wind power is an important low-carbon technology and the most rapidly growing renewable energy technology in the U.S. Despite recent advances in wind deployment, significant state-by-state variation in wind power distribution cannot be explained solely by wind resource patterns nor by state policy. Other factors embedded within the state-level socio-political context also contribute to wind deployment patterns. We explore this socio-political context in four U.S. states by integrating multiple research methods. Through comparative state-level analysis of the energy system, energy policy, and public discourse as represented in the media, we examine variation in the context for wind deployment in Massachusetts, Minnesota, Montana, and Texas. Our results demonstrate that these states have different patterns of wind deployment, are engaged in different debates about wind power, and appear to frame the risks and benefits of wind power in different ways. This comparative assessment highlights the complex variation of the state-level socio-political context and contributes depth to our understanding of energy technology deployment processes, decision-making, and outcomes.

Improving Energy Security for Air Force Installations

DTIC Science & Technology

2015-09-01

Wind power is a mature technology, with wind turbines first being used for electricity in the late 19th century. The Air Force operates two wind ...company, and the military unit receives energy credits back on its bill. Two concepts are important when considering the turbine size for a wind ...generation and consumption must remain balanced for a grid, so wind turbines are rarely used as a sole energy source since power is only generated

The roles of direct input of energy from the solar wind and unloading of stored magnetotail energy in driving magnetospheric substorms

NASA Technical Reports Server (NTRS)

Rostoker, G.; Akasofu, S. I.; Baumjohann, W.; Kamide, Y.; Mcpherron, R. L.

1987-01-01

The contributions to the substorm expansive phase of direct energy input from the solar wind and from energy stored in the magnetotail which is released in an unpredictable manner are considered. Two physical processes for the dispensation of the energy input from the solar wind are identified: (1) a driven process in which energy supplied from the solar wind is directly dissipated in the ionosphere; and (2) a loading-unloading process in which energy from the solar wind is first stored in the magnetotail and then is suddenly released to be deposited in the ionosphere. The pattern of substorm development in response to changes in the interplanetary medium has been elucidated for a canonical isolated substorm.

High-efficiency wind turbine

NASA Technical Reports Server (NTRS)

Hein, L. A.; Myers, W. N.

1980-01-01

Vertical axis wind turbine incorporates several unique features to extract more energy from wind increasing efficiency 20% over conventional propeller driven units. System also features devices that utilize solar energy or chimney effluents during periods of no wind.

Wind for Schools: Fostering the Human Talent Supply Chain for a 20% Wind Energy Future (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baring-Gould, I.

2011-03-01

As the United States dramatically expands wind energy deployment, the industry is challenged with developing a skilled workforce and addressing public resistance. Wind Powering America's Wind for Schools project addresses these issues by: 1) Developing Wind Application Centers (WACs) at universities; WAC students assist in implementing school wind turbines and participate in wind courses. 2) Installing small wind turbines at community "host" schools. 3) Implementing teacher training with interactive curricula at each host school.

Smart structure for small wind turbine blade

NASA Astrophysics Data System (ADS)

Supeni, E. E.; Epaarachchi, J. A.; Islam, M. M.; Lau, K. T.

2013-08-01

Wind energy is seen as a viable alternative energy option for future energy demand. The blades of wind turbines are generally regarded as the most critical component of the wind turbine system. Ultimately, the blades act as the prime mover of the whole system which interacts with the wind flow during the production of energy. During wind turbine operation the wind loading cause the deflection of the wind turbine blade which can be significant and affect the turbine efficiency. Such a deflection in wind blade not only will result in lower performance in electrical power generation but also increase of material degradation due high fatigue life and can significantly shorten the longevity for the wind turbine material. In harnessing stiffness of the blade will contribute massive weight factor and consequently excessive bending moment. To overcome this excessive deflection due to wind loading on the blade, it is feasible to use shape memory alloy (SMA) wires which has ability take the blade back to its optimal operational shape. This paper details analytical and experimental work being carried out to minimize blade flapping deflection using SMA.

77 FR 52754 - Draft Midwest Wind Energy Multi-Species Habitat Conservation Plan Within Eight-State Planning Area

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-30

... include new and existing small-scale wind energy facilities, such as single-turbine demonstration projects, as well as large, multi-turbine commercial wind facilities. Covered Species The planning partners are...-FF03E00000] Draft Midwest Wind Energy Multi-Species Habitat Conservation Plan Within Eight-State Planning...

Studying wind energy/bird interactions: a guidance document. Metrics and methods for determining or monitoring potential impacts on birds at existing and proposed wind energy sites

USGS Publications Warehouse

Anderson, R.; Morrison, M.; Sinclair, K.; Strickland, D.; Davis, H.; Kendall, W.

1999-01-01

In the 1980s little was known about the potential environmental effects associated with large scale wind energy development. Although wind turbines have been used in farming and remote location applications throughout this country for centuries, impacts on birds resulting from these dispersed turbines had not been reported. Thus early wind energy developments were planned, permitted, constructed, and operated with little consideration for the potential effects on birds. In the ensuing years wind plant impacts on birds became a source of concern among a number of stakeholder groups. Based on the studies that have been done to date, significant levels of bird fatalities have been identified at only one major commercial wind energy development in the United States. Research on wind energy/bird interactions has spanned such a wide variety of protocols and vastly different levels of study effort that it is difficult to make comparisons among study findings. As a result there continues to be interest, confusion, and concern over wind energy development's potential impacts on birds. Some hypothesize that technology changes, such as less dense wind farms with larger, slower-moving turbines, will decrease the number of bird fatalities from wind turbines. Others hypothesize that, because the tip speed may be the same or faster, new turbines will not result in decreased bird fatalities but may actually increase bird impacts. Statistically significant data sets from scientifically rigorous studies will be required before either hypothesis can be tested.

Plans and status of the NASA-Lewis Research Center wind energy project

NASA Technical Reports Server (NTRS)

Thomas, R.; Puthoff, R.; Savino, J.; Johnson, W.

1975-01-01

This report describes that portion of the national five-year wind energy program that is being managed by the NASA-Lewis Research Center for the ERDA. The Lewis Research Center's Wind Power Office, its organization and plans and status are briefly described. The three major elements of the wind energy project at Lewis are the experimental 100 kW wind-turbine generator; the first generation industry-built and user-operated wind turbine generators; and the supporting research and technology tasks which are each briefly described.

Basic Wind Tech Course - Lesson Plans and Activities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swapp, Andy

2011-07-01

The funds from this project were used to purchase tools and instrumentation to help replicate actual on-the-job wind energy scenarios which provided the students with the practical or applied components of wind energy jobs. This project enhanced the educational experiences provided for the students in terms of engineering and science components of wind energy by using electronics, control systems, and electro-mechanical instrumentation to help students learn standardized wind-specific craftsman skills. In addition the tools and instrumentation helped the students learn the safety necessary to work in the wind industry.

Operation of a wind turbine-flywheel energy storage system under conditions of stochastic change of wind energy.

PubMed

Tomczewski, Andrzej

2014-01-01

The paper presents the issues of a wind turbine-flywheel energy storage system (WT-FESS) operation under real conditions. Stochastic changes of wind energy in time cause significant fluctuations of the system output power and as a result have a negative impact on the quality of the generated electrical energy. In the author's opinion it is possible to reduce the aforementioned effects by using an energy storage of an appropriate type and capacity. It was assumed that based on the technical parameters of a wind turbine-energy storage system and its geographical location one can determine the boundary capacity of the storage, which helps prevent power cuts to the grid at the assumed probability. Flywheel energy storage was selected due to its characteristics and technical parameters. The storage capacity was determined based on an empirical relationship using the results of the proposed statistical and energetic analysis of the measured wind velocity courses. A detailed algorithm of the WT-FESS with the power grid system was developed, eliminating short-term breaks in the turbine operation and periods when the wind turbine power was below the assumed level.

Portable Wind Energy Harvesters for Low-Power Applications: A Survey

PubMed Central

Nabavi, Seyedfakhreddin; Zhang, Lihong

2016-01-01

Energy harvesting has become an increasingly important topic thanks to the advantages in renewability and environmental friendliness. In this paper, a comprehensive study on contemporary portable wind energy harvesters has been conducted. The electrical power generation methods of portable wind energy harvesters are surveyed in three major groups, piezoelectric-, electromagnetic-, and electrostatic-based generators. The paper also takes another view of this area by gauging the required mechanisms for trapping wind flow from ambient environment. In this regard, rotational and aeroelastic mechanisms are analyzed for the portable wind energy harvesting devices. The comparison between both mechanisms shows that the aeroelastic mechanism has promising potential in producing an energy harvester in smaller scale although how to maintain the resonator perpendicular to wind flow for collecting the maximum vibration is still a major challenge to overcome for this mechanism. Furthermore, this paper categorizes the previously published portable wind energy harvesters to macro and micro scales in terms of their physical dimensions. The power management systems are also surveyed to explore the possibility of improving energy conversion efficiency. Finally some insights and research trends are pointed out based on an overall analysis of the previously published works along the historical timeline. PMID:27438834

Operation of a Wind Turbine-Flywheel Energy Storage System under Conditions of Stochastic Change of Wind Energy

PubMed Central

2014-01-01

The paper presents the issues of a wind turbine-flywheel energy storage system (WT-FESS) operation under real conditions. Stochastic changes of wind energy in time cause significant fluctuations of the system output power and as a result have a negative impact on the quality of the generated electrical energy. In the author's opinion it is possible to reduce the aforementioned effects by using an energy storage of an appropriate type and capacity. It was assumed that based on the technical parameters of a wind turbine-energy storage system and its geographical location one can determine the boundary capacity of the storage, which helps prevent power cuts to the grid at the assumed probability. Flywheel energy storage was selected due to its characteristics and technical parameters. The storage capacity was determined based on an empirical relationship using the results of the proposed statistical and energetic analysis of the measured wind velocity courses. A detailed algorithm of the WT-FESS with the power grid system was developed, eliminating short-term breaks in the turbine operation and periods when the wind turbine power was below the assumed level. PMID:25215326

Portable Wind Energy Harvesters for Low-Power Applications: A Survey.

PubMed

Nabavi, Seyedfakhreddin; Zhang, Lihong

2016-07-16

Energy harvesting has become an increasingly important topic thanks to the advantages in renewability and environmental friendliness. In this paper, a comprehensive study on contemporary portable wind energy harvesters has been conducted. The electrical power generation methods of portable wind energy harvesters are surveyed in three major groups, piezoelectric-, electromagnetic-, and electrostatic-based generators. The paper also takes another view of this area by gauging the required mechanisms for trapping wind flow from ambient environment. In this regard, rotational and aeroelastic mechanisms are analyzed for the portable wind energy harvesting devices. The comparison between both mechanisms shows that the aeroelastic mechanism has promising potential in producing an energy harvester in smaller scale although how to maintain the resonator perpendicular to wind flow for collecting the maximum vibration is still a major challenge to overcome for this mechanism. Furthermore, this paper categorizes the previously published portable wind energy harvesters to macro and micro scales in terms of their physical dimensions. The power management systems are also surveyed to explore the possibility of improving energy conversion efficiency. Finally some insights and research trends are pointed out based on an overall analysis of the previously published works along the historical timeline.

Optimizing Lidar Scanning Strategies for Wind Energy Measurements (Invited)

NASA Astrophysics Data System (ADS)

Newman, J. F.; Bonin, T. A.; Klein, P.; Wharton, S.; Chilson, P. B.

2013-12-01

Environmental concerns and rising fossil fuel prices have prompted rapid development in the renewable energy sector. Wind energy, in particular, has become increasingly popular in the United States. However, the intermittency of available wind energy makes it difficult to integrate wind energy into the power grid. Thus, the expansion and successful implementation of wind energy requires accurate wind resource assessments and wind power forecasts. The actual power produced by a turbine is affected by the wind speeds and turbulence levels experienced across the turbine rotor disk. Because of the range of measurement heights required for wind power estimation, remote sensing devices (e.g., lidar) are ideally suited for these purposes. However, the volume averaging inherent in remote sensing technology produces turbulence estimates that are different from those estimated by a sonic anemometer mounted on a standard meteorological tower. In addition, most lidars intended for wind energy purposes utilize a standard Doppler beam-swinging or Velocity-Azimuth Display technique to estimate the three-dimensional wind vector. These scanning strategies are ideal for measuring mean wind speeds but are likely inadequate for measuring turbulence. In order to examine the impact of different lidar scanning strategies on turbulence measurements, a WindCube lidar, a scanning Halo lidar, and a scanning Galion lidar were deployed at the Southern Great Plains Atmospheric Radiation Measurement (ARM) site in Summer 2013. Existing instrumentation at the ARM site, including a 60-m meteorological tower and an additional scanning Halo lidar, were used in conjunction with the deployed lidars to evaluate several user-defined scanning strategies. For part of the experiment, all three scanning lidars were pointed at approximately the same point in space and a tri-Doppler analysis was completed to calculate the three-dimensional wind vector every 1 second. In another part of the experiment, one of the scanning lidars ran a Doppler beam-swinging technique identical to that used by the WindCube lidar while another scanning lidar used a novel six-beam technique that has been presented in the literature as a better alternative for measuring turbulence. In this presentation, turbulence measurements from these techniques are compared to turbulence measured by the WindCube lidar and sonic anemometers on the 60-m meteorological tower. In addition, recommendations are made for lidar measurement campaigns for wind energy applications.

Observation of atomic oxygen O(1S) green-line emission in the summer polar upper mesosphere associated with high-energy (≥30 keV) electron precipitation during high-speed solar wind streams

NASA Astrophysics Data System (ADS)

Lee, Young-Sook; Kwak, Young-Sil; Kim, Kyung-Chan; Solheim, Brian; Lee, Regina; Lee, Jaejin

2017-01-01

The auroral green-line emission at 557.7 nm wavelength as arising from the atomic oxygen O(1S → 1D) transition typically peaks at an altitude of 100 km specifically in the nightside oval, induced by auroral electrons within an energy range of 100 eV-30 keV. Intense aurora is known as being suppressed by sunlight in summer daytime but usually occurs in low electrical background conductivity. However, in the present study in summer (July) sunlit condition, enhancements of O(1S) emission rates observed by using the Wind Imaging Interferometer/UARS were frequently observed at low altitudes below 90 km, where ice particles are created initially as subvisible and detected as polar mesosphere summer echoes, emerging to be an optical phenomenon of polar mesospheric clouds. The intense O(1S) emission occurring in summer exceeds those occurring in the daytime in other seasons both in occurrence and in intensity, frequently accompanied by occurrences of supersonic neutral velocity (300-1500 m s-1). In the mesosphere, ion motion is controlled by electric field and the momentum is transferred to neutrals. The intense O(1S) emission is well associated with high-energy electron precipitation as observed during an event of high-speed solar wind streams. Meanwhile, since the minimum occurrences of O(1S) emission and supersonic velocity are maintained even in the low precipitation flux, the mechanism responsible is not only related to high-energy electron precipitation but also presumably to the local conditions, including the composition of meteoric-charged ice particles and charge separation expected in extremely low temperatures (<150 K).

The influence of spatially and temporally high-resolution wind forcing on the power input to near-inertial waves in the ocean

NASA Astrophysics Data System (ADS)

Rimac, A.; Eden, C.; von Storch, J.

2012-12-01

Coexistence of stable stratification, the meridional overturning circulation and meso-scale eddies and their influence on the ocean's circulation still raise complex questions concerning the ocean energetics. Oceanic general circulation is mainly forced by the wind field and deep water tides. Its essential energetics are the conversion of kinetic energy of the winds and tides into oceanic potential and kinetic energy. Energy needed for the circulation is bound to internal wave fields. Direct internal wave generation by the wind at the sea surface is one of the sources of this energy. Previous studies using mixed-layer type of models and low frequency wind forcings (six-hourly and daily) left room for improvement. Using mixed-layer models it is not possible to assess the distribution of near-inertial energy into the deep ocean. Also, coarse temporal resolution of wind forcing strongly underestimates the near-inertial wave energy. To overcome this difficulty we use a high resolution ocean model with high frequency wind forcings. We establish the following model setup: We use the Max Planck Institute Ocean Model (MPIOM) on a tripolar grid with 45km horizontal resolution and 40 vertical levels. We run the model with wind forcings that vary in horizontal (250km versus 40km) and temporal resolution (six versus one-hourly). In our study we answer the following questions: How big is the wind kinetic energy input to the near-inertial waves? Is the kinetic energy of the near-inertial waves enhanced when high-frequency wind forcings are used? If so, by how much and why, due to higher level of temporal wind variability or due to better spatial representation of the near-inertial waves? How big is the total power of near-inertial waves generated by the wind at the surface of the ocean? We run the model for one year. Our model results show that the near-inertial waves are excited both using wind forcings of high and low horizontal and temporal resolution. Near-inertial energy is almost two times higher when we force the model with high frequency wind forcings. The influence on the energy mostly depends on the time difference between two forcing fields while the spatial difference has little influence.

Control Strategy: Wind Energy Powered Variable Chiller with Thermal Ice Storage

DTIC Science & Technology

2014-12-01

New York, 2013. [8] A. Togelou et al., “Wind power forecasting in the absence of historical data,” IEEE trans. on sustainable energy, vol. 3, no...WIND ENERGY POWERED VARIABLE CHILLER WITH THERMAL ICE STORAGE by Rex A. Boonyobhas December 2014 Thesis Advisor: Anthony J. Gannon Co...AND DATES COVERED December 20 14 Master ’s Thesis 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS CONTROL STRATEGY: WIND ENERGY POWERED VARIABLE CHILLER

76 FR 69720 - NaturEner Rim Rock Wind Energy, LLC; Supplemental Notice That Initial Market-Based Rate Filing...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-09

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [ Docket No. ER12-295-000] NaturEner Rim Rock Wind Energy, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for... NaturEner Rim Rock Wind Energy, LLC's application for market-based rate authority, with an accompanying...

77 FR 21555 - Flat Ridge 2 Wind Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-10

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER12-1400-000] Flat Ridge 2 Wind Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket... Wind Energy LLC's application for market-based rate authority, with an accompanying rate tariff, noting...

A Comparison of the Impacts of Wind Energy and Unconventional Gas Development on Land-use and Ecosystem Services: An Example from the Anadarko Basin of Oklahoma, USA.

PubMed

Davis, Kendall M; Nguyen, Michael N; McClung, Maureen R; Moran, Matthew D

2018-05-01

The United States energy industry is transforming with the rapid development of alternative energy sources and technological advancements in fossil fuels. Two major changes include the growth of wind turbines and unconventional oil and gas. We measured land-use impacts and associated ecosystem services costs of unconventional gas and wind energy development within the Anadarko Basin of the Oklahoma Woodford Shale, an area that has experienced large increases in both energy sectors. Unconventional gas wells developed three times as much land compared to wind turbines (on a per unit basis), resulting in higher ecosystem services costs for gas. Gas wells had higher impacts on intensive agricultural lands (i.e., row crops) compared to wind turbines that had higher impacts on natural grasslands/pastures. Because wind turbines produced on average less energy compared to gas wells, the average land-use-related ecosystem cost per gigajoule of energy produced was almost the same. Our results demonstrate that both unconventional gas and wind energy have substantial impacts on land use, which likely affect wildlife populations and land-use-related ecosystem services. Although wind energy does not have the associated greenhouse gas emissions, we suggest that the direct impacts on ecosystems in terms of land use are similar to unconventional fossil fuels. Considering the expected rapid global expansion of these two forms of energy production, many ecosystems are likely to be at risk.

Termination Shock Transition in Multi-ion Multi-fluid MHD Models of the Heliosphere

NASA Astrophysics Data System (ADS)

Zieger, B.; Opher, M.; Toth, G.

2013-12-01

As evidenced by Voyager 2 observations, pickup ions (PUIs) play a significant role in the termination shock (TS) transition of the solar wind [Richardson et al., Nature, 2008]. Recent kinetic simulations [Ariad and Gedalin, JGR, 2013] came to the conclusion that the contribution of the high energy tail of PUIs is negligible at the shock transition. The Rankine-Hugoniot (R-H) relations are determined by the low energy body of PUIs. Particle-in-cell simulations by Wu et al. [JGR, 2010] have shown that the sum of the thermal solar wind and non-thermal PUI distributions downstream of the TS can be approximated with a 2-Maxwellian distribution. It is important to note that this 2-Maxwellian distribution neglects the suprathermal tail population that has a characteristic power-law distribution. These results justify the fluid description of PUIs in our large-scale multi-ion multi-fluid MHD simulations of the heliospheric interface [Prested et al., JGR, 2013; Zieger et al., GRL, 2013]. The closure of the multi-ion MHD equations could be implemented with separate momentum and energy equations for the different ion species (thermal solar wind and PUIs) where the transfer rate of momentum and energy between the two ion species are considered as source terms, like in Glocer et al. [JGR, 2009]. Another option is to solve for the total energy equation with an additional equation for the PUI pressure, as suggested by Fahr and Chalov [A&A, 2008]. In this paper, we validate the energy conservation and the R-H relations across the TS in different numerical implementations of our latest multi-ion multi-fluid MHD model. We assume an instantaneous pickup process, where the convection velocity of the two ion fluids are the same, and the so-called strong scattering approximation, where newly born PUIs attain their spherical shell distribution within a short distance on fluid scales (spatial scales much larger than the respective ion gyroradius).

Research Needs for Wind Resource Characterization

NASA Astrophysics Data System (ADS)

Schreck, S. J.; Lundquist, J. K.; Shaw, W. J.

2008-12-01

Currently, wind energy provides about 1 percent of U.S. electricity generation. A recent analysis by DOE, NREL, and AWEA showed the feasibility of expanding U.S. wind energy capacity to 20 percent, comprising approximately 300 gigawatts. Though not a prediction of the future, this represents a plausible scenario for U.S. wind energy. To exploit these opportunities, a workshop on Research Needs for Wind Resource Characterization was held during January 2008. This event was organized on behalf of two DOE organizations; the Office of Biological and Environmental Research and the Office of Energy Efficiency and Renewable Energy. Over 120 atmospheric science and wind energy researchers attended the workshop from industry, academia, and federal laboratories in North America and Europe. Attendees identified problems that could impede achieving the 20 percent wind scenario and formulated research recommendations to attack these problems. Findings were structured into four focus areas: 1) Turbine Dynamics, 2) Micrositing and Array Effects, 3) Mesoscale Processes, and 4) Climate Effects. In the Turbine Dynamics area, detailed characterizations of inflows and turbine flow fields were deemed crucial to attaining accuracy levels in aerodynamics loads required for future designs. To address the complexities inherent in this area, an incremental approach involving hierarchical computational modeling and detailed measurements was recommended. Also recommended was work to model extreme and anomalous atmospheric inflow events and aerostructural responses of turbines to these events. The Micrositing and Array Effects area considered improved wake models important for large, multiple row wind plants. Planetary boundary layer research was deemed necessary to accurately determine inflow characteristics in the presence of atmospheric stability effects and complex surface characteristics. Finally, a need was identified to acquire and exploit large wind inflow data sets, covering heights to 200 meters and encompassing spatial and temporal resolution ranges unique to wind energy. The Mesoscale Processes area deemed improved understanding of mesoscale and local flows crucial to providing enhanced model outputs for wind energy production forecasts and wind plant siting. Modeling approaches need to be developed to resolve spatial scales in the 100 to 1000 meter range, a notable gap in current capabilities. Validation of these models will require new instruments and observational strategies, including augmented analyses of existing measurements. In the Climate Effects area, research was recommended to understand historical trends in wind resource variability. This was considered a prerequisite for improved predictions of future wind climate and resources, which would enable reliable wind resource estimation for future planning. Participants also considered it important to characterize interactions between wind plants and climates through modeling and observations that suitably emphasize atmospheric boundary layer dynamics. High-penetration wind energy deployment represents a crucial and attainable U.S. strategic objective. Achieving the 20 percent wind scenario will require an unprecedented ability for characterizing large wind turbines arrayed in gigawatt wind plants and extracting elevated energy levels from the atmosphere. DOE national laboratories, with industry and academia, represents a formidable capability for attaining these objectives.

Reliability and cost/worth evaluation of generating systems utilizing wind and solar energy

NASA Astrophysics Data System (ADS)

Bagen

The utilization of renewable energy resources such as wind and solar energy for electric power supply has received considerable attention in recent years due to adverse environmental impacts and fuel cost escalation associated with conventional generation. At the present time, wind and/or solar energy sources are utilized to generate electric power in many applications. Wind and solar energy will become important sources for power generation in the future because of their environmental, social and economic benefits, together with public support and government incentives. The wind and sunlight are, however, unstable and variable energy sources, and behave far differently than conventional sources. Energy storage systems are, therefore, often required to smooth the fluctuating nature of the energy conversion system especially in small isolated applications. The research work presented in this thesis is focused on the development and application of reliability and economic benefits assessment associated with incorporating wind energy, solar energy and energy storage in power generating systems. A probabilistic approach using sequential Monte Carlo simulation was employed in this research and a number of analyses were conducted with regards to the adequacy and economic assessment of generation systems containing wind energy, solar energy and energy storage. The evaluation models and techniques incorporate risk index distributions and different operating strategies associated with diesel generation in small isolated systems. Deterministic and probabilistic techniques are combined in this thesis using a system well-being approach to provide useful adequacy indices for small isolated systems that include renewable energy and energy storage. The concepts presented and examples illustrated in this thesis will help power system planners and utility managers to assess the reliability and economic benefits of utilizing wind energy conversion systems, solar energy conversion systems and energy storage in electric power systems and provide useful input to the managerial decision process.

Numerical solutions of atmospheric flow over semielliptical simulated hills

NASA Technical Reports Server (NTRS)

Shieh, C. F.; Frost, W.

1981-01-01

Atmospheric motion over obstacles on plane surfaces to compute simulated wind fields over terrain features was studied. Semielliptical, two dimensional geometry and numerical simulation of flow over rectangular geometries is also discussed. The partial differential equations for the vorticity, stream function, turbulence kinetic energy, and turbulence length scale were solved by a finite difference technique. The mechanism of flow separation induced by a semiellipse is the same as flow over a gradually sloping surface for which the flow separation is caused by the interaction between the viscous force, the pressure force, and the turbulence level. For flow over bluff bodies, a downstream recirculation bubble is created which increases the aspect ratio and/or the turbulence level results in flow reattachment close behind the obstacle.

77 FR 55829 - Western Area Power Administration; Grapevine Canyon Wind Project Record of Decision (DOE/EIS-0427)

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-11

... megawatts of electricity from wind turbine generators (WTGs). The proposed project includes a wind energy... about the installation of red flashing lights on wind turbine generators per Federal Aviation... DEPARTMENT OF ENERGY Western Area Power Administration; Grapevine Canyon Wind Project Record of...

77 FR 41777 - Combined Notice of Filings #1

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-16

...., Commonwealth Edison Company, PECO Energy Company, Wind Capital Holdings, LLC, Constellation Power Source... Generation II, LLC, Constellation Mystic Power, LLC, Cassia Gulch Wind Park, LLC, Michigan Wind 1, LLC, Tuana Springs Energy, LLC, Harvest Windfarm, LLC, CR Clearing, LLC, Exelon Wind 4, LLC, Cow Branch Wind Power, L...

FINAL Report LTC-DOE DE-EE0000537

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gibbs, Michelle

2013-02-28

At the time of LTC’s application we were home to a small / mid-sized Wind Energy Research and Teaching Center, funded in part by We Energies, and offered the state of Wisconsin’s first Associate of Applied Science (A.A.S.) Degree in Wind Energy Technology. With President Obama promising investment in wind, LTC and its partners were uniquely situated to meet the challenge through an organized career pathways approach that utilized industry drivers and occupationally verified curriculum to train the workers who “transform our energy sector.” LTC’s employer partners validated the findings of the “20% Wind Energy by 2030: Increasing Wind Energy'smore » Contribution to U.S. Electricity Supply” report by the US Department of Energy which recognized programs like LTC’s as an “excellent beginning,” noting that many more like them are necessary to meet the challenges of the 20% Wind scenario.One of the focuses of the study was the lack of trained technicians to work on installation and maintenance of renewables (and more specifically for our grant application wind turbines). LTC’s goal, made possible with the funding provided in this grant, was to increase the number of skilled graduates to help meet this national objective. LTC was already a leader in wind for the state of Wisconsin but wanted to upscale from a single school to a statewide (and potentially regional) center for wind energy. LTC planned to leverage our facilities, curriculum, and faculty expertise to meet this goal.« less

Wind for Schools: Developing Educational Programs to Train a New Workforce and the Next Generation of Wind Energy Experts (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flowers, L.; Baring-Gould, I.

2010-04-01

As the United States dramatically expands wind energy deployment, the industry is challenged with developing a skilled workforce and addressing public resistance. Wind Powering America's Wind for Schools project addresses these issues by: Developing Wind Application Centers (WACs) at universities; installing small wind turbines at community "host" schools; and implementing teacher training with interactive curricula at each host school.

Assessment of the present and future offshore wind power potential: a case study in a target territory of the Baltic Sea near the Latvian coast.

PubMed

Lizuma, Lita; Avotniece, Zanita; Rupainis, Sergejs; Teilans, Artis

2013-01-01

Offshore wind energy development promises to be a significant domestic renewable energy source in Latvia. The reliable prediction of present and future wind resources at offshore sites is crucial for planning and selecting the location for wind farms. The overall goal of this paper is the assessment of offshore wind power potential in a target territory of the Baltic Sea near the Latvian coast as well as the identification of a trend in the future wind energy potential for the study territory. The regional climate model CLM and High Resolution Limited Area Model (Hirlam) simulations were used to obtain the wind climatology data for the study area. The results indicated that offshore wind energy is promising for expanding the national electricity generation and will continue to be a stable resource for electricity generation in the region over the 21st century.

Stabilization of Wind Energy Conversion System with Hydrogen Generator by Using EDLC Energy Storage System

NASA Astrophysics Data System (ADS)

Shishido, Seiji; Takahashi, Rion; Murata, Toshiaki; Tamura, Junji; Sugimasa, Masatoshi; Komura, Akiyoshi; Futami, Motoo; Ichinose, Masaya; Ide, Kazumasa

The spread of wind power generation is progressed hugely in recent years from a viewpoint of environmental problems including global warming. Though wind power is considered as a very prospective energy source, wind power fluctuation due to the random fluctuation of wind speed has still created some problems. Therefore, research has been performed how to smooth the wind power fluctuation. This paper proposes Energy Capacitor System (ECS) for the smoothing of wind power which consists of Electric Double-Layer Capacitor (EDLC) and power electronics devices and works as an electric power storage system. Moreover, hydrogen has received much attention in recent years from a viewpoint of exhaustion problem of fossil fuel. Therefore it is also proposed that a hydrogen generator is installed at the wind farm to generate hydrogen. In this paper, the effectiveness of the proposed system is verified by the simulation analyses using PSCAD/EMTDC.

Small Wind Electric Systems: A Guide Produced for the Tennessee Valley Authority (Revised) (Brochure)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2009-06-01

Small Wind Electric Systems: A Guide Produced for the Tennessee Valley Authority provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connectmore » a system to the utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a regional wind resource map and a list of incentives and contacts for more information.« less

Offshore Wind Initiatives at the U.S. Department of Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

Coastal and Great Lakes states account for nearly 80% of U.S. electricity demand, and the winds off the shores of these coastal load centers have a technical resource potential twice as large as the nation’s current electricity use. With the costs of offshore wind energy falling globally and the first U.S. offshore wind farm installed off the coast of Block Island, Rhode Island in 2016, offshore wind has the potential to contribute significantly to a clean, affordable, and secure national energy mix. To support the development of a world-class offshore wind industry, the U.S. Department of Energy has been supportingmore » a broad portfolio of offshore wind research, development, and demonstration projects since 2011 and released a new National Offshore Wind Strategy jointly with the U.S. Department of the Interior in 2016.« less

Statistical and Spectral Analysis of Wind Characteristics Relevant to Wind Energy Assessment Using Tower Measurements in Complex Terrain

DOE PAGES

Belu, Radian; Koracin, Darko

2013-01-01

The main objective of the study was to investigate spatial and temporal characteristics of the wind speed and direction in complex terrain that are relevant to wind energy assessment and development, as well as to wind energy system operation, management, and grid integration. Wind data from five tall meteorological towers located in Western Nevada, USA, operated from August 2003 to March 2008, used in the analysis. The multiannual average wind speeds did not show significant increased trend with increasing elevation, while the turbulence intensity slowly decreased with an increase were the average wind speed. The wind speed and direction weremore » modeled using the Weibull and the von Mises distribution functions. The correlations show a strong coherence between the wind speed and direction with slowly decreasing amplitude of the multiday periodicity with increasing lag periods. The spectral analysis shows significant annual periodicity with similar characteristics at all locations. The relatively high correlations between the towers and small range of the computed turbulence intensity indicate that wind variability is dominated by the regional synoptic processes. Knowledge and information about daily, seasonal, and annual wind periodicities are very important for wind energy resource assessment, wind power plant operation, management, and grid integration.« less

Turbulence measurements in an Alpine valley: The CividatEX Experiment case

NASA Astrophysics Data System (ADS)

Falocchi, Marco; Barontini, Stefano; Zardi, Dino; Ranzi, Roberto

2015-04-01

Results regarding the analysis of turbulence data, collected during Summer 2012, 2013 and 2014 in the framework of the CividatEX Experiment, are presented. The CividatEX Experiment, kicked off in July 2012 and still ongoing, aims at quantifying the mass and energy fluxes exchanged at the soil-atmosphere interface in an Alpine valley. A micro-meteorological station, equipped with standard meteorological devices, four TDR probes, soil heat-flux plate, soil thermometers and an eddy-covariance system (sonic anemometer and gas analyser), was installed on the valley floor of Valle Camonica at Cividate Camuno (274ma.s.l., Oglio river basin, Central Italian Alps). The experimental site is a gentle-sloping Technosol lawn, covered by common grass and surrounded by a steep hill (E and S) and by an anthropized landscape (W and N). Such complex terrain conditions affect the wind regime that, especially during fair weather conditions, is mainly regulated by thermally-driven winds. At least three winds were recognized, i.e. (1) the local wind Óra del Sebino (WSW, speed ranging from 2 to 4 ms-1), which rises the valley from Lake Iseo (Sebino) in the afternoon; (2) a katabatic flow with small speed (from 0.5 to 1.5 ms-1) blowing down the hillslope (directions ranging from E to SE) since the evening to the sunrise; and (3) an up-slope cross-valley wind (W, from 0.5 to 1.5 ms-1) flowing in the late morning. The 15 and 30-minutes eddy-covariance fluxes of momentum (τ), latent heat (λE) and sensible heat (Hs) were estimated using the software EddyPro. The surface energy imbalance was calculated as 1 - (λE + Hs)/(Rn - G), where Rn and G are the net radiation and the ground heat flux respectively. For all the three data-sets the imbalance assumes values ranging between 0.3 and 0.4. A dependence of its magnitude from the atmospheric stability and from the blowing wind was observed. In fact the imbalance reduces during unstable conditions, when the Óra occurs, and it increases during the night when the wind speed is small and stable conditions are approached. The separation of the turbulent components from the low-frequency unsteadiness of the mean-flow was investigated by means of three different approaches, that are the block average, the linear detrending and a digital recursive-filtering technique. The obtained dimensionless standard deviations of the wind velocities and of the temperature fluctuations were analyzed in the framework of the Monin-Obukhov similarity theory by checking their thickening on the similarity relationships. Due to the presence of meaningful unsteadiness during the investigated time-windows, the block average and the linear detrending were less effective than the recursive-filtering procedure at separating the turbulent fluctuations from the mean-flow.

Wind Fins: Novel Lower-Cost Wind Power System

DOE Office of Scientific and Technical Information (OSTI.GOV)

David C. Morris; Dr. Will D. Swearingen

This project evaluated the technical feasibility of converting energy from the wind with a novel “wind fin” approach. This patent-pending technology has three major components: (1) a mast, (2) a vertical, hinged wind structure or fin, and (3) a power takeoff system. The wing structure responds to the wind with an oscillating motion, generating power. The overall project goal was to determine the basic technical feasibility of the wind fin technology. Specific objectives were the following: (1) to determine the wind energy-conversion performance of the wind fin and the degree to which its performance could be enhanced through basic designmore » improvements; (2) to determine how best to design the wind fin system to survive extreme winds; (3) to determine the cost-effectiveness of the best wind fin designs compared to state-of-the-art wind turbines; and (4) to develop conclusions about the overall technical feasibility of the wind fin system. Project work involved extensive computer modeling, wind-tunnel testing with small models, and testing of bench-scale models in a wind tunnel and outdoors in the wind. This project determined that the wind fin approach is technically feasible and likely to be commercially viable. Project results suggest that this new technology has the potential to harvest wind energy at approximately half the system cost of wind turbines in the 10kW range. Overall, the project demonstrated that the wind fin technology has the potential to increase the economic viability of small wind-power generation. In addition, it has the potential to eliminate lethality to birds and bats, overcome public objections to the aesthetics of wind-power machines, and significantly expand wind-power’s contribution to the national energy supply.« less

Potential Offshore Wind Energy Areas in California: An Assessment of Locations, Technology, and Costs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Musial, Walter; Beiter, Philipp; Tegen, Suzanne

This report summarizes a study of possible offshore wind energy locations, technologies, and levelized cost of energy in the state of California between 2015 and 2030. The study was funded by the U.S. Department of the Interior's Bureau of Ocean Energy Management (BOEM), the federal agency responsible for regulating renewable energy development on the Outer Continental Shelf. It is based on reference wind energy areas where representative technology and performance characteristics were evaluated. These reference areas were identified as sites that were suitable to represent offshore wind cost and technology based on physical site conditions, wind resource quality, known existingmore » site use, and proximity to necessary infrastructure. The purpose of this study is to assist energy policy decision-making by state utilities, independent system operators, state government officials and policymakers, BOEM, and its key stakeholders. The report is not intended to serve as a prescreening exercise for possible future offshore wind development.« less

In Brief: Impacts of wind energy assessed

NASA Astrophysics Data System (ADS)

Zielinski, Sarah

2007-05-01

By 2020, greater use of wind energy could reduce carbon dioxide emissions by the U.S. energy sector by about 4.5%. However, greater effort is needed to address potentially negative impacts of this growing energy source, according to a new report from a committee of the U.S. National Research Council. Potential impacts of wind energy projects include deaths of birds and bats, reduced value of property located near a turbine, and habitat loss and fragmentation. However, because these are generally local projects, there is little information available to determine the cumulative effects of wind turbines over a whole region. The report makes several recommendations on how to improve regulation at the local, state, and federal levels. The report also sets out a guide for evaluating wind-energy projects, which includes questions about potential environmental, economic, cultural, and aesthetic impacts. The report, ``Environmental Impacts of Wind-Energy Projects,'' is available at http://books.nap.edu/catalog.php?record_id=11935

Economics of wind energy for irrigation pumping

NASA Astrophysics Data System (ADS)

Lansford, R. R.; Supalla, R. J.; Gilley, J. R.; Martin, D. L.

1980-07-01

The economic questions associated with wind power as an energy source for irrigation under different situations with seven regions of the nation were studied. Target investment costs for wind turbines used for irrigation pumping and policy makers with bases for adjusting taxes to make alternative sources of energy investments more attractive are analyzed. Three types of wind systems are considered for each of the seven regions. The three types of wind powered irrigation systems evaluated for each region are: (1) wind assist combustion engines (diesel, natural gas, propane panel); (2) wind assist electric engines, with or without sale of surplus electricity; and (3) stand alone reservoir systems with gravity flow reservoirs.

Final Technical Report, Wind Generator Project (Ann Arbor)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geisler, Nathan

A Final Technical Report (57 pages) describing educational exhibits and devices focused on wind energy, and related outreach activities and programs. Project partnership includes the City of Ann Arbor, MI and the Ann Arbor Hands-on Museum, along with additional sub-recipients, and U.S. Department of Energy/Office of Energy Efficiency and Renewable Energy (EERE). Report relays key milestones and sub-tasks as well as numerous graphics and images of five (5) transportable wind energy demonstration devices and five (5) wind energy exhibits designed and constructed between 2014 and 2016 for transport and use by the Ann Arbor Hands-on Museum.

An integrated biohydrogen refinery: synergy of photofermentation, extractive fermentation and hydrothermal hydrolysis of food wastes.

PubMed

Redwood, Mark D; Orozco, Rafael L; Majewski, Artur J; Macaskie, Lynne E

2012-09-01

An Integrated Biohydrogen Refinery (IBHR) and experimental net energy analysis are reported. The IBHR converts biomass to electricity using hydrothermal hydrolysis, extractive biohydrogen fermentation and photobiological hydrogen fermentation for electricity generation in a fuel cell. An extractive fermentation, developed previously, is applied to waste-derived substrates following hydrothermal pre-treatment, achieving 83-99% biowaste destruction. The selective separation of organic acids from waste-fed fermentations provided suitable substrate for photofermentative hydrogen production, which enhanced the gross energy generation up to 11-fold. Therefore, electrodialysis provides the key link in an IBHR for 'waste to energy'. The IBHR compares favourably to 'renewables' (photovoltaics, on-shore wind, crop-derived biofuels) and also emerging biotechnological options (microbial electrolysis) and anaerobic digestion. Copyright © 2012 Elsevier Ltd. All rights reserved.

Renewable energy and sustainable communities: Alaska's wind generator experience.

PubMed

Konkel, R Steven

2013-01-01

In 1984, the Alaska Department of Commerce and Economic Development (DCED) issued the State's first inventory/economic assessment of wind generators, documenting installed wind generator capacity and the economics of replacing diesel-fuel-generated electricity. Alaska's wind generation capacity had grown from hundreds of installed kilowatts to over 15.3 megawatts (MW) by January 2012. This article reviews data and conclusions presented in "Alaska's Wind Energy Systems; Inventory and Economic Assessment" (1). (Alaska Department of Commerce and Economic Development, S. Konkel, 1984). It provides a foundation and baseline for understanding the development of this renewable energy source. Today's technologies have evolved at an astonishing pace; a typical generator in an Alaska wind farm now is likely rated at 1.5-MW capacity, compared to the single-kilowatt (kW) machines present in 1984. Installed capacity has mushroomed, illustrated by Unalakleet's 600-kW wind farm dwarfing the original three 10-kW machines included in the 1984 inventory. Kodiak Electric had three 1.5-MW turbines installed at Pillar Mountain in 2009, with three additional turbines of 4.5-MW capacity installed in 2012. Utilities now actively plan for wind generation and compete for state funding. State of Alaska energy policy provides the context for energy project decision-making. Substantial renewable energy fund (REF) awards--$202,000,000 to date for 227 REF projects in the first 5 cycles of funding--along with numerous energy conservation programs--are now in place. Increasing investment in wind is driven by multiple factors. Stakeholders have interests both in public policy and meeting private investment objectives. Wind generator investors should consider project economics and potential impacts of energy decisions on human health. Specifically this article considers: changing environmental conditions in remote Alaska villages, impacts associated with climate change on human health, progress in better understanding wind energy potential through resource assessments and new tools for detailed feasibility and project planning, need for comprehensive monitoring and data analysis, and state funding requirements and opportunity costs. The energy policy choices ahead for Alaska will have important implications for Arctic population health, especially for those villages whose relatively small size and remote locations make energy a key component of subsistence lifestyles and community sustainability. Wind generation can contribute to meeting renewable energy goals and is a particularly important resource for rural and remote Alaskan communities currently dependent on diesel fuel for generating electricity and heat.

Improving battery safety by early detection of internal shorting with a bifunctional separator

NASA Astrophysics Data System (ADS)

Wu, Hui; Zhuo, Denys; Kong, Desheng; Cui, Yi

2014-10-01

Lithium-based rechargeable batteries have been widely used in portable electronics and show great promise for emerging applications in transportation and wind-solar-grid energy storage, although their safety remains a practical concern. Failures in the form of fire and explosion can be initiated by internal short circuits associated with lithium dendrite formation during cycling. Here we report a new strategy for improving safety by designing a smart battery that allows internal battery health to be monitored in situ. Specifically, we achieve early detection of lithium dendrites inside batteries through a bifunctional separator, which offers a third sensing terminal in addition to the cathode and anode. The sensing terminal provides unique signals in the form of a pronounced voltage change, indicating imminent penetration of dendrites through the separator. This detection mechanism is highly sensitive, accurate and activated well in advance of shorting and can be applied to many types of batteries for improved safety.

A Physicochemical Method for Separating Rare Earths: Addressing an Impending Shortfall

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schelter, Eric

2017-03-14

There are currently zero operating suppliers of critical rare earth elements La–Lu, Sc, Y (REs), in the western hemisphere. REs are critical materials due to their importance in clean energy and defense applications, including permanent magnets in wind turbines and phosphors in energy efficient lighting. It is not economically viable to produce pure REs in the U.S. given current separations technology. REs production is dominated by suppliers in the People’s Republic of China (PRC) because of their capacity in liquid­liquid solvent extraction (SX) used to purify mixtures. Weak environmental regulations in the PRC also contribute to a competitive advantage. SXmore » is a cost, time, solvent and waste intensive process but is highly optimized and scalable. The low efficiency of SX derives from the small thermodynamic differences in solvation enthalpy between the RE3+ cations. To foster stable domestic RE production there is a critical need for fundamentally new REs chemistry that contributes to disruptive technologies in RE separations. The overall goal of this project was to develop new thermodynamic bases, and apply them, for the solution separation of rare earth metals. We have developed the chemistry of rare earth metals: La–Lu, Sc and Y, with redox active ligands. Our hypothesis for the project was that electron­hole coupling in complexes of certain lanthanide metals with redox active ligands can be used to manifest chemical distinctiveness and affect separations. We also developed separations based on unique solution equilibria from tailored ligands.« less

Bibliography of NASA-related publications on wind turbine technology 1973-1995

NASA Technical Reports Server (NTRS)

Spera, David A.

1995-01-01

A major program of research and development projects on wind turbines for generating electricity was conducted at the NASA Lewis Research Center from 1973 to 1988. Most of these projects were sponsored by the U.S. Department of Energy (DOE), as a major element of its Federal Wind Energy Program. One other large-scale wind turbine project was sponsored by the Bureau of Reclamation of the Department of Interior (DOI). The peak years for wind energy work at Lewis were 1979-80, when almost 100 engineers, technicians, and administrative personnel were involved. From 1988 their conclusion in 1995, NASA wind energy activities have been directed toward the transfer of technology to commercial and academic organizations. Wind energy activities at NASA can be divided into two broad categories which are closely related and often overlapping: (1) Designing, building, and testing a series of 12 large-scale, experimental, horizontal-axis wind turbines (HAWT's); and (2) conducting supporting research and technology (SR&T) projects. The purpose of this bibliography is to assist those active in the field of wind energy in locating the technical information they need on wind power planning, wind loads, turbine design and analysis, fabrication and installation, laboratory and field testing, and operations and maintenance. This bibliography contains approximately 620 citations of publications by over 520 authors and co-authors. Sources are: (1) NASA reports authored by government grantee, and contractor personnel, (2) papers presented by attendees at NASA-sponsored workshops and conferences, (3) papers presented by NASA personnel at outside workshops and conferences, and (4) outside publications related to research performed at NASA/ DOE wind turbine sites.

Design of Hybrid Solar and Wind Energy Harvester for Fishing Boat

NASA Astrophysics Data System (ADS)

Banjarnahor, D. A.; Hanifan, M.; Budi, E. M.

2017-07-01

In southern beach of West Java, Indonesia, there are many villagers live as fishermen. They use small boats for fishing, in one to three days. Therefore, they need a fish preservation system. Fortunately, the area has high potential of solar and wind energy. This paper presents the design of a hybrid solar and wind energy harvester to power a refrigerator in the fishing boat. The refrigerator should keep the fish in 2 - 4 °C. The energy needed is 720 Wh daily. In the area, the daily average wind velocity is 4.27 m/s and the sun irradiation is 672 W/m2. The design combined two 100W solar panels and a 300W wind turbine. The testing showed that the solar panels can harvest 815 - 817 Wh of energy, while the wind turbine can harvest 43 - 62 Wh of energy daily. Therefore, the system can fulfil the energy requirement in fishing boat, although the solar panels were more dominant. To install the wind turbine on the fishing-boat, a computational design had been conducted. The boat hydrostatic dimension was measured to determine its stability condition. To reach a stable equilibrium condition, the wind turbine should be installed no more than 1.7 m of height.

Wind energy potential assessment of Cameroon's coastal regions for the installation of an onshore wind farm.

PubMed

Arreyndip, Nkongho Ayuketang; Joseph, Ebobenow; David, Afungchui

2016-11-01

For the future installation of a wind farm in Cameroon, the wind energy potentials of three of Cameroon's coastal cities (Kribi, Douala and Limbe) are assessed using NASA average monthly wind data for 31 years (1983-2013) and compared through Weibull statistics. The Weibull parameters are estimated by the method of maximum likelihood, the mean power densities, the maximum energy carrying wind speeds and the most probable wind speeds are also calculated and compared over these three cities. Finally, the cumulative wind speed distributions over the wet and dry seasons are also analyzed. The results show that the shape and scale parameters for Kribi, Douala and Limbe are 2.9 and 2.8, 3.9 and 1.8 and 3.08 and 2.58, respectively. The mean power densities through Weibull analysis for Kribi, Douala and Limbe are 33.7 W/m2, 8.0 W/m2 and 25.42 W/m2, respectively. Kribi's most probable wind speed and maximum energy carrying wind speed was found to be 2.42 m/s and 3.35 m/s, 2.27 m/s and 3.03 m/s for Limbe and 1.67 m/s and 2.0 m/s for Douala, respectively. Analysis of the wind speed and hence power distribution over the wet and dry seasons shows that in the wet season, August is the windiest month for Douala and Limbe while September is the windiest month for Kribi while in the dry season, March is the windiest month for Douala and Limbe while February is the windiest month for Kribi. In terms of mean power density, most probable wind speed and wind speed carrying maximum energy, Kribi shows to be the best site for the installation of a wind farm. Generally, the wind speeds at all three locations seem quite low, average wind speeds of all the three studied locations fall below 4.0m/s which is far below the cut-in wind speed of many modern wind turbines. However we recommend the use of low cut-in speed wind turbines like the Savonius for stand alone low energy needs.

Gradients and anisotropies of high energy cosmic rays in the outer heliosphere

NASA Technical Reports Server (NTRS)

Fillius, W.; Roelof, E. C.; Smith, E. J.; Wood, D.; Ip, W. H.

1985-01-01

Two cosmic rays which pass through the same point going in opposite directions will, in the absence of scattering and inhomogeneities in the magnetic field, trace helices about adjacent flux tubes, whose centerlines are separated by one gyrodiameter. A directional anisotropy at the point suggests a difference in the number of cosmic rays loading the two flux tubes; that is, a density gradient over the baseline of a gyrodiameter. Previous studies at lower energies have shown that the cosmic ray density gradients vary in time and space. It is suggested that the radial gradient associated with solar cycle modulation is supported largely by narrow barriers which encircle the sun and propagate outward with the solar wind. If so, the anisotropy is a desirable way to detect spatial gradients, because it can be associated with the local solar wind and magnetic field conditions. Anisotropic measurements made by Cerenkov detectors on Pioneers 10 and 11 were studied. It was found that local anisotropy varies greatly, but that the long term average is consistent with the global radial gradient measured between two spacecraft over a baseline of many AU.

Storing wind energy into electrical accumulators

NASA Astrophysics Data System (ADS)

Dordescu, M.; Petrescu, D. I.; Erdodi, G. M.

2016-12-01

Shall be determined, in this work, the energy stored in the accumulators electrical, AE, at a wind system operating at wind speeds time-varying. mechanical energy caught in the turbine from the wind, (TV), is transformed into electrical energy by the generator synchronous with the permanent magnets, GSMP. The Generator synchronous with the permanent magnets saws, via a rectifier, energy in a battery AE, finished in a choice of two: variant 1-unregulated rectifier and variant of the 2-controlled rectifier and task adapted. Through simulation determine the differences between the two versions

Integration of Wind Energy Systems into Power Engineering Education Program at UW-Madison

DOE Office of Scientific and Technical Information (OSTI.GOV)

Venkataramanan, Giri; Lesieutre, Bernard; Jahns, Thomas

This project has developed an integrated curriculum focused on the power engineering aspects of wind energy systems that builds upon a well-established graduate educational program at UW- Madison. Five new courses have been developed and delivered to students. Some of the courses have been offered on multiple occasions. The courses include: Control of electric drives for Wind Power applications, Utility Applications of Power Electronics (Wind Power), Practicum in Small Wind Turbines, Utility Integration of Wind Power, and Wind and Weather for Scientists and Engineers. Utility Applications of Power Electronics (Wind Power) has been provided for distance education as well asmore » on-campus education. Several industrial internships for students have been organized. Numerous campus seminars that provide discussion on emerging issues related to wind power development have been delivered in conjunction with other campus events. Annual student conferences have been initiated, that extend beyond wind power to include sustainable energy topics to draw a large group of stakeholders. Energy policy electives for engineering students have been identified for students to participate through a certificate program. Wind turbines build by students have been installed at a UW-Madison facility, as a test-bed. A Master of Engineering program in Sustainable Systems Engineering has been initiated that incorporates specializations that include in wind energy curricula. The project has enabled UW-Madison to establish leadership at graduate level higher education in the field of wind power integration with the electric grid.« less

Wind power generation and dispatch in competitive power markets

NASA Astrophysics Data System (ADS)

Abreu, Lisias

Wind energy is currently the fastest growing type of renewable energy. The main motivation is led by more strict emission constraints and higher fuel prices. In addition, recent developments in wind turbine technology and financial incentives have made wind energy technically and economically viable almost anywhere. In restructured power systems, reliable and economical operation of power systems are the two main objectives for the ISO. The ability to control the output of wind turbines is limited and the capacity of a wind farm changes according to wind speeds. Since this type of generation has no production costs, all production is taken by the system. Although, insufficient operational planning of power systems considering wind generation could result in higher system operation costs and off-peak transmission congestions. In addition, a GENCO can participate in short-term power markets in restructured power systems. The goal of a GENCO is to sell energy in such a way that would maximize its profitability. However, due to market price fluctuations and wind forecasting errors, it is essential for the wind GENCO to keep its financial risk at an acceptable level when constituting market bidding strategies. This dissertation discusses assumptions, functions, and methodologies that optimize short-term operations of power systems considering wind energy, and that optimize bidding strategies for wind producers in short-term markets. This dissertation also discusses uncertainties associated with electricity market environment and wind power forecasting that can expose market participants to a significant risk level when managing the tradeoff between profitability and risk.

76 FR 69279 - Notice of Intent to Prepare an Environmental Impact Statement for the Quaking Aspen Wind Energy...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-08

... to 100 1.5 megawatt (MW) to 3 MW wind turbine generators with a nameplate capacity of 250 MW of power... Intent to Prepare an Environmental Impact Statement for the Quaking Aspen Wind Energy Project, Wyoming... Statement (EIS) for the Quaking Aspen Wind Energy Project (Quaking Aspen). By this notice, BLM is: (1...

Blowing in the wind: evaluating wind energy projects on the national forests

Treesearch

Kerry Schlichting; Evan Mercer

2011-01-01

The 650 million ac of federal lands are facing increased scrutiny for wind energy development. As a result, the US Forest Service has been directed to develop policies and procedures for siting wind energy projects. We incorporate geospatial site suitability analysis with applicable policy and management principles to illustrate the use of a Spatial Decision Support...

77 FR 24941 - Vantage Wind Energy LLC; Order Accepting Updated Market Power Analysis and Providing Direction on...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-26

.... 1. In this order, the Commission accepts an updated market power analysis filed by Vantage Wind.... Background 3. On December 20, 2010, Vantage Wind filed an updated market power analysis in compliance with... power analysis filed by Puget Sound Energy, Inc. (Puget).\\4\\ \\3\\ See Vantage Wind Energy LLC, Docket No...

Prediction of Wind Energy Resources (PoWER) Users Guide

DTIC Science & Technology

2016-01-01

ARL-TR-7573● JAN 2016 US Army Research Laboratory Prediction of Wind Energy Resources (PoWER) User’s Guide by David P Sauter...not return it to the originator. ARL-TR-7573 ● JAN 2016 US Army Research Laboratory Prediction of Wind Energy Resources (PoWER...2016 2. REPORT TYPE Final 3. DATES COVERED (From - To) 09/2015–11/2015 4. TITLE AND SUBTITLE Prediction of Wind Energy Resources (PoWER) User’s

Modeling Spectral Variations of Dusty Circumstellar Envelopes During Microlensing Events

NASA Astrophysics Data System (ADS)

Bunker, Christina; Ignace, R.; Bjorkman, J. E.

2007-12-01

Microlensing surveys have proven to be tremendously fruitful in providing valuable data products for many fields of astrophysics, from eclipse lightcurves for substellar candidates to limb darkening in stellar atmospheres. We report on a program of modeling observables from microlensing of circumstellar envelopes, particularly those of red giant stars that are the most likely to show finite source effects. Recent modeling results for the time dependent spectral energy distributions from microlensing of dusty winds are presented. In effect, wavelength-dependent continuum variations that occur as the lens-star separation changes can provide information about the emissivity distribution of dust in the wind. This project was funded by a partnership between the National Science Foundation (NSF AST-0552798), Research Experiences for Undergraduates (REU), and the Department of Defense (DoD) ASSURE (Awards to Stimulate and Support Undergraduate Research Experiences) programs.

Wind Energy Workforce Development: Engineering, Science, & Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lesieutre, George A.; Stewart, Susan W.; Bridgen, Marc

2013-03-29

Broadly, this project involved the development and delivery of a new curriculum in wind energy engineering at the Pennsylvania State University; this includes enhancement of the Renewable Energy program at the Pennsylvania College of Technology. The new curricula at Penn State includes addition of wind energy-focused material in more than five existing courses in aerospace engineering, mechanical engineering, engineering science and mechanics and energy engineering, as well as three new online graduate courses. The online graduate courses represent a stand-alone Graduate Certificate in Wind Energy, and provide the core of a Wind Energy Option in an online intercollege professional Mastersmore » degree in Renewable Energy and Sustainability Systems. The Pennsylvania College of Technology erected a 10 kilowatt Xzeres wind turbine that is dedicated to educating the renewable energy workforce. The entire construction process was incorporated into the Renewable Energy A.A.S. degree program, the Building Science and Sustainable Design B.S. program, and other construction-related coursework throughout the School of Construction and Design Technologies. Follow-on outcomes include additional non-credit opportunities as well as secondary school career readiness events, community outreach activities, and public awareness postings.« less

Energy Security: From Deal Killers to Game Changers

NASA Astrophysics Data System (ADS)

Cooke, Charlie

2010-03-01

Five energy security ``deal killers" are identified: 1) Global warming and CO2 emissions from fossil fuel combustion; 2) Intermittent energy sources (wind, solar) and the presence and stability of the grid; 3) Penetration of plant defenses to produce transportation fuels from biomass; 4) Mimicking nature: artificial photosynthesis for solar energy to fuels; and 5) Spent fuel from nuclear power reactors. Transformational basic research is required to successfully change the ground rules, to transform these ``deal killers" into ``game changers." T hey are: 1) Offsetting carbon capture and storage costs through enhanced oil recovery and methane generation from high temperature geothermal saline aquifers; 2) Electrical energy storage, through batteries and super-capacitors; 3) Genetic modification of plant cell walls, and catalytic methods for transforming plant sugars into fuels; 4) Separation of solar-induced electrons from holes, and catalysis to produce fuels; and 5) Closing the nuclear fuel cycle. Basic research can revolutionize our approach to carbon-free energy by enhancing nature to achieve energy security.

77 FR 28594 - Bethel Wind Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-15

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER12-1739-000] Bethel Wind Energy LLC; Supplemental Notice That Initial Market- Based Rate Filing Includes Request for Blanket Section 204 Authorization This is a supplemental notice in the above-referenced proceeding of Bethel Wind...

77 FR 28593 - Rippey Wind Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-15

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER12-1740-000] Rippey Wind Energy LLC; Supplemental Notice That Initial Market- Based Rate Filing Includes Request for Blanket Section 204 Authorization This is a supplemental notice in the above-referenced proceeding of Rippey Wind...

75 FR 77654 - Notice of Intent To Prepare a Land Use Plan Amendment and an Environmental Impact Statement for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-13

..., maintenance, and decommissioning of wind turbine generators and associated facilities necessary to... the Pattern Energy Group Ocotillo Express Wind Energy Project, Imperial County, CA AGENCY: Bureau of... Pattern Energy Group Ocotillo Express Wind Energy Project Draft EIR/EIS by any of the following methods...

76 FR 23198 - Segregation of Lands-Renewable Energy

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-26

... could be used to carry the power generated from a specific wind or solar energy ROW project, and the... included in a pending or future wind or solar energy generation right- of-way (ROW) application, or public lands identified by the BLM for a potential future wind or solar energy generation ROW authorization...

76 FR 23230 - Segregation of Lands-Renewable Energy

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-26

... within the wind energy right-of- way application areas in FY 2009 and 2010, we estimate the total cost of... transmission facilities that could be used to carry the power generated from a specific wind or solar energy..., public lands included in a pending or future wind or solar energy generation right-of-way (ROW...

Summary of atmospheric wind design criteria for wind energy conversion system development

NASA Technical Reports Server (NTRS)

Frost, W.; Turner, R. E.

1979-01-01

Basic design values are presented of significant wind criteria, in graphical format, for use in the design and development of wind turbine generators for energy research. It is a condensed version of portions of the Engineering Handbook on the Atmospheric Environmental Guidelines for Use in Wind Turbine Generator Development.

75 FR 70021 - South Dakota Prairie Winds Project; Partial Term Relinquishment and Release of Easement for Wind...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-16

... certain easement rights for the construction, operation, and maintenance of the proposed wind energy... certain easement rights for the construction, operation, and maintenance of proposed wind energy... were: No Action Alternative (i.e., wind turbines would have to be sited on lands not encumbered with...

Roles of divergent and rotational winds in the kinetic energy balance during intense convective activity

NASA Technical Reports Server (NTRS)

Fuelberg, H. E.; Browning, P. A.

1983-01-01

Contributions of divergent and rotational wind components to the synoptic-scale kinetic energy balance are described using rawinsonde data at 3 and 6 h intervals from NASA's fourth Atmospheric Variability experiment. Two intense thunderstorm complexes occurred during the period. Energy budgets are described for the entire computational region and for limited volumes that enclosed storm-induced, upper level wind maxima located poleward of convection. Although small in magnitude, the divergent wind component played an important role in the cross-contour generation and horizontal flux divergence of kinetic energy. The importance of V(D) appears directly related to the presence and intensity of convection. Although K(D) usually comprised less than 10 percent of the total kinetic energy content, generation of kinetic energy by V(D) was a major factor in the creation of upper-level wind maxima to the north of the storm complexes. Omission of the divergent wind apparently would lead to serious misrepresentations of the energy balance. A random error analysis is presented to assess confidence limits in the various energy parameters.

Observations of the directional distribution of the wind energy input function over swell waves

NASA Astrophysics Data System (ADS)

Shabani, Behnam; Babanin, Alex V.; Baldock, Tom E.

2016-02-01

Field measurements of wind stress over shallow water swell traveling in different directions relative to the wind are presented. The directional distribution of the measured stresses is used to confirm the previously proposed but unverified directional distribution of the wind energy input function. The observed wind energy input function is found to follow a much narrower distribution (β∝cos⁡3.6θ) than the Plant (1982) cosine distribution. The observation of negative stress angles at large wind-wave angles, however, indicates that the onset of negative wind shearing occurs at about θ≈ 50°, and supports the use of the Snyder et al. (1981) directional distribution. Taking into account the reverse momentum transfer from swell to the wind, Snyder's proposed parameterization is found to perform exceptionally well in explaining the observed narrow directional distribution of the wind energy input function, and predicting the wind drag coefficients. The empirical coefficient (ɛ) in Snyder's parameterization is hypothesised to be a function of the wave shape parameter, with ɛ value increasing as the wave shape changes between sinusoidal, sawtooth, and sharp-crested shoaling waves.

SIMWEST - A simulation model for wind energy storage systems

NASA Technical Reports Server (NTRS)

Edsinger, R. W.; Warren, A. W.; Gordon, L. H.; Chang, G. C.

1978-01-01

This paper describes a comprehensive and efficient computer program for the modeling of wind energy systems with storage. The level of detail of SIMWEST (SImulation Model for Wind Energy STorage) is consistent with evaluating the economic feasibility as well as the general performance of wind energy systems with energy storage options. The software package consists of two basic programs and a library of system, environmental, and control components. The first program is a precompiler which allows the library components to be put together in building block form. The second program performs the technoeconomic system analysis with the required input/output, and the integration of system dynamics. An example of the application of the SIMWEST program to a current 100 kW wind energy storage system is given.

A comparison of Loon balloon observations and stratospheric reanalysis products

NASA Astrophysics Data System (ADS)

Friedrich, Leon S.; McDonald, Adrian J.; Bodeker, Gregory E.; Cooper, Kathy E.; Lewis, Jared; Paterson, Alexander J.

2017-01-01

Location information from long-duration super-pressure balloons flying in the Southern Hemisphere lower stratosphere during 2014 as part of X Project Loon are used to assess the quality of a number of different reanalyses including National Centers for Environmental Prediction Climate Forecast System version 2 (NCEP-CFSv2), European Centre for Medium-Range Weather Forecasts (ERA-Interim), NASA Modern Era Retrospective-Analysis for Research and Applications (MERRA), and the recently released MERRA version 2. Balloon GPS location information is used to derive wind speeds which are then compared with values from the reanalyses interpolated to the balloon times and locations. All reanalysis data sets accurately describe the winds, with biases in zonal winds of less than 0.37 m s-1 and meridional biases of less than 0.08 m s-1. The standard deviation on the differences between Loon and reanalyses zonal winds is latitude-dependent, ranging between 2.5 and 3.5 m s-1, increasing equatorward. Comparisons between Loon trajectories and those calculated by applying a trajectory model to reanalysis wind fields show that MERRA-2 wind fields result in the most accurate simulated trajectories with a mean 5-day balloon-reanalysis trajectory separation of 621 km and median separation of 324 km showing significant improvements over MERRA version 1 and slightly outperforming ERA-Interim. The latitudinal structure of the trajectory statistics for all reanalyses displays marginally lower mean separations between 15 and 35° S than between 35 and 55° S, despite standard deviations in the wind differences increasing toward the equator. This is shown to be related to the distance travelled by the balloon playing a role in the separation statistics.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Small Wind Electric Systems: A Colorado Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and their economics. Topics discussed in the guide include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to themore » utility grid, and whether it's possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a regional wind resource map and a list of incentives and contacts for more information.« less

Analysis of superconducting magnetic energy storage applications at a proposed wind farm site near Browning, Montana

NASA Astrophysics Data System (ADS)

Gaustad, K. L.; Desteese, J. G.

1993-07-01

A computer program was developed to analyze the viability of integrating superconducting magnetic energy storage (SMES) with proposed wind farm scenarios at a site near Browning, Montana. The program simulated an hour-by-hour account of the charge/discharge history of a SMES unit for a representative wind-speed year. Effects of power output, storage capacity, and power conditioning capability on SMES performance characteristics were analyzed on a seasonal, diurnal, and hourly basis. The SMES unit was assumed to be charged during periods when power output of the wind resource exceeded its average value. Energy was discharged from the SMES unit into the grid during periods of low wind speed to compensate for below-average output of the wind resource. The option of using SMES to provide power continuity for a wind farm supplemented by combustion turbines was also investigated. Levelizing the annual output of large wind energy systems operating in the Blackfeet area of Montana was found to require a storage capacity too large to be economically viable. However, it appears that intermediate-sized SMES economically levelize the wind energy output on a seasonal basis.

Legal requirements for human-health based appeals of wind energy projects in ontario.

PubMed

Engel, Albert M

2014-01-01

In 2009, the government of the province of Ontario, Canada passed new legislation to promote the development of renewable energy facilities, including wind energy facilities in the province. Throughout the legislative process, concerns were raised with respect to the effect of wind energy facilities on human health. Ultimately, the government established setbacks and sound level limits for wind energy facilities and provided Ontario residents with the right to appeal the approval of a wind energy facility on the ground that engaging in the facility in accordance with its approval will cause serious harm to human health. The first approval of a wind facility under the new legislation was issued in 2010 and since then, Ontario's Environmental Review Tribunal as well as Ontario's courts has been considering evidence proffered by appellants seeking revocation of approvals on the basis of serious harm to human health. To date, the evidence has been insufficient to support the revocation of a wind facility approval. This article reviews the legal basis for the dismissal of human-health based appeals.

Distributed Wind Competitiveness Improvement Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

The Competitiveness Improvement Project (CIP) is a periodic solicitation through the U.S. Department of Energy and its National Renewable Energy Laboratory. The Competitiveness Improvement Project (CIP) is a periodic solicitation through the U.S. Department of Energy and its National Renewable Energy Laboratory. Manufacturers of small and medium wind turbines are awarded cost-shared grants via a competitive process to optimize their designs, develop advanced manufacturing processes, and perform turbine testing. The goals of the CIP are to make wind energy cost competitive with other distributed generation technology and increase the number of wind turbine designs certified to national testing standards. Thismore » fact sheet describes the CIP and funding awarded as part of the project.ufacturers of small and medium wind turbines are awarded cost-shared grants via a competitive process to optimize their designs, develop advanced manufacturing processes, and perform turbine testing. The goals of the CIP are to make wind energy cost competitive with other distributed generation technology and increase the number of wind turbine designs certified to national testing standards. This fact sheet describes the CIP and funding awarded as part of the project.« less

A Spatial-Economic Cost-Reduction Pathway Analysis for U.S. Offshore Wind Energy Development from 2015–2030

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beiter, Philipp; Musial, Walter; Smith, Aaron

This report describes a comprehensive effort undertaken by the National Renewable Energy Laboratory (NREL) to understand the cost of offshore wind energy for markets in the United States. The study models the cost impacts of a range of offshore wind locational cost variables for more than 7,000 potential coastal sites in U.S. offshore wind resource areas. It also assesses the impact of more than 50 technology innovations on potential future costs for both fixed-bottom and floating wind systems. Comparing these costs to an initial site-specific assessment of local avoided generating costs, the analysis provides a framework for estimating the economicmore » potential for offshore wind. The analysis is intended to inform a broad set of stakeholders and enable an assessment of offshore wind as part of energy development and energy portfolio planning. It provides information that federal and state agencies and planning commissions could use to inform initial strategic decisions about offshore wind developments in the United States.« less

Abrupt acceleration of a 'cold' ultrarelativistic wind from the Crab pulsar.

PubMed

Aharonian, F A; Bogovalov, S V; Khangulyan, D

2012-02-15

Pulsars are thought to eject electron-positron winds that energize the surrounding environment, with the formation of a pulsar wind nebula. The pulsar wind originates close to the light cylinder, the surface at which the pulsar co-rotation velocity equals the speed of light, and carries away much of the rotational energy lost by the pulsar. Initially the wind is dominated by electromagnetic energy (Poynting flux) but later this is converted to the kinetic energy of bulk motion. It is unclear exactly where this takes place and to what speed the wind is accelerated. Although some preferred models imply a gradual acceleration over the entire distance from the magnetosphere to the point at which the wind terminates, a rapid acceleration close to the light cylinder cannot be excluded. Here we report that the recent observations of pulsed, very high-energy γ-ray emission from the Crab pulsar are explained by the presence of a cold (in the sense of the low energy of the electrons in the frame of the moving plasma) ultrarelativistic wind dominated by kinetic energy. The conversion of the Poynting flux to kinetic energy should take place abruptly in the narrow cylindrical zone of radius between 20 and 50 light-cylinder radii centred on the axis of rotation of the pulsar, and should accelerate the wind to a Lorentz factor of (0.5-1.0) × 10(6). Although the ultrarelativistic nature of the wind does support the general model of pulsars, the requirement of the very high acceleration of the wind in a narrow zone not far from the light cylinder challenges current models.

Wind Energy Developments: Incentives In Selected Countries

EIA Publications

1999-01-01

This paper discusses developments in wind energy for the countries with significant wind capacity. After a brief overview of world capacity, it examines development trends, beginning with the United States - the number one country in wind electric generation capacity until 1997.

78 FR 5798 - Grouse Creek Wind Park, LLC, Grouse Creek Wind Park II, LLC; Notice of Petition for Enforcement

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-28

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket Nos. El13-39-000, QF11-32-001, QF11-33-001] Grouse Creek Wind Park, LLC, Grouse Creek Wind Park II, LLC; Notice of Petition for... Policies Act of 1978 (PURPA), Grouse Creek Wind Park, LLC and Grouse Creek Wind Park II, LLC filed a...

Wind Generator & Biomass No-draft Gasification Hybrid

NASA Astrophysics Data System (ADS)

Hein, Matthew R.

The premise of this research is that underutilized but vast intermittent renewable energy resources, such as wind, can become more market competitive by coupling with storable renewable energy sources, like biomass; thereby creating a firm capacity resource. Specifically, the Midwest state of South Dakota has immense wind energy potential that is not used because of economic and logistic barriers of electrical transmission or storage. Coupling the state's intermittent wind resource with another of the state's energy resources, cellulosic non-food biomass, by using a wind generator and no-draft biomass gasification hybrid system will result in a energy source that is both firm and storable. The average energy content of common biomass feedstock was determined, 14.8 MJ/kg (7.153 Btu/lb), along with the assumed typical biomass conversion efficiency of the no-draft gasifier, 65%, so that an average electrical energy round trip efficiency (RTE) of 214% can be expected (i.e. One unit of wind electrical energy can produce 2.14 kWh of electrical energy stored as syngas.) from a wind generator and no-draft biomass gasification system. Wind characteristics are site specific so this analysis utilizes a synthetic wind resource to represent a statistically sound gross representation of South Dakota's wind regime based on data from the Wind Resource Assessment Network (WRAN) locations. A synthetic wind turbine generated from common wind turbine power curves and scaled to 1-MW rated capacity was utilized for this analysis in order to remove equipment bias from the results. A standard 8,760-hour BIN Analysis model was constructed within HOMER, powerful simulation software developed by the National Renewable Energy Laboratory (NREL) to model the performance of renewable power systems. It was found that the optimum configuration on a per-megawatt-transmitted basis required a wind generator (wind farm) rated capacity of 3-MW with an anticipated annual biomass feedstock of 26,132 GJ or an anticipated 1,766 tonnes of biomass. The levelized cost of electricity (COE) ranged from 65.6/GJ (236/MWh) to 208.9/GJ (752/MWh) with the price of generated electricity being most sensitive to the biomass feedstock cost and the levelized COE being significantly impacted by the high cost of compressed storage. The resulting electrical energy available to the grid has an approximate wholesale value of 13.5/GJ (48.6/MWh) based on year 2007 Midwest Reliability Organization (MRO) regional averages [1]. Therefore, the annual average wholesale value of the generated electricity is lower than the cost to produce the electricity. A significant deficiency of this simple comparison is that it does not consider the fact that the proposed wind and biomass gasification hybrid is now a dispatchable source of electricity with a near net-zero lifetime carbon footprint and storage capability. Dispatchable power can profit from market fluctuations that dramatically increase the value of available electricity so that in addition to providing base power the hybrid facility can store energy during low price points in the market and generate at full capacity during points of high prices. Any financial incentive for energy generated from reduced carbon technologies will also increase the value of electricity produced. Also, alternative operational parameters that do not require the costly storage of synthetic natural gas (SNG) will likely result in a more competitive levelized COE. Additional benefits of the system are in the flexibility of transporting wind and biomass energy produced as well as the end use of the energy. Instead of high-voltage electrical transmission a gas line can now be used to transport energy produced by the wind. Syngas can also be further processed into higher energy density liquefied syngas. Liquid fuels can then be transported via commercial freight on existing road infrastructure.

Small Horizontal Axis Wind Turbine under High Speed Operation: Study of Power Evaluation

NASA Astrophysics Data System (ADS)

Moh. M. Saad, Magedi; Mohd, Sofian Bin; Zulkafli, Mohd Fadhli Bin; Abdullah, Aslam Bin; Rahim, Mohammad Zulafif Bin; Subari, Zulkhairi Bin; Rosly, Nurhayati Binti

2017-10-01

Mechanical energy is produced through the rotation of wind turbine blades by air that convert the mechanical energy into electrical energy. Wind turbines are usually designed to be use for particular applications and design characteristics may vary depending on the area of use. The variety of applications is reflected on the size of turbines and their infrastructures, however, performance enhancement of wind turbine may start by analyzing the small horizontal axis wind turbine (SHAWT) under high wind speed operation. This paper analyzes the implementations of SHAWT turbines and investigates their performance in both simulation and real life. Depending on the real structure of the rotor geometry and aerodynamic test, the power performance of the SHAWT was simulated using ANSYS-FLUENT software at different wind speed up to 33.33 m/s (120km/h) in order to numerically investigate the actual turbine operation. Dynamic mesh and user define function (UDF) was used for revolving the rotor turbine via wind. Simulation results were further validated by experimental data and hence good matching was yielded. And for reducing the energy producing cost, car alternator was formed to be used as a small horizontal wind turbine. As a result, alternator-based turbine system was found to be a low-cost solution for exploitation of wind energy.

Analysis of the solar/wind resources in Southern Spain for optimal sizing of hybrid solar-wind power generation systems

NASA Astrophysics Data System (ADS)

Quesada-Ruiz, S.; Pozo-Vazquez, D.; Santos-Alamillos, F. J.; Lara-Fanego, V.; Ruiz-Arias, J. A.; Tovar-Pescador, J.

2010-09-01

A drawback common to the solar and wind energy systems is their unpredictable nature and dependence on weather and climate on a wide range of time scales. In addition, the variation of the energy output may not match with the time distribution of the load demand. This can partially be solved by the use of batteries for energy storage in stand-alone systems. The problem caused by the variable nature of the solar and wind resources can be partially overcome by the use of energy systems that uses both renewable resources in a combined manner, that is, hybrid wind-solar systems. Since both resources can show complementary characteristics in certain location, the independent use of solar or wind systems results in considerable over sizing of the batteries system compared to the use of hybrid solar-wind systems. Nevertheless, to the day, there is no single recognized method for properly sizing these hybrid wind-solar systems. In this work, we present a method for sizing wind-solar hybrid systems in southern Spain. The method is based on the analysis of the wind and solar resources on daily scale, particularly, its temporal complementary characteristics. The method aims to minimize the size of the energy storage systems, trying to provide the most reliable supply.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Small Wind Electric Systems: A Colorado Consumer's Guide provides consumers with information to help them determine whether a small wind electric system can provide all or a portion of the energy they need for their home or business based on their wind resource, energy needs, and economics. Topics include how to make a home more energy efficient, how to choose the correct turbine size, the parts of a wind electric system, how to determine whether enough wind resource exists, how to choose the best site for a turbine, how to connect a system to the utility grid, and whether it'smore » possible to become independent of the utility grid using wind energy. In addition, the cover of the guide contains a list of contacts for more information.« less

United States Supports Distributed Wind Technology Improvements; NREL (National Renewable Energy Laboratory)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinclair, Karin

2015-06-15

This presentation provides information on the activities conducted through the Competitiveness Improvement Project (CIP), initiated in 2012 by the U.S. Department of Energy (DOE) and executed through the National Renewable Energy Laboratory (NREL) to support the distributed wind industry. The CIP provides research and development funding and technical support to improve distributed wind turbine technology and increase the competitiveness of U.S. small and midsize wind turbine manufacturers. Through this project, DOE/NREL assists U.S. manufacturers to lower the levelized cost of energy of wind turbines through component improvements, manufacturing process upgrades, and turbine testing. Ultimately, this support is expected to leadmore » to turbine certification through testing to industry-recognized wind turbine performance and safety standards.« less

Wind Energy Resource Assessment on Alaska Native Lands in Cordova Region of Prince William Sound

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whissel, John C.; Piche, Matthew

The Native Village of Eyak (NVE) has been monitoring wind resources around Cordova, Alaska in order to determine whether there is a role for wind energy to play in the city’s energy scheme, which is now supplies entirely by two run-of-the-river hydro plants and diesel generators. These data are reported in Appendices A and B. Because the hydro resources decline during winter months, and wind resources increase, wind is perhaps an ideal counterpart to round out Cordova’s renewable energy supply. The results of this effort suggests that this is the case, and that developing wind resources makes sense for ourmore » small, isolated community.« less

Development of large wind energy power generation system

NASA Technical Reports Server (NTRS)

1985-01-01

The background and development of an experimental 100 kW wind-energy generation system are described, and the results of current field tests are presented. The experimental wind turbine is a two-bladed down-wind horizontal axis propeller type with a 29.4 m diameter rotor and a tower 28 m in height. The plant was completed in March, 1983, and has been undergoing trouble-free tests since then. The present program calls for field tests during two years from fiscal 1983 to 1984. The development of technologies relating to the linkage and operation of wind-energy power generation system networks is planned along with the acquisition of basic data for the development of a large-scale wind energy power generation system.

Aerodynamic results of wind tunnel tests on a 0.010-scale model (32-QTS) space shuttle integrated vehicle in the AEDC VKF-40-inch supersonic wind tunnel (IA61)

NASA Technical Reports Server (NTRS)

Daileda, J. J.

1976-01-01

Plotted and tabulated aerodynamic coefficient data from a wind tunnel test of the integrated space shuttle vehicle are presented. The primary test objective was to determine proximity force and moment data for the orbiter/external tank and solid rocket booster (SRB) with and without separation rockets firing for both single and dual booster runs. Data were obtained at three points (t = 0, 1.25, and 2.0 seconds) on the nominal SRB separation trajectory.

Geophysical Potential for Wind Energy over the Open Oceans

NASA Astrophysics Data System (ADS)

Possner, A.; Caldeira, K.

2017-12-01

Wind turbines continuously remove kinetic energy from the lower troposphere thereby reducing the wind speed near hub height. The rate of electricity generation in large wind farms containing multiple wind arrays is therefore constrained by the rate of kinetic energy replenishment from the atmosphere above. In particular, this study focuses on the maximum sustained transport of kinetic energy through the troposphere to the lowest hundreds of meters above the surface. In recent years, a growing body of research argues that the rate of generated power is limited to around 1.5 Wm-2 within large wind farms. However, in this study we demonstrate that considerably higher power generation rates may be sustainable over some open ocean areas in giant wind farms. We find that in the North Atlantic maximum extraction rates of up to 6.7 Wm-2 may be sustained by the atmosphere in the annual mean over giant wind farm areas approaching the size of Greenland. In contrast, only a third of this rate is sustained on land for areas of equivalent size. Our simulations indicate a fundamental difference in response of the troposphere and its vertical kinetic energy flux to giant near-surface wind farms. We find that the surface heat flux from the oceans to the atmosphere may play an important role in creating regions where large sustained rates of downward transport of kinetic energy and thus rates of kinetic energy extraction may be geophysically possible. While no commercial-scale deep-water wind turbines yet exist, our results suggest that such technologies, if they became technically and economically feasible, could potentially provide civilization-scale power.

Introduction to wind energy systems

NASA Astrophysics Data System (ADS)

Wagner, H.-J.

2017-07-01

This article presents the basic concepts of wind energy and deals with the physics and mechanics of operation. It describes the conversion of wind energy into rotation of turbine, and the critical parameters governing the efficiency of this conversion. After that it presents an overview of various parts and components of windmills. The connection to the electrical grid, the world status of wind energy use for electricity production, the cost situation and research and development needs are further aspects which will be considered.

Introduction to wind energy systems

NASA Astrophysics Data System (ADS)

Wagner, H.-J.

2015-08-01

This article presents the basic concepts of wind energy and deals with the physics and mechanics of operation. It describes the conversion of wind energy into rotation of turbine, and the critical parameters governing the efficiency of this conversion. After that it presents an overview of various parts and components of windmills. The connection to the electrical grid, the world status of wind energy use for electricity production, the cost situation and research and development needs are further aspects which will be considered.

Modeling Innovations Advance Wind Energy Industry

NASA Technical Reports Server (NTRS)

2009-01-01

In 1981, Glenn Research Center scientist Dr. Larry Viterna developed a model that predicted certain elements of wind turbine performance with far greater accuracy than previous methods. The model was met with derision from others in the wind energy industry, but years later, Viterna discovered it had become the most widely used method of its kind, enabling significant wind energy technologies-like the fixed pitch turbines produced by manufacturers like Aerostar Inc. of Westport, Massachusetts-that are providing sustainable, climate friendly energy sources today.

The Impact of Natural Hazards such as Turbulent Wind Gusts on the Wind Energy Conversion Process

NASA Astrophysics Data System (ADS)

Wächter, M.; Hölling, M.; Milan, P.; Morales, A.; Peinke, J.

2012-12-01

Wind turbines operate in the atmospheric boundary layer, where they are exposed to wind gusts and other types of natural hazards. As the response time of wind turbines is typically in the range of seconds, they are affected by the small scale intermittent properties of the turbulent wind. We show evidence that basic features which are known for small-scale homogeneous isotropic turbulence, and in particular the well-known intermittency problem, have an important impact on the wind energy conversion process. Intermittent statistics include high probabilities of extreme events which can be related to wind gusts and other types of natural hazards. As a summarizing result we find that atmospheric turbulence imposes its intermittent features on the complete wind energy conversion process. Intermittent turbulence features are not only present in atmospheric wind, but are also dominant in the loads on the turbine, i.e. rotor torque and thrust, and in the electrical power output signal. We conclude that profound knowledge of turbulent statistics and the application of suitable numerical as well as experimental methods are necessary to grasp these unique features and quantify their effects on all stages of wind energy conversion.

A Generalized Electron Heat Flow Relation and its Connection to the Thermal Force and the Solar Wind Parallel Electric Field

NASA Astrophysics Data System (ADS)

Scudder, J. D.

2017-12-01

Enroute to a new formulation of the heat law for the solar wind plasma the role of the invariably neglected, but omnipresent, thermal force for the multi-fluid physics of the corona and solar wind expansion will be discussed. This force (a) controls the size of the collisional ion electron energy exchange, favoring the thermal vs supra thermal electrons; (b) occurs whenever heat flux occurs; (c) remains after the electron and ion fluids come to a no slip, zero parallel current, equilibrium; (d) enhances the equilibrium parallel electric field; but (e) has a size that is theoretically independent of the electron collision frequency - allowing its importance to persist far up into the corona where collisions are invariably ignored in first approximation. The constituent parts of the thermal force allow the derivation of a new generalized electron heat flow relation that will be presented. It depends on the separate field aligned divergences of electron and ion pressures and the gradients of the ion gravitational potential and parallel flow energies and is based upon a multi-component electron distribution function. The new terms in this heat law explicitly incorporate the astrophysical context of gradients, acceleration and external forces that make demands on the parallel electric field and quasi-neutrality; essentially all of these effects are missing in traditional formulations.

Voyager observations of O(+6) and other minor ions in the solar wind

NASA Technical Reports Server (NTRS)

Villanueva, Louis; Mcnutt, Ralph L., Jr.; Lazarus, Alan J.; Steinberg, John T.

1994-01-01

The plasma science (PLS) experiments on the Voyager 1 and 2 spacecraft began making measurements of the solar wind shortly after the two launches in the fall of 1977. In reviewing the data obtained prior to the Jupiter encounters in 1979, we have found that the large dynamic range of the PLS instrument generally allows a clean separation of signatures of minor ions (about 2.5% of the time) during a single instrument scan in energy per charge. The minor ions, most notably O(+6), are well separated from the protons and alpha particles during times when the solar wind Mach number (ratio of streaming speed to thermal speed) is greater than approximately 15. During the Earth to Jupiter cruise we find that the average ratio of alpha particle number density to that of oxygen is 66 +/- 7 (Voyager 1) and 71 +/- 17 (Voyager 2). These values are consistent with the value 75 +/- 20 inferred from the Ion Composition Instrument on ISEE 3 during the period spanning 1978 and 1982. We have inferred an average coronal temperature of (1.7 +/- 0.1) x 10(exp 6) K based on the ratio of O(+7) to O(+6) number densities. Our observations cover a period of increasing solar activity. During this time we have found that the alpha particle to proton number density ratio is increasing with the solar cycle, the oxygen to proton ratio increases, and the alpha particle to oxygen ratio remains relatively constant in time.

Coordinated control strategy for improving the two drops of the wind storage combined system

NASA Astrophysics Data System (ADS)

Qian, Zhou; Chenggen, Wang; Jing, Bu

2018-05-01

In the power system with high permeability wind power, due to wind power fluctuation, the operation of large-scale wind power grid connected to the system brings challenges to the frequency stability of the system. When the doubly fed wind power generation unit does not reserve spare capacity to participate in the system frequency regulation, the system frequency will produce two drops in different degrees when the wind power exits frequency modulation and enters the speed recovery stage. To solve this problem, based on the complementary advantages of wind turbines and energy storage systems in power transmission and frequency modulation, a wind storage combined frequency modulation strategy based on sectional control is proposed in this paper. Based on the TOP wind power frequency modulation strategy, the wind power output reference value is determined according to the linear relationship between the output and the speed of the wind turbine, and the auxiliary wind power load reduction is controlled when the wind power exits frequency modulation into the speed recovery stage, so that the wind turbine is recovered to run at the optimal speed. Then, according to the system frequency and the wind turbine operation state, set the energy storage system frequency modulation output. Energy storage output active support is triggered during wind speed recovery. And then when the system frequency to return to the normal operating frequency range, reduce energy storage output or to exit frequency modulation. The simulation results verify the effectiveness of the proposed method.

Energy Storage on the Grid and the Short-term Variability of Wind

NASA Astrophysics Data System (ADS)

Hittinger, Eric Stephen

Wind generation presents variability on every time scale, which must be accommodated by the electric grid. Limited quantities of wind power can be successfully integrated by the current generation and demand-side response mix but, as deployment of variable resources increases, the resulting variability becomes increasingly difficult and costly to mitigate. In Chapter 2, we model a co-located power generation/energy storage block composed of wind generation, a gas turbine, and fast-ramping energy storage. A scenario analysis identifies system configurations that can generate power with 30% of energy from wind, a variability of less than 0.5% of the desired power level, and an average cost around $70/MWh. While energy storage technologies have existed for decades, fast-ramping grid-level storage is still an immature industry and is experiencing relatively rapid improvements in performance and cost across a variety of technologies. Decreased capital cost, increased power capability, and increased efficiency all would improve the value of an energy storage technology and each has cost implications that vary by application, but there has not yet been an investigation of the marginal rate of technical substitution between storage properties. The analysis in chapter 3 uses engineering-economic models of four emerging fast-ramping energy storage technologies to determine which storage properties have the greatest effect on cost-of-service. We find that capital cost of storage is consistently important, and identify applications for which power/energy limitations are important. In some systems with a large amount of wind power, the costs of wind integration have become significant and market rules have been slowly changing in order to internalize or control the variability of wind generation. Chapter 4 examines several potential market strategies for mitigating the effects of wind variability and estimate the effect that each strategy would have on the operation and profitability of wind farms. We find that market scenarios using existing price signals to motivate wind to reduce variability allow wind generators to participate in variability reduction when the market conditions are favorable, and can reduce short-term (30-minute) fluctuations while having little effect on wind farm revenue.

The largest renewable, easily exploitable, and economically sustainable energy resource

NASA Astrophysics Data System (ADS)

Abbate, Giancarlo; Saraceno, Eugenio

2018-02-01

Sun, the ultimate energy resource of our planet, transfers energy to the Earth at an average power of 23,000 TW. Earth surface can be regarded as a huge panel transforming solar energy into a more convenient mechanical form, the wind. Since millennia wind is recognized as an exploitable form of energy and it is common knowledge that the higher you go, the stronger the winds flow. To go high is difficult; however Bill Gates cites high wind among possible energy miracles in the near future. Public awareness of this possible miracle is still missing, but today's technology is ready for it.

Proceedings: Panel on Information Dissemination for Wind Energy

NASA Astrophysics Data System (ADS)

Weis, P.

1980-04-01

A program for coordinating and strengthening technical information activities related to the commercialization of solar energy research and development results is described. The program contains a project for each of the following technologies: biomass; ocean thermal energy conversion; photovoltaics; solar thermal power; and wind energy conversion systems. In addition to the production and dissemination of several types of information materials, the wind energy project aims to support efforts of others in the field. The meeting is the first attempt to acquaint people with the information activities of others, to discuss information needs as an aid to planning, and to promote cooperation in disseminating information on wind energy.

Conception et validation d'un modele d'analyse et de suivi pour une politique energetique durable et acceptable de l'energie eolienne: Une etude comparative France-Quebec

NASA Astrophysics Data System (ADS)

Feurtey, Evariste

In this research, we built a conceptual model of a sustainable and acceptable wind power policy that we tried to validate through the case study of France and Quebec in the wind energy sector. Our qualitative and comparative approach helps us to illustrate the interaction of institutional variables studied, including the national context of emergence, the balance of power between pressure groups, the supranational and exogenous influences, level of political commitment, policy and regulatory instruments, social acceptance and energy policy mechanisms. The research confirms that the neo-corporatism is present in France as in Quebec. With the unfavorable energy context (low cost of electricity tariff, lack of electricity demand, and an already low zero carbon electric mix), it is an important factor explaining : 1) the 20 years delay accumulated by France and Quebec in the development of wind projects or industrial sector; 2) the 10% limited penetration scale given to wind energy. We also demonstrate that the political commitment to develop wind energy fluctuates with the government majority, the energy context or the influence of pressure groups. This manifests itself in a lack of continuity of policies and tariff instruments used. In both national case studies, the results also show that balanced policies and regulations ensure sustainable development of wind energy only if they allow a sufficient market size. The search results also illustrates that the conceptual division made between acceptance of wind sector, acceptance of ownership, local acceptance is very instructive. Social controversies, though multifactorial, are connected to both a critique of the development model too industrial and private, territorial dilemmas (closed environment), energy context (electric surplus in Quebec), or related to strategic planning system and centralized decision. An important issue for a more acceptable wind policy in the future will come to a greater plurality of ownership, variety of wind projects scale, diversity of financial support mechanisms. This transformation to a more territorial policy that require renewables also calls for decentralization and ecological modernization of institutions. Sustainable and acceptable energy policy requires obtaining a stabilized consensus on the long-term energy mix, which should be done by a comprehensive energy and public debate upstream the development of energy policy. Keywords: energy policy, social acceptance, wind energy, environmental assessment, components, interactions.