Science.gov

Sample records for small-scale wind power

  1. Power Spectra, Power Law Exponents, and Anisotropy of Solar Wind Turbulence at Small Scales

    NASA Technical Reports Server (NTRS)

    Podesta, J. J.; Roberts, D. A.; Goldstein, M. L.

    2006-01-01

    The Wind spacecraft provides simultaneous solar wind velocity and magnetic field measurements with 3- second time resolution, roughly an order of magnitude faster than previous measurements, enabling the small scale features of solar wind turbulence to be studied in unprecedented detail. Almost the entire inertial range can now be explored (the inertial range extends from approximately 1 to 10(exp 3) seconds in the spacecraft frame) although the dissipation range of the velocity fluctuations is still out of reach. Improved measurements of solar wind turbulence spectra at 1 AU in the ecliptic plane are presented including spectra of the energy and cross-helicity, the magnetic and kinetic energies, the Alfven ratio, the normalized cross-helicity, and the Elsasser ratio. Some recent observations and theoretical challenges are discussed including the observation that the velocity and magnetic field spectra often show different power law exponents with values close to 3/2 and 5/3, respectively; the energy (kinetic plus magnetic) and cross-helicity often have approximately equal power law exponents with values intermediate between 3/2 and 5/3; and the Alfven ratio, the ratio of the kinetic to magnetic energy spectra, is often a slowly increasing function of frequency increasing from around 0.4 to 1 for frequencies in the inertial range. Differences between high- and low-speed wind are also discussed. Comparisons with phenomenological turbulence theories show that important aspects of the physics are yet unexplained.

  2. Investment Timing and Capacity Choice for Small-Scale Wind PowerUnder Uncertainty

    SciTech Connect

    Fleten, Stein-Erik; Maribu, Karl Magnus

    2004-11-28

    This paper presents a method for evaluation of investments in small-scale wind power under uncertainty. It is assumed that the price of electricity is uncertain and that an owner of a property with wind resources has a deferrable opportunity to invest in one wind power turbine within a capacity range. The model evaluates investment in a set of projects with different capacity. It is assumed that the owner substitutes own electricity load with electricity from the wind mill and sells excess electricity back to the grid on an hourly basis. The problem for the owner is to find the price levels at which it is optimal to invest, and in which capacity to invest. The results suggests it is optimal to wait for significantly higher prices than the net present value break-even. Optimal scale and timing depend on the expected price growth rate and the uncertainty in the future prices.

  3. Small-Scale Hydroelectric Power Demonstration Project

    SciTech Connect

    Gleeson, L.

    1991-12-01

    The US Department of Energy Field Office, Idaho, Small-Scale Hydroelectric Power Program was initiated in conjunction with the restoration of three power generating plants in Idaho Falls, Idaho, following damage caused by the Teton Dam failure on June 5, 1976. There were many parties interested in this project, including the state and environmental groups, with different concerns. This report was prepared by the developer and describes the design alternatives the applicant provided in an attempt to secure the Federal Energy Regulatory Commission license. Also included are correspondence between the related parties concerning the project, major design alternatives/project plan diagrams, the license, and energy and project economics.

  4. Some features of the small-scale solar wind fluctuations

    NASA Technical Reports Server (NTRS)

    Zastenker, G.; Eiges, P.; Avanov, L.; Astafyeva, N.; Zurbuchen, Th.; Bochsler, P.

    1995-01-01

    We have investigated small-scale variations of the solar wind ion flux measured with Faraday cups onboard the Prognoz-8 satellite. These measurements have a high time resolution of 1.24 seconds for intervals with a duration of several hours and as high as 0.02 seconds for some periods of about 1 hour duration. The main goal of this work is the determination of the quantitative features of fast ion flux fluctuations using mainly spectral analysis but also other methods. We also identify their association with interplanetary plasma parameters. Particularly, it is shown that the slope of the power spectra in the frequency range from 1E-4 to 6E-2 Hz is close to the classical Kolmogorov (-5/3) law. We also discuss some intervals with a very high level of the relative amplitude of flux fluctuations (10-20 percent) which were observed near the Earth's bow shock in the foreshock region. The use of the wavelet method for the long time series allows us to study the temporal evolution of power spectra.

  5. Dynamic properties of small-scale solar wind plasma fluctuations.

    PubMed

    Riazantseva, M O; Budaev, V P; Zelenyi, L M; Zastenker, G N; Pavlos, G P; Safrankova, J; Nemecek, Z; Prech, L; Nemec, F

    2015-05-13

    The paper presents the latest results of the studies of small-scale fluctuations in a turbulent flow of solar wind (SW) using measurements with extremely high temporal resolution (up to 0.03 s) of the bright monitor of SW (BMSW) plasma spectrometer operating on astrophysical SPECTR-R spacecraft at distances up to 350,000 km from the Earth. The spectra of SW ion flux fluctuations in the range of scales between 0.03 and 100 s are systematically analysed. The difference of slopes in low- and high-frequency parts of spectra and the frequency of the break point between these two characteristic slopes was analysed for different conditions in the SW. The statistical properties of the SW ion flux fluctuations were thoroughly analysed on scales less than 10 s. A high level of intermittency is demonstrated. The extended self-similarity of SW ion flux turbulent flow is constantly observed. The approximation of non-Gaussian probability distribution function of ion flux fluctuations by the Tsallis statistics shows the non-extensive character of SW fluctuations. Statistical characteristics of ion flux fluctuations are compared with the predictions of a log-Poisson model. The log-Poisson parametrization of the structure function scaling has shown that well-defined filament-like plasma structures are, as a rule, observed in the turbulent SW flows.

  6. Small-scale wind disturbances observed by the MU radar during the passage of typhoon Kelly

    SciTech Connect

    Sato, Kaoru )

    1993-02-14

    This paper describes small-scale wind disturbances associated with Typhoon Kelly (October 1987) that were observed by the MU radar, one of the MST (mesosphere, stratosphere, and troposphere) radars, for about 60 hours with fine time and height resolution. To elucidate the background of small-scale disturbances, synoptic-scale variation in atmospheric stability related to the typhoon structure during the observation is examined. When the typhoon passed near the MU radar site, the structure was no longer axisymmetric. There is deep convection only in north-northeast side of the typhoon while convection behind it is suppressed by a synoptic-scale cold air mass moving eastward to the west of the typhoon. A change in atmospheric stability over the radar site as indicated by echo power profiles is likely due to the passage of the sharp transition zone of convection. Strong small-scale wind disturbances were observed around the typhoon passage. The statistical characteristics are different before (BT) and after (AT) the typhoon passage, especially in frequency spectra of vertical wind fluctuations. The spectra for BT are unique compared with earlier studies of vertical winds observed by VHF radars. Another difference is dominance of a horizontal wind component with a vertical wavelength of about 3 km, observed only in AT. Further analyses are made of characteristics and vertical momentum fluxes for dominant disturbances. Some disturbances are generated to remove the momentum of cyclonic wind rotation of the typhoon. Deep convection, topographic effects in strong winds, and strong vertical shear of horizontal winds around an inversion layer are possible sources of the disturbances. Two monochromatic disturbances lasting for more than 10 h in the lower stratosphere observed in BT and AT are identified as inertio-gravity waves, by obtaining wave parameters consistent with all observed quantities. Both of the inertio-gravity waves propagate energy away from the typhoon.

  7. Numerical study on small scale vertical axis wind turbine

    NASA Astrophysics Data System (ADS)

    Parra-Santos, Teresa; Gallegos, Armando; Uzarraga, Cristóbal N.; Rodriguez, Miguel A.

    2016-03-01

    The performance of a Vertical Axis Wind Turbine (VAWT) is numerically analyzed. The set-up is Hdarrieus with three straight blades airfoils NACA attached to a rotating vertical shaft. The wind turbine has solidity equals to the unity operating with wind velocity of 7 m/s. Influence of pitch angle is tested to get design tendencies. 2D, transient, Navier Stokes equations are solved using the code Ansys-Fluent. Conservation equations were solved with a Third-Order MUSCL scheme using SIMPLE to couple pressure and velocity. More than six revolutions must be simulated to get the periodic behavior. Two models of turbulence have been contrasted Realizable k-epsilon and Transition SST concluding the last one show more realistic flow features. Pitch angles of 0º, -6º and -10º have been tested with Tip Speed Ratios ranging from 0.7 and 1.6. The no null pitch angles improve the performance of the wind turbine. Instantaneous and averaged power coefficients as well as detailed flow field around the airfoils are showed.

  8. A triboelectric wind turbine for small-scale energy harvesting

    NASA Astrophysics Data System (ADS)

    Perez, Matthias; Boisseau, Sebastien; Geisler, Matthias; Despesse, Ghislain; Reboud, Jean Luc

    2016-11-01

    This paper deals with a rotational energy harvester including a Horizontal Axis Wind Turbine (HAWT), a cylindrical stator covered by several electrodes, and thin Teflon dielectric membranes hung on the rotor. The sliding contact of the Teflon membranes on the stator provides simultaneously large capacitance variations and a polarization source for the electrostatic converter by exploiting triboelectric phenomena. 1μW has been harvested at 4m/s; 130μW at 10m/s and 550μW at 20m/s with a 40mmØ device. In order to validate the energy harvesting chain, the airflow energy harvester has been connected to a power management circuit implementing Synchronous Electric Charge Extraction (SECE) to supply a wireless sensor node with temperature and acceleration measurements, transmitted to a computer at 868MHz.

  9. An experimental study of potential residential and commercial applications of small-scale hybrid power systems

    NASA Astrophysics Data System (ADS)

    Acosta, Michael Anthony

    The research presented in this thesis provides an understanding of small-scale hybrid power systems. Experiments were conducted to identify potential applications of renewable energy in residential and commercial applications in the Rio Grande Valley of Texas. Solar and wind energy converted into electric energy was stored in batteries and inverted to power common household and commercial appliances. Several small to medium size hybrid power systems were setup and utilized to conduct numerous tests to study renewable energy prospects and feasibility for various applications. The experimental results obtained indicate that carefully constructed solar power systems can provide people living in isolated communities with sufficient energy to consistently meet their basic power needs.

  10. Torque Characteristics Simulation on Small Scale Combined Type Vertical Axis Wind Turbine

    NASA Astrophysics Data System (ADS)

    Feng, Fang; Li, Shengmao; Li, Yan; Xu, Dan

    The straight-bladed vertical axis wind turbine (SB-VAWT) receives more attentions recently for its goodness of simple design, low cost and good maintenance. However, its starting performance is poor. To increase its starting torque, Savonius rotor was combined on the SB-VAWT in this study because Savonius rotor has good starting torque coefficient. Based on the wind tunnel tests data, a small scaled combined type SB-VAWT (CSB-VAWT) which has 50W rated power output was designed. The starting torque coefficient, dynamic torque and power performance were analyzed. Both the starting and dynamic torque performance of the CSB-VAWT have been greatly improved according to the simulation results.

  11. Performance of small-scale tidal power plants

    NASA Astrophysics Data System (ADS)

    Fay, J. A.; Smachlo, M. A.

    1983-12-01

    Small-scale tidal power plants - having electric power between 1 and 100 MW, approximately - possess several attractive economic and environmental benefits. The dynamical behavior of such systems is calculated in terms of dimensionless variables and parameters, so that the size of the system is inconsequential (except for one parameter related to the slope of the walls of the tidal basin). Two measures of system performance are defined: capacity factor (ratio of average to rated power) and effectiveness (ratio of average to ideal tidal power). It was found that improving both parameters is mutually incompatible so that an economic analysis will determine the optimum values of the system design and performance parameters. The effects of variation of tidal range and basin shape were determined. Using typical variable flow properties of low-head hydroturbines, a favorable design head could be determined from the analysis. It was found that the change in the area of the intertidal zone relative to the surface area of the tidal pond is greater for small, as compared to large, systems, possibly leading to proportionately greater environmental effects. A comparison of the performance of several tidal power plant designs with the methodology of this paper showed generally good agreement with the dimensionless performance parameters and only a modest difference among them over several orders of magnitude in size of power plant.

  12. Small-Scale Geothermal Power Plant Field Verification Projects: Preprint

    SciTech Connect

    Kutscher, C.

    2001-07-03

    In the spring of 2000, the National Renewable Energy Laboratory issued a Request for Proposal for the construction of small-scale (300 kilowatt [kW] to 1 megawatt [MW]) geothermal power plants in the western United States. Five projects were selected for funding. Of these five, subcontracts have been completed for three, and preliminary design work is being conducted. The three projects currently under contract represent a variety of concepts and locations: a 1-MW evaporatively enhanced, air-cooled binary-cycle plant in Nevada; a 1-MW water-cooled Kalina-cycle plant in New Mexico; and a 750-kW low-temperature flash plant in Utah. All three also incorporate direct heating: onion dehydration, heating for a fish hatchery, and greenhouse heating, respectively. These projects are expected to begin operation between April 2002 and September 2003. In each case, detailed data on performance and costs will be taken over a 3-year period.

  13. Small-scale Geothermal Power Plants Using Hot Spring Water

    NASA Astrophysics Data System (ADS)

    Tosha, T.; Osato, K.; Kiuchi, T.; Miida, H.; Okumura, T.; Nakashima, H.

    2013-12-01

    The installed capacity of the geothermal power plants has been summed up to be about 515MW in Japan. However, the electricity generated by the geothermal resources only contributes to 0.2% of the whole electricity supply. After the catastrophic earthquake and tsunami devastated the Pacific coast of north-eastern Japan on Friday, March 11, 2011, the Japanese government is encouraging the increase of the renewable energy supply including the geothermal. It needs, however, more than 10 years to construct the geothermal power plant with more than 10MW capacity since the commencement of the development. Adding the problem of the long lead time, high temperature fluid is mainly observed in the national parks and the high quality of the geothermal resources is limited. On the other hand hot springs are often found. The utilisation of the low temperature hot water becomes worthy of notice. The low temperature hot water is traditionally used for bathing and there are many hot springs in Japan. Some of the springs have enough temperature and enthalpy to turn the geothermal turbine but a new technology of the binary power generation makes the lower temp fluid to generate electricity. Large power generators with the binary technology are already installed in many geothermal fields in the world. In the recent days small-scale geothermal binary generators with several tens to hundreds kW capacity are developed, which are originally used by the waste heat energy in an iron factory and so on. The newly developed binary unit is compact suitable for the installation in a Japanese inn but there are the restrictions for the temperature of the hot water and the working fluid. The binary power unit using alternatives for chlorofluorocarbon as the working fluid is relatively free from the restriction. KOBELCO, a company of the Kobe Steel Group, designed and developed the binary power unit with an alternative for chlorofluorocarbon. The unit has a 70 MW class electric generator. Three

  14. Integrated bioenergy conversion concepts for small scale gasification power systems

    NASA Astrophysics Data System (ADS)

    Aldas, Rizaldo Elauria

    Thermal and biological gasification are promising technologies for addressing the emerging concerns in biomass-based renewable energy, environmental protection and waste management. However, technical barriers such as feedstock quality limitations, tars, and high NOx emissions from biogas fueled engines impact their full utilization and make them suffer at the small scale from the need to purify the raw gas for most downstream processes, including power generation other than direct boiler use. The two separate gasification technologies may be integrated to better address the issues of power generation and waste management and to complement some of each technologies' limitations. This research project investigated the technical feasibility of an integrated thermal and biological gasification concept for parameters critical to appropriately matching an anaerobic digester with a biomass gasifier. Specific studies investigated the thermal gasification characteristics of selected feedstocks in four fixed-bed gasification experiments: (1) updraft gasification of rice hull, (2) indirect-heated gasification of rice hull, (3) updraft gasification of Athel wood, and (4) downdraft gasification of Athel and Eucalyptus woods. The effects of tars and other components of producer gas on anaerobic digestion at mesophilic temperature of 36°C and the biodegradation potentials and soil carbon mineralization of gasification tars during short-term aerobic incubation at 27.5°C were also examined. Experiments brought out the ranges in performance and quality and quantity of gasification products under different operating conditions and showed that within the conditions considered in the study, these gasification products did not adversely impact the overall digester performance. Short-term aerobic incubation demonstrated variable impacts on carbon mineralization depending on tar and soil conditions. Although tars exhibited low biodegradation indices, degradation may be improved if the

  15. Proceedings of a Topical Meeting On Small Scale Geothermal Power Plants and Geothermal Power Plant Projects

    SciTech Connect

    1986-02-12

    These proceedings describe the workshop of the Topical Meeting on Small Scale Geothermal Power Plants and Geothermal Power Plant Projects. The projects covered include binary power plants, rotary separator, screw expander power plants, modular wellhead power plants, inflow turbines, and the EPRI hybrid power system. Active projects versus geothermal power projects were described. In addition, a simple approach to estimating effects of fluid deliverability on geothermal power cost is described starting on page 119. (DJE-2005)

  16. Energetic Ion Acceleration by Small-scale Solar Wind Flux Ropes

    NASA Astrophysics Data System (ADS)

    le Roux, J. A.; Webb, G. M.; Zank, G. P.; Khabarova, O.

    2015-09-01

    We consider different limits of our recently developed kinetic transport theory to investigate the potential of supersonic solar wind regions containing several small-scale flux ropes to explain the acceleration of suprathermal ions to power-law spectra as observations show. Particle acceleration is modeled in response to flux-rope activity involving contraction, merging (reconnection), and collisions in the limit where the particle gyoradius is smaller than the characteristic flux-rope scale length. The emphasis is mainly on the statistical variance in the electric fields induced by flux-rope dynamics rather than on the mean electric field induced by multiple flux ropes whose acceleration effects are discussed elsewhere. Our steady-state analytical solutions suggest that ion drift acceleration by flux ropes, irrespective of whether displaying incompressible or compressible behavior, can yield power laws asymptotically at higher energies whereas an exponential spectral rollover results asymptotically when field-aligned guiding center motion acceleration occur by reconnection electric fields from merging flux ropes. This implies that at sufficiently high particle energies, drift acceleration might dominate. We also expect compressive flux ropes to yield harder power-law spectra than incompressible flux ropes.

  17. SMALL SCALE FUEL CELL AND REFORMER SYSTEMS FOR REMOTE POWER

    SciTech Connect

    Dennis Witmer

    2003-12-01

    New developments in fuel cell technologies offer the promise of clean, reliable affordable power, resulting in reduced environmental impacts and reduced dependence on foreign oil. These developments are of particular interest to the people of Alaska, where many residents live in remote villages, with no roads or electrical grids and a very high cost of energy, where small residential power systems could replace diesel generators. Fuel cells require hydrogen for efficient electrical production, however. Hydrogen purchased through conventional compressed gas suppliers is very expensive and not a viable option for use in remote villages, so hydrogen production is a critical piece of making fuel cells work in these areas. While some have proposed generating hydrogen from renewable resources such as wind, this does not appear to be an economically viable alternative at this time. Hydrogen can also be produced from hydrocarbon feed stocks, in a process known as reforming. This program is interested in testing and evaluating currently available reformers using transportable fuels: methanol, propane, gasoline, and diesel fuels. Of these, diesel fuels are of most interest, since the existing energy infrastructure of rural Alaska is based primarily on diesel fuels, but this is also the most difficult fuel to reform, due to the propensity for coke formation, due to both the high vaporization temperature and to the high sulfur content in these fuels. There are several competing fuel cell technologies being developed in industry today. Prior work at UAF focused on the use of PEM fuel cells and diesel reformers, with significant barriers identified to their use for power in remote areas, including stack lifetime, system efficiency, and cost. Solid Oxide Fuel Cells have demonstrated better stack lifetime and efficiency in demonstrations elsewhere (though cost still remains an issue), and procuring a system for testing was pursued. The primary function of UAF in the fuel cell

  18. Large- and small-scale constraints on power spectra in Omega = 1 universes

    NASA Technical Reports Server (NTRS)

    Gelb, James M.; Gradwohl, Ben-Ami; Frieman, Joshua A.

    1993-01-01

    The CDM model of structure formation, normalized on large scales, leads to excessive pairwise velocity dispersions on small scales. In an attempt to circumvent this problem, we study three scenarios (all with Omega = 1) with more large-scale and less small-scale power than the standard CDM model: (1) cold dark matter with significantly reduced small-scale power (inspired by models with an admixture of cold and hot dark matter); (2) cold dark matter with a non-scale-invariant power spectrum; and (3) cold dark matter with coupling of dark matter to a long-range vector field. When normalized to COBE on large scales, such models do lead to reduced velocities on small scales and they produce fewer halos compared with CDM. However, models with sufficiently low small-scale velocities apparently fail to produce an adequate number of halos.

  19. Analyzing the dynamic response of rotating blades in small-scale wind turbines

    NASA Astrophysics Data System (ADS)

    Hsiung, Wan-Ying; Huang, Yu-Ting; Loh, Chin-Hsiung; Loh, Kenneth J.; Kamisky, Robert J.; Nip, Danny; van Dam, Cornelis

    2014-03-01

    The objective of this study was to validate modal analysis, system identification and damage detection of small-scale rotating wind turbine blades in the laboratory and in the field. Here, wind turbine blades were instrumented with accelerometers and strain gages, and data acquisition was achieved using a prototype wireless sensing system. In the first portion of this study conducted in the laboratory, sensors were installed onto metallic structural elements that were fabricated to be representative of an actual wind blade. In order to control the excitation (rotation of the wind blade), a motor was used to spin the blades at controlled angular velocities. The wind turbine was installed on a shaking table for testing under rotation of turbine blades. Data measured by the sensors were recorded while the blade was operated at different speeds. On the other hand, the second part of this study utilized a small-scale wind turbine system mounted on the rooftop of a building. The main difference, as compared to the lab tests, was that the field tests relied on actual wind excitations (as opposed to a controlled motor). The raw data from both tests were analyzed using signal processing and system identification techniques for deriving the model response of the blades. The multivariate singular spectrum analysis (MSSA) and covariance-driven stochastic subspace identification method (SSI-COV) were used to identify the dynamic characteristics of the system. Damage of one turbine blade (loose bolts connection) in the lab test was also conducted. The extracted modal properties for both undamaged and damage cases under different ambient or forced excitations (earthquake loading) were compared. These tests confirmed that dynamic characterization of rotating wind turbines was feasible, and the results will guide future monitoring studies planned for larger-scale systems.

  20. Development of a Small Scale BIGGT Power Plant

    DTIC Science & Technology

    1994-10-02

    cotton gin trash, SERDP 8 Western Regional Biomass Energy Program 16. PRICE CODE N/A 17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19...by the Western Regional Biomass Energy Program. INTRODUCTION The most economically promising path for supplying electrical and thermal power to...we could never have completed an uneventful 24 hour run. ACKNOWLEDGEMENTS The U.S. Department of Energy’s Western Regional Biomass Energy Program

  1. Observations and analysis of small-scale magnetic flux ropes in the solar wind

    NASA Astrophysics Data System (ADS)

    Zheng, Jinlei; Hu, Qiang

    2016-11-01

    The small-scale magnetic flux ropes (of duration ranging from a few minutes to a few hours) in the solar wind have the typical topology of winding field lines around a central axis, which is similar to the large-scale flux ropes, i.e., magnetic clouds. However, accumulating evidence suggests that their plasma characteristics, origin, formation mechanism and evolution are different from those of large-scale flux ropes. The small-scale flux ropes are intensively studied in recent years, since they affect particle transport and energization, and are considered as the potential source of local acceleration. The Grad-Shafranov reconstruction technique is a tool to reconstruct the two and a half dimensional field structure based on in-situ measurements captured by an observing platform moving past it. In this study, we reconstruct the flux rope structures in two events using the Grad-Shafranov reconstruction approach. In one event, a twin flux rope structure at 1 AU occurring on 2002 February 1 and two following single flux rope structures are identified behind an interplanetary shock. In the other event, we reconstruct the flux rope structures occurring on 1998 March 25 and 26 at 1 AU in the ambient solar wind. The associated energetic particle signatures and the possible origin of these flux rope structures are discussed.

  2. Small-scale hydroelectric power in the southeast: new impetus for an old energy source

    SciTech Connect

    Not Available

    1980-06-01

    The Southeastern conference, Small-Scale Hydroelectric Power: New Impetus for an Old Energy Source, was convened to provide a forum for state legislators and other interested persons to discuss the problems facing small-scale hydro developers, and to recommend appropriate solutions to resolve those problems. During the two-day meeting state legislators and their staffs, along with dam developers, utility and industry representatives, environmentalists and federal/state officials examined and discussed the problems impeding small-scale hydro development at the state level. Based upon the problem-oriented discussions, alternative policy options were recommended for consideration by the US Department of Energy, state legislatures and the staff of the National Conference of State Legislatures (NCSL). Emphasis was placed on the legal, institutional, environmental and economic barriers at the state level, as well as the federal delays associated with licensing small-scale hydro projects. Whereas other previously held conferences have emphasized the identification and technology of small-scale hydro as an alternative energy source, this conference stressed legislative resolution of the problems and delays in small-scale hydro licensing and development. Panel discussions and workshops are summarized. Papers on the environmental, economic, and legal aspects of small-scale hydropower development are presented. (LCL)

  3. Detection of small-scale structures in the dissipation regime of solar-wind turbulence.

    PubMed

    Perri, S; Goldstein, M L; Dorelli, J C; Sahraoui, F

    2012-11-09

    Recent observations of the solar wind have pointed out the existence of a cascade of magnetic energy from the scale of the proton Larmor radius ρ(p) down to the electron Larmor radius ρ(e) scale. In this Letter we study the spatial properties of magnetic field fluctuations in the solar wind and find that at small scales the magnetic field does not resemble a sea of homogeneous fluctuations, but rather a two-dimensional plane containing thin current sheets and discontinuities with spatial sizes ranging from l >/~ ρ(p) down to ρ(e) and below. These isolated structures may be manifestations of intermittency that localize sites of turbulent dissipation. Studying the relationship between turbulent dissipation, reconnection, and intermittency is crucial for understanding the dynamics of laboratory and astrophysical plasmas.

  4. Small scale hydroelectric power potential in Nevada: a preliminary reconnaissance survey

    SciTech Connect

    Cochran, G.F.; Fordham, J.W.; Richard, K.; Loux, R.

    1981-04-01

    This preliminary reconnaissance survey is intended to: develop a first estimate as to the potential number, location and characteristics of small-scale (50 kW to 15 MW) hydroelectric sites in Nevada; provide a compilation of various Federal and state laws and regulations, including tax and financing regulations, that affect small-scale hydroelectric development and provide information on sources of small-scale hydroelectric generation hardware and consultants/ contractors who do small scale hydroelectric work. The entire survey has been conducted in the office working with various available data bases. The site survey and site evaluation methods used are described, and data are tabulated on the flow, power potential, predicted capital expenditures required, etc. for 61 potential sites with measured flows and for 77 sites with derived flows. A map showing potential site locations is included. (LCL)

  5. Small-scale hydroelectric power in the Pacific Northwest: new impetus for an old energy source

    SciTech Connect

    Not Available

    1980-07-01

    Energy supply is one of the most important issues facing Northwestern legislators today. To meet the challenge, state legislatures must address the development of alternative energy sources. The Small-Scale Hydroelectric Power Policy Project of the National Conference of State Legislators (NCSL) was designed to assist state legislators in looking at the benefits of one alternative, small-scale hydro. Because of the need for state legislative support in the development of small-scale hydroelectric, NCSL, as part of its contract with the Department of Energy, conducted the following conference on small-scale hydro in the Pacific Northwest. The conference was designed to identify state obstacles to development and to explore options for change available to policymakers. A summary of the conference proceedings is presented.

  6. Small-scale structures in common-volume meteor wind measurements

    NASA Astrophysics Data System (ADS)

    Fraser, G. J.; Marsh, S. H.; Baggaley, W. J.; Bennett, R. G. T.; Lawrence, B. N.; McDonald, A. J.; Plank, G. E.

    2006-02-01

    Observational differences occur when different techniques are used for measuring mesospheric winds because the different instruments observe different physical quantities to infer the wind velocity, and have differing time and space resolution. The AMOR meteor wind radar near Christchurch, New Zealand [Marsh et al., 2000. Journal of Atmospheric and Solar-Terrestrial Physics 62,1129 1133.] has good resolution in time (˜0.1 s) and height (˜1 km) and a narrow beam centred in the geographic N S meridian. The meteor echoes randomly sample the atmosphere in a region extending over several hundred kilometres to the South of the radar. The volume of data obtained from the one instrument has made it possible to use correlations between measurements made from individual meteor trails to identify the contribution of atmospheric variability to the observational differences. Measurements of the meridional wind component made from May July 1997 inclusive show that a large part (20 30 m/s r.m.s.) of the atmospheric variation is due to inhomogeneities with small scales, of the order of 10 km and 1 h. There is also a component which has a random time phase over the observation interval but a spatial scale which is coherent over several hundred kilometres, consistent with the behaviour of gravity waves.

  7. Extreme small-scale wind episodes over the Barents Sea: When, where and why?

    NASA Astrophysics Data System (ADS)

    Kolstad, Erik W.

    2015-04-01

    The Barents Sea is mostly ice-free during winter and therefore prone to severe weather associated with marine cold air outbreaks, such as polar lows. With the increasing marine activity in the region, it is important to study the climatology and variability of episodes with strong winds, as well as to understand their causes. Explosive marine cyclogenesis is usually caused by a combination of several mechanisms: upper-level forcing, stratospheric dry intrusions, latent heat release, surface energy fluxes, low-level baroclinicity. An additional factor that has been linked to extremely strong surface winds, is low static stability in the lower atmosphere, which allows for downward transfer of high-momentum air. Here the most extreme small-scale wind episodes in a high-resolution (5 km) 35-year hindcast were analyzed from a dynamical perspective, and it was found that they were associated with unusually strong low-level baroclinicity and surface heat fluxes. And crucially, the 12 most severe episodes had stronger cold-air advection than 12 slightly less severe cases, suggesting that marine cold air outbreaks are the most important mechanism for extreme winds on small spatial scales over the Barents Sea. Observational data is sparse in the Arctic, so forecasters are often in need of simple indicators when evaluating the potential for strong winds. Polar low forecasters in northern Norway monitor the vertical difference between the SST and the temperature at 500 hPa, which is a simple and effective indicator of cold air outbreaks. Already 24 hours before the most intense storms' peak intensity, this difference was higher than normal, acting as a possible harbinger of extreme winds for experienced forecasters. As the quality and resolution of the forecast models increase with time, it is in data-sparse regions such as the Barents Sea that human experience still gives a vital edge.

  8. Transient flows of the solar wind associated with small-scale solar activity in solar minimum

    NASA Astrophysics Data System (ADS)

    Slemzin, Vladimir; Veselovsky, Igor; Kuzin, Sergey; Gburek, Szymon; Ulyanov, Artyom; Kirichenko, Alexey; Shugay, Yulia; Goryaev, Farid

    The data obtained by the modern high sensitive EUV-XUV telescopes and photometers such as CORONAS-Photon/TESIS and SPHINX, STEREO/EUVI, PROBA2/SWAP, SDO/AIA provide good possibilities for studying small-scale solar activity (SSA), which is supposed to play an important role in heating of the corona and producing transient flows of the solar wind. During the recent unusually weak solar minimum, a large number of SSA events, such as week solar flares, small CMEs and CME-like flows were observed and recorded in the databases of flares (STEREO, SWAP, SPHINX) and CMEs (LASCO, CACTUS). On the other hand, the solar wind data obtained in this period by ACE, Wind, STEREO contain signatures of transient ICME-like structures which have shorter duration (<10h), weaker magnetic field strength (<10 nT) and lower proton temperature than usual ICMEs. To verify the assumption that ICME-like transients may be associated with the SSA events we investigated the number of weak flares of C-class and lower detected by SPHINX in 2009 and STEREO/EUVI in 2010. The flares were classified on temperature and emission measure using the diagnostic means of SPHINX and Hinode/EIS and were confronted with the parameters of the solar wind (velocity, density, ion composition and temperature, magnetic field, pitch angle distribution of the suprathermal electrons). The outflows of plasma associated with the flares were identified by their coronal signatures - CMEs (only in few cases) and dimmings. It was found that the mean parameters of the solar wind projected to the source surface for the times of the studied flares were typical for the ICME-like transients. The results support the suggestion that weak flares can be indicators of sources of transient plasma flows contributing to the slow solar wind at solar minimum, although these flows may be too weak to be considered as separate CMEs and ICMEs. The research leading to these results has received funding from the European Union’s Seventh Programme

  9. Small Scale Electrical Power Generation from Heat Co-Produced in Geothermal Fluids: Mining Operation

    SciTech Connect

    Clark, Thomas M.; Erlach, Celeste

    2014-12-30

    Demonstrate the technical and economic feasibility of small scale power generation from low temperature co-produced fluids. Phase I is to Develop, Design and Test an economically feasible low temperature ORC solution to generate power from lower temperature co-produced geothermal fluids. Phase II &III are to fabricate, test and site a fully operational demonstrator unit on a gold mine working site and operate, remotely monitor and collect data per the DOE recommended data package for one year.

  10. Achieving Full Dynamic Similarity with Small-Scale Wind Turbine Models

    NASA Astrophysics Data System (ADS)

    Miller, Mark; Kiefer, Janik; Westergaard, Carsten; Hultmark, Marcus

    2016-11-01

    Power and thrust data as a function of Reynolds number and Tip Speed Ratio are presented at conditions matching those of a full scale turbine. Such data has traditionally been very difficult to acquire due to the large length-scales of wind turbines, and the limited size of conventional wind tunnels. Ongoing work at Princeton University employs a novel, high-pressure wind tunnel (up to 220 atmospheres of static pressure) which uses air as the working fluid. This facility allows adjustment of the Reynolds number (via the fluid density) independent of the Tip Speed Ratio, up to a Reynolds number (based on chord and velocity at the tip) of over 3 million. Achieving dynamic similarity using this approach implies very high power and thrust loading, which results in mechanical loads greater than 200 times those experienced by a similarly sized model in a conventional wind tunnel. In order to accurately report the power coefficients, a series of tests were carried out on a specially designed model turbine drive-train using an external testing bench to replicate tunnel loading. An accurate map of the drive-train performance at various operating conditions was determined. Finally, subsequent corrections to the power coefficient are discussed in detail. Supported by: National Science Foundation Grant CBET-1435254 (program director Gregory Rorrer).

  11. Coronal hole boundaries evolution at small scales. II. XRT view. Can small-scale outflows at CHBs be a source of the slow solar wind

    NASA Astrophysics Data System (ADS)

    Subramanian, S.; Madjarska, M. S.; Doyle, J. G.

    2010-06-01

    Aims: We aim to further explore the small-scale evolution of coronal hole boundaries using X-ray high-resolution and high-cadence images. We intend to determine the fine structure and dynamics of the events causing changes of coronal hole boundaries and to explore the possibility that these events are the source of the slow solar wind. Methods: We developed an automated procedure for the identification of transient brightenings in images from the X-ray telescope on-board Hinode taken with an Al Poly filter in the equatorial coronal holes, polar coronal holes, and the quiet Sun with and without transient coronal holes. Results: We found that in comparison to the quiet Sun, the boundaries of coronal holes are abundant with brightening events including areas inside the coronal holes where closed magnetic field structures are present. The visual analysis of these brightenings revealed that around 70% of them in equatorial, polar and transient coronal holes and their boundaries show expanding loop structures and/or collimated outflows. In the quiet Sun only 30% of the brightenings show flows with most of them appearing to be contained in the solar corona by closed magnetic field lines. This strongly suggests that magnetic reconnection of co-spatial open and closed magnetic field lines creates the necessary conditions for plasma outflows to large distances. The ejected plasma always originates from pre-existing or newly emerging (at X-ray temperatures) bright points. Conclusions: The present study confirms our findings that the evolution of loop structures known as coronal bright points is associated with the small-scale changes of coronal hole boundaries. The loop structures show an expansion and eruption with the trapped plasma consequently escaping along the “quasi” open magnetic field lines. These ejections appear to be triggered by magnetic reconnection, e.g. the so-called interchange reconnection between the closed magnetic field lines (BPs) and the open

  12. Small scale aspects of warm dark matter: Power spectra and acoustic oscillations

    SciTech Connect

    Boyanovsky, Daniel; Wu Jun

    2011-02-15

    We provide a semianalytic derivation of approximate evolution equations for density perturbations of warm dark matter candidates that decoupled while relativistic with arbitrary distribution functions, their solutions at small scales, and a simple numerical implementation that yields their transfer functions and power spectra. Density perturbations evolve through three stages: radiation domination when the particle is relativistic and nonrelativistic and matter domination. An early integrated Sachs-Wolfe effect during the first stage leads to an enhancement of density perturbations and a plateau in the transfer function for k < or approx. k{sub fs}, the free-streaming wave vector. An effective fluid description emerges at small scales which includes the effects of free streaming in initial conditions and inhomogeneities. The transfer function features warm dark matter acoustic oscillations at scales k > or approx. 2k{sub fs}. A simple analytic interpolation of the power spectra between large and small scales and a numerical implementation valid for arbitrary distribution functions is provided. As an application we study the power spectra for two models of sterile neutrinos with m{approx}keV produced nonresonantly and compare our results to those obtained from Boltzmann codes.

  13. Legal obstacles and incentives to the development of small scale hydroelectric power in Kentucky

    SciTech Connect

    None,

    1980-05-01

    The legal and institutional obstacles to the development of small-scale hydroelectric energy at the state level are examined. The introductory section examines the dual regulatory system from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and concludes with an inquiry into the practical use of the doctrine by the FERC. Additional sections cover acquisition; liability; Department for Natural Resources and Environmental Protection; energy utilities; local regulations; incidental impacts; financial considerations; and sources of information. In Kentucky, many of the impacts have not been implemented with regard to small-scale hydroelectric energy, since in Kentucky most electricity is coal-generated and any hydroelectric power that does exist, is derived from TVA or the Army Corp of Engineer projects.

  14. Electricity's future: the shift to efficiency and small-scale power

    SciTech Connect

    Flavin, C.

    1984-01-01

    Because most countries have rigid, centralized utility systems, small-scale power generation has barely caught on outside the US. In many countries a single state utility or a few large private utilities have exclusive rights to generate power, and these bureaucracies have concentrated on large power plants. But rapid advances under way in a wide range of small-scale generating technologies may soon encourage changes worldwide. Research programs are widespread, and international developments are closely followed. Improved energy efficiency and load management should also be considered as alternatives to building new power plants. In most regions of the world inefficient appliances can be replaced, houses weatherized, and industrial equipment upgraded for a fraction of the cost of building a new generating plant. Efficiency can be promoted many ways, but some of the best include utility-sponsored information and financing programs, with a return allowed on the investment, just as a new power plant would receive. Electricity prices can be adjusted to encourage less power use at peak periods, thus avoiding the need to build additional plants. Many utilities have recently adopted efficiency programs at the insistence of government regulators, but most are just token efforts. 101 references.

  15. Legal obstacles and incentives to the development of small scale hydroelectric power in New Jersey

    SciTech Connect

    None,

    1980-05-01

    The legal and institutional obstacles to the development of small-scale hydroelectric energy at the state level in New Jersey are described. The Federal government also exercises extensive regulatory authority in the area. The dual regulatory system from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and an inquiry into the practical use of the doctrine by the FERC is discussed. New Jersey follows the riparian theory of water law. Following an extensive discussion of the New Jersey water law, New Jersey regulatory law and financial considerations regarding hydroelectric power development are discussed.

  16. Small scale noise and wind tunnel tests of upper surface blowing nozzle flap concepts. Volume 1. Aerodynamic test results

    NASA Technical Reports Server (NTRS)

    Renselaer, D. J.; Nishida, R. S.; Wilkin, C. A.

    1975-01-01

    The results and analyses of aerodynamic and acoustic studies conducted on the small scale noise and wind tunnel tests of upper surface blowing nozzle flap concepts are presented. Various types of nozzle flap concepts were tested. These are an upper surface blowing concept with a multiple slot arrangement with seven slots (seven slotted nozzle), an upper surface blowing type with a large nozzle exit at approximately mid-chord location in conjunction with a powered trailing edge flap with multiple slots (split flow or partially slotted nozzle). In addition, aerodynamic tests were continued on a similar multi-slotted nozzle flap, but with 14 slots. All three types of nozzle flap concepts tested appear to be about equal in overall aerodynamic performance but with the split flow nozzle somewhat better than the other two nozzle flaps in the landing approach mode. All nozzle flaps can be deflected to a large angle to increase drag without significant loss in lift. The nozzle flap concepts appear to be viable aerodynamic drag modulation devices for landing.

  17. SMALL-SCALE PRESSURE-BALANCED STRUCTURES DRIVEN BY OBLIQUE SLOW MODE WAVES MEASURED IN THE SOLAR WIND

    SciTech Connect

    Yao Shuo; He, J.-S.; Tu, C.-Y.; Wang, L.-H.; Marsch, E.

    2013-09-01

    Recently, small-scale pressure-balanced structures (PBSs) were identified in the solar wind, but their formation mechanism remains unclear. This work aims to reveal the dependence of the properties of small-scale PBSs on the background magnetic field (B{sub 0}) direction and thus to corroborate the in situ mechanism that forms them. We analyze the plasma and magnetic field data obtained by WIND in the quiet solar wind at 1 AU. First, we use a developed moving-average method to obtain B{sub 0}(s, t) for every temporal scale (s) at each time moment (t). By wavelet cross-coherence analysis, we obtain the correlation coefficients between the thermal pressure P{sub th} and the magnetic pressure P{sub B}, distributing against the temporal scale and the angle {theta}{sub xB} between B{sub 0}(s, t) and Geocentric Solar Ecliptic coordinates (GSE)-x. We note that the angle coverage of a PBS decreases with shorter temporal scale, but the occurrence of the PBSs is independent of {theta}{sub xB}. Suspecting that the isolated small PBSs are formed by compressive waves in situ, we continue this study by testing the wave modes forming a small-scale PBS with B{sub 0}(s, t) quasi-parallel to GSE-x. As a result, we identify that the cross-helicity and the compressibility attain values for a slow mode from theoretical calculations. The wave vector is derived from minimum variance analysis. Besides, the proton temperatures obey T < T{sub Parallel-To} derived from the velocity distribution functions, excluding a mirror mode, which is the other candidate for the formation of PBSs in situ. Thus, a small-scale PBS is shown to be driven by oblique, slow-mode waves in the solar wind.

  18. SMALL-SCALE SOLAR WIND TURBULENCE DUE TO NONLINEAR ALFVÉN WAVES

    SciTech Connect

    Kumar, Sanjay; Moon, Y.-J.; Sharma, R. P.

    2015-10-10

    We present an evolution of wave localization and magnetic power spectra in solar wind plasma using kinetic Alfvén waves (AWs) and fast AWs. We use a two-fluid model to derive the dynamical equations of these wave modes and then numerically solve these nonlinear dynamical equations to analyze the power spectra and wave localization at different times. The ponderomotive force associated with the kinetic AW (or pump) is responsible for the wave localization, and these thin slabs (or sheets) become more chaotic as the system evolves with time until the modulational instability (or oscillating two-stream instability) saturates. From our numerical results, we notice a steepening of the spectra from the inertial range (k{sup −1.67}) to the dispersion range (k{sup −3.0}). The steepening of the spectra could be described as the energy transference from longer to smaller scales. The formation of complex magnetic thin slabs and the change of the spectral index may be considered to be the main reason for the charged particles acceleration in solar wind plasma.

  19. Validation of a power-law noise model for simulating small-scale breast tissue

    NASA Astrophysics Data System (ADS)

    Reiser, I.; Edwards, A.; Nishikawa, R. M.

    2013-09-01

    We have validated a small-scale breast tissue model based on power-law noise. A set of 110 patient images served as truth. The statistical model parameters were determined by matching the radially averaged power-spectrum of the projected simulated tissue with that of the central tomosynthesis patient breast projections. Observer performance in a signal-known exactly detection task in simulated and actual breast backgrounds was compared. Observers included human readers, a pre-whitening observer model and a channelized Hotelling observer model. For all observers, good agreement between performance in the simulated and actual backgrounds was found, both in the tomosynthesis central projections and the reconstructed images. This tissue model can be used for breast x-ray imaging system optimization. The complete statistical description of the model is provided.

  20. Legal obstacles and incentives to the development of small scale hydroelectric power in New York

    SciTech Connect

    None,

    1980-05-01

    The legal and institutional obstacles to the development of small-scale hydroelectric energy at the state level are discussed. The Federal government also exercises extensive regulatory authority in the area, and the dual regulatory system from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and an inquiry into the practical use of the doctrine by the FERC is examined. The first step the small scale hydroelectric developer must take is that of acquiring title to the real property comprising the development site. The real estate parcel must include the requisite interest in the land adjacent to the watercourse, access to the underlying streambed and where needed, the land necessary for an upstream impoundment area. Land acquisition may be effectuated by purchase, lease, or grant by the state. In addition to these methods, New York permits the use of the eminent domain power of the state for public utilities under certain circumstances.

  1. Legal obstacles and incentives to the development of small scale hydroelectric power in West Virginia

    SciTech Connect

    None,

    1980-05-01

    The legal and institutional obstacles to the development of small-scale hydroelectric in West Virginia at the state level are described. The Federal government also exercises extensive regulatory authority in the area. The introductory section examines the dual regulatory system from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and concludes with an inquiry into the practical use of the doctrine by FERC. The development of small-scale hydroelectric energy depends on the selection of a site which will produce sufficient water power capacity to make the project economically attractive to a developer. In West Virginia, the right to use the flowing waters of a stream, creek, or river is appurtenant to the ownership of the lands bordering the watercourse. The lands are known as riparian lands. The water rights are known as riparian rights. Thus, the first obstacle a developer faces involves the acquisition of riparian lands and the subsequent right to the use of the water. The water law in West Virginia is discussed in detail followed by discussions on direct and indirect regulations; continuing obligations; financial considerations; and interstate organizations.

  2. An investigation of rotor harmonic noise by the use of small scale wind tunnel models

    NASA Technical Reports Server (NTRS)

    Sternfeld, H., Jr.; Schaffer, E. G.

    1982-01-01

    Noise measurements of small scale helicopter rotor models were compared with noise measurements of full scale helicopters to determine what information about the full scale helicopters could be derived from noise measurements of small scale helicopter models. Comparisons were made of the discrete frequency (rotational) noise for 4 pairs of tests. Areas covered were tip speed effects, isolated rotor, tandem rotor, and main rotor/tail rotor interaction. Results show good comparison of noise trends with configuration and test condition changes, and good comparison of absolute noise measurements with the corrections used except for the isolated rotor case. Noise measurements of the isolated rotor show a great deal of scatter reflecting the fact that the rotor in hover is basically unstable.

  3. Customer adoption of small-scale on-site power generation

    SciTech Connect

    Siddiqui, Afzal S.; Marnay, Chris; Hamachi, Kristina S.; Rubio, F. Javier

    2001-04-01

    The electricity supply system is undergoing major regulatory and technological change with significant implications for the way in which the sector will operate (including its patterns of carbon emissions) and for the policies required to ensure socially and environmentally desirable outcomes. One such change stems from the rapid emergence of viable small-scale (i.e., smaller than 500 kW) generators that are potentially competitive with grid delivered electricity, especially in combined heat and power configurations. Such distributed energy resources (DER) may be grouped together with loads in microgrids. These clusters could operate semi-autonomously from the established power system, or macrogrid, matching power quality and reliability more closely to local end-use requirements. In order to establish a capability for analyzing the effect that microgrids may have on typical commercial customers, such as office buildings, restaurants, shopping malls, and grocery stores, an economic mod el of DER adoption is being developed at Berkeley Lab. This model endeavors to indicate the optimal quantity and type of small on-site generation technologies that customers could employ given their electricity requirements. For various regulatory schemes and general economic conditions, this analysis produces a simple operating schedule for any installed generators. Early results suggest that many commercial customers can benefit economically from on-site generation, even without considering potential combined heat and power and reliability benefits, even though they are unlikely to disconnect from the established power system.

  4. Legal obstacles and incentives to the development of small scale hydroelectric power in Connecticut

    SciTech Connect

    None,

    1980-05-01

    The legal and institutional obstacles to the development of small-scale hydroelectric power in Connecticut are discussed. The Federal government also exercises extensive regulatory authority in the area and this dual system is examined from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and an inquiry into the practical use of the doctrine by the FERC. Connecticut follows the riparian theory of water law. Under this theory of the water law, private rights in rivers and streams are confined to the use of flowing water. A riparian proprietor does not own the water that flows by his estate. Licensing, permitting, and review procedures are discussed followed by discussion on public utilities regulation and indirect considerations.

  5. Legal obstacles and incentives to the development of small scale hydroelectric power in Ohio

    SciTech Connect

    None,

    1980-05-01

    The legal and institutional obstacles to the development of small-scale hydroelectric energy at the state level is described. The Federal government also exercises extensive regulatory authority in the area. The introductory section examines the regulatory system from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and concludes with an inquiry into the practical use of the doctrine by the FERC. A developer must obtain title or interest to a streambed from the proper riparian owners. Ohio provides assistance to an electric company in this undertaking by providing it with the power of eminent domain in the event it is unable to reach a purchase agreement with the riparian proprietors. The Ohio Water Law is discussed in detail, followed by discussions: Licensing, Permitting, and Review Procedures; Indirect Considerations; Ohio Public Utilities Commission; Ohio Department of Energy; Incidental Provision; and Financial Considerations.

  6. A study of large scale gust generation in a small scale atmospheric wind tunnel with applications to Micro Aerial Vehicles

    NASA Astrophysics Data System (ADS)

    Roadman, Jason Markos

    Modern technology operating in the atmospheric boundary layer can always benefit from more accurate wind tunnel testing. While scaled atmospheric boundary layer tunnels have been well developed, tunnels replicating portions of the atmospheric boundary layer turbulence 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 Micro Aerial Vehicle(MAV) development, the wind energy industry, fuel efficient vehicle design, and the study of bird and insect flight, to name just a few. The small scale of MAVs provide the somewhat unique capability of full scale Reynolds number testing in a wind tunnel. However, that same small scale creates interactions under real world flight conditions, atmospheric gusts for example, that lead to a need for testing under more complex flows than the standard uniform flow found in most wind tunnels. It is for these reasons that MAVs are used as the initial testing application for the atmospheric gust tunnel. An analytical model for both discrete gusts and a continuous spectrum of gusts is examined. Then, methods for generating gusts in agreement with that model are investigated. Previously used methods are reviewed and a gust generation apparatus is designed. Expected turbulence and gust characteristics of this apparatus are compared with atmospheric data. 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 weather 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

  7. Power spectrum of small-scale density irregularities in the interstellar medium

    NASA Technical Reports Server (NTRS)

    Armstrong, J. W.; Rickett, B. J.

    1981-01-01

    Observations of the interstellar scintillation of radiation from 17 pulsars are reported which are used to place limits on the power spectrum of small-scale electron density irregularities in the interstellar medium. Measurements made at 340, 408, and 450 MHz in the dispersion measure range 3-57/cu cm pc of the time-dependent radio frequency spectrum of interstellar scintillations were analyzed to determine the scintillation index and a scintillation frequency-correlation scale based on the autocorrelation function in radio frequency of the fluctuations in scintillation. The dispersion-measure dependence of the scintillation frequency correlation scale is found to be consistent with both Gaussian model interstellar medium spectra and power-law spectra with indices between 3.0 and 4, while the radio-frequency scaling of the frequency correlation scale is consistent with power law indices between 2.8 and 3.9. However comparison of the shape of the radio-frequency autocorrelation function with model calculations indicates power law models with indices greater than 3.6 are possible. Data are also consistent with a local three-dimensional density spectrum at a wave number of 10 to the -9th/m of 3 x 10 to the 28th to 3 x 10 to the 29th/cu m.

  8. Performance and aerodynamic braking of a horizontal-axis wind turbine from small-scale wind tunnel tests

    NASA Technical Reports Server (NTRS)

    Cao, H. V.; Wentz, W. H., Jr.

    1987-01-01

    Wind tunnel tests of three 20" diameter, zero twist, zero pitch wind turbine rotor models were conducted in a 7' x 10' wind tunnel to determine the performance of such rotors with NACA 23024 and NACA 64 sub 3-621 airfoil sections. Aerodynamic braking characteristics of a 38% span, 30% chord, vented aileron configuration were measured on the NACA 23024 rotor. Surface flow patterns were observed using fluorescent mini-tufts attached to the suction side of the rotor blades. Experimental results with and without ailerons are compared to predictions using airfoil section data and a momentum performance code. Results of the performance studies show that the 64 sub 3-621 rotor produces higher peak power than the 23024 rotor for a given rotor speed. Analytical studies, however, indicate that the 23024 should produce higher power. Transition strip experiments show that the 23024 rotor is much more sensitive to roughness than the 64 sub 3-621 rotor. These trends agree with analytical predictions. Results of the aileron test show that this aileron, when deflected, produces a braking torque at all tip speed ratios. In free wheeling coastdowns the rotor blade stopped, then rotated backward at a tip speed ratio of -0.6.

  9. Small scale wind tunnel model investigation of hybrid high lift systems combining upper surface blowing with the internally blown flap

    NASA Technical Reports Server (NTRS)

    Waites, W. L.; Chin, Y. T.

    1974-01-01

    A small-scale wind tunnel test of a two engine hybrid model with upper surface blowing on a simulated expandable duct internally blown flap was accomplished in a two phase program. The low wing Phase I model utilized 0.126c radius Jacobs/Hurkamp flaps and 0.337c radius Coanda flaps. The high wing Phase II model was utilized for continued studies on the Jacobs/Hurkamp flap. Principal study areas included: basic data both engines operative and with an engine out, control flap utilization, horizontal tail effectiveness, spoiler effectiveness, USB nacelle deflector study and USB/IBF pressure ratio effects.

  10. RAPID COMMUNICATION: Novel high performance small-scale thermoelectric power generation employing regenerative combustion systems

    NASA Astrophysics Data System (ADS)

    Weinberg, F. J.; Rowe, D. M.; Min, G.

    2002-07-01

    Hydrocarbon fuels have specific energy contents some two orders of magnitude greater than any electrical storage device. They therefore proffer an ideal source in the universal quest for compact, lightweight, long-lasting alternatives for batteries to power the ever-proliferating electronic devices. The motivation lies in the need to power, for example, equipment for infantry troops, for weather stations and buoys in polar regions which need to signal their readings intermittently to passing satellites, unattended over long periods, and many others. Fuel cells, converters based on miniaturized gas turbines, and other systems under intensive study, give rise to diverse practical difficulties. Thermoelectric devices are robust, durable and have no moving parts, but tend to be exceedingly inefficient. We propose regenerative combustion systems which mitigate this impediment and are likely to make high performance small-scale thermoelectric power generation applicable in practice. The efficiency of a thermoelectric generating system using preheat when operated between ambient and 1200 K is calculated to exceed the efficiency of the best present day thermoelectric conversion system by more than 20%.

  11. Wind Power Now!

    ERIC Educational Resources Information Center

    Inglis, David Rittenhouse

    1975-01-01

    The government promotes and heavily subsidizes research in nuclear power plants. Federal development of wind power is slow in comparison even though much research with large wind-electric machines has already been conducted. Unless wind power programs are accelerated it will not become a major energy alternative to nuclear power. (MR)

  12. Wind power soars

    SciTech Connect

    Flavin, C.

    1996-12-31

    Opinions on the world market for wind power are presented in this paper. Some data for global wind power generating capacity are provided. European and other markets are discussed individually. Estimated potential for wind power is given for a number of countries. 3 figs.

  13. Villacidro solar demo plant: Integration of small-scale CSP and biogas power plants in an industrial microgrid

    NASA Astrophysics Data System (ADS)

    Camerada, M.; Cau, G.; Cocco, D.; Damiano, A.; Demontis, V.; Melis, T.; Musio, M.

    2016-05-01

    The integration of small scale concentrating solar power (CSP) in an industrial district, in order to develop a microgrid fully supplied by renewable energy sources, is presented in this paper. The plant aims to assess in real operating conditions, the performance, the effectiveness and the reliability of small-scale concentrating solar power technologies in the field of distributed generation. In particular, the potentiality of small scale CSP with thermal storage to supply dispatchable electricity to an industrial microgrid will be investigated. The microgrid will be realized in the municipal waste treatment plant of the Industrial Consortium of Villacidro, in southern Sardinia (Italy), which already includes a biogas power plant. In order to achieve the microgrid instantaneous energy balance, the analysis of the time evolution of the waste treatment plant demand and of the generation in the existing power systems has been carried out. This has allowed the design of a suitable CSP plant with thermal storage and an electrochemical storage system for supporting the proposed microgrid. At the aim of obtaining the expected energy autonomy, a specific Energy Management Strategy, which takes into account the different dynamic performances and characteristics of the demand and the generation, has been designed. In this paper, the configuration of the proposed small scale concentrating solar power (CSP) and of its thermal energy storage, based on thermocline principle, is initially described. Finally, a simulation study of the entire power system, imposing scheduled profiles based on weather forecasts, is presented.

  14. Harvesting wind energy from the sea breeze in peri-urban coastal areas by means of small scale wind turbines - Case study: Viladecans, Llobregat Delta, northeast of Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Rojas, Jose I.; Cabrera, Barbara; Mazon, Jordi

    2016-04-01

    Wind speed data recorded during 18 years (1993-2010) in the Llobregat Delta (15 km south of Barcelona city; northeast of the Iberian Peninsula) were used to assess the wind energy generated by off-grid small scale wind turbines (the IT-PE-100 and the HP-600W) for the whole year and for the sea breeze period. The computations were made using QBlade, FAST and AeroDyn simulation tools and manufacturer power curves. Using manufacturer data, the HP-600W with hub-height 8 m would deliver 157 kWh during the whole year (78 kWh during the sea breeze period), with an average power of 18 W (37 W). In this work, the results of the simulations are compared with power and energy production data measured in an HP-600W turbine installed in situ from December 2014 to April 2016. Also, the measured power is compared to the power obtained by applying the measured wind in the period 2014-2016 to the manufacturer power curve and the power curve obtained with the simulations. The results of the computations agree with the experimental data, thus validating the proposed approach for wind resource estimation. The feasibility of using a vertical axis wind turbine for obtaining wind energy from the local, thermal wind regimes is also studied. This research confirms that the sea-breeze is an interesting wind energy resource for micro-generation in peri-urban coastal areas where large-scale wind farms cannot be implemented.

  15. Performance evaluation of an integrated small-scale SOFC-biomass gasification power generation system

    NASA Astrophysics Data System (ADS)

    Wongchanapai, Suranat; Iwai, Hiroshi; Saito, Motohiro; Yoshida, Hideo

    2012-10-01

    The combination of biomass gasification and high-temperature solid oxide fuel cells (SOFCs) offers great potential as a future sustainable power generation system. In order to provide insights into an integrated small-scale SOFC-biomass gasification power generation system, system simulation was performed under diverse operating conditions. A detailed anode-supported planar SOFC model under co-flow operation and a thermodynamic equilibrium for biomass gasification model were developed and verified by reliable experimental and simulation data. The other peripheral components include three gas-to-gas heat exchangers (HXs), heat recovery steam generator (HRSG), burner, fuel and air compressors. To determine safe operating conditions with high system efficiency, energy and exergy analysis was performed to investigate the influence through detailed sensitivity analysis of four key parameters, e.g. steam-to-biomass ratio (STBR), SOFC inlet stream temperatures, fuel utilization factor (Uf) and anode off-gas recycle ratio (AGR) on system performance. Due to the fact that SOFC stack is accounted for the most expensive part of the initial investment cost, the number of cells required for SOFC stack is economically optimized as well. Through the detailed sensitivity analysis, it shows that the increase of STBR positively affects SOFC while gasifier performance drops. The most preferable operating STBR is 1.5 when the highest system efficiencies and the smallest number of cells. The increase in SOFC inlet temperature shows negative impact on system and gasifier performances while SOFC efficiencies are slightly increased. The number of cells required for SOFC is reduced with the increase of SOFC inlet temperature. The system performance is optimized for Uf of 0.75 while SOFC and system efficiencies are the highest with the smallest number of cells. The result also shows the optimal anode off-gas recycle ratio of 0.6. Regarding with the increase of anode off-gas recycle ratio

  16. Homemade Electricity: An Introduction to Small-Scale Wind, Hydro, and Photovoltaic Systems.

    ERIC Educational Resources Information Center

    Smith, Diane

    This report consists of three parts. The first part provides advice (in the form of questions and answers) to prospective individual power producers who are considering investing in electricity-producing systems and in generating their own power. A list of Public Utilities Regulatory Policies Act (PURPA) regulations is included. This legislation…

  17. Wind Power Outlook 2004

    SciTech Connect

    anon.

    2004-01-01

    The brochure, expected to be updated annually, provides the American Wind Energy Association's (AWAE's) up-to-date assessment of the wind industry. It provides a summary of the state of wind power in the U.S., including the challenges and opportunities facing the industry. It provides summary information on the growth of the industry, policy-related factors such as the federal wind energy production tax credit status, comparisons with natural gas, and public views on wind energy.

  18. Wind power. [electricity generation

    NASA Technical Reports Server (NTRS)

    Savino, J. M.

    1975-01-01

    A historical background on windmill use, the nature of wind, wind conversion system technology and requirements, the economics of wind power and comparisons with alternative systems, data needs, technology development needs, and an implementation plan for wind energy are presented. Considerable progress took place during the 1950's. Most of the modern windmills feature a wind turbine electricity generator located directly at the top of their rotor towers.

  19. Wind power today

    SciTech Connect

    1998-04-01

    This publication highlights initiatives of the US DOE`s Wind Energy Program. 1997 yearly activities are also very briefly summarized. The first article describes a 6-megawatt wind power plant installed in Vermont. Another article summarizes technical advances in wind turbine technology, and describes next-generation utility and small wind turbines in the planning stages. A village power project in Alaska using three 50-kilowatt turbines is described. Very brief summaries of the Federal Wind Energy Program and the National Wind Technology Center are also included in the publication.

  20. Wind structure and small-scale wind variability in the stratosphere and mesosphere during the November 1980 Energy Budget Campaign

    NASA Technical Reports Server (NTRS)

    Schmidlin, F. J.; Carlson, M.; Rees, D.; Offermann, D.; Philbrick, C. R.; Widdel, H. U.

    1982-01-01

    Rocket observations made from two sites in northern Scandinavia between November 6 and December 1, 1980, as part of the Energy Budget Campaign are discussed. It was found that significant vertical and temporal changes in the wind structure were present and that they coincided with different geomagnetic conditions, that is, quiet and enhanced. Before November 16, the meridional wind component above 60 km was found to be positive (southerly), whereas the magnitude of the zonal wind component increased with altitude. After November 16 the meridional component became negative (northerly), and the magnitude of the zonal wind component was observed to decrease with altitude. Time sections of the perturbations of the zonal wind reveal the presence of vertically propagating waves, suggesting gravity wave activity. The waves are found to increase in wavelength from 3-4 km near 40 km to more than 12 km near 80 km. The observational techniques made use of chaff foil, chemical trails, inflatable spheres, and parachutes.

  1. Dynamic simulation of a solar-driven carbon dioxide transcritical power system for small scale combined heat and power production

    SciTech Connect

    Chen, Y.; Lundqvist, Per; Pridasawas, Wimolsiri

    2010-07-15

    Carbon dioxide is an environmental benign natural working fluid and has been proposed as a working media for a solar-driven power system. In the current work, the dynamic performance of a small scale solar-driven carbon dioxide power system is analyzed by dynamic simulation tool TRNSYS 16 and Engineering Equation Solver (EES) using co-solving technique. Both daily performance and yearly performance of the proposed system have been simulated. Different system operating parameters, which will influence the system performance, have been discussed. Under the Swedish climatic condition, the maximum daily power production is about 12 kW h and the maximum monthly power production is about 215 kW h with the proposed system working conditions. Besides the power being produced, the system can also produce about 10 times much thermal energy, which can be used for space heating, domestic hot water supply or driving absorption chillers. The simulation results show that the proposed system is a promising and environmental benign alternative for conventional low-grade heat source utilization system. (author)

  2. PROBING THE INFLATON: SMALL-SCALE POWER SPECTRUM CONSTRAINTS FROM MEASUREMENTS OF THE COSMIC MICROWAVE BACKGROUND ENERGY SPECTRUM

    SciTech Connect

    Chluba, Jens; Erickcek, Adrienne L.; Ben-Dayan, Ido

    2012-10-20

    In the early universe, energy stored in small-scale density perturbations is quickly dissipated by Silk damping, a process that inevitably generates {mu}- and y-type spectral distortions of the cosmic microwave background (CMB). These spectral distortions depend on the shape and amplitude of the primordial power spectrum at wavenumbers k {approx}< 10{sup 4} Mpc{sup -1}. Here, we study constraints on the primordial power spectrum derived from COBE/FIRAS and forecasted for PIXIE. We show that measurements of {mu} and y impose strong bounds on the integrated small-scale power, and we demonstrate how to compute these constraints using k-space window functions that account for the effects of thermalization and dissipation physics. We show that COBE/FIRAS places a robust upper limit on the amplitude of the small-scale power spectrum. This limit is about three orders of magnitude stronger than the one derived from primordial black holes in the same scale range. Furthermore, this limit could be improved by another three orders of magnitude with PIXIE, potentially opening up a new window to early universe physics. To illustrate the power of these constraints, we consider several generic models for the small-scale power spectrum predicted by different inflation scenarios, including running-mass inflation models and inflation scenarios with episodes of particle production. PIXIE could place very tight constraints on these scenarios, potentially even ruling out running-mass inflation models if no distortion is detected. We also show that inflation models with sub-Planckian field excursion that generate detectable tensor perturbations should simultaneously produce a large CMB spectral distortion, a link that could potentially be established with PIXIE.

  3. The Spectrum of Wind Power Fluctuations

    NASA Astrophysics Data System (ADS)

    Bandi, Mahesh

    2016-11-01

    Wind is a variable energy source whose fluctuations threaten electrical grid stability and complicate dynamical load balancing. The power generated by a wind turbine fluctuates due to the variable wind speed that blows past the turbine. Indeed, the spectrum of wind power fluctuations is widely believed to reflect the Kolmogorov spectrum; both vary with frequency f as f - 5 / 3. This variability decreases when aggregate power fluctuations from geographically distributed wind farms are averaged at the grid via a mechanism known as geographic smoothing. Neither the f - 5 / 3 wind power fluctuation spectrum nor the mechanism of geographic smoothing are understood. In this work, we explain the wind power fluctuation spectrum from the turbine through grid scales. The f - 5 / 3 wind power fluctuation spectrum results from the largest length scales of atmospheric turbulence of order 200 km influencing the small scales where individual turbines operate. This long-range influence spatially couples geographically distributed wind farms and synchronizes farm outputs over a range of frequencies and decreases with increasing inter-farm distance. Consequently, aggregate grid-scale power fluctuations remain correlated, and are smoothed until they reach a limiting f - 7 / 3 spectrum. This work was funded by the Collective Interactions Unit, OIST Graduate University, Japan.

  4. Wind Power Career Chat

    SciTech Connect

    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.

  5. Wind power generator

    SciTech Connect

    Ross, F.

    1980-08-26

    A wind power generator comprises element opposing the force of the wind pivotally mounted and extending radially from the pivot. A counterweight also mounts to the pivot and extends radially from the same. The wind opposing element also mounts to another pivot between a first and second portion thereof. A second weight aids the turning of the wind opposing element about the first pivot to create a rocking motion of the counterweight.

  6. Wind power prediction models

    NASA Technical Reports Server (NTRS)

    Levy, R.; Mcginness, H.

    1976-01-01

    Investigations were performed to predict the power available from the wind at the Goldstone, California, antenna site complex. The background for power prediction was derived from a statistical evaluation of available wind speed data records at this location and at nearby locations similarly situated within the Mojave desert. In addition to a model for power prediction over relatively long periods of time, an interim simulation model that produces sample wind speeds is described. The interim model furnishes uncorrelated sample speeds at hourly intervals that reproduce the statistical wind distribution at Goldstone. A stochastic simulation model to provide speed samples representative of both the statistical speed distributions and correlations is also discussed.

  7. Enabling Wind Power Nationwide

    SciTech Connect

    Jose, Zayas; Michael, Derby; Patrick, Gilman; Ananthan, Shreyas; Lantz, Eric; Cotrell, Jason; Beck, Fredic; Tusing, Richard

    2015-05-01

    Leveraging this experience, the U.S. Department of Energy’s (DOE’s) Wind and Water Power Technologies Office has evaluated the potential for wind power to generate electricity in all 50 states. This report analyzes and quantifies the geographic expansion that could be enabled by accessing higher above ground heights for wind turbines and considers the means by which this new potential could be responsibly developed.

  8. Legal obstacles and incentives to the development of small scale hydroelectric power in Pennsylvania

    SciTech Connect

    None,

    1980-05-01

    The legal and institutional obstacles to the development of small-scale hydroelectric energy at the state level are discussed. The Federal government also exercises extensive regulatory authority in the area, and the dual regulatory system from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and an inquiry into the practical use of the doctrine by the FERC is examined. In Pennsylvania, there are 3 methods by which rights in water may be acquired: riparian ownership, prescription, and condemnation. These are discussed.

  9. Small-scale gravity waves in ER-2 MMS/MTP wind and temperature measurements during CRYSTAL-FACE

    NASA Astrophysics Data System (ADS)

    Wang, L.; Alexander, M. J.; Bui, T. P.; Mahoney, M. J.

    2005-11-01

    ER-2 MMS and MTP wind and temperature measurements during the CRYSTAL-FACE campaign in July 2002 were analyzed to retrieve information on small scale gravity waves (GWs) at aircraft's flight level. For a given flight segment, the S-transform was used to search for and identify small horizontal scale GW events, and to estimate the apparent horizontal wavelengths of the events. The horizontal propagation directions of the events were determined using the Stokes parameters method combined with the cross S-transform analysis. The MTP temperature gradient method was used to determine the vertical wavelengths of the events. GW momentum fluxes were calculated from the cross S-transform. Other wave parameters such as intrinsic frequencies were calculated using the GW dispersion relation. More than 100 GW events were identified. They were generally short horizontal scale and high frequency waves with λz of ~5 km and λh generally shorter than 20 km. Their intrinsic propagation directions were predominantly toward the east, whereas their ground-based propagation directions were primarily toward the west. Among the events, ~20% of them had very short horizontal wavelength (<10 km), very high intrinsic frequency (ω/N≥0.8), and relatively small momentum fluxes, and thus they were likely trapped in the lower stratosphere. The averaged magnitude of vertical flux of horizontal momentum was ~0.026 kg m-1 s-2, and the maximum magnitude was ~0.13 kg m-1 s-2. Using the estimated GW parameters and the background winds and stabilities from the NCAR/NCEP reanalysis data, we were able to trace the sources of the events using a simple reverse ray-tracing. More than 70% of the events were traced back to convective sources in the troposphere, and the sources were generally located upstream to the events. Finally, a probability density function of GW cooling rates was obtained in this study, which may be used in cirrus cloud models.

  10. Small-Scale Gravity Waves in ER-2 MMS/MTP Wind and Temperature Measurements during CRYSTAL-FACE

    NASA Technical Reports Server (NTRS)

    Wang, L.; Alexander, M. J.; Bui, T. P.; Mahoney, M. J.

    2006-01-01

    Lower stratospheric wind and temperature measurements made from NASA's high-altitude ER-2 research aircraft during the CRYSTAL-FACE campaign in July 2002 were analyzed to retrieve information on small scale gravity waves (GWs) at the aircraft's flight level (typically approximately 20 km altitude). For a given flight segment, the S-transform (a Gaussian wavelet transform) was used to search for and identify small horizontal scale GW events, and to estimate their apparent horizontal wavelengths. The horizontal propagation directions of the events were determined using the Stokes parameter method combined with the cross S-transform analysis. The vertical temperature gradient was used to determine the vertical wavelengths of the events. GW momentum fluxes were calculated from the cross S-transform. Other wave parameters such as intrinsic frequencies were calculated using the GW dispersion relation. More than 100GW events were identified. They were generally high frequency waves with vertical wavelength of approximately 5 km and horizontal wavelength generally shorter than 20 km. Their intrinsic propagation directions were predominantly toward the east, whereas their ground-based propagation directions were primarily toward the west. Among the events, approximately 20% of them had very short horizontal wavelength, very high intrinsic frequency, and relatively small momentum fluxes, and thus they were likely trapped in the lower stratosphere. Using the estimated GW parameters and the background winds and stabilities from the NCAR/NCEP reanalysis data, we were able to trace the sources of the events using a simple reverse ray-tracing. More than 70% of the events were traced back to convective sources in the troposphere, and the sources were generally located upstream of the locations of the events observed at the aircraft level. Finally, a probability density function of the reversible cooling rate due to GWs was obtained in this study, which may be useful for cirrus

  11. Small-Scale Hydroelectric Power Demonstration Project. Pennsylvania Hydroelectric Development Corporation Flat Rock Dam: Project summary report

    SciTech Connect

    Gleeson, L.

    1991-12-01

    The US Department of Energy Field Office, Idaho, Small-Scale Hydroelectric Power Program was initiated in conjunction with the restoration of three power generating plants in Idaho Falls, Idaho, following damage caused by the Teton Dam failure on June 5, 1976. There were many parties interested in this project, including the state and environmental groups, with different concerns. This report was prepared by the developer and describes the design alternatives the applicant provided in an attempt to secure the Federal Energy Regulatory Commission license. Also included are correspondence between the related parties concerning the project, major design alternatives/project plan diagrams, the license, and energy and project economics.

  12. Legal obstacles and incentives to the development of small-scale hydroelectric power in Rhode Island

    SciTech Connect

    None,

    1980-05-01

    The legal and institutional obstacles to the development of small-scale hydroelectric energy at the state level are discussed. The Federal government also exercises extensive regulatory authority in the area, and the dual regulatory system from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and an inquiry into the practical use of the doctrine by the FERC is examined. In Rhode Island, any private rights in the flowing waters of a river or stream depend upon ownership of the abutting land. It appears Rhode Island follows the reasonable use theory of riparian law. The Department of Environmental Management is the most significant administrative agency with regard to dam construction, alteration, and operation in the state of Rhode Island.

  13. Legal obstacles and incentives to the development of small scale hydroelectric power in Vermont

    SciTech Connect

    None,

    1980-05-01

    The legal and institutional obstacles to the development of small-scale hydroelectric energy at the state level in Vermont are discussed. The dual regulatory system involving state and Federal governments is discussed followed by discussions on property interests; direct regulation by the Public Service Board; indirect regulation; and financial considerations. An initial step required of any developer is that of real property acquisition. Ordinarily this involves acquiring the stream bed, land along the stream banks, and land needed for the impoundment reservoir. Ownership of land along the stream banks places the developer in the position of a riparian owner. This status is important in that only riparian owners are entitled to a reasonable use of the flowing water. In addition to acquisition by sale, lease, or gift, Vermont law allows certain developers to acquire property via eminent domain. Some general rules which have evolved as riparian law and applied in Vermont are discussed.

  14. Legal obstacles and incentives to the development of small scale hydroelectric power in Indiana

    SciTech Connect

    None,

    1980-05-01

    The legal and institutional obstacles to the development of small-scale hydroelectric energy in Indiana are examined. The Federal government also exercises extensive regulatory authority in the area. An examination is made of the Federal-state relationships with the aim of creating a more orderly understanding of the vagaries of the system. The introductory chapter examines the dual regulatory system from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and concludes with an inquiry into the practical use of the doctrine by the FERC. The Indiana water law; direct and indirect regulations; the Public Service Commission of Indiana; and financial considerations are examined.

  15. High-z objects and cold dark matter cosmogonies - Constraints on the primordial power spectrum on small scales

    NASA Technical Reports Server (NTRS)

    Kashlinsky, A.

    1993-01-01

    Modified cold dark matter (CDM) models were recently suggested to account for large-scale optical data, which fix the power spectrum on large scales, and the COBE results, which would then fix the bias parameter, b. We point out that all such models have deficit of small-scale power where density fluctuations are presently nonlinear, and should then lead to late epochs of collapse of scales M between 10 exp 9 - 10 exp 10 solar masses and (1-5) x 10 exp 14 solar masses. We compute the probabilities and comoving space densities of various scale objects at high redshifts according to the CDM models and compare these with observations of high-z QSOs, high-z galaxies and the protocluster-size object found recently by Uson et al. (1992) at z = 3.4. We show that the modified CDM models are inconsistent with the observational data on these objects. We thus suggest that in order to account for the high-z objects, as well as the large-scale and COBE data, one needs a power spectrum with more power on small scales than CDM models allow and an open universe.

  16. Legal obstacles and incentives to the development of small scale hydroelectric power in Maryland

    SciTech Connect

    None,

    1980-05-01

    The legal and institutional obstacles to the development of small-scale hydroelectric energy at the state level in Maryland are described. The Federal government also exercises extensive regulatory authority in the area. The dual regulatory system is examined with the aim of creating a more orderly understanding of the vagaries of the system, focusing on the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and an inquiry into the practical use of the doctrine by the FERC. In Maryland, by common law rule, title to all navigable waters and to the soil below the high-water mark of those waters is vested in the state as successor to the Lord Proprietary who had received it by grant from the Crown. Rights to non-navigable water, public trust doctrine, and eminent domain are also discussed. Direct and indirect regulations, continuing obligations, loan programs, and regional organizations are described in additional sections.

  17. Legal obstacles and incentives to the development of small scale hydroelectric power in Delaware

    SciTech Connect

    None,

    1980-05-01

    The legal and institutional obstacles to the development of small-scale hydroelectric energy at the state level are discussed. The Federal government also exercises extensive regulatory authority in the area, and the dual regulatory system from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and an inquiry into the practical use of the doctrine by the FERC is examined. In Delaware, a watercourse is not to be confused with surface water. Each gives rise to certain riparian rights, but the law makes certain distinctions between the two. The presence of both surface waters and watercourses give rise to private and public rights related to the presence of the water. Some of these rights are vested in riparian owners. Recent Delaware case law has described the riparian owner as one who owns land on the bank of a river, or who is owner of land along, bordering upon, bounded by, fronting upon, abutting, or adjacent and contiguous to and in contact with a river. But, ownership of the bank does not give the riparian ownership of the water. Some law cases are cited to discuss the laws in Delaware.

  18. Legal obstacles and incentives to the development of small scale hydroelectric power in New Hampshire

    SciTech Connect

    None,

    1980-05-01

    The legal and institutional obstacles to the development of small-scale hydroelectric energy at the state level are described. The Federal government also exercises extensive regulatory authority in the area and the dual regulatory system from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and an inquiry into the practical use of the doctrine by the FERC is examined. The first step any developer must take is that of acquiring the real estate parcel. The step involves acquisition in some manner of both river banks, the river bed, and where necessary the land needed for the upstream impoundment area. The developer must acquire the river banks to be considered a riparian owner. Classification as a riparian is important for only a use of water by a riparian owner is deemed a reasonable use and hence legal. Apart from acquisition by sale, lease, or gift, New Hampshire law permits a number of other methods. In part use of these methods will depend on whether the developer is the state, a municipality, a private corporation, or a public utility. Provided the developer avails himself of the five (5) megawatts exemption, his main regulatory agency will be the Water Resources Board. However, the state is not free from the problems of legal uncertainty inherent in determinations of reasonableness.

  19. Legal obstacles and incentives to the development of small-scale hydroelectric power in Virginia

    SciTech Connect

    None,

    1980-05-01

    The legal and institutional obstacles to the development of small-scale hydroelectric energy in Virginia are described. The state regulatory system does not comprise final authority; the Federal government also exercises extensive regulatory authority in the area. This dual system is a function of the federalist nature of our government. The introductory section examines the dual system from the standpoint of the appropriate legal doctrine, the law of pre-emption, application of the law to the case of hydroelectric development, and inquires into the practical use of the doctrine by the FERC. The use of a natural-surface watercourse in Virginia is governed generally by the doctrine of riparian rights. Riparian rights is a system of water rights based on ownership of land bordering on a natural stream or watercourse. For land to be considered riparian to a stream, that land must be located on the watershed of that portion of the stream. The theory of riparian rights followed in Virginia is one of reasonable use. Under the reasonable-use doctrine, each riparian owner has an equal right to the reasonable use of the water running naturally through or by his land for any useful purpose. The water must continue to run after such use without material diminution or alteration and without pollution.

  20. Case studies of the legal and institutional obstacles and incentives to the development of small-scale hydroelectric power: Bull Run, Portland, Oregon

    SciTech Connect

    1980-05-01

    The National Conference of State Legislatures' Small-Scale Hydroelectric Policy Project is designed to assist selected state legislatures in looking at the benefits that a state can derive from the development of small-scale hydro, and in carrying out a review of state laws and regulations that affect the development of the state's small-scale hydro resources. The successful completion of the project should help establish state statutes and regulations that are consistent with the efficient development of small-scale hydro. As part of the project's work with state legislatures, seven case studies of small-scale hydro sites were conducted to provide a general analysis and overview of the significant problems and opportunities for the development of this energy resource. The case study approach was selected to expose the actual difficulties and advantages involved in developing a specific site. Such an examination of real development efforts will clearly reveal the important aspects about small-scale hydro development which could be improved by statutory or regulatory revision. Moreover, the case study format enables the formulation of generalized opportunities for promoting small-scale hydro based on specific development experiences. The case study for small-scale hydro power development at the City of Portland's water reserve in the Bull Run Forest is presented with information included on the Bull Run hydro power potential, current water usage, hydro power regulations and plant licensing, technical and economic aspects of Bull Run project, and the environmental impact. (LCL)

  1. Development of a New Generation of Small Scale Biomass-Fueled Electric Generating Power Plants.

    DTIC Science & Technology

    1995-08-01

    Product Gases. Energy from Biomass and Wastes X, Washington, DC, April 7-10, 1986. 2. Newby, R.A., and R.L. Bannister. Hot Gas Cleaning System for Coal ... Gasification Processes, Journal of Engineering for Gas Turbines and Power, April, 1994, Vol. 116, pp. 338. 3. Craig, J.D. Development of a Small

  2. Electricity's Future: The Shift to Efficiency and Small-Scale Power. Worldwatch Paper 61.

    ERIC Educational Resources Information Center

    Flavin, Christopher

    Electricity, which has largely supplanted oil as the most controversial energy issue of the 1980s, is at the center of some of the world's bitterest economic and environmental controversies. Soaring costs, high interest rates, and environmental damage caused by large power plants have wreaked havoc on the once booming electricity industry.…

  3. Effect of operating and sampling conditions on the exhaust gas composition of small-scale power generators.

    PubMed

    Smits, Marianne; Vanpachtenbeke, Floris; Horemans, Benjamin; De Wael, Karolien; Hauchecorne, Birger; Van Langenhove, Herman; Demeestere, Kristof; Lenaerts, Silvia

    2012-01-01

    Small stationary diesel engines, like in generator sets, have limited emission control measures and are therefore responsible for 44% of the particulate matter (PM) emissions in the United States. The diesel exhaust composition depends on operating conditions of the combustion engine. Furthermore, the measurements are influenced by the used sampling method. This study examines the effect of engine loading and exhaust gas dilution on the composition of small-scale power generators. These generators are used in different operating conditions than road-transport vehicles, resulting in different emission characteristics. Experimental data were obtained for gaseous volatile organic compounds (VOC) and PM mass concentration, elemental composition and nitrate content. The exhaust composition depends on load condition because of its effect on fuel consumption, engine wear and combustion temperature. Higher load conditions result in lower PM concentration and sharper edged particles with larger aerodynamic diameters. A positive correlation with load condition was found for K, Ca, Sr, Mn, Cu, Zn and Pb adsorbed on PM, elements that originate from lubricating oil or engine corrosion. The nitrate concentration decreases at higher load conditions, due to enhanced nitrate dissociation to gaseous NO at higher engine temperatures. Dilution on the other hand decreases PM and nitrate concentration and increases gaseous VOC and adsorbed metal content. In conclusion, these data show that operating and sampling conditions have a major effect on the exhaust gas composition of small-scale diesel generators. Therefore, care must be taken when designing new experiments or comparing literature results.

  4. Effect of Operating and Sampling Conditions on the Exhaust Gas Composition of Small-Scale Power Generators

    PubMed Central

    Smits, Marianne; Vanpachtenbeke, Floris; Horemans, Benjamin; De Wael, Karolien; Hauchecorne, Birger; Van Langenhove, Herman; Demeestere, Kristof; Lenaerts, Silvia

    2012-01-01

    Small stationary diesel engines, like in generator sets, have limited emission control measures and are therefore responsible for 44% of the particulate matter (PM) emissions in the United States. The diesel exhaust composition depends on operating conditions of the combustion engine. Furthermore, the measurements are influenced by the used sampling method. This study examines the effect of engine loading and exhaust gas dilution on the composition of small-scale power generators. These generators are used in different operating conditions than road-transport vehicles, resulting in different emission characteristics. Experimental data were obtained for gaseous volatile organic compounds (VOC) and PM mass concentration, elemental composition and nitrate content. The exhaust composition depends on load condition because of its effect on fuel consumption, engine wear and combustion temperature. Higher load conditions result in lower PM concentration and sharper edged particles with larger aerodynamic diameters. A positive correlation with load condition was found for K, Ca, Sr, Mn, Cu, Zn and Pb adsorbed on PM, elements that originate from lubricating oil or engine corrosion. The nitrate concentration decreases at higher load conditions, due to enhanced nitrate dissociation to gaseous NO at higher engine temperatures. Dilution on the other hand decreases PM and nitrate concentration and increases gaseous VOC and adsorbed metal content. In conclusion, these data show that operating and sampling conditions have a major effect on the exhaust gas composition of small-scale diesel generators. Therefore, care must be taken when designing new experiments or comparing literature results. PMID:22442670

  5. Small-Scale Low Cost Solid Oxide Fuel Cell Power Systems

    SciTech Connect

    S. D. Vora

    2008-02-01

    Progress in tasks seeking greater cell power density and lower cost through new cell designs, new cell materials and lower operating temperature is summarized. The design of the program required Proof-of-Concept unit of residential capacity scale is reviewed along with a summary of results from its successful test. Attachment 1 summarizes the status of cell development. Attachment 2 summarizes the status of generator design, and Attachment 3 of BOP design.

  6. Small-Scale Low Cost Solid Oxide Fuel Cell Power Systems

    SciTech Connect

    S.D. Vora

    2003-02-28

    Tasks carried out during the first six months of the program are summarized. Development of seal-less cells with increased power density at lower operating temperature (800 C) was started. This required a new cell design and investigation of new cell materials. Conceptual design of the generator and balance of plant (BOP) for a residential system was initiated. Attachment 1 describes the progress in cell development and Attachments 2 and 3 deal with status of the generator and BOP design. Overall progress during the first six months and plans for future work are summarized in Attachment 4.

  7. Simulation and Evaluation of Small Scale Solar Power Tower Performance under Malaysia Weather Conditions

    NASA Astrophysics Data System (ADS)

    Gamil, A. M.; Gilani, S. I.; Al-Kayiem, H. H.

    2013-06-01

    Solar energy is the most available, clean, and inexpensive source of energy among the other renewable sources of energy. Malaysia is an encouraging location for the development of solar energy systems due to abundant sunshine (10 hours daily with average solar energy received between 1400 and 1900 kWh/m2). In this paper the design of heliostat field of 3 dual-axis heliostat units located in Ipoh, Malaysia is introduced. A mathematical model was developed to estimate the sun position and calculate the cosine losses in the field. The study includes calculating the incident solar power to a fixed target on the tower by analysing the tower height and ground distance between the heliostat and the tower base. The cosine efficiency was found for each heliostat according to the sun movement. TRNSYS software was used to simulate the cosine efficiencies and field hourly incident solar power input to the fixed target. The results show the heliostat field parameters and the total incident solar input to the receiver.

  8. Tension between the power spectrum of density perturbations measured on large and small scales

    NASA Astrophysics Data System (ADS)

    Battye, Richard A.; Charnock, Tom; Moss, Adam

    2015-05-01

    There is a tension between measurements of the amplitude of the power spectrum of density perturbations inferred using the cosmic microwave background (CMB) and directly measured by large-scale structure (LSS) on smaller scales. We show that this tension exists, and is robust, for a range of LSS indicators including clusters, lensing and redshift space distortions and using CMB data from either Planck or WMAP +SPT /ACT . One obvious way to try to reconcile this is the inclusion of a massive neutrino which could be either active or sterile. Using Planck and a combination of all the LSS data we find that (i) for an active neutrino ∑mν=(0.357 ±0.099 ) eV and (ii) for a sterile neutrino msterileeff=(0.67 ±0.18 ) eV and Δ Neff=0.32 ±0.20 . This is, however, at the expense of a degraded fit to Planck temperature data, and we quantify the residual tension at 2.5 σ and 1.6 σ for massive and sterile neutrinos, respectively. We also consider alternative explanations including a lower redshift for reionization that would be in conflict with polarization measurements made by WMAP and ad hoc modifications to the primordial power spectrum.

  9. Linear perturbation theory for tidal streams and the small-scale CDM power spectrum

    NASA Astrophysics Data System (ADS)

    Bovy, Jo; Erkal, Denis; Sanders, Jason L.

    2017-04-01

    Tidal streams in the Milky Way are sensitive probes of the population of low-mass dark matter subhaloes predicted in cold dark matter (CDM) simulations. We present a new calculus for computing the effect of subhalo fly-bys on cold streams based on the action-angle representation of streams. The heart of this calculus is a line-of-parallel-angle approach that calculates the perturbed distribution function of a stream segment by undoing the effect of all relevant impacts. This approach allows one to compute the perturbed stream density and track in any coordinate system in minutes for realizations of the subhalo distribution down to 105 M⊙, accounting for the stream's internal dispersion and overlapping impacts. We study the statistical properties of density and track fluctuations with large suites of simulations of the effect of subhalo fly-bys. The one-dimensional density and track power spectra along the stream trace the subhalo mass function, with higher mass subhaloes producing power only on large scales, while lower mass subhaloes cause structure on smaller scales. We also find significant density and track bispectra that are observationally accessible. We further demonstrate that different projections of the track all reflect the same pattern of perturbations, facilitating their observational measurement. We apply this formalism to data for the Pal 5 stream and make a first rigorous determination of 10^{+11}_{-6} dark matter subhaloes with masses between 106.5 and 109 M⊙ within 20 kpc from the Galactic centre [corresponding to 1.4^{+1.6}_{-0.9} times the number predicted by CDM-only simulations or to fsub(r < 20 kpc) ≈ 0.2 per cent] assuming that the Pal 5 stream is 5 Gyr old. Improved data will allow measurements of the subhalo mass function down to 105 M⊙, thus definitively testing whether dark matter is clumpy on the smallest scales relevant for galaxy formation.

  10. Wind power freshens water

    SciTech Connect

    Pavlor, V.; Sidorov, V.

    1981-01-01

    A wind-powered lighthouse water-freshening installation was installed at lighthouse locations along the Caspian Sea's coast and at one of the collective farms in the Moldavian SSR. From sea water containing up to 36 grams of salts per liter, fresh water with up to 1 gram per liter was produced. Output was 60 liters per hour.

  11. On the use of a small-scale two-phase thermosiphon to cool high-power electronics

    NASA Astrophysics Data System (ADS)

    Schrage, D. S.

    1990-01-01

    An experimental and analytical investigation of the steady-state thermal-hydraulic operating characteristics of a small-scale two-phase thermosiphon cooling actual power electronics are presented. Boiling heat transfer coefficients and circulation mass velocities were measured while varying heat load and pressure. Both a plain and augmented riser structure, utilizing micro-fins and reentrant cavities, were simultaneously tested. The boiling heat transfer coefficients increased with both increasing heat load and pressure. The mass velocity increased with increasing pressure while both increasing and then decreasing with increasing heat load. The reentrant cavity enhancement factor, a ratio of the augmented-to-plain riser nucleate boiling heat transfer coefficients, ranged from 1 to 1.4. High-speed photography revealed bubbly, slug, churn, wispy-annular and annular flow patterns. The experimental mass velocity and heat transfer coefficient data were compared to an analytical model with average absolute deviations of 16.3 and 26.3 percent, respectively.

  12. Remote sensing for wind power potential: a prospector's handbook

    SciTech Connect

    Wade, J.E.; Maule, P.A.; Bodvarsson, G.; Rosenfeld, C.L.; Woolley, S.G.; McClenahan, M.R.

    1983-02-01

    Remote sensing can aid in identifying and locating indicators of wind power potential from the terrestrial, marine, and atmospheric environments (i.e.: wind-deformed trees, white caps, and areas of thermal flux). It is not considered as a tool for determining wind power potential. A wide variety of remotely sensed evidence is described in terms of the scale at which evidence of wind power can be identified, and the appropriate remote sensors for finding such evidence. Remote sensing can be used for regional area prospecting using small-scale imagery. The information from such small-scale imagery is most often qualitative, and if it is transitory, examination of a number of images to verify presistence of the feature may be required. However, this evidence will allow rapid screening of a large area. Medium-scale imagery provides a better picture of the evidence obtained from small-scale imagery. At this level it is best to use existing imagery. Criteria relating to land use, accessibility, and proximity of candidate sites to nearby transmission lines can also be effectively evaluated from medium-scale imagery. Large-scale imagery provides the most quantitative evidence of the strength of wind. Wind-deformed trees can be identified at a large number of sites using only a few hours in locally chartered aircraft. A handheld 35mm camera can adequately document any evidence of wind. Three case studies that employ remote sensing prospecting techniques are described. Based on remotely sensed evidence, the wind power potential in three geographically and climatically diverse areas of the United States is estimated, and the estimates are compared to actual wind data in those regions. In addition, the cost of each survey is discussed. The results indicate that remote sensing for wind power potential is a quick, cost effective, and fairly reliable method for screening large areas for wind power potential.

  13. Wind power machine

    SciTech Connect

    Denehi, D.

    1992-07-28

    This patent describes wind powered apparatus for producing electricity. It comprises: an endless chain trained over and movable in a continuous path about two substantially spaced-apart sprockets, a plurality of sails fixedly attached to the chain, guide means positioned adjacent the chain and operable, a rotary electrical generator; means connecting at least one of the sprockets to the generator to rotate the latter in response to movement of the chain by wind acting upon the sail flaps when in the first, open position thereof.

  14. Wind Powering America Webinar Series (Postcard), Wind Powering America (WPA)

    SciTech Connect

    Not Available

    2012-02-01

    Wind Powering America offers a free monthly webinar series that provides expert information on today?s key wind energy topics. This postcard is an outreach tool that provides a brief description of the webinars as well as the URL.

  15. The effects of the small-scale DM power on the cosmological neutral hydrogen (HI) distribution at high redshifts

    NASA Astrophysics Data System (ADS)

    Sarkar, Abir; Mondal, Rajesh; Das, Subinoy; Sethi, Shiv. K.; Bharadwaj, Somnath; Marsh, David J. E.

    2016-04-01

    The particle nature of dark matter remains a mystery. In this paper, we consider two dark matter models—Late Forming Dark Matter (LFDM) and Ultra-Light Axion (ULA) models—where the matter power spectra show novel effects on small scales. The high redshift universe offers a powerful probe of their parameters. In particular, we study two cosmological observables: the neutral hydrogen (HI) redshifted 21-cm signal from the epoch of reionization, and the evolution of the collapsed fraction of HI in the redshift range 2 < z < 5. We model the theoretical predictions of the models using CDM-like N-body simulations with modified initial conditions, and generate reionization fields using an excursion set model. The N-body approximation is valid on the length and halo mass scales studied. We show that LFDM and ULA models predict an increase in the HI power spectrum from the epoch of reionization by a factor between 2-10 for a range of scales 0.1 < k < 4 Mpc-1. Assuming a fiducial model where a neutral hydrogen fraction bar xHI = 0.5 must be achieved by z = 8, the reionization process allows us to put approximate bounds on the redshift of dark matter formation zf > 4 × 105 (for LFDM) and the axion mass ma > 2.6 × 10-23 eV (for ULA). The comparison of the collapsed mass fraction inferred from damped Lyman-α observations to the theoretical predictions of our models lead to the weaker bounds: zf > 2 × 105 and ma > 10-23 eV. These bounds are consistent with other constraints in the literature using different observables; we briefly discuss how these bounds compare with possible constraints from the observation of luminosity function of galaxies at high redshifts. In the case of ULAs, these constraints are also consistent with a solution to the cusp-core problem of CDM.

  16. Wind Powering America Podcasts, Wind Powering America (WPA)

    SciTech Connect

    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 for podcast episodes.

  17. Developing a hybrid solar/wind powered irrigation system for crops in the Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some small scale irrigation systems (< 2 ha) powered by wind or solar do not require subsidies, but this paper discusses ways to achieve an economical renewable energy powered center pivot irrigation system for crops in the Great Plains. By adding a solar-photovoltaic (PV) array together with a wind...

  18. Wind tunnel study of the power output spectrum in a micro wind farm

    NASA Astrophysics Data System (ADS)

    Bossuyt, Juliaan; Howland, Michael F.; Meneveau, Charles; Meyers, Johan

    2016-09-01

    Instrumented small-scale porous disk models are used to study the spectrum of a surrogate for the power output in a micro wind farm with 100 models of wind turbines. The power spectra of individual porous disk models in the first row of the wind farm show the expected -5/3 power law at higher frequencies. Downstream models measure an increased variance due to wake effects. Conversely, the power spectrum of the sum of the power over the entire wind farm shows a peak at the turbine-to-turbine travel frequency between the model turbines, and a near -5/3 power law region at a much wider range of lower frequencies, confirming previous LES results. Comparison with the spectrum that would result when assuming that the signals are uncorrelated, highlights the strong effects of correlations and anti-correlations in the fluctuations at various frequencies.

  19. BIOMASS-FUELED, SMALL-SCALE, INTEGRATED-GASIFIER, GAS-TURBINE POWER PLANT: PROGRESS REPORT ON THE PHASE 2 DEVELOPMENT

    EPA Science Inventory

    The paper reports the latest efforts to complete development of Phase 2 of a three-phase effort to develop a family of small-scale (1 to 20 MWe) biomass-fueled power plants. The concept envisioned is an air-blown pressurized fluidized-bed gasifier followed by a dry hot gas clean...

  20. The effects of the small-scale DM power on the cosmological neutral hydrogen (HI) distribution at high redshifts

    SciTech Connect

    Sarkar, Abir; Sethi, Shiv K.; Mondal, Rajesh; Bharadwaj, Somnath; Das, Subinoy; Marsh, David J.E. E-mail: rm@phy.iitkgp.ernet.in E-mail: sethi@rri.res.in E-mail: david.marsh@kcl.ac.uk

    2016-04-01

    The particle nature of dark matter remains a mystery. In this paper, we consider two dark matter models—Late Forming Dark Matter (LFDM) and Ultra-Light Axion (ULA) models—where the matter power spectra show novel effects on small scales. The high redshift universe offers a powerful probe of their parameters. In particular, we study two cosmological observables: the neutral hydrogen (HI) redshifted 21-cm signal from the epoch of reionization, and the evolution of the collapsed fraction of HI in the redshift range 2 < z < 5. We model the theoretical predictions of the models using CDM-like N-body simulations with modified initial conditions, and generate reionization fields using an excursion set model. The N-body approximation is valid on the length and halo mass scales studied. We show that LFDM and ULA models predict an increase in the HI power spectrum from the epoch of reionization by a factor between 2–10 for a range of scales 0.1 < k < 4 Mpc{sup −1}. Assuming a fiducial model where a neutral hydrogen fraction x-bar {sub HI} = 0.5 must be achieved by z = 8, the reionization process allows us to put approximate bounds on the redshift of dark matter formation z{sub f} > 4 × 10{sup 5} (for LFDM) and the axion mass m{sub a} > 2.6 × 10{sup −23} eV (for ULA). The comparison of the collapsed mass fraction inferred from damped Lyman-α observations to the theoretical predictions of our models lead to the weaker bounds: z{sub f} > 2 × 10{sup 5} and m{sub a} > 10{sup −23} eV. These bounds are consistent with other constraints in the literature using different observables; we briefly discuss how these bounds compare with possible constraints from the observation of luminosity function of galaxies at high redshifts. In the case of ULAs, these constraints are also consistent with a solution to the cusp-core problem of CDM.

  1. Small Scale Organic Techniques

    ERIC Educational Resources Information Center

    Horak, V.; Crist, DeLanson R.

    1975-01-01

    Discusses the advantages of using small scale experimentation in the undergraduate organic chemistry laboratory. Describes small scale filtration techniques as an example of a semi-micro method applied to small quantities of material. (MLH)

  2. SMALL-SCALE MAGNETIC ISLANDS IN THE SOLAR WIND AND THEIR ROLE IN PARTICLE ACCELERATION. I. DYNAMICS OF MAGNETIC ISLANDS NEAR THE HELIOSPHERIC CURRENT SHEET

    SciTech Connect

    Khabarova, O.; Zank, G. P.; Li, G.; Roux, J. A. le; Webb, G. M.; Dosch, A.; Malandraki, O. E.

    2015-08-01

    Increases of ion fluxes in the keV–MeV range are sometimes observed near the heliospheric current sheet (HCS) during periods when other sources are absent. These resemble solar energetic particle events, but the events are weaker and apparently local. Conventional explanations based on either shock acceleration of charged particles or particle acceleration due to magnetic reconnection at interplanetary current sheets (CSs) are not persuasive. We suggest instead that recurrent magnetic reconnection occurs at the HCS and smaller CSs in the solar wind, a consequence of which is particle energization by the dynamically evolving secondary CSs and magnetic islands. The effectiveness of the trapping and acceleration process associated with magnetic islands depends in part on the topology of the HCS. We show that the HCS possesses ripples superimposed on the large-scale flat or wavy structure. We conjecture that the ripples can efficiently confine plasma and provide tokamak-like conditions that are favorable for the appearance of small-scale magnetic islands that merge and/or contract. Particles trapped in the vicinity of merging islands and experiencing multiple small-scale reconnection events are accelerated by the induced electric field and experience first-order Fermi acceleration in contracting magnetic islands according to the transport theory of Zank et al. We present multi-spacecraft observations of magnetic island merging and particle energization in the absence of other sources, providing support for theory and simulations that show particle energization by reconnection related processes of magnetic island merging and contraction.

  3. Wind Power Generation Design Considerations.

    DTIC Science & Technology

    1984-12-01

    sites. have low starting torques, operate at high tip-to- wind speeds, and generate high power output per turbine weight. 5 The Savonius rotor operates...DISTRIBUTION 4 I o ....................................... . . . e . * * TABLES Number Page I Wind Turbine Characteristics II 0- 2 Maximum Economic Life II 3...Ratio of Blade Tip Speed to Wind Speed 10 4 Interference with Microwave and TV Reception by Wind Turbines 13 5 Typical Flow Patterns Over Two

  4. 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,…

  5. Wind power outlook 2006

    SciTech Connect

    anon.

    2006-04-15

    This annual brochure provides the American Wind Energy Association's up-to-date assessment of the wind industry in the United States. This 2006 general assessment shows positive signs of growth, use and acceptance of wind energy as a vital component of the U.S. energy mix.

  6. Philippines: Small-scale renewable energy update

    SciTech Connect

    1997-12-01

    This paper gives an overview of the application of small scale renewable energy sources in the Philippines. Sources looked at include solar, biomass, micro-hydroelectric, mini-hydroelectric, wind, mini-geothermal, and hybrid. A small power utilities group is being spun off the major utility, to provide a structure for developing rural electrification programs. In some instances, private companies have stepped forward, avoiding what is perceived as overwhelming beaurocracy, and installed systems with private financing. The paper provides information on survey work which has been done on resources, and the status of cooperative programs to develop renewable systems in the nation.

  7. Wind and solar powered turbine

    NASA Technical Reports Server (NTRS)

    Wells, I. D.; Koh, J. L.; Holmes, M. (Inventor)

    1984-01-01

    A power generating station having a generator driven by solar heat assisted ambient wind is described. A first plurality of radially extendng air passages direct ambient wind to a radial flow wind turbine disposed in a centrally located opening in a substantially disc-shaped structure. A solar radiation collecting surface having black bodies is disposed above the fist plurality of air passages and in communication with a second plurality of radial air passages. A cover plate enclosing the second plurality of radial air passages is transparent so as to permit solar radiation to effectively reach the black bodies. The second plurality of air passages direct ambient wind and thermal updrafts generated by the black bodies to an axial flow turbine. The rotating shaft of the turbines drive the generator. The solar and wind drien power generating system operates in electrical cogeneration mode with a fuel powered prime mover.

  8. Limits to Wind Power Utilization.

    ERIC Educational Resources Information Center

    Gustavson, M. R.

    1979-01-01

    Discusses noneconomic factors limiting the total power that can be extracted from the wind. These factors are examined with a macroscopic approach. Some general conclusions are also reached regarding the sites that would have to be utilized and the usable wind energy potentials. (HM)

  9. Starting to Explore Wind Power

    ERIC Educational Resources Information Center

    Hare, Jonathan

    2008-01-01

    Described is a simple, cheap and versatile homemade windmill and electrical generator suitable for a school class to use to explore many aspects and practicalities of using wind to generate electrical power. (Contains 8 figures.)

  10. Wind Power Charged Aerosol Generator

    SciTech Connect

    Marks, A.M.

    1980-07-01

    This describes experimental results on a Charged Aerosol Wind/Electric Power Generator, using Induction Electric Charging with a water jet issuing under water pressure from a small diameter (25-100 ..mu..m) orifice.

  11. 2008 Wind Energy Projects, Wind Powering America (Poster)

    SciTech Connect

    Not Available

    2009-01-01

    The Wind Powering America program produces a poster at the end of every calendar year that depicts new U.S. wind energy projects. The 2008 poster includes the following projects: Stetson Wind Farm in Maine; Dutch Hill Wind Farm in New York; Grand Ridge Wind Energy Center in Illinois; Hooper Bay, Alaska; Forestburg, South Dakota; Elbow Creek Wind Project in Texas; Glacier Wind Farm in Montana; Wray, Colorado; Smoky Hills Wind Farm in Kansas; Forbes Park Wind Project in Massachusetts; Spanish Fork, Utah; Goodland Wind Farm in Indiana; and the Tatanka Wind Energy Project on the border of North Dakota and South Dakota.

  12. Integrated Wind Power Planning Tool

    NASA Astrophysics Data System (ADS)

    Rosgaard, Martin; Giebel, Gregor; Skov Nielsen, Torben; Hahmann, Andrea; Sørensen, Poul; Madsen, Henrik

    2013-04-01

    This poster presents the current state of the public service obligation (PSO) funded project PSO 10464, with the title "Integrated Wind Power Planning Tool". The goal is to integrate a mesoscale numerical weather prediction (NWP) model with purely statistical tools in order to assess wind power fluctuations, with focus on long term power system planning for future wind farms as well as short term forecasting for existing wind farms. Currently, wind power fluctuation models are either purely statistical or integrated with NWP models of limited resolution. Using the state-of-the-art mesoscale NWP model Weather Research & Forecasting model (WRF) the forecast error is sought quantified in dependence of the time scale involved. This task constitutes a preparative study for later implementation of features accounting for NWP forecast errors in the DTU Wind Energy maintained Corwind code - a long term wind power planning tool. Within the framework of PSO 10464 research related to operational short term wind power prediction will be carried out, including a comparison of forecast quality at different mesoscale NWP model resolutions and development of a statistical wind power prediction tool taking input from WRF. The short term prediction part of the project is carried out in collaboration with ENFOR A/S; a Danish company that specialises in forecasting and optimisation for the energy sector. The integrated prediction model will allow for the description of the expected variability in wind power production in the coming hours to days, accounting for its spatio-temporal dependencies, and depending on the prevailing weather conditions defined by the WRF output. The output from the integrated short term prediction tool constitutes scenario forecasts for the coming period, which can then be fed into any type of system model or decision making problem to be solved. The high resolution of the WRF results loaded into the integrated prediction model will ensure a high accuracy

  13. Developing wind and/or solar powered crop irrigation systems for the Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some small scale, off-grid irrigation systems (less than 2.5 ha) that are powered by wind or solar energy are cost effective, but this paper discusses ways to achieve an economical renewable energy powered center pivot irrigation system for crops in the Great Plains. It was found that partitioning t...

  14. Long-Term Wind Power Variability

    SciTech Connect

    Wan, Y. H.

    2012-01-01

    The National Renewable Energy Laboratory started collecting wind power data from large commercial wind power plants (WPPs) in southwest Minnesota with dedicated dataloggers and communication links in the spring of 2000. Over the years, additional WPPs in other areas were added to and removed from the data collection effort. The longest data stream of actual wind plant output is more than 10 years. The resulting data have been used to analyze wind power fluctuations, frequency distribution of changes, the effects of spatial diversity, and wind power ancillary services. This report uses the multi-year wind power data to examine long-term wind power variability.

  15. Power Quality Aspects in a Wind Power Plant: Preprint

    SciTech Connect

    Muljadi, E.; Butterfield, C. P.; Chacon, J.; Romanowitz, H.

    2006-01-01

    Although many operational aspects affect wind power plant operation, this paper focuses on power quality. Because a wind power plant is connected to the grid, it is very important to understand the sources of disturbances that affect the power quality.

  16. Integrated Wind Power Planning Tool

    NASA Astrophysics Data System (ADS)

    Rosgaard, M. H.; Giebel, G.; Nielsen, T. S.; Hahmann, A.; Sørensen, P.; Madsen, H.

    2012-04-01

    This poster presents the current state of the public service obligation (PSO) funded project PSO 10464, with the working title "Integrated Wind Power Planning Tool". The project commenced October 1, 2011, and the goal is to integrate a numerical weather prediction (NWP) model with purely statistical tools in order to assess wind power fluctuations, with focus on long term power system planning for future wind farms as well as short term forecasting for existing wind farms. Currently, wind power fluctuation models are either purely statistical or integrated with NWP models of limited resolution. With regard to the latter, one such simulation tool has been developed at the Wind Energy Division, Risø DTU, intended for long term power system planning. As part of the PSO project the inferior NWP model used at present will be replaced by the state-of-the-art Weather Research & Forecasting (WRF) model. Furthermore, the integrated simulation tool will be improved so it can handle simultaneously 10-50 times more turbines than the present ~ 300, as well as additional atmospheric parameters will be included in the model. The WRF data will also be input for a statistical short term prediction model to be developed in collaboration with ENFOR A/S; a danish company that specialises in forecasting and optimisation for the energy sector. This integrated prediction model will allow for the description of the expected variability in wind power production in the coming hours to days, accounting for its spatio-temporal dependencies, and depending on the prevailing weather conditions defined by the WRF output. The output from the integrated prediction tool constitute scenario forecasts for the coming period, which can then be fed into any type of system model or decision making problem to be solved. The high resolution of the WRF results loaded into the integrated prediction model will ensure a high accuracy data basis is available for use in the decision making process of the Danish

  17. Offshore Wind Power Integration in severely fluctuating Wind Conditions

    NASA Astrophysics Data System (ADS)

    von Bremen, L.

    2010-09-01

    Strong power fluctuations from offshore wind farms that are induced by wind speed fluctuations pose a severe problem to the save integration of offshore wind power into the power supply system. Experience at the first large-scale offshore wind farm Horns Rev showed that spatial smoothing of power fluctuations within a single wind farm is significantly smaller than onshore results suggest when distributed wind farms of 160 MW altogether are connected to a single point of common-coupling. Wind power gradients larger than 10% of the rated capacity within 5 minutes require large amount of regulation power that is very expensive for the grid operator. It must be noted that a wind speed change of only 0.5m/s result in a wind power change of 10% (within the range of 9-11 m/s where the wind power curve is steepest). Hence, it is very important for the grid operator to know if strong fluctuations are likely or not. Observed weather conditions at the German wind energy research platform FINO1 in the German bight are used to quantify wind fluctuations. With a standard power curve these wind fluctuations are transfered to wind power. The aim is to predict the probability of exceedence of certain wind power gradients that occur in a time interval of e.g. 12 hours. During 2006 and 2009 the distribution of wind power fluctuations looks very similar giving hope that distinct atmospheric processes can be determined that act as a trigger. Most often high wind power fluctuations occur in a range of wind speeds between 9-12 m/s as can be expected from the shape of the wind power curve. A cluster analysis of the 500 hPa geopotential height to detect predominant weather regimes shows that high fluctuations are more likely in north-western flow. It is shown that most often high fluctuations occur in non-stable atmospheric stratification. The description of stratification by means of the vertical gradient of the virtual potential temperature is chosen to be indicative for convection, i

  18. Wind turbine sound power measurements.

    PubMed

    Keith, Stephen E; Feder, Katya; Voicescu, Sonia A; Soukhovtsev, Victor; Denning, Allison; Tsang, Jason; Broner, Norm; Richarz, Werner; van den Berg, Frits

    2016-03-01

    This paper provides experimental validation of the sound power level data obtained from manufacturers for the ten wind turbine models examined in Health Canada's Community Noise and Health Study (CNHS). Within measurement uncertainty, the wind turbine sound power levels measured using IEC 61400-11 [(2002). (International Electrotechnical Commission, Geneva)] were consistent with the sound power level data provided by manufacturers. Based on measurements, the sound power level data were also extended to 16 Hz for calculation of C-weighted levels. The C-weighted levels were 11.5 dB higher than the A-weighted levels (standard deviation 1.7 dB). The simple relationship between A- and C- weighted levels suggests that there is unlikely to be any statistically significant difference between analysis based on either C- or A-weighted data.

  19. 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…

  20. Wind Power Utilization Guide.

    DTIC Science & Technology

    1981-09-01

    turbines, by John C. Yeoman. Dec 1978. 158 Table 7.4 also shows the power conditioning system and the tower height chosen for the installation. Next, the...Intersociety Energy Conversion Engineering Conference, Washington, D.C., Sep 22-26, 1969, pp 606-613. 173 , -.V ..-- - , 1 Smeaton , J. (1757). "An...Contact: John Harold or 2398 Fourth Street Tom Cummins Berkeley, CA 94710 Telephone: 415-848-2710 Aerowatt, S.A. Contact: Robert Dodge or c/o Automatic

  1. Wind Fins: Novel Lower-Cost Wind Power System

    SciTech Connect

    David C. Morris; Dr. Will D. Swearingen

    2007-10-08

    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 design 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.

  2. Wind Powering America Initiative (Fact Sheet)

    SciTech Connect

    Not Available

    2011-01-01

    The U.S. Department of Energy's Wind Powering America initiative engages in technology market acceptance, barrier reduction, and technology deployment support activities. This fact sheet outlines ways in which the Wind Powering America team works to reduce barriers to appropriate wind energy deployment, primarily by focusing on six program areas: workforce development, communications and outreach, stakeholder analysis and resource assessment, wind technology technical support, wind power for Native Americans, and federal sector support and collaboration.

  3. Optimizing modes of a small-scale combined-cycle power plant with atmospheric-pressure gasifier

    NASA Astrophysics Data System (ADS)

    Donskoi, I. G.; Marinchenko, A. Yu.; Kler, A. M.; Ryzhkov, A. F.

    2015-09-01

    The scheme of an integrated coal gasification combined-cycle power plant with small capacity is proposed. Using the built mathematical model a feasibility study of this unit was performed, taking into account the kinetics of physical and chemical transformations in the fuel bed. The estimates of technical and economic efficiency of the plant have been obtained and compared with the alternative options.

  4. Spectrum of Wind Power Fluctuations

    NASA Astrophysics Data System (ADS)

    Bandi, M. M.

    2017-01-01

    Wind power fluctuations for an individual turbine and plant have been widely reported to follow the Kolmogorov spectrum of atmospheric turbulence; both vary with a fluctuation time scale τ as τ2 /3. Yet, this scaling has not been explained through turbulence theory. Using turbines as probes of turbulence, we show the τ2 /3 scaling results from a large scale influence of atmospheric turbulence. Owing to this long-range influence spanning 100s of kilometers, when power from geographically distributed wind plants is summed into aggregate power at the grid, fluctuations average (geographic smoothing) and their scaling steepens from τ2 /3→τ4 /3, beyond which further smoothing is not possible. Our analysis demonstrates grids have already reached this τ4 /3 spectral limit to geographic smoothing.

  5. Primer on Wind Power for Utility Applications

    SciTech Connect

    Wan, Y.

    2005-12-01

    The wind industry still faces many market barriers, some of which stem from utilities' lack of experience with the technology. Utility system operators and planners need to understand the effects of fluctuating wind power on system regulation and stability. Without high-frequency wind power data and realistic wind power plant models to analyze the problem, utilities often rely on conservative assumptions and worst-case scenarios to make engineering decisions. To remedy the situation, the National Renewable Energy Laboratory (NREL) has undertaken a project to record long-term, high-resolution (1-hertz [Hz]) wind power output data from large wind power plants in various regions. The objective is to systematically collect actual wind power data from large commercial wind power plants so that wind power fluctuations, their frequency distribution, the effects of spatial diversity, and the ancillary services of large commercial wind power plants can be analyzed. It also aims to provide the industry with nonproprietary wind power data in different wind regimes for system planning and operating impact studies. This report will summarize the results of data analysis performed at NREL and discuss the wind power characteristics related to power system operation and planning.

  6. Exposure to electric power generator noise among small scale business operators in selected communities in Ibadan, Nigeria.

    PubMed

    Ana, Godson R E E; Luqman, Yesufu A; Shendell, Derek G; Owoaje, Eme T

    2014-11-01

    Inadequate and erratic power supplies mean small businesses use electric generators for alternative power. The authors' goal in the study described here was to assess noise from electric generators and impacts in the commercial areas of Agbowo and Ajibode in Ibadan, Nigeria. Noise levels (A-weighted decibels [dBA]) were measured over 12 weeks, three times a day, during the 2010 dry season using a sound level meter. A questionnaire was administered (515 respondents; 304 in Agbowo, 211 in Ajibode) and audiometric measurements were conducted on 40% of respondents. Mean noise levels varied by source (104 ± 7.7 dBA [diesel], 94.0 ± 6.3 dBA [petrol]) and were highest midday (90.6 ± 5.3 dBA [Agbowo], 70.9 ± 6.2 dBA [Ajibode]). Mean noise levels in Agbowo (78.5 ± 3.9 dBA) and Ajibode (65.7 ± 4.4 dBA) exceeded World Health Organization guidelines (65 dBA) for outdoor commercial environments. Working and living in Agbowo was significantly associated with current evidence of hearing impairment (odds ratio: 6.8, 95% confidence interval: 3.4-13.7). Reducing exposure to noise from electric power generators serving urban small businesses and homes is warranted.

  7. Success Stories (Postcard), Wind Powering America (WPA)

    SciTech Connect

    Not Available

    2012-02-01

    Wind Powering America shares best practices and lessons learned on the Wind Powering America website. This postcard is an outreach tool that provides a brief description of the success stories as well as the URL.

  8. Wind wheel electric power generator

    SciTech Connect

    Kaufman, J.W.

    1980-03-04

    Wind wheel electric power generator apparatus is disclosed as including a housing rotatably mounted upon a vertically disposed support column. Primary and auxiliary funnel-type, venturi ducts are fixedly mounted upon the housing for capturing wind currents and for conducting the same to a bladed wheel adapted to be operatively connected with generator apparatus. Additional air flows are also conducted onto the bladed wheel, all of the air flows positively effecting rotation of the wheel in a cumulative manner. The auxiliary ducts are disposed at an acute angle with respect to the longitudinal axis of the housing, and this feature , together with the rotatability of the housing and the ducts, permits capture of wind currents within a variable directional range.

  9. Wind wheel electric power generator

    NASA Technical Reports Server (NTRS)

    Kaufman, J. W. (Inventor)

    1980-01-01

    Wind wheel electric power generator apparatus includes a housing rotatably mounted upon a vertical support column. Primary and auxiliary funnel-type, venturi ducts are fixed onto the housing for capturing wind currents and conducting to a bladed wheel adapted to be operatively connected with the generator apparatus. Additional air flows are also conducted onto the bladed wheel; all of the air flows positively effecting rotation of the wheel in a cumulative manner. The auxiliary ducts are disposed at an acute angle with respect to the longitudinal axis of the housing, and this feature, together with the rotatability of the housing and the ducts, permits capture of wind currents within a variable directional range.

  10. Wind for Schools: A Wind Powering America Project

    SciTech Connect

    Not Available

    2007-12-01

    This brochure serves as an introduction to Wind Powering America's Wind for Schools Project, including a description of the project, the participants, funding sources, and the basic configurations of the project.

  11. Wind for Schools: A Wind Powering America Project (Alaska) (Brochure)

    SciTech Connect

    Not Available

    2010-02-01

    This brochure provides an overview of Wind Powering America's Wind for Schools Project, including a description of the project, the participants, funding sources, the basic configurations, and how interested parties can become involved.

  12. Wind for Schools: A Wind Powering America Project (Brochure)

    SciTech Connect

    Baring-Gould, I.

    2009-08-01

    This brochure provides an overview of Wind Powering America's Wind for Schools Project, including a description of the project, the participants, funding sources, the basic configurations, and how interested parties can become involved.

  13. PSS Controller for Wind Power Generation Systems

    NASA Astrophysics Data System (ADS)

    Domínguez-García, J. L.; Gomis-Bellmunt, O.; Bianchi, F.; Sumper, A.

    2012-10-01

    Small signal stability analysis for power systems with wind farm interaction is presented. Power systems oscillation modes can be excited by disturbance or fault in the grid. Variable speed wind turbines can be regulated to reduce these oscillations, stabilising the power system. A power system stabiliser (PSS) control loop for wind power is designed in order to increase the damping of the oscillation modes. The proposed power system stabiliser controller is evaluated by small signal analysis.

  14. Small-Scale Hydroelectric Power Demonstration Project: reactivation of the Elk Rapids Hydroelectric Facility. Final technical and construction cost report

    SciTech Connect

    Not Available

    1985-05-01

    The Elk Rapids powerhouse dam is located on the Elk River channel in the Village of Elk Rapids, Michigan. Together with a small spillway structure located approximately 500 ft south of the dam, it constitutes the outlet to Lake Michigan for Elk Lake, Skegemog Lake, Torch Lake, Lake Bellaire, Clam Lake, and several smaller lakes. Power has been generated at the Elk Rapids site since the late nineteenth century, but the history of the present facility goes back to 1916 with the construction of the existing powerhouse dam by the Elk Rapids Iron Works Company. The facility was designed to contain four vertical-shaft generating units; however, only a single 270 hp Leffel type K unit was installed in 1916. In 1929, two additional Leffel units, rated 525 hp, were installed, and in 1930 a third 525 hp Leffel unit was added completely utilizing the capacity of the powerhouse and bringing the combined turbine capacity to 1845 hp.

  15. Power Quality Aspects in a Wind Power Plant

    SciTech Connect

    Muljadi, E.; Butterfield, C. P.; Chacon, J.; Romanowitz, H.

    2006-01-01

    Like conventional power plants, wind power plants must provide the power quality required to ensure the stability and reliability of the power system it is connected to and to satisfy the customers connected to the same grid. When wind energy development began, wind power plants were very small, ranging in size from under one megawatt to tens megawatts with less than 100 turbines in each plant. Thus, the impact of wind power plant on the grid was very small, and any disturbance within or created by the plant was considered to be in the noise level. In the past 30 years, the size of wind turbines and the size of wind power plants have increased significantly. Notably, in Tehachapi, California, the amount of wind power generation has surpassed the infrastructure for which it was designed. At the same time, the lack of rules, standards, and regulations during early wind development has proven to be an increasing threat to the stability and power quality of the grid connected to a wind power plant. Fortunately, many new wind power plants are equipped with state of the art technology, which enables them to provide good service while producing clean power for the grid. The advances in power electronics have allowed many power system applications to become more flexible and to accomplish smoother regulation. Applications such as reactive power compensation, static transfer switches, energy storage, and variable-speed generations are commonly found in modern wind power plants. Although many operational aspects affect wind power plant operation, this paper, focuses on power quality. Because a wind power plant is connected to the grid, it is very important to understand the sources of disturbances that affect the power quality. In general, the voltage and frequency must be kept as stable as possible. The voltage and current distortions created by harmonics will also be discussed in this paper as will self-excitation, which may occur in a wind power plant due to loss of line.

  16. Wind Power Plant SCADA and Controls

    SciTech Connect

    Badrzadeh, Babak; Castillo, Nestor; Bradt, M.; Janakiraman, R.; Kennedy, R.; Klein, S.; Smith, Travis M; Vargas, L.

    2011-01-01

    Modern Wind Power Plants (WPPs) contain a variety of intelligent electronic devices (IEDs), Supervisory Control and Data Acquisition (SCADA) and communication systems. This paper discusses the issues related to a typical WPP's SCADA and Control. Presentation topics are: (1) Wind Turbine Controls; (2) Wind Plant SCADA, OEM SCADA Solutions, Third-Party SCADA Solutions; (3) Wind Plant Control; and (4) Security and Reliability Compliance.

  17. Engineering innovation to reduce wind power COE

    SciTech Connect

    Ammerman, Curtt Nelson

    2011-01-10

    There are enough wind resources in the US to provide 10 times the electric power we currently use, however wind power only accounts for 2% of our total electricity production. One of the main limitations to wind use is cost. Wind power currently costs 5-to-8 cents per kilowatt-hour, which is more than twice the cost of electricity generated by burning coal. Our Intelligent Wind Turbine LDRD Project is applying LANL's leading-edge engineering expertise in modeling and simulation, experimental validation, and advanced sensing technologies to challenges faced in the design and operation of modern wind turbines.

  18. Blowing in the Wind: A Review of Wind Power Technology

    ERIC Educational Resources Information Center

    Harris, Frank

    2014-01-01

    The use of wind as a replenishable energy resource has come back into favour in recent decades. It is much promoted as a viable, clean energy option that will help towards reducing CO[subscript 2] emissions in the UK. This article examines the history of wind power and considers the development of wind turbines, together with their economic,…

  19. SMALL SCALE BIOMASS FUELED GAS TURBINE ENGINE

    EPA Science Inventory

    A new generation of small scale (less than 20 MWe) biomass fueled, power plants are being developed based on a gas turbine (Brayton cycle) prime mover. These power plants are expected to increase the efficiency and lower the cost of generating power from fuels such as wood. The n...

  20. Wind power error estimation in resource assessments.

    PubMed

    Rodríguez, Osvaldo; Del Río, Jesús A; Jaramillo, Oscar A; Martínez, Manuel

    2015-01-01

    Estimating the power output is one of the elements that determine the techno-economic feasibility of a renewable project. At present, there is a need to develop reliable methods that achieve this goal, thereby contributing to wind power penetration. In this study, we propose a method for wind power error estimation based on the wind speed measurement error, probability density function, and wind turbine power curves. This method uses the actual wind speed data without prior statistical treatment based on 28 wind turbine power curves, which were fitted by Lagrange's method, to calculate the estimate wind power output and the corresponding error propagation. We found that wind speed percentage errors of 10% were propagated into the power output estimates, thereby yielding an error of 5%. The proposed error propagation complements the traditional power resource assessments. The wind power estimation error also allows us to estimate intervals for the power production leveled cost or the investment time return. The implementation of this method increases the reliability of techno-economic resource assessment studies.

  1. Wind Power Error Estimation in Resource Assessments

    PubMed Central

    Rodríguez, Osvaldo; del Río, Jesús A.; Jaramillo, Oscar A.; Martínez, Manuel

    2015-01-01

    Estimating the power output is one of the elements that determine the techno-economic feasibility of a renewable project. At present, there is a need to develop reliable methods that achieve this goal, thereby contributing to wind power penetration. In this study, we propose a method for wind power error estimation based on the wind speed measurement error, probability density function, and wind turbine power curves. This method uses the actual wind speed data without prior statistical treatment based on 28 wind turbine power curves, which were fitted by Lagrange's method, to calculate the estimate wind power output and the corresponding error propagation. We found that wind speed percentage errors of 10% were propagated into the power output estimates, thereby yielding an error of 5%. The proposed error propagation complements the traditional power resource assessments. The wind power estimation error also allows us to estimate intervals for the power production leveled cost or the investment time return. The implementation of this method increases the reliability of techno-economic resource assessment studies. PMID:26000444

  2. A survey on wind power ramp forecasting.

    SciTech Connect

    Ferreira, C.; Gama, J.; Matias, L.; Botterud, A.; Wang, J.

    2011-02-23

    The increasing use of wind power as a source of electricity poses new challenges with regard to both power production and load balance in the electricity grid. This new source of energy is volatile and highly variable. The only way to integrate such power into the grid is to develop reliable and accurate wind power forecasting systems. Electricity generated from wind power can be highly variable at several different timescales: sub-hourly, hourly, daily, and seasonally. Wind energy, like other electricity sources, must be scheduled. Although wind power forecasting methods are used, the ability to predict wind plant output remains relatively low for short-term operation. Because instantaneous electrical generation and consumption must remain in balance to maintain grid stability, wind power's variability can present substantial challenges when large amounts of wind power are incorporated into a grid system. A critical issue is ramp events, which are sudden and large changes (increases or decreases) in wind power. This report presents an overview of current ramp definitions and state-of-the-art approaches in ramp event forecasting.

  3. 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.

  4. High Voltage Power Transmission for Wind Energy

    NASA Astrophysics Data System (ADS)

    Kim, Young il

    The high wind speeds and wide available area at sea have recently increased the interests on offshore wind farms in the U.S.A. As offshore wind farms become larger and are placed further from the shore, the power transmission to the onshore grid becomes a key feature. Power transmission of the offshore wind farm, in which good wind conditions and a larger installation area than an onshore site are available, requires the use of submarine cable systems. Therefore, an underground power cable system requires unique design and installation challenges not found in the overhead power cable environment. This paper presents analysis about the benefit and drawbacks of three different transmission solutions: HVAC, LCC/VSC HVDC in the grid connecting offshore wind farms and also analyzed the electrical characteristics of underground cables. In particular, loss of HV (High Voltage) subsea power of the transmission cables was evaluated by the Brakelmann's theory, taking into account the distributions of current and temperature.

  5. Small scale sanitation technologies.

    PubMed

    Green, W; Ho, G

    2005-01-01

    Small scale systems can improve the sustainability of sanitation systems as they more easily close the water and nutrient loops. They also provide alternate solutions to centrally managed large scale infrastructures. Appropriate sanitation provision can improve the lives of people with inadequate sanitation through health benefits, reuse products as well as reduce ecological impacts. In the literature there seems to be no compilation of a wide range of available onsite sanitation systems around the world that encompasses black and greywater treatment plus stand-alone dry and urine separation toilet systems. Seventy technologies have been identified and classified according to the different waste source streams. Sub-classification based on major treatment methods included aerobic digestion, composting and vermicomposting, anaerobic digestion, sand/soil/peat filtration and constructed wetlands. Potential users or suppliers of sanitation systems can choose from wide range of technologies available and examine the different treatment principles used in the technologies. Sanitation systems need to be selected according to the local social, economic and environmental conditions and should aim to be sustainable.

  6. Wind Farm Power System Model Development: Preprint

    SciTech Connect

    Muljadi, E.; Butterfield, C. P.

    2004-07-01

    In some areas, wind power has reached a level where it begins to impact grid operation and the stability of local utilities. In this paper, the model development for a large wind farm will be presented. Wind farm dynamic behavior and contribution to stability during transmission system faults will be examined.

  7. Wind for Schools Project Power System Brief

    SciTech Connect

    Not Available

    2007-08-01

    This fact sheet provides an overview of the system components of a Wind Powering America Wind for Schools project. Wind Powering America's (WPA's) Wind for Schools project uses a basic system configuration for each school project. The system incorporates a single SkyStream(TM) wind turbine, a 70-ft guyed tower, disconnect boxes at the base of the turbine and at the school, and an interconnection to the school's electrical system. A detailed description of each system component is provided in this document.

  8. Wind Powering America's Wind for Schools Project: Summary Report

    SciTech Connect

    Baring-Gould, I.; Newcomb, C.

    2012-06-01

    This report provides an overview of the U.S. Department of Energy, Wind Powering America, Wind for Schools project. It outlines teacher-training activities and curriculum development; discusses the affiliate program that allows school districts and states to replicate the program; and contains reports that provide an update on activities and progress in the 11 states in which the Wind for Schools project operates.

  9. ValidWind applications: wind power prospecting, aerosol transport

    NASA Astrophysics Data System (ADS)

    Wilkerson, T.; Marchant, A.; Apedaile, T.; Scholes, D.; Simmons, J.; Bradford, B.

    2010-10-01

    The ValidWind™ system employs an XL200 laser rangefinder to track small, lightweight, helium-filled balloons (0.33 meters, 0.015 kg). We record their trajectories (range resolution 0.5 meters) and automatically produce local wind profiles in real time. Tracking range is enhanced beyond 2 km by applying retro-reflector tape to the balloons. Aerodynamic analysis shows that ValidWind balloon motion is well coupled to the local wind within relaxation times { 1 second, due to drag forces at subcritical Reynolds numbers Re < 2×105. Such balloons are Lagrangian sensors; i.e., they move with the wind as opposed to being fixed in space. In a field campaign involving many balloons, slight variations in ground level winds at launch lead to trajectory patterns that we analyze to derive 3D maps of the vertical and horizontal wind profiles downwind of the launch area. Field campaigns are focused on likely sites for wind power generation and on facilities from which airborne particulates are emitted. We describe results of wind measurements in Utah near the cities of Clarkston, Logan, and Ogden. ValidWind is a relatively inexpensive wind sensor that is easily and rapidly transported and deployed at remote sites. It is an ideal instrument for wind prospecting to support early decisions required, for example, in siting meteorology towers. ValidWind provides high-resolution, real time characterization of the average and changing 3D wind fields in which wind power turbines and other remote sensors must operate.

  10. Utility interconnection issues for wind power generation

    NASA Technical Reports Server (NTRS)

    Herrera, J. I.; Lawler, J. S.; Reddoch, T. W.; Sullivan, R. L.

    1986-01-01

    This document organizes the total range of utility related issues, reviews wind turbine control and dynamic characteristics, identifies the interaction of wind turbines to electric utility systems, and identifies areas for future research. The material is organized at three levels: the wind turbine, its controls and characteristics; connection strategies as dispersed or WPSs; and the composite issue of planning and operating the electric power system with wind generated electricity.

  11. Wind power forecasting: IEA Wind Task 36 & future research issues

    SciTech Connect

    Giebel, G.; Cline, J.; Frank, H.; Shaw, W.; Pinson, P.; Hodge, B-M; Kariniotakis, G.; Madsen, J.; Möhrlen, C.

    2016-10-03

    Here, this paper presents the new International Energy Agency Wind Task 36 on Forecasting, and invites to collaborate within the group. Wind power forecasts have been used operatively for over 20 years. Despite this fact, there are still several possibilities to improve the forecasts, both from the weather prediction side and from the usage of the forecasts. The new International Energy Agency (IEA) Task on Forecasting for Wind Energy tries to organise international collaboration, among national meteorological centres with an interest and/or large projects on wind forecast improvements (NOAA, DWD, MetOffice, met.no, DMI,...), operational forecaster and forecast users. The Task is divided in three work packages: Firstly, a collaboration on the improvement of the scientific basis for the wind predictions themselves. This includes numerical weather prediction model physics, but also widely distributed information on accessible datasets. Secondly, we will be aiming at an international pre-standard (an IEA Recommended Practice) on benchmarking and comparing wind power forecasts, including probabilistic forecasts. This WP will also organise benchmarks, in cooperation with the IEA Task WakeBench. Thirdly, we will be engaging end users aiming at dissemination of the best practice in the usage of wind power predictions. As first results, an overview of current issues for research in short-term forecasting of wind power is presented.

  12. Wind power forecasting: IEA Wind Task 36 & future research issues

    DOE PAGES

    Giebel, G.; Cline, J.; Frank, H.; ...

    2016-10-03

    Here, this paper presents the new International Energy Agency Wind Task 36 on Forecasting, and invites to collaborate within the group. Wind power forecasts have been used operatively for over 20 years. Despite this fact, there are still several possibilities to improve the forecasts, both from the weather prediction side and from the usage of the forecasts. The new International Energy Agency (IEA) Task on Forecasting for Wind Energy tries to organise international collaboration, among national meteorological centres with an interest and/or large projects on wind forecast improvements (NOAA, DWD, MetOffice, met.no, DMI,...), operational forecaster and forecast users. The Taskmore » is divided in three work packages: Firstly, a collaboration on the improvement of the scientific basis for the wind predictions themselves. This includes numerical weather prediction model physics, but also widely distributed information on accessible datasets. Secondly, we will be aiming at an international pre-standard (an IEA Recommended Practice) on benchmarking and comparing wind power forecasts, including probabilistic forecasts. This WP will also organise benchmarks, in cooperation with the IEA Task WakeBench. Thirdly, we will be engaging end users aiming at dissemination of the best practice in the usage of wind power predictions. As first results, an overview of current issues for research in short-term forecasting of wind power is presented.« less

  13. Wind power forecasting: IEA Wind Task 36 & future research issues

    NASA Astrophysics Data System (ADS)

    Giebel, G.; Cline, J.; Frank, H.; Shaw, W.; Pinson, P.; Hodge, B.-M.; Kariniotakis, G.; Madsen, J.; Möhrlen, C.

    2016-09-01

    This paper presents the new International Energy Agency Wind Task 36 on Forecasting, and invites to collaborate within the group. Wind power forecasts have been used operatively for over 20 years. Despite this fact, there are still several possibilities to improve the forecasts, both from the weather prediction side and from the usage of the forecasts. The new International Energy Agency (IEA) Task on Forecasting for Wind Energy tries to organise international collaboration, among national meteorological centres with an interest and/or large projects on wind forecast improvements (NOAA, DWD, MetOffice, met.no, DMI,...), operational forecaster and forecast users. The Task is divided in three work packages: Firstly, a collaboration on the improvement of the scientific basis for the wind predictions themselves. This includes numerical weather prediction model physics, but also widely distributed information on accessible datasets. Secondly, we will be aiming at an international pre-standard (an IEA Recommended Practice) on benchmarking and comparing wind power forecasts, including probabilistic forecasts. This WP will also organise benchmarks, in cooperation with the IEA Task WakeBench. Thirdly, we will be engaging end users aiming at dissemination of the best practice in the usage of wind power predictions. As first results, an overview of current issues for research in short-term forecasting of wind power is presented.

  14. Harmonics in a Wind Power Plant: Preprint

    SciTech Connect

    Preciado, V.; Madrigal, M.; Muljadi, E.; Gevorgian, V.

    2015-04-02

    Wind power generation has been growing at a very fast pace for the past decade, and its influence and impact on the electric power grid is significant. As in a conventional power plant, a wind power plant (WPP) must ensure that the quality of the power being delivered to the grid is excellent. At the same time, the wind turbine should be able to operate immune to small disturbances coming from the grid. Harmonics are one of the more common power quality issues presented by large WPPs because of the high switching frequency of the power converters and the possible nonlinear behavior from electric machines (generator, transformer, reactors) within a power plant. This paper presents a summary of the most important issues related to harmonics in WPPs and discusses practical experiences with actual Type 1 and Type 3 wind turbines in two WPPs.

  15. Small Scale Discharge Studies

    DTIC Science & Technology

    1975-08-31

    pumping, the principal limitation on average laser power achievable can be calculated from the average power that can be put through the foil...separating the electron gun vacuum chamber from the laser cavity. The limitations on the average power through this foil can be calculated from a...density of a particular ro- tational line J NV,(2J + 1) r-BKJ+Dl Nv’(J) = VKT /B eXP (15) where N , is total number density of the NO

  16. Value of Wind Power Forecasting

    SciTech Connect

    Lew, D.; Milligan, M.; Jordan, G.; Piwko, R.

    2011-04-01

    This study, building on the extensive models developed for the Western Wind and Solar Integration Study (WWSIS), uses these WECC models to evaluate the operating cost impacts of improved day-ahead wind forecasts.

  17. PowerJet Wind Turbine Project

    SciTech Connect

    Bartlett, Raymond J.

    2008-11-30

    The PowerJet wind turbine overcomes problems characteristic of the small wind turbines that are on the market today by providing reliable output at a wide range of wind speeds, durability, silent operation at all wind speeds, and bird-safe operation. Prime Energy's objective for this project was to design and integrate a generator with an electrical controller and mechanical controls to maximize the generation of electricity by its wind turbine. The scope of this project was to design, construct and test a mechanical back plate to control rotational speed in high winds, and an electronic controller to maximize power output and to assist the base plate in controlling rotational speed in high winds.

  18. Active Power Controls from Wind Power: Bridging the Gaps

    SciTech Connect

    Ela, E.; Gevorgian, V.; Fleming, P.; Zhang, Y. C.; Singh, M.; Muljadi, E.; Scholbrook, A.; Aho, J.; Buckspan, A.; Pao, L.; Singhvi, V.; Tuohy, A.; Pourbeik, P.; Brooks, D.; Bhatt, N.

    2014-01-01

    This paper details a comprehensive study undertaken by the National Renewable Energy Laboratory, Electric Power Research Institute, and the University of Colorado to understand how the contribution of wind power providing active power control (APC) can benefit the total power system economics, increase revenue streams, improve the reliability and security of the power system, and provide superior and efficient response while reducing any structural and loading impacts that may reduce the life of the wind turbine or its components. The study includes power system simulations, control simulations, and actual field tests using turbines at NREL's National Wind Technology Center (NWTC). The study focuses on synthetic inertial control, primary frequency control, and automatic generation control, and analyzes timeframes ranging from milliseconds to minutes to the lifetime of wind turbines, locational scope ranging from components of turbines to large wind plants to entire synchronous interconnections, and additional topics ranging from economics to power system engineering to control design.

  19. 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.

  20. Optimizing wind power generation while minimizing wildlife impacts in an urban area.

    PubMed

    Bohrer, Gil; Zhu, Kunpeng; Jones, Robert L; Curtis, Peter S

    2013-01-01

    The location of a wind turbine is critical to its power output, which is strongly affected by the local wind field. Turbine operators typically seek locations with the best wind at the lowest level above ground since turbine height affects installation costs. In many urban applications, such as small-scale turbines owned by local communities or organizations, turbine placement is challenging because of limited available space and because the turbine often must be added without removing existing infrastructure, including buildings and trees. The need to minimize turbine hazard to wildlife compounds the challenge. We used an exclusion zone approach for turbine-placement optimization that incorporates spatially detailed maps of wind distribution and wildlife densities with power output predictions for the Ohio State University campus. We processed public GIS records and airborne lidar point-cloud data to develop a 3D map of all campus buildings and trees. High resolution large-eddy simulations and long-term wind climatology were combined to provide land-surface-affected 3D wind fields and the corresponding wind-power generation potential. This power prediction map was then combined with bird survey data. Our assessment predicts that exclusion of areas where bird numbers are highest will have modest effects on the availability of locations for power generation. The exclusion zone approach allows the incorporation of wildlife hazard in wind turbine siting and power output considerations in complex urban environments even when the quantitative interaction between wildlife behavior and turbine activity is unknown.

  1. Optimizing Wind Power Generation while Minimizing Wildlife Impacts in an Urban Area

    PubMed Central

    Bohrer, Gil; Zhu, Kunpeng; Jones, Robert L.; Curtis, Peter S.

    2013-01-01

    The location of a wind turbine is critical to its power output, which is strongly affected by the local wind field. Turbine operators typically seek locations with the best wind at the lowest level above ground since turbine height affects installation costs. In many urban applications, such as small-scale turbines owned by local communities or organizations, turbine placement is challenging because of limited available space and because the turbine often must be added without removing existing infrastructure, including buildings and trees. The need to minimize turbine hazard to wildlife compounds the challenge. We used an exclusion zone approach for turbine-placement optimization that incorporates spatially detailed maps of wind distribution and wildlife densities with power output predictions for the Ohio State University campus. We processed public GIS records and airborne lidar point-cloud data to develop a 3D map of all campus buildings and trees. High resolution large-eddy simulations and long-term wind climatology were combined to provide land-surface-affected 3D wind fields and the corresponding wind-power generation potential. This power prediction map was then combined with bird survey data. Our assessment predicts that exclusion of areas where bird numbers are highest will have modest effects on the availability of locations for power generation. The exclusion zone approach allows the incorporation of wildlife hazard in wind turbine siting and power output considerations in complex urban environments even when the quantitative interaction between wildlife behavior and turbine activity is unknown. PMID:23409117

  2. Wind Power America Final Report

    SciTech Connect

    Spangler, Brian; Montgomery, Kathi; Cartwright, Paul

    2012-01-30

    The objective of this grant was to further the development of Montana’s vast wind resources for small, medium and large scale benefits to Montana and the nation. This was accomplished through collaborative work with wind industry representatives, state and local governments, the agricultural community and interested citizens. Through these efforts DEQ was able to identify development barriers, educate and inform citizens as well as participate in regional and national dialogue that will spur the development of wind resources

  3. Optimizing Baseload Power of Interconnected Wind Farms

    NASA Astrophysics Data System (ADS)

    Kobrin, B. H.

    2010-12-01

    Interconnecting wind farms has been proposed as a way to reduce the natural unreliability of wind power caused by the intermittency of winds. In a previous study, the benefits of interconnecting up to 19 sites in the Midwestern United States were evaluated with the assumption that the same number of turbines would be installed at each site. The goal of this study was to avoid this assumption and examine the advantages of optimizing the ratio of turbines at each site. An optimization algorithm based on the gradient method was used to maximize the baseload power, or guaranteed power 87.5% of the year, using hourly wind speed data for the same 19 sites. The result was a significant improvement in the reliability of the array, increasing the baseload power by 38% compared to the array with equally-weighted sites. Further analysis showed that the turbines were generally distributed according to the average wind power at each site and the wind correlation among sites. In addition to optimizing the average baseload of the array, this study examined the benefits of optimizing the baseload for peak usage time (between noon and 7 p.m), and thus a simplified model was created to analyze how interconnecting wind farms could increase correlation with energy consumption. Optimization for peak usage hours, however, provided no additional benefit over the original optimized array because the variation of average hourly wind speeds was well-correlated among the sites.

  4. Dynamic Models for Wind Turbines and Wind Power Plants

    SciTech Connect

    Singh, M.; Santoso, S.

    2011-10-01

    The primary objective of this report was to develop universal manufacturer-independent wind turbine and wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Manufacturer-specific models of wind turbines are favored for use in wind power interconnection studies. While they are detailed and accurate, their usages are limited to the terms of the non-disclosure agreement, thus stifling model sharing. The primary objective of the work proposed is to develop universal manufacturer-independent wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Each of these models includes representations of general turbine aerodynamics, the mechanical drive-train, and the electrical characteristics of the generator and converter, as well as the control systems typically used. To determine how realistic model performance is, the performance of one of the models (doubly-fed induction generator model) has been validated using real-world wind power plant data. This work also documents selected applications of these models.

  5. Short-Term Power Fluctuations of Large Wind Power Plants: Preprint

    SciTech Connect

    Wan, Y.; Bucaneg, D.

    2002-01-01

    With electric utilities and other power providers showing increased interest in wind power and with growing penetration of wind capacity into the market, questions about how wind power fluctuations affect power system operations and about wind power's ancillary services requirements are receiving lots of attention. The project's purpose is to acquire actual, long-term wind power output data for analyzing wind power fluctuations, frequency distribution of the changes, the effects of spatial diversity, and wind power ancillary services.

  6. The impact of wind power on electricity prices

    SciTech Connect

    Brancucci Martinez-Anido, Carlo; Brinkman, Greg; Hodge, Bri-Mathias

    2016-08-01

    This paper investigates the impact of wind power on electricity prices using a production cost model of the Independent System Operator - New England power system. Different scenarios in terms of wind penetration, wind forecasts, and wind curtailment are modeled in order to analyze the impact of wind power on electricity prices for different wind penetration levels and for different levels of wind power visibility and controllability. The analysis concludes that electricity price volatility increases even as electricity prices decrease with increasing wind penetration levels. The impact of wind power on price volatility is larger in the shorter term (5-min compared to hour-to-hour). The results presented show that over-forecasting wind power increases electricity prices while under-forecasting wind power reduces them. The modeling results also show that controlling wind power by allowing curtailment increases electricity prices, and for higher wind penetrations it also reduces their volatility.

  7. Study of a Wind Farm Power System: Preprint

    SciTech Connect

    Muljadi, E.; Wan, Y.; Butterfield, C. P.; Parsons, B.

    2002-01-01

    A wind power system differs from a conventional power system. In a conventional power plant, the operator can control the plant's output. The output of a wind farm cannot be controlled because the output fluctuates with the wind. In this paper, we investigate the power-system interaction resulting from power variations at wind farms using steady-state analysis.

  8. A new spatially scanning 2.7 µm laser hygrometer and new small-scale wind tunnel for direct analysis of the H2O boundary layer structure at single plant leaves

    NASA Astrophysics Data System (ADS)

    Wunderle, K.; Rascher, U.; Pieruschka, R.; Schurr, U.; Ebert, V.

    2015-01-01

    A new spatially scanning TDLAS in situ hygrometer based on a 2.7-µm DFB diode laser was constructed and used to analyse the water vapour concentration boundary layer structure at the surface of a single plant leaf. Using an absorption length of only 5.4 cm, the TDLAS hygrometer permits a H2O vapour concentration resolution of 31 ppmv. This corresponds to a normalized precision of 1.7 ppm m. In order to preserve and control the H2O boundary layer on an individual leaf and to study the boundary layer dependence on the wind speed to which the leaf might be exposed in nature, we also constructed a new, application specific, small-scale, wind tunnel for individual plant leaves. The rectangular, closed-loop tunnel has overall dimensions of 1.2 × 0.6 m and a measurement chamber dimension of 40 × 54 mm (H × W). It allows to generate a laminar flow with a precisely controlled wind speed at the plant leaf surface. Combining honeycombs and a miniaturized compression orifice, we could generate and control stable wind speeds from 0.1 to 0.9 m/s, and a highly laminar and homogeneous flow with an excellent relative spatial homogeneity of 0.969 ± 0.03. Combining the spectrometer and the wind tunnel, we analysed (for the first time) non-invasively the wind speed-dependent vertical structure of the H2O vapour distribution within the boundary layer of a single plant leaf. Using our time-lag-free data acquisition procedure for phase locked signal averaging, we achieved a temporal resolution of 0.2 s for an individual spatial point, while a complete vertical spatial scan at a spatial resolution of 0.18 mm took 77 s. The boundary layer thickness was found to decrease from 6.7 to 3.6 mm at increasing wind speeds of 0.1-0.9 m/s. According to our knowledge, this is the first experimental quantification of wind speed-dependent H2O vapour boundary layer concentration profiles of single plant leaves.

  9. Wind Powering America FY06 Activities Summary

    SciTech Connect

    Not Available

    2007-02-01

    The Wind Powering America FY06 Activities Summary reflects the accomplishments of our state wind working groups, our programs at the National Renewable Energy Laboratory, and our partner organizations. The national WPA team remains a leading force for moving wind energy forward in the United States. WPA continues to work with its national, regional, and state partners to communicate the opportunities and benefits of wind energy to a diverse set of stakeholders. WPA now has 29 state wind working groups (welcoming New Jersey, Indiana, Illinois, and Missouri in 2006) that form strategic alliances to communicate wind's benefits to the state stakeholders. More than 120 members of national and state public and private sector organizations from 34 states attended the 5th Annual WPA All-States Summit in Pittsburgh in June.

  10. Are local wind power resources well estimated?

    NASA Astrophysics Data System (ADS)

    Lundtang Petersen, Erik; Troen, Ib; Jørgensen, Hans E.; Mann, Jakob

    2013-03-01

    Planning and financing of wind power installations require very importantly accurate resource estimation in addition to a number of other considerations relating to environment and economy. Furthermore, individual wind energy installations cannot in general be seen in isolation. It is well known that the spacing of turbines in wind farms is critical for maximum power production. It is also well established that the collective effect of wind turbines in large wind farms or of several wind farms can limit the wind power extraction downwind. This has been documented by many years of production statistics. For the very large, regional sized wind farms, a number of numerical studies have pointed to additional adverse changes to the regional wind climate, most recently by the detailed studies of Adams and Keith [1]. They show that the geophysical limit to wind power production is likely to be lower than previously estimated. Although this problem is of far future concern, it has to be considered seriously. In their paper they estimate that a wind farm larger than 100 km2 is limited to about 1 W m-2. However, a 20 km2 off shore farm, Horns Rev 1, has in the last five years produced 3.98 W m-2 [5]. In that light it is highly unlikely that the effects pointed out by [1] will pose any immediate threat to wind energy in coming decades. Today a number of well-established mesoscale and microscale models exist for estimating wind resources and design parameters and in many cases they work well. This is especially true if good local data are available for calibrating the models or for their validation. The wind energy industry is still troubled by many projects showing considerable negative discrepancies between calculated and actually experienced production numbers and operating conditions. Therefore it has been decided on a European Union level to launch a project, 'The New European Wind Atlas', aiming at reducing overall uncertainties in determining wind conditions. The

  11. Wind for Schools Project Power System Brief, Wind Powering America Fact Sheet Series

    SciTech Connect

    Baring-Gould, I.

    2009-05-01

    Wind Powering America's (WPA's) Wind for Schools project uses a basic system configuration for each school project. The system incorporates a single SkyStream wind turbine, a 70-ft guyed tower, disconnect boxes at the base of the turbine and at the school, and an interconnection to the school's electrical system. This document provides a detailed description of each system component.

  12. Suprathermal Charged Particle Acceleration by Small-scale Flux Ropes.

    NASA Astrophysics Data System (ADS)

    Zank, G. P.; le Roux, J. A.; Webb, G. M.

    2015-12-01

    We consider different limits of our recently developed kinetic transport theory to investigate the potential of super-Alvenic solar wind regions containing several small-scale flux ropes to explain the acceleration of suprathermal ions to power-law spectra as observations show. Particle acceleration is modeled in response to flux-rope activity involving contraction, merging (reconnection), and collisions in the limit where the particle gyoradius is smaller than the characteristic flux-rope scale length. The emphasis is mainly on the statistical variance in the electric fields induced by flux-rope dynamics rather than on the mean electric field induced by multiple flux ropes whose acceleration effects are discussed elsewhere. Our steady-state analytical solutions suggest that particle drift acceleration by flux ropes, irrespective of whether displaying incompressible or compressible behavior, can yield power laws asymptotically at higher energies whereas an exponential spectral rollover results asymptotically when field-aligned guiding center motion acceleration occur by reconnection electric fields from merging flux ropes. This implies that at sufficiently high particle energies, drift acceleration might dominate. We also expect compressive flux ropes to yield harder power-law spectra than incompressible flux ropes. Preliminary results will be discussed to illustrate how particle acceleration might be affected when both diffusive shock and small-scale flux acceleration occur simultaneously at interplanetary shocks.

  13. Saturation wind power potential and its implications for wind energy

    PubMed Central

    Jacobson, Mark Z.; Archer, Cristina L.

    2012-01-01

    Wind turbines convert kinetic to electrical energy, which returns to the atmosphere as heat to regenerate some potential and kinetic energy. As the number of wind turbines increases over large geographic regions, power extraction first increases linearly, but then converges to a saturation potential not identified previously from physical principles or turbine properties. These saturation potentials are >250 terawatts (TW) at 100 m globally, approximately 80 TW at 100 m over land plus coastal ocean outside Antarctica, and approximately 380 TW at 10 km in the jet streams. Thus, there is no fundamental barrier to obtaining half (approximately 5.75 TW) or several times the world’s all-purpose power from wind in a 2030 clean-energy economy. PMID:23019353

  14. Saturation wind power potential and its implications for wind energy.

    PubMed

    Jacobson, Mark Z; Archer, Cristina L

    2012-09-25

    Wind turbines convert kinetic to electrical energy, which returns to the atmosphere as heat to regenerate some potential and kinetic energy. As the number of wind turbines increases over large geographic regions, power extraction first increases linearly, but then converges to a saturation potential not identified previously from physical principles or turbine properties. These saturation potentials are >250 terawatts (TW) at 100 m globally, approximately 80 TW at 100 m over land plus coastal ocean outside Antarctica, and approximately 380 TW at 10 km in the jet streams. Thus, there is no fundamental barrier to obtaining half (approximately 5.75 TW) or several times the world's all-purpose power from wind in a 2030 clean-energy economy.

  15. 77 FR 31839 - Wind and Water Power Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-30

    ... of Energy Efficiency and Renewable Energy Wind and Water Power Program AGENCY: Office of Energy... Water Power Program, Wind Power Peer Review Meeting will review wind technology development and market... and Water Power Program's wind technology development and market acceleration and deployment...

  16. Variability in large-scale wind power generation: Variability in large-scale wind power generation

    SciTech Connect

    Kiviluoma, Juha; Holttinen, Hannele; Weir, David; Scharff, Richard; Söder, Lennart; Menemenlis, Nickie; Cutululis, Nicolaos A.; Danti Lopez, Irene; Lannoye, Eamonn; Estanqueiro, Ana; Gomez-Lazaro, Emilio; Bai, Jianhua; Wan, Yih-Huei; Milligan, Michael

    2015-10-25

    The paper demonstrates the characteristics of wind power variability and net load variability in multiple power systems based on real data from multiple years. Demonstrated characteristics include probability distribution for different ramp durations, seasonal and diurnal variability and low net load events. The comparison shows regions with low variability (Sweden, Spain and Germany), medium variability (Portugal, Ireland, Finland and Denmark) and regions with higher variability (Quebec, Bonneville Power Administration and Electric Reliability Council of Texas in North America; Gansu, Jilin and Liaoning in China; and Norway and offshore wind power in Denmark). For regions with low variability, the maximum 1 h wind ramps are below 10% of nominal capacity, and for regions with high variability, they may be close to 30%. Wind power variability is mainly explained by the extent of geographical spread, but also higher capacity factor causes higher variability. It was also shown how wind power ramps are autocorrelated and dependent on the operating output level. When wind power was concentrated in smaller area, there were outliers with high changes in wind output, which were not present in large areas with well-dispersed wind power.

  17. An estimate of the relative magnitude of small-scale tracer fluxes

    NASA Technical Reports Server (NTRS)

    Bacmeister, Julio T.; Schoeberl, Mark R.; Loewenstein, Max; Podolske, Jim R.; Strahan, Susan E.; Chan, K. R.

    1992-01-01

    The wind and constituent measurements from the polar aircraft data are used to compute the flux spectra. Although there is variation from flight to flight, the flux spectra generally fit a -2 to -1.5 power law as expected theoretically. This result suggests that tracer fluxes from small scale features do not substantially contribute to the overall tracer budget relative to the fluxes from the larger scales.

  18. Wind Powering America FY07 Activities Summary

    SciTech Connect

    Not Available

    2008-02-01

    The Wind Powering America FY07 Activities Summary reflects the accomplishments of our state wind working groups, our programs at the National Renewable Energy Laboratory, and our partner organizations. The national WPA team remains a leading force for moving wind energy forward in the United States. WPA continues to work with its national, regional, and state partners to communicate the opportunities and benefits of wind energy to a diverse set of stakeholders. WPA now has 30 state wind working groups (welcoming Georgia and Wisconsin in 2007) that form strategic alliances to communicate wind's benefits to the state stakeholders. More than 140 members of national and state public and private sector organizations from 39 U.S. states and Canada attended the 6th Annual WPA All-States Summit in Los Angeles in June. WPA's emphasis remains on the rural agricultural sector, which stands to reap the significant economic development benefits of wind energy development. Additionally, WPA continues its program of outreach, education, and technical assistance to Native American communities, public power entities, and regulatory and legislative bodies.

  19. WIND Toolkit Power Data Site Index

    DOE Data Explorer

    Draxl, Caroline; Mathias-Hodge, Bri

    2016-10-19

    This spreadsheet contains per-site metadata for the WIND Toolkit sites and serves as an index for the raw data hosted on Globus connect (nrel#globus:/globusro/met_data). Aside from the metadata, per site average power and capacity factor are given. This data was prepared by 3TIER under contract by NREL and is public domain. Authoritative documentation on the creation of the underlying dataset is at: Final Report on the Creation of the Wind Integration National Dataset (WIND) Toolkit and API: http://www.nrel.gov/docs/fy16osti/66189.pdf

  20. Short time ahead wind power production forecast

    NASA Astrophysics Data System (ADS)

    Sapronova, Alla; Meissner, Catherine; Mana, Matteo

    2016-09-01

    An accurate prediction of wind power output is crucial for efficient coordination of cooperative energy production from different sources. Long-time ahead prediction (from 6 to 24 hours) of wind power for onshore parks can be achieved by using a coupled model that would bridge the mesoscale weather prediction data and computational fluid dynamics. When a forecast for shorter time horizon (less than one hour ahead) is anticipated, an accuracy of a predictive model that utilizes hourly weather data is decreasing. That is because the higher frequency fluctuations of the wind speed are lost when data is averaged over an hour. Since the wind speed can vary up to 50% in magnitude over a period of 5 minutes, the higher frequency variations of wind speed and direction have to be taken into account for an accurate short-term ahead energy production forecast. In this work a new model for wind power production forecast 5- to 30-minutes ahead is presented. The model is based on machine learning techniques and categorization approach and using the historical park production time series and hourly numerical weather forecast.

  1. Equivalencing the Collector System of a Large Wind Power Plant

    SciTech Connect

    Muljadi, E.; Butterfield, C. P.; Ellis, A.; Mechenbier, J.; Hocheimer, J.; Young, R.; Miller, N.; Delmerico, R.; Zavadil, R.; Smith, J. C.

    2006-01-01

    As the size and number of wind power plants (also called wind farms) increases, power system planners will need to study their impact on the power system in more detail. As the level of wind power penetration into the grid increases, the transmission system integration requirements will become more critical [1-2]. A very large wind power plant may contain hundreds of megawatt-size wind turbines. These turbines are interconnected by an intricate collector system. While the impact of individual turbines on the larger power system network is minimal, collectively, wind turbines can have a significant impact on the power systems during a severe disturbance such as a nearby fault. Since it is not practical to represent all individual wind turbines to conduct simulations, a simplified equivalent representation is required. This paper focuses on our effort to develop an equivalent representation of a wind power plant collector system for power system planning studies. The layout of the wind power plant, the size and type of conductors used, and the method of delivery (overhead or buried cables) all influence the performance of the collector system inside the wind power plant. Our effort to develop an equivalent representation of the collector system for wind power plants is an attempt to simplify power system modeling for future developments or planned expansions of wind power plants. Although we use a specific large wind power plant as a case study, the concept is applicable for any type of wind power plant.

  2. Powerful Winds in Extreme RBS quasars (POWER)

    NASA Astrophysics Data System (ADS)

    Piconcelli, Enrico

    2013-10-01

    This proposal aims at studying powerful outflows in ultra-luminous (log Lx >45) Radio-Quiet Quasars (RQQ). We propose to observe four objects extracted from a luminosity limited sample in the ROSAT Bright Survey for a full orbit (130 ks) each. Both models and observations suggest that the efficiency of driving energetic outflows increases with the AGN luminosity. Therefore, our targets are potentially the best objects to hunt for very powerful outflows expected in the AGN/galaxy feedback scenario. Our observations represent the first attempt ever to obtain deep, high-resolution-driven spectroscopy of a representative sample of RQQ in this high-luminosity regime.

  3. Wind Power Plant Voltage Stability Evaluation: Preprint

    SciTech Connect

    Muljadi, E.; Zhang, Y. C.

    2014-09-01

    Voltage stability refers to the ability of a power system to maintain steady voltages at all buses in the system after being subjected to a disturbance from a given initial operating condition. Voltage stability depends on a power system's ability to maintain and/or restore equilibrium between load demand and supply. Instability that may result occurs in the form of a progressive fall or rise of voltages of some buses. Possible outcomes of voltage instability are the loss of load in an area or tripped transmission lines and other elements by their protective systems, which may lead to cascading outages. The loss of synchronism of some generators may result from these outages or from operating conditions that violate a synchronous generator's field current limit, or in the case of variable speed wind turbine generator, the current limits of power switches. This paper investigates the impact of wind power plants on power system voltage stability by using synchrophasor measurements.

  4. Breezy Power: From Wind to Energy

    ERIC Educational Resources Information Center

    Claymier, Bob

    2009-01-01

    This lesson combines the science concepts of renewable energy and producing electricity with the technology concepts of design, constraints, and technology's impact on the environment. Over five class periods, sixth-grade students "work" for a fictitious power company as they research wind as an alternative energy source and design and test a…

  5. Small-Scale-Field Dynamo

    SciTech Connect

    Gruzinov, A.; Cowley, S.; Sudan, R. ||

    1996-11-01

    Generation of magnetic field energy, without mean field generation, is studied. Isotropic mirror-symmetric turbulence of a conducting fluid amplifies the energy of small-scale magnetic perturbations if the magnetic Reynolds number is high, and the dimensionality of space {ital d} satisfies 2.103{lt}{ital d}{lt}8.765. The result does not depend on the model of turbulence, incompressibility, and isotropy being the only requirements. {copyright} {ital 1996 The American Physical Society.}

  6. Navy Applications Experience with Small Wind Power Systems

    DTIC Science & Technology

    1985-05-01

    This report describes the experience gained and lesson learned from the ongoing field evaluations of seven small, 2-to 20-kW wind energy conversion... energy conversion systems, Wind energy power conditioning, Inverters, Electromagnetic interference, and Renewable energy sources....The field evaluations are continuing on the small WECS in order to develop operation, maintenance, and reliability data. Keywords: Wind power, Wind

  7. Wind Power Plant Prediction by Using Neural Networks: Preprint

    SciTech Connect

    Liu, Z.; Gao, W.; Wan, Y. H.; Muljadi, E.

    2012-08-01

    This paper introduces a method of short-term wind power prediction for a wind power plant by training neural networks based on historical data of wind speed and wind direction. The model proposed is shown to achieve a high accuracy with respect to the measured data.

  8. Wind-powered heat pump experiment

    SciTech Connect

    Regan, D.C.

    1983-05-01

    The work described in this report was completed in two parts. The first part was an evaluation of an automotive type freon compressor, which demonstrated that such a device could be operated at slow speeds (600 to 1200 rpm) and still produce useful amounts of heat transfer. This device was evaluated and output measured by temperature measurements made on tanks of water in which the condenser and evaporator coils were immersed. The second portion of the project was to have been a demonstration using a wind turbine as the motive power and construction of a full scale system. However, after several different attempts to construct a working system, the work had to be terminated because the device to convert the wind power to mechanical power for turning the compressor coud never be successfully operated for any extended period of time. A description of the work completed and the reasons for the failure of the concept are delineated.

  9. Autonomous Aerial Sensors for Wind Power Meteorology

    NASA Astrophysics Data System (ADS)

    Giebel, Gregor; Schmidt Paulsen, Uwe; Reuder, Joachim; La Cour-Harbo, Anders; Thomsen, Carsten; Bange, Jens; Buschmann, Marco

    2010-05-01

    This poster describes a new approach for measurements in wind power meteorology using small unmanned flying platforms. During a week of flying a lighter-than-air vehicle, two small electrically powered aeroplanes and a larger helicopter at the Risø test station at Høvsøre, we will compare wind speed measurements with fixed mast and LIDAR measurements, investigate optimal flight patterns for each measurement task, and measure other interesting meteorological features like the air-sea boundary in the vicinity of the wind farm. In order to prepare the measurement campaign, a workshop is held, soliciting input from various communities. Large-scale wind farms, especially offshore, need an optimisation between installed wind power density and the losses in the wind farm due to wake effects between the turbines. While the wake structure behind single wind turbines onshore is fairly well understood, there are different problems offshore, thought to be due mainly to the low turbulence. Good measurements of the wake and wake structure are not easy to come by, as the use of a met mast is static and expensive, while the use of remote sensing instruments either needs significant access to the turbine to mount an instrument, or is complicated to use on a ship due to the ship's own movement. In any case, a good LIDAR or SODAR will cost many tens of thousands of euros. Another current problem in wind energy is the coming generation of wind turbines in the 10-12 MW class, with tip heights of over 200 m. Very few measurement masts exist to verify our knowledge of atmospheric physics - all that is known is that the boundary layer description we used so far is not valid any more. Here, automated Unmanned Aerial Vehicles (UAVs) could be used as either an extension of current high masts or to build a network of very high ‘masts' in a region of complex terrain or coastal flow conditions. In comparison to a multitude of high masts, UAVs could be quite cost-effective. In order to test

  10. Measurement of unsteady loading and power output variability in a micro wind farm model in a wind tunnel

    NASA Astrophysics Data System (ADS)

    Bossuyt, Juliaan; Howland, Michael F.; Meneveau, Charles; Meyers, Johan

    2017-01-01

    Unsteady loading and spatiotemporal characteristics of power output are measured in a wind tunnel experiment of a microscale wind farm model with 100 porous disk models. The model wind farm is placed in a scaled turbulent boundary layer, and six different layouts, varied from aligned to staggered, are considered. The measurements are done by making use of a specially designed small-scale porous disk model, instrumented with strain gages. The frequency response of the measurements goes up to the natural frequency of the model, which corresponds to a reduced frequency of 0.6 when normalized by the diameter and the mean hub height velocity. The equivalent range of timescales, scaled to field-scale values, is 15 s and longer. The accuracy and limitations of the acquisition technique are documented and verified with hot-wire measurements. The spatiotemporal measurement capabilities of the experimental setup are used to study the cross-correlation in the power output of various porous disk models of wind turbines. A significant correlation is confirmed between streamwise aligned models, while staggered models show an anti-correlation.

  11. Synchrophasor Applications for Wind Power Generation

    SciTech Connect

    Muljadi, E.; Zhang, Y. C.; Allen, A.; Singh, M.; Gevorgian, V.; Wan, Y. H.

    2014-02-01

    The U.S. power industry is undertaking several initiatives that will improve the operations of the electric power grid. One of those is the implementation of wide-area measurements using phasor measurement units to dynamically monitor the operations and status of the network and provide advanced situational awareness and stability assessment. The overviews of synchrophasors and stability analyses in this report are intended to present the potential future applications of synchrophasors for power system operations under high penetrations of wind and other renewable energy sources.

  12. Replacing baseload power plants with wind plants

    SciTech Connect

    Cavallo, A.J.

    1995-12-31

    Baseload nuclear power plants supply about 21 percent of the electricity consumed in the United States today, and as these plants are retired over the next 10 to 25 years, they will not be replicated. This will open a vast market for new generating facilities which should, if possible, be non-fossil fueled. Wind energy baseload systems are able to equal or exceed the technical performance of these nuclear plants at a delivered cost of energy of less than $0.05/kWh in wind class 4 regions. However, unless a new externality (the cost of maintaining the security of fossil fuel supply) is factored in to the extremely low market price of fossil fuels, wind and other renewable energy resources will not be able to compete with these fuels on the basis of simple economics over the next 20 to 30 years.

  13. Operation of Power Grids with High Penetration of Wind Power

    NASA Astrophysics Data System (ADS)

    Al-Awami, Ali Taleb

    The integration of wind power into the power grid poses many challenges due to its highly uncertain nature. This dissertation involves two main components related to the operation of power grids with high penetration of wind energy: wind-thermal stochastic dispatch and wind-thermal coordinated bidding in short-term electricity markets. In the first part, a stochastic dispatch (SD) algorithm is proposed that takes into account the stochastic nature of the wind power output. The uncertainty associated with wind power output given the forecast is characterized using conditional probability density functions (CPDF). Several functions are examined to characterize wind uncertainty including Beta, Weibull, Extreme Value, Generalized Extreme Value, and Mixed Gaussian distributions. The unique characteristics of the Mixed Gaussian distribution are then utilized to facilitate the speed of convergence of the SD algorithm. A case study is carried out to evaluate the effectiveness of the proposed algorithm. Then, the SD algorithm is extended to simultaneously optimize the system operating costs and emissions. A modified multi-objective particle swarm optimization algorithm is suggested to identify the Pareto-optimal solutions defined by the two conflicting objectives. A sensitivity analysis is carried out to study the effect of changing load level and imbalance cost factors on the Pareto front. In the second part of this dissertation, coordinated trading of wind and thermal energy is proposed to mitigate risks due to those uncertainties. The problem of wind-thermal coordinated trading is formulated as a mixed-integer stochastic linear program. The objective is to obtain the optimal tradeoff bidding strategy that maximizes the total expected profits while controlling trading risks. For risk control, a weighted term of the conditional value at risk (CVaR) is included in the objective function. The CVaR aims to maximize the expected profits of the least profitable scenarios, thus

  14. U.S. Wind Power Project Database

    SciTech Connect

    2007-12-15

    The database represents an inventory of wind power projects under development in the U.S. The database is designed to provide a concise overview of the current status of domestic projects (200 as of 1 Dec 2007). The database contains key project data on wind power plants currently being evaluated, developed, or constructed. It is of value to anyone interested in tracking wind power development including utilities, power project developers, equipment manufacturers, transporters and other vendors, investment banks, regulators, consultants, and analysts. The database is a Microsoft Excel spreadsheet which enables users to easily and quickly search for projects of interest by developer, technology, location, size, cost, status, or other characteristics. The database is updated as project specifics change to ensure that information is kept timely. Updates are provided via email on a monthly basis as part of an annual subscription. Database fields include: developer, owner, project name and description, location, technology, capacity, investment cost, proposed in-service date, status, air quality permit, and CPCN/siting approval.

  15. Wind power. Citations from the NTIS data base

    NASA Astrophysics Data System (ADS)

    Hundemann, A. S.

    1980-06-01

    The feasibility, use, and engineering aspects of wind power and windmills are discussed in these citations of Federally funded research reports. Abstracts primarily cover the use of wind power for electric power generation and wind turbine design and performance. General studies dealing with comparative analyses of wind power and alternative energy sources are included, as are energy storage devices which can be used in these systems. This updated bibliography contains 253 abstracts, none of which are new entries to the previous edition.

  16. Wind power. Citations from the NTIS data base

    NASA Astrophysics Data System (ADS)

    Hundemann, A. S.

    1980-06-01

    The feasibility, use and engineering aspects of wind power and windmills are discussed in these citations of Federally funded research reports. Abstracts primarily cover the use of wind power for electric power generation and wind turbine design and performance. General studies dealing with comparative analyses of wind power and alternative energy sources are included, as are energy storage devices which can be used in these systems. This updated bibliography contains 135 abstracts, 112 of which are new entries to the previous edition.

  17. 77 FR 5002 - Wind and Water Power Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-01

    ... of Energy Efficiency and Renewable Energy Wind and Water Power Program AGENCY: Office of Energy..., request for comment. SUMMARY: The Wind and Water Power Program (WWPP) within the U.S. Department of Energy...: Michael Hahn, Wind and Water Power Program, 1617 Cole Blvd. Golden, CO 80401. Please submit one...

  18. 77 FR 38277 - Wind and Water Power Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-27

    ... of Energy Efficiency and Renewable Energy Wind and Water Power Program AGENCY: Office of Energy... Department of Energy (DOE) Wind and Water Power Program is planning a coordination workshop to exchange... in Washington, DC on June 13, 2012. Mark Higgins, Wind and Water Power Acting Program Manager,...

  19. Observations of How Magnetofluid Turbulence Dissipates at Small Scales

    NASA Technical Reports Server (NTRS)

    Goldstein, M. L.; Sahraoui, Fouad

    2012-01-01

    The solar wind is a turbulent magneto fluid that can be studied intensively at multiple scales. Investigations using single spacecraft have revealed much about the properties of the solar wind throughout the heliosphere (from 0.3 AU to 100 AU). More recently, data from multiple spacecraft have provided further details of both the statistical properties of the turbulence and its small-scale structure. In particular, high time resolution magnetic field measurements from the four Cluster spacecrafl have led to the conclusion that at spatial scales of order the proton inertial length and smaller, the turbulence becomes strongly anisotropic and the power in fluctuations that are perpendicular to the (local) magnetic field is measured to be much larger than that in fluctuations that are parallel to the magnetic field. As the spatial scales approach the electron inertial length, the power is almost completely dissipated. Various analysis techniques and theoretical ideas have been put forward to account for the properties of those measurements. The talk will describe the current state of observations, theory and simulations.

  20. Wind tunnel testing of a closed-loop wake deflection controller for wind farm power maximization

    NASA Astrophysics Data System (ADS)

    Campagnolo, Filippo; Petrović, Vlaho; Schreiber, Johannes; Nanos, Emmanouil M.; Croce, Alessandro; Bottasso, Carlo L.

    2016-09-01

    This paper presents results from wind tunnel tests aimed at evaluating a closed- loop wind farm controller for wind farm power maximization by wake deflection. Experiments are conducted in a large boundary layer wind tunnel, using three servo-actuated and sensorized wind turbine scaled models. First, we characterize the impact on steady-state power output of wake deflection, achieved by yawing the upstream wind turbines. Next, we illustrate the capability of the proposed wind farm controller to dynamically driving the upstream wind turbines to the optimal yaw misalignment setting.

  1. Wind Power on Native American Lands: Process and Progress (Poster)

    SciTech Connect

    Jimenez, A.; Flowers, L.; Gough, R.; Taylor, R.

    2005-05-01

    The United States is home to more than 700 American Indian tribes and Native Alaska villages and corporations located on 96 million acres. Many of these tribes and villages have excellent wind resources that could be commercially developed to meet their electricity needs or for electricity export. The Wind Powering America program engages Native Americans in wind energy development. This poster describes the process and progress of Wind Powering America's involvement with Native American wind energy projects.

  2. Development of an efficient, low cost, small-scale natural gas fuel reformer for residential scale electric power generation. Final report for the period October 1, 1998 - December 31, 1999

    SciTech Connect

    Kreutz, Thomas G; Ogden, Joan M

    2000-07-01

    In the final report, we present results from a technical and economic assessment of residential scale PEM fuel cell power systems. The objectives of our study are to conceptually design an inexpensive, small-scale PEMFC-based stationary power system that converts natural gas to both electricity and heat, and then to analyze the prospective performance and economics of various system configurations. We developed computer models for residential scale PEMFC cogeneration systems to compare various system designs (e.g., steam reforming vs. partial oxidation, compressed vs. atmospheric pressure, etc.) and determine the most technically and economically attractive system configurations at various scales (e.g., single family, residential, multi-dwelling, neighborhood).

  3. Concurrent Wind Cooling in Power Transmission Lines

    SciTech Connect

    Jake P Gentle

    2012-08-01

    Idaho National Laboratory and the Idaho Power Company, with collaboration from Idaho State University, have been working on a project to monitor wind and other environmental data parameters along certain electrical transmission corridors. The combination of both real-time historical weather and environmental data is being used to model, validate, and recommend possibilities for dynamic operations of the transmission lines for power and energy carrying capacity. The planned results can also be used to influence decisions about proposed design criteria for or upgrades to certain sections of the transmission lines.

  4. High-efficiency grid-connected photovoltaic module integrated converter system with high-speed communication interfaces for small-scale distribution power generation

    SciTech Connect

    Choi, Woo-Young; Lai, Jih-Sheng

    2010-04-15

    This paper presents a high-efficiency grid-connected photovoltaic (PV) module integrated converter (MIC) system with reduced PV current variation. The proposed PV MIC system consists of a high-efficiency step-up DC-DC converter and a single-phase full-bridge DC-AC inverter. An active-clamping flyback converter with a voltage-doubler rectifier is proposed for the step-up DC-DC converter. The proposed step-up DC-DC converter reduces the switching losses by eliminating the reverse-recovery current of the output rectifying diodes. To reduce the PV current variation introduced by the grid-connected inverter, a PV current variation reduction method is also suggested. The suggested PV current variation reduction method reduces the PV current variation without any additional components. Moreover, for centralized power control of distributed PV MIC systems, a PV power control scheme with both a central control level and a local control level is presented. The central PV power control level controls the whole power production by sending out reference power signals to each individual PV MIC system. The proposed step-up DC-DC converter achieves a high-efficiency of 97.5% at 260 W output power to generate the DC-link voltage of 350 V from the PV voltage of 36.1 V. The PV MIC system including the DC-DC converter and the DC-AC inverter achieves a high-efficiency of 95% with the PV current ripple less than 3% variation of the rated PV current. (author)

  5. Wind Power Ramping Product for Increasing Power System Flexibility

    SciTech Connect

    Cui, Mingjian; Zhang, Jie; Wu, Hongyu; Hodge, Bri-Mathias; Ke, Deping; Sun, Yuanzhang

    2016-05-05

    With increasing penetrations of wind power, system operators are concerned about a potential lack of system flexibility and ramping capacity in real-time dispatch stages. In this paper, a modified dispatch formulation is proposed considering the wind power ramping product (WPRP). A swinging door algorithm (SDA) and dynamic programming are combined and used to detect WPRPs in the next scheduling periods. The detected WPRPs are included in the unit commitment (UC) formulation considering ramping capacity limits, active power limits, and flexible ramping requirements. The modified formulation is solved by mixed integer linear programming. Numerical simulations on a modified PJM 5-bus System show the effectiveness of the model considering WPRP, which not only reduces the production cost but also does not affect the generation schedules of thermal units.

  6. Capacity value assessments of wind power: Capacity value assessments of wind power

    SciTech Connect

    Milligan, Michael; Frew, Bethany; Ibanez, Eduardo; Kiviluoma, Juha; Holttinen, Hannele; Söder, Lennart

    2016-10-05

    This article describes some of the recent research into the capacity value of wind power. With the worldwide increase in wind power during the past several years, there is increasing interest and significance regarding its capacity value because this has a direct influence on the amount of other (nonwind) capacity that is needed. We build on previous reviews from IEEE and IEA Wind Task 25a and examine recent work that evaluates the impact of multiple-year data sets and the impact of interconnected systems on resource adequacy. We also provide examples that explore the use of alternative reliability metrics for wind capacity value calculations. We show how multiple-year data sets significantly increase the robustness of results compared to single-year assessments. Assumptions regarding the transmission interconnections play a significant role. To date, results regarding which reliability metric to use for probabilistic capacity valuation show little sensitivity to the metric.

  7. Validation of Power Output for the WIND Toolkit

    SciTech Connect

    King, J.; Clifton, A.; Hodge, B. M.

    2014-09-01

    Renewable energy integration studies require wind data sets of high quality with realistic representations of the variability, ramping characteristics, and forecast performance for current wind power plants. The Wind Integration National Data Set (WIND) Toolkit is meant to be an update for and expansion of the original data sets created for the weather years from 2004 through 2006 during the Western Wind and Solar Integration Study and the Eastern Wind Integration Study. The WIND Toolkit expands these data sets to include the entire continental United States, increasing the total number of sites represented, and it includes the weather years from 2007 through 2012. In addition, the WIND Toolkit has a finer resolution for both the temporal and geographic dimensions. Three separate data sets will be created: a meteorological data set, a wind power data set, and a forecast data set. This report describes the validation of the wind power data set.

  8. Analytical expressions for maximum wind turbine average power in a Rayleigh wind regime

    SciTech Connect

    Carlin, P.W.

    1996-12-01

    Average or expectation values for annual power of a wind turbine in a Rayleigh wind regime are calculated and plotted as a function of cut-out wind speed. This wind speed is expressed in multiples of the annual average wind speed at the turbine installation site. To provide a common basis for comparison of all real and imagined turbines, the Rayleigh-Betz wind machine is postulated. This machine is an ideal wind machine operating with the ideal Betz power coefficient of 0.593 in a Rayleigh probability wind regime. All other average annual powers are expressed in fractions of that power. Cases considered include: (1) an ideal machine with finite power and finite cutout speed, (2) real machines operating in variable speed mode at their maximum power coefficient, and (3) real machines operating at constant speed.

  9. Small Scale High Speed Turbomachinery

    NASA Technical Reports Server (NTRS)

    London, Adam P. (Inventor); Droppers, Lloyd J. (Inventor); Lehman, Matthew K. (Inventor); Mehra, Amitav (Inventor)

    2015-01-01

    A small scale, high speed turbomachine is described, as well as a process for manufacturing the turbomachine. The turbomachine is manufactured by diffusion bonding stacked sheets of metal foil, each of which has been pre-formed to correspond to a cross section of the turbomachine structure. The turbomachines include rotating elements as well as static structures. Using this process, turbomachines may be manufactured with rotating elements that have outer diameters of less than four inches in size, and/or blading heights of less than 0.1 inches. The rotating elements of the turbomachines are capable of rotating at speeds in excess of 150 feet per second. In addition, cooling features may be added internally to blading to facilitate cooling in high temperature operations.

  10. Case studies of the legal and institutional obstacles and incentives to the development of small-scale hydroelectric power: South Columbia Basin Irrigation District, Pasco, Washington

    SciTech Connect

    Schwartz, L.

    1980-05-01

    The case study concerns two modern human uses of the Columbia River - irrigation aimed at agricultural land reclamation and hydroelectric power. The Grand Coulee Dam has become synonomous with large-scale generation of hydroelectric power providing the Pacific Northwest with some of the least-expensive electricity in the United States. The Columbia Basin Project has created a half-million acres of farmland in Washington out of a spectacular and vast desert. The South Columbia River Basin Irrigation District is seeking to harness the energy present in the water which already runs through its canals, drains, and wasteways. The South District's development strategy is aimed toward reducing the costs its farmers pay for irrigation and raising the capital required to serve the remaining 550,000 acres originally planned as part of the Columbia Basin Project. The economic, institutional, and regulatory problems of harnessing the energy at site PEC 22.7, one of six sites proposed for development, are examined in this case study.

  11. Wind Power: A Turning Point. Worldwatch Paper 45.

    ERIC Educational Resources Information Center

    Flavin, Christopher

    Recent studies have shown wind power to be an eminently practical and potentially substantial source of electricity and direct mechanical power. Wind machines range from simple water-pumping devices made of wood and cloth to large electricity producing turbines with fiberglass blades nearly 300 feet long. Wind is in effect a form of solar…

  12. Introducing Wind Power: Essentials for Bringing It into the Classroom

    ERIC Educational Resources Information Center

    Swapp, Andy; Schreuders, Paul; Reeve, Edward

    2011-01-01

    As a renewable source of energy, wind energy will play a significant role in the future. Public, commercial, and privately owned organizations are increasingly finding the value and profits in wind power. Including wind power in a technology and engineering education curriculum teaches students about an important technology that may effect their…

  13. New England Wind Forum: A Wind Powering America Project - Newsletter #6 - September 2010, (NEWF)

    SciTech Connect

    Grace, R.; Gifford, J.; Leeds, T.; Bauer, S.

    2010-09-01

    Wind Powering America program launched the New England Wind Forum (NEWF) in 2005 to provide a single comprehensive source of up-to-date, Web-based information on a broad array of wind energy issues pertaining to New England. The NEWF newsletter provides New England stakeholders with updates on wind energy development in the region.

  14. Small-scale hydroelectric power demonstration project. Riegel Textile Corporation, Fries, Virginia plant hydro-project. Final operation and maintenance report

    SciTech Connect

    Not Available

    1983-12-01

    Riegel Textile Corporation completed a 2163 KW rated turbine generator project at its plant on the New River in Fries, Virginia. A new powerhouse was constructed to enclose a used 2900 HP vertical Kaplan turbine and Westinghouse generator. The turbine is a 4-bladed 72-inch S. Morgan Smith manufactured in 1939. At the original setting of 46 feet, the unit had a rating of 3880 HP and the generator had a rating of 3000 KVA. Overhaul and installation of the used equipment was accomplished by the plant maintenance department. Overhaul of the used equipment and preparation of the license application began in June 1979. Construction of the new powerhouse began in June 1980. On July 24, 1981, construction was completed, the new unit was synchronized with Appalachian Power Company, and the first electrical energy was produced. The installation of this equipment, in conjunction with existing equipment already in place, increased the total plant generating capacity to 5251 KW. A total of four generators are now used and approximately 75% of the manufacturing plant's electrical requirements are self-generated. The purpose of this report is to summarize the operating and maintenance activities, costs, and revenues for the first two years of operation.

  15. 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.

  16. Small-scale universality in fluid turbulence

    PubMed Central

    Schumacher, Jörg; Scheel, Janet D.; Krasnov, Dmitry; Donzis, Diego A.; Yakhot, Victor; Sreenivasan, Katepalli R.

    2014-01-01

    Turbulent flows in nature and technology possess a range of scales. The largest scales carry the memory of the physical system in which a flow is embedded. One challenge is to unravel the universal statistical properties that all turbulent flows share despite their different large-scale driving mechanisms or their particular flow geometries. In the present work, we study three turbulent flows of systematically increasing complexity. These are homogeneous and isotropic turbulence in a periodic box, turbulent shear flow between two parallel walls, and thermal convection in a closed cylindrical container. They are computed by highly resolved direct numerical simulations of the governing dynamical equations. We use these simulation data to establish two fundamental results: (i) at Reynolds numbers Re ∼ 102 the fluctuations of the velocity derivatives pass through a transition from nearly Gaussian (or slightly sub-Gaussian) to intermittent behavior that is characteristic of fully developed high Reynolds number turbulence, and (ii) beyond the transition point, the statistics of the rate of energy dissipation in all three flows obey the same Reynolds number power laws derived for homogeneous turbulence. These results allow us to claim universality of small scales even at low Reynolds numbers. Our results shed new light on the notion of when the turbulence is fully developed at the small scales without relying on the existence of an extended inertial range. PMID:25024175

  17. New England Wind Forum: A Wind Powering America Project, Newsletter #5 -- January 2010, Wind and Hydropower Technologies Program (WHTP)

    SciTech Connect

    Grace, R. C.; Gifford, J.

    2010-01-01

    Wind Powering America program launched the New England Wind Forum (NEWF) in 2005 to provide a single comprehensive source of up-to-date, Web-based information on a broad array of wind energy issues pertaining to New England. The NEWF newsletter provides New England stakeholders with updates on wind energy development in the region. In addition to regional updates, Issue #5 offers an interview with Angus King, former governor of Maine and co-founder of Independence Wind.

  18. Wind Power: How Much, How Soon, and At What Cost?

    SciTech Connect

    Wiser, Ryan H; Hand, Maureen

    2010-01-01

    The global wind power market has been growing at a phenomenal pace, driven by favorable policies towards renewable energy and the improving economics of wind projects. On a going forward basis, utility-scale wind power offers the potential for significant reductions in the carbon footprint of the electricity sector. Specifically, the global wind resource is vast and, though accessing this potential is not costless or lacking in barriers, wind power can be developed at scale in the near to medium term at what promises to be an acceptable cost.

  19. Cooperative Extension Service & Wind Powering America Collaborate to Provide Wind Energy Information to Rural Stakeholders (Poster)

    SciTech Connect

    Jimenez, A.; Flower, L.; Hamlen, S.

    2009-05-01

    Cooperative Extension's presence blankets much of the United States and has been a trusted information source to rural Americans. By working together, Cooperative Extension, Wind Powering America, and the wind industry can better educate the public and rural stakeholders about wind energy and maximize the benefits of wind energy to local communities. This poster provides an overview of Cooperative Extension, wind energy issues addressed by the organization, and related activities.

  20. Demonstrating a new framework for the comparison of environmental impacts from small- and large-scale hydropower and wind power projects.

    PubMed

    Bakken, Tor Haakon; Aase, Anne Guri; Hagen, Dagmar; Sundt, Håkon; Barton, David N; Lujala, Päivi

    2014-07-01

    Climate change and the needed reductions in the use of fossil fuels call for the development of renewable energy sources. However, renewable energy production, such as hydropower (both small- and large-scale) and wind power have adverse impacts on the local environment by causing reductions in biodiversity and loss of habitats and species. This paper compares the environmental impacts of many small-scale hydropower plants with a few large-scale hydropower projects and one wind power farm, based on the same set of environmental parameters; land occupation, reduction in wilderness areas (INON), visibility and impacts on red-listed species. Our basis for comparison was similar energy volumes produced, without considering the quality of the energy services provided. The results show that small-scale hydropower performs less favourably in all parameters except land occupation. The land occupation of large hydropower and wind power is in the range of 45-50 m(2)/MWh, which is more than two times larger than the small-scale hydropower, where the large land occupation for large hydropower is explained by the extent of the reservoirs. On all the three other parameters small-scale hydropower performs more than two times worse than both large hydropower and wind power. Wind power compares similarly to large-scale hydropower regarding land occupation, much better on the reduction in INON areas, and in the same range regarding red-listed species. Our results demonstrate that the selected four parameters provide a basis for further development of a fair and consistent comparison of impacts between the analysed renewable technologies.

  1. Use of wind power forecasting in operational decisions.

    SciTech Connect

    Botterud, A.; Zhi, Z.; Wang, J.; Bessa, R.J.; Keko, H.; Mendes, J.; Sumaili, J.; Miranda, V.

    2011-11-29

    The rapid expansion of wind power gives rise to a number of challenges for power system operators and electricity market participants. The key operational challenge is to efficiently handle the uncertainty and variability of wind power when balancing supply and demand in ths system. In this report, we analyze how wind power forecasting can serve as an efficient tool toward this end. We discuss the current status of wind power forecasting in U.S. electricity markets and develop several methodologies and modeling tools for the use of wind power forecasting in operational decisions, from the perspectives of the system operator as well as the wind power producer. In particular, we focus on the use of probabilistic forecasts in operational decisions. Driven by increasing prices for fossil fuels and concerns about greenhouse gas (GHG) emissions, wind power, as a renewable and clean source of energy, is rapidly being introduced into the existing electricity supply portfolio in many parts of the world. The U.S. Department of Energy (DOE) has analyzed a scenario in which wind power meets 20% of the U.S. electricity demand by 2030, which means that the U.S. wind power capacity would have to reach more than 300 gigawatts (GW). The European Union is pursuing a target of 20/20/20, which aims to reduce greenhouse gas (GHG) emissions by 20%, increase the amount of renewable energy to 20% of the energy supply, and improve energy efficiency by 20% by 2020 as compared to 1990. Meanwhile, China is the leading country in terms of installed wind capacity, and had 45 GW of installed wind power capacity out of about 200 GW on a global level at the end of 2010. The rapid increase in the penetration of wind power into power systems introduces more variability and uncertainty in the electricity generation portfolio, and these factors are the key challenges when it comes to integrating wind power into the electric power grid. Wind power forecasting (WPF) is an important tool to help

  2. 76 FR 66284 - Wind and Water Power Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-26

    ... Office of Energy Efficiency and Renewable Energy Wind and Water Power Program AGENCY: Office of Energy... Wind and Water Power Program, Water Power Peer Review Meeting will review the Program's portfolio of conventional hydropower and marine and hydrokinetic research and development and projects. The 2011 Water...

  3. Improving the Accuracy of Wind Turbine Power Curve Validation by the Rotor Equivalent Wind Speed Concept

    NASA Astrophysics Data System (ADS)

    Scheurich, Frank; Enevoldsen, Peder B.; Paulsen, Henrik N.; Dickow, Kristoffer K.; Fiedel, Moritz; Loeven, Alex; Antoniou, Ioannis

    2016-09-01

    The measurement of the wind speed at hub height is part of the current IEC standard procedure for the power curve validation of wind turbines. The inherent assumption is thereby made that this measured hub height wind speed sufficiently represents the wind speed across the entire rotor area. It is very questionable, however, whether the hub height wind speed (HHWS) method is appropriate for rotor sizes of commercial state-of-the-art wind turbines. The rotor equivalent wind speed (REWS) concept, in which the wind velocities are measured at several different heights across the rotor area, is deemed to be better suited to represent the wind speed in power curve measurements and thus results in more accurate predictions of the annual energy production (AEP) of the turbine. The present paper compares the estimated AEP, based on HHWS power curves, of two different commercial wind turbines to the AEP that is based on REWS power curves. The REWS was determined by LiDAR measurements of the wind velocities at ten different heights across the rotor area. It is shown that a REWS power curve can, depending on the wind shear profile, result in higher, equal or lower AEP estimations compared to the AEP predicted by a HHWS power curve.

  4. Scientists Track Collision of Powerful Stellar Winds

    NASA Astrophysics Data System (ADS)

    2005-04-01

    Astronomers using the National Science Foundation's Very Long Baseline Array (VLBA) radio telescope have tracked the motion of a violent region where the powerful winds of two giant stars slam into each other. The collision region moves as the stars, part of a binary pair, orbit each other, and the precise measurement of its motion was the key to unlocking vital new information about the stars and their winds. WR 140 Image Sequence Motion of Wind Collision Region Graphic superimposes VLBA images of wind collision region on diagram of orbit of Wolf-Rayet (WR) star and its giant (O) companion. Click on image for larger version (412K) CREDIT: Dougherty et al., NRAO/AUI/NSF In Motion: Shockwave File Animated Gif File AVI file Both stars are much more massive than the Sun -- one about 20 times the mass of the Sun and the other about 50 times the Sun's mass. The 20-solar-mass star is a type called a Wolf-Rayet star, characterized by a very strong wind of particles propelled outward from its surface. The more massive star also has a strong outward wind, but one less intense than that of the Wolf-Rayet star. The two stars, part of a system named WR 140, circle each other in an elliptical orbit roughly the size of our Solar System. "The spectacular feature of this system is the region where the stars' winds collide, producing bright radio emission. We have been able to track this collision region as it moves with the orbits of the stars," said Sean Dougherty, an astronomer at the Herzberg Institute for Astrophysics in Canada. Dougherty and his colleagues presented their findings in the April 10 edition of the Astrophysical Journal. The supersharp radio "vision" of the continent-wide VLBA allowed the scientists to measure the motion of the wind collision region and then to determine the details of the stars' orbits and an accurate distance to the system. "Our new calculations of the orbital details and the distance are vitally important to understanding the nature of these

  5. KANSAS WIND POWERING AMERICAN STATE OUTREACH: KANSAS WIND WORKING GROUP

    SciTech Connect

    HAMMARLUND, RAY

    2010-10-27

    The Kansas Wind Working Group (WWG) is a 33-member group announced by former Governor Kathleen Sebelius on Jan. 7, 2008. Formed through Executive Order 08-01, the WWG will educate stakeholder groups with the current information on wind energy markets, technologies, economics, policies, prospects and issues. Governor Mark Parkinson serves as chair of the Kansas Wind Working Group. The group has been instrumental in focusing on the elements of government and coordinating government and private sector efforts in wind energy development. Those efforts have moved Kansas from 364 MW of wind three years ago to over 1000 MW today. Further, the Wind Working Group was instrumental in fleshing out issues such as a state RES and net metering, fundamental parts of HB 2369 that was passed and is now law in Kansas. This represents the first mandatory RES and net metering in Kansas history.

  6. Wind Power Finance and Investment Workshop 2004

    SciTech Connect

    anon.

    2004-11-01

    The workshop had 33 presentations by the leading industry experts in the wind finance and investment area. The workshop presented wind industry opportunities and advice to the financial community. The program also included two concurrent sessions, Wind 100, which offered wind energy novices a comprehensive introduction to wind energy fundamentals, and Transmission Policy and Regulations. Other workshop topics included: Bringing environmental and other issues into perspective; Policy impacts on wind financing; Technical/wind issues; Monetizing green attributes (Sale of green tags); Contractual issues; Debt issues; and Equity issues. There were approximately 230 attendees.

  7. Evaluation of a wind turbine electric power generator

    NASA Technical Reports Server (NTRS)

    Swim, W. B.

    1981-01-01

    A technical assessment of the aerodynamic performance of the wind wheel turbine (WWT) is reported. The potential of the WWT in utilizing wind as an alternate power source was evaluated. Scaling parameters were developed to predict the aerodynamic performance of WWT prototype sized to produce 3, 9, 30, and 100 kw outputs in a 6.7 m/sec wind.

  8. Wind Power in Australia: Overcoming Technological and Institutional Barriers

    ERIC Educational Resources Information Center

    Healey, Gerard; Bunting, Andrea

    2008-01-01

    Until recently, Australia had little installed wind capacity, although there had been many investigations into its potential during the preceding decades. Formerly, state-owned monopoly utilities showed only token interest in wind power and could dictate the terms of energy debates. This situation changed in the late 1990s: Installed wind capacity…

  9. Compensation of Reactive Power of Isolated Wind-Diesel Hybrid Power Systems

    NASA Astrophysics Data System (ADS)

    Sharma, P.; Bhatti, T. S.; Ramakrishna, K. S. S.

    2012-03-01

    This paper presents the automatic reactive power control of an isolated wind-diesel hybrid power system with a synchronous generator (SG) for a diesel genset and an induction generator (IG) with wind energy conversion systems (WECS) to generate electricity. To reduce the gap between reactive power generation and demand, a variable source of reactive power is used such as static synchronous compensator (STATCOM). The mathematical model of the system based on reactive power flow equations is developed. Three examples of the wind-diesel hybrid power systems are considered with different wind power generation capacities to study the effect of the wind power generation on the system performance. The study is based on small signal analysis by considering IEEE type-1 excitation system for the SG. The paper also shows the transient performance of the hybrid systems for 1 % step increase in reactive power load and 1 % step increase in reactive power load plus 1 % step increase in input wind power.

  10. Power Performance Test Report for the SWIFT Wind Turbine

    SciTech Connect

    Mendoza, I.; Hur, J.

    2012-12-01

    This report summarizes the results of a power performance test that NREL conducted on the SWIFT wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 12: Power Performance Measurements of Electricity Producing Wind Turbines, IEC 61400-12-1 Ed.1.0, 2005-12. However, because the SWIFT is a small turbine as defined by IEC, NREL also followed Annex H that applies to small wind turbines. In these summary results, wind speed is normalized to sea-level air density.

  11. SMALL-SCALE ANISOTROPIES OF COSMIC RAYS FROM RELATIVE DIFFUSION

    SciTech Connect

    Ahlers, Markus; Mertsch, Philipp

    2015-12-10

    The arrival directions of multi-TeV cosmic rays show significant anisotropies at small angular scales. It has been argued that this small-scale structure can naturally arise from cosmic ray scattering in local turbulent magnetic fields that distort a global dipole anisotropy set by diffusion. We study this effect in terms of the power spectrum of cosmic ray arrival directions and show that the strength of small-scale anisotropies is related to properties of relative diffusion. We provide a formalism for how these power spectra can be inferred from simulations and motivate a simple analytic extension of the ensemble-averaged diffusion equation that can account for the effect.

  12. An improved AVC strategy applied in distributed wind power system

    NASA Astrophysics Data System (ADS)

    Zhao, Y. N.; Liu, Q. H.; Song, S. Y.; Mao, W.

    2016-08-01

    Traditional AVC strategy is mainly used in wind farm and only concerns about grid connection point, which is not suitable for distributed wind power system. Therefore, this paper comes up with an improved AVC strategy applied in distributed wind power system. The strategy takes all nodes of distribution network into consideration and chooses the node having the most serious voltage deviation as control point to calculate the reactive power reference. In addition, distribution principles can be divided into two conditions: when wind generators access to network on single node, the reactive power reference is distributed according to reactive power capacity; when wind generators access to network on multi-node, the reference is distributed according to sensitivity. Simulation results show the correctness and reliability of the strategy. Compared with traditional control strategy, the strategy described in this paper can make full use of generators reactive power output ability according to the distribution network voltage condition and improve the distribution network voltage level effectively.

  13. Power fluctuations smoothing and regulations in wind turbine generator systems

    NASA Astrophysics Data System (ADS)

    Babazadehrokni, Hamed

    Wind is one of the most popular renewable energy sources and it has the potential to become the biggest energy source in future. Since the wind does not always blow constantly, the output wind power is not constant which may make some problem for the power grid. According to the grid code which is set by independent system operator, ISO, wind turbine generator systems need to follow some standards such as the predetermined acceptable power fluctuations. In order to smooth the output powers, the energy storage system and some power electronics modules are employed. The utilized power electronics modules in the wind turbine system can pursue many different goals, such as maintaining the voltage stability, frequency stability, providing the available and predetermined output active and reactive power. On the other side, the energy storage system can help achieving some of these goals but its main job is to store the extra energy when not needed and release the stored energy when needed. The energy storage system can be designed in different sizes, material and also combination of different energy storage systems (hybrid designs). Combination of power electronics devises and also energy storage system helps the wind turbine systems to smooth the output power according to the provided standards. In addition prediction of wind speed may improve the performance of wind turbine generator systems. In this research study all these three topics are studied and the obtained results are written in 10 papers which 7 of them are published and three of them are under process.

  14. The Potential Wind Power Resource in Australia: A New Perspective

    PubMed Central

    Hallgren, Willow; Gunturu, Udaya Bhaskar; Schlosser, Adam

    2014-01-01

    Australia’s wind resource is considered to be very good, and the utilization of this renewable energy resource is increasing rapidly: wind power installed capacity increased by 35% from 2006 to 2011 and is predicted to account for over 12% of Australia’s electricity generation in 2030. Due to this growth in the utilization of the wind resource and the increasing importance of wind power in Australia’s energy mix, this study sets out to analyze and interpret the nature of Australia’s wind resources using robust metrics of the abundance, variability and intermittency of wind power density, and analyzes the variation of these characteristics with current and potential wind turbine hub heights. We also assess the extent to which wind intermittency, on hourly or greater timescales, can potentially be mitigated by the aggregation of geographically dispersed wind farms, and in so doing, lessen the severe impact on wind power economic viability of long lulls in wind and power generated. Our results suggest that over much of Australia, areas that have high wind intermittency coincide with large expanses in which the aggregation of turbine output does not mitigate variability. These areas are also geographically remote, some are disconnected from the east coast’s electricity grid and large population centers, which are factors that could decrease the potential economic viability of wind farms in these locations. However, on the eastern seaboard, even though the wind resource is weaker, it is less variable, much closer to large population centers, and there exists more potential to mitigate it’s intermittency through aggregation. This study forms a necessary precursor to the analysis of the impact of large-scale circulations and oscillations on the wind resource at the mesoscale. PMID:24988222

  15. The potential wind power resource in Australia: a new perspective.

    PubMed

    Hallgren, Willow; Gunturu, Udaya Bhaskar; Schlosser, Adam

    2014-01-01

    Australia's wind resource is considered to be very good, and the utilization of this renewable energy resource is increasing rapidly: wind power installed capacity increased by 35% from 2006 to 2011 and is predicted to account for over 12% of Australia's electricity generation in 2030. Due to this growth in the utilization of the wind resource and the increasing importance of wind power in Australia's energy mix, this study sets out to analyze and interpret the nature of Australia's wind resources using robust metrics of the abundance, variability and intermittency of wind power density, and analyzes the variation of these characteristics with current and potential wind turbine hub heights. We also assess the extent to which wind intermittency, on hourly or greater timescales, can potentially be mitigated by the aggregation of geographically dispersed wind farms, and in so doing, lessen the severe impact on wind power economic viability of long lulls in wind and power generated. Our results suggest that over much of Australia, areas that have high wind intermittency coincide with large expanses in which the aggregation of turbine output does not mitigate variability. These areas are also geographically remote, some are disconnected from the east coast's electricity grid and large population centers, which are factors that could decrease the potential economic viability of wind farms in these locations. However, on the eastern seaboard, even though the wind resource is weaker, it is less variable, much closer to large population centers, and there exists more potential to mitigate it's intermittency through aggregation. This study forms a necessary precursor to the analysis of the impact of large-scale circulations and oscillations on the wind resource at the mesoscale.

  16. National-Scale Wind Resource Assessment for Power Generation (Presentation)

    SciTech Connect

    Baring-Gould, E. I.

    2013-08-01

    This presentation describes the current standards for conducting a national-scale wind resource assessment for power generation, along with the risk/benefit considerations to be considered when beginning a wind resource assessment. The presentation describes changes in turbine technology and viable wind deployment due to more modern turbine technology and taller towers and shows how the Philippines national wind resource assessment evolved over time to reflect changes that arise from updated technologies and taller towers.

  17. Wind turbine power tracking using an improved multimodel quadratic approach.

    PubMed

    Khezami, Nadhira; Benhadj Braiek, Naceur; Guillaud, Xavier

    2010-07-01

    In this paper, an improved multimodel optimal quadratic control structure for variable speed, pitch regulated wind turbines (operating at high wind speeds) is proposed in order to integrate high levels of wind power to actively provide a primary reserve for frequency control. On the basis of the nonlinear model of the studied plant, and taking into account the wind speed fluctuations, and the electrical power variation, a multimodel linear description is derived for the wind turbine, and is used for the synthesis of an optimal control law involving a state feedback, an integral action and an output reference model. This new control structure allows a rapid transition of the wind turbine generated power between different desired set values. This electrical power tracking is ensured with a high-performance behavior for all other state variables: turbine and generator rotational speeds and mechanical shaft torque; and smooth and adequate evolution of the control variables.

  18. Calculation of guaranteed mean power from wind turbine generators

    NASA Technical Reports Server (NTRS)

    Spera, D. A.

    1981-01-01

    A method for calculating the 'guaranteed mean' power output of a wind turbine generator is proposed. The term 'mean power' refers to the average power generated at specified wind speeds during short-term tests. Correlation of anemometers, the method of bins for analyzing non-steady data, the PROP Code for predicting turbine power, and statistical analysis of deviations in test data from theory are discussed. Guaranteed mean power density for the Clayton Mod-OA system was found to be 8 watts per square meter less than theoretical power density at all power levels, with a confidence level of 0.999. This amounts to 4 percent of rated power.

  19. Self Excitation and Harmonics in Wind Power Generation: Preprint

    SciTech Connect

    Muljadi, E.; Butterfield, C. P.; Romanowitz, H.; Yinger, R.

    2004-11-01

    Traditional wind turbines are equipped with induction generators. Induction generators are preferred because they are inexpensive, rugged, and require very little maintenance. Unfortunately, induction generators require reactive power from the grid to operate. Because reactive power varies with the output power, the terminal voltage at the generator may become too low to compensate the induction generator. The interactions among the wind turbine, the power network, and the capacitor compensation, are important aspects of wind generation. In this paper, we will show the interactions among the induction generator, capacitor compensation, power system network, and magnetic saturations and examine the cause of resonance conditions and self-excitation.

  20. Self-Excitation and Harmonics in Wind Power Generation

    SciTech Connect

    Muljadi, E.; Butterfield, C. P.; Romanowitz, H.; Yinger, R.

    2005-11-01

    Traditional wind turbines are commonly equipped with induction generators because they are inexpensive, rugged, and require very little maintenance. Unfortunately, induction generators require reactive power from the grid to operate; capacitor compensation is often used. Because the level of required reactive power varies with the output power, the capacitor compensation must be adjusted as the output power varies. The interactions among the wind turbine, the power network, and the capacitor compensation are important aspects of wind generation that may result in self-excitation and higher harmonic content in the output current. This paper examines the factors that control these phenomena and gives some guidelines on how they can be controlled or eliminated.

  1. Simulation and optimization of wind and diesel power supply systems

    NASA Astrophysics Data System (ADS)

    Lukutin, B. V.; Shandarova, E. B.; Matukhin, D. L.; Igisenov, A. A.; Shandarov, S. M.

    2017-02-01

    The paper proposes an algorithm to optimize the structure and the choice of capacity of wind and diesel power units of the combined power plant, depending on the wind energy potential and electricity consumption of electrified facility. The algorithm is based on mathematical models of technical and economic characteristics of wind and diesel power plants as well as an optimization method of coordinate descent. The algorithm takes into account the structure of the combined power plant, changing modes of its operation, construction and operation costs of the power facility. The objective function of the algorithm is to minimize the cost of electricity generated.

  2. 2. LOOKING DOWN THE LINED POWER CANAL AS IT WINDS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. LOOKING DOWN THE LINED POWER CANAL AS IT WINDS ITS WAY TOWARD THE CEMENT MILL Photographer: Walter J. Lubken, November 19, 1907 - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ

  3. 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.

  4. Wind Power Forecasting Error Distributions: An International Comparison; Preprint

    SciTech Connect

    Hodge, B. M.; Lew, D.; Milligan, M.; Holttinen, H.; Sillanpaa, S.; Gomez-Lazaro, E.; Scharff, R.; Soder, L.; Larsen, X. G.; Giebel, G.; Flynn, D.; Dobschinski, J.

    2012-09-01

    Wind power forecasting is expected to be an important enabler for greater penetration of wind power into electricity systems. Because no wind forecasting system is perfect, a thorough understanding of the errors that do occur can be critical to system operation functions, such as the setting of operating reserve levels. This paper provides an international comparison of the distribution of wind power forecasting errors from operational systems, based on real forecast data. The paper concludes with an assessment of similarities and differences between the errors observed in different locations.

  5. System-wide emissions implications of increased wind power penetration.

    PubMed

    Valentino, Lauren; Valenzuela, Viviana; Botterud, Audun; Zhou, Zhi; Conzelmann, Guenter

    2012-04-03

    This paper discusses the environmental effects of incorporating wind energy into the electric power system. We present a detailed emissions analysis based on comprehensive modeling of power system operations with unit commitment and economic dispatch for different wind penetration levels. First, by minimizing cost, the unit commitment model decides which thermal power plants will be utilized based on a wind power forecast, and then, the economic dispatch model dictates the level of production for each unit as a function of the realized wind power generation. Finally, knowing the power production from each power plant, the emissions are calculated. The emissions model incorporates the effects of both cycling and start-ups of thermal power plants in analyzing emissions from an electric power system with increasing levels of wind power. Our results for the power system in the state of Illinois show significant emissions effects from increased cycling and particularly start-ups of thermal power plants. However, we conclude that as the wind power penetration increases, pollutant emissions decrease overall due to the replacement of fossil fuels.

  6. System-wide emissions implications of increased wind power penetration.

    SciTech Connect

    Valentino, L.; Valenzuela, V.; Botterud, A.; Zhou, Z.; Conzelmann, G.

    2012-01-01

    This paper discusses the environmental effects of incorporating wind energy into the electric power system. We present a detailed emissions analysis based on comprehensive modeling of power system operations with unit commitment and economic dispatch for different wind penetration levels. First, by minimizing cost, the unit commitment model decides which thermal power plants will be utilized based on a wind power forecast, and then, the economic dispatch model dictates the level of production for each unit as a function of the realized wind power generation. Finally, knowing the power production from each power plant, the emissions are calculated. The emissions model incorporates the effects of both cycling and start-ups of thermal power plants in analyzing emissions from an electric power system with increasing levels of wind power. Our results for the power system in the state of Illinois show significant emissions effects from increased cycling and particularly start-ups of thermal power plants. However, we conclude that as the wind power penetration increases, pollutant emissions decrease overall due to the replacement of fossil fuels.

  7. A nonlinear dynamics approach for incorporating wind-speed patterns into wind-power project evaluation.

    PubMed

    Huffaker, Ray; Bittelli, Marco

    2015-01-01

    Wind-energy production may be expanded beyond regions with high-average wind speeds (such as the Midwest U.S.A.) to sites with lower-average speeds (such as the Southeast U.S.A.) by locating favorable regional matches between natural wind-speed and energy-demand patterns. A critical component of wind-power evaluation is to incorporate wind-speed dynamics reflecting documented diurnal and seasonal behavioral patterns. Conventional probabilistic approaches remove patterns from wind-speed data. These patterns must be restored synthetically before they can be matched with energy-demand patterns. How to accurately restore wind-speed patterns is a vexing problem spurring an expanding line of papers. We propose a paradigm shift in wind power evaluation that employs signal-detection and nonlinear-dynamics techniques to empirically diagnose whether synthetic pattern restoration can be avoided altogether. If the complex behavior of observed wind-speed records is due to nonlinear, low-dimensional, and deterministic system dynamics, then nonlinear dynamics techniques can reconstruct wind-speed dynamics from observed wind-speed data without recourse to conventional probabilistic approaches. In the first study of its kind, we test a nonlinear dynamics approach in an application to Sugarland Wind-the first utility-scale wind project proposed in Florida, USA. We find empirical evidence of a low-dimensional and nonlinear wind-speed attractor characterized by strong temporal patterns that match up well with regular daily and seasonal electricity demand patterns.

  8. Wind Turbine Generator System Power Performance Test Report for the ARE442 Wind Turbine

    SciTech Connect

    van Dam, J.; Jager, D.

    2010-02-01

    This report summarizes the results of a power performance test that NREL conducted on the ARE 442 wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 12: Power Performance Measurements of Electricity Producing Wind Turbines, IEC 61400-12-1 Ed.1.0, 2005-12. However, because the ARE 442 is a small turbine as defined by IEC, NREL also followed Annex H that applies to small wind turbines. In these summary results, wind speed is normalized to sea-level air density.

  9. Cold dark matter: Controversies on small scales.

    PubMed

    Weinberg, David H; Bullock, James S; Governato, Fabio; Kuzio de Naray, Rachel; Peter, Annika H G

    2015-10-06

    The cold dark matter (CDM) cosmological model has been remarkably successful in explaining cosmic structure over an enormous span of redshift, but it has faced persistent challenges from observations that probe the innermost regions of dark matter halos and the properties of the Milky Way's dwarf galaxy satellites. We review the current observational and theoretical status of these "small-scale controversies." Cosmological simulations that incorporate only gravity and collisionless CDM predict halos with abundant substructure and central densities that are too high to match constraints from galaxy dynamics. The solution could lie in baryonic physics: Recent numerical simulations and analytical models suggest that gravitational potential fluctuations tied to efficient supernova feedback can flatten the central cusps of halos in massive galaxies, and a combination of feedback and low star formation efficiency could explain why most of the dark matter subhalos orbiting the Milky Way do not host visible galaxies. However, it is not clear that this solution can work in the lowest mass galaxies, where discrepancies are observed. Alternatively, the small-scale conflicts could be evidence of more complex physics in the dark sector itself. For example, elastic scattering from strong dark matter self-interactions can alter predicted halo mass profiles, leading to good agreement with observations across a wide range of galaxy mass. Gravitational lensing and dynamical perturbations of tidal streams in the stellar halo provide evidence for an abundant population of low-mass subhalos in accord with CDM predictions. These observational approaches will get more powerful over the next few years.

  10. Cold dark matter: Controversies on small scales

    PubMed Central

    Weinberg, David H.; Bullock, James S.; Governato, Fabio; Kuzio de Naray, Rachel; Peter, Annika H. G.

    2015-01-01

    The cold dark matter (CDM) cosmological model has been remarkably successful in explaining cosmic structure over an enormous span of redshift, but it has faced persistent challenges from observations that probe the innermost regions of dark matter halos and the properties of the Milky Way’s dwarf galaxy satellites. We review the current observational and theoretical status of these “small-scale controversies.” Cosmological simulations that incorporate only gravity and collisionless CDM predict halos with abundant substructure and central densities that are too high to match constraints from galaxy dynamics. The solution could lie in baryonic physics: Recent numerical simulations and analytical models suggest that gravitational potential fluctuations tied to efficient supernova feedback can flatten the central cusps of halos in massive galaxies, and a combination of feedback and low star formation efficiency could explain why most of the dark matter subhalos orbiting the Milky Way do not host visible galaxies. However, it is not clear that this solution can work in the lowest mass galaxies, where discrepancies are observed. Alternatively, the small-scale conflicts could be evidence of more complex physics in the dark sector itself. For example, elastic scattering from strong dark matter self-interactions can alter predicted halo mass profiles, leading to good agreement with observations across a wide range of galaxy mass. Gravitational lensing and dynamical perturbations of tidal streams in the stellar halo provide evidence for an abundant population of low-mass subhalos in accord with CDM predictions. These observational approaches will get more powerful over the next few years. PMID:25646464

  11. Quantifying the hurricane catastrophe risk to offshore wind power.

    PubMed

    Rose, Stephen; Jaramillo, Paulina; Small, Mitchell J; Apt, Jay

    2013-12-01

    The U.S. Department of Energy has estimated that over 50 GW of offshore wind power will be required for the United States to generate 20% of its electricity from wind. Developers are actively planning offshore wind farms along the U.S. Atlantic and Gulf coasts and several leases have been signed for offshore sites. These planned projects are in areas that are sometimes struck by hurricanes. We present a method to estimate the catastrophe risk to offshore wind power using simulated hurricanes. Using this method, we estimate the fraction of offshore wind power simultaneously offline and the cumulative damage in a region. In Texas, the most vulnerable region we studied, 10% of offshore wind power could be offline simultaneously because of hurricane damage with a 100-year return period and 6% could be destroyed in any 10-year period. We also estimate the risks to single wind farms in four representative locations; we find the risks are significant but lower than those estimated in previously published results. Much of the hurricane risk to offshore wind turbines can be mitigated by designing turbines for higher maximum wind speeds, ensuring that turbine nacelles can turn quickly to track the wind direction even when grid power is lost, and building in areas with lower risk.

  12. Modeling the Benefits of Storage Technologies to Wind Power

    SciTech Connect

    Sullivan, P.; Short, W.; Blair, N.

    2008-06-01

    Rapid expansion of wind power in the electricity sector is raising questions about how wind resource variability might affect the capacity value of wind farms at high levels of penetration. Electricity storage, with the capability to shift wind energy from periods of low demand to peak times and to smooth fluctuations in output, may have a role in bolstering the value of wind power at levels of penetration envisioned by a new Department of Energy report ('20% Wind by 2030, Increasing Wind Energy's Contribution to U.S. Electricity Supply'). This paper quantifies the value storage can add to wind. The analysis was done employing the Regional Energy Deployment System (ReEDS) model, formerly known as the Wind Deployment System (WinDS) model. ReEDS was used to estimate the cost and development path associated with 20% penetration of wind in the report. ReEDS differs from the WinDS model primarily in that the model has been modified to include the capability to build and use three storage technologies: pumped-hydroelectric storage (PHS), compressed-air energy storage (CAES), and batteries. To assess the value of these storage technologies, two pairs of scenarios were run: business-as-usual, with and without storage; 20% wind energy by 2030, with and without storage. This paper presents the results from those model runs.

  13. Wind Energy: A Maturing Power Supply Possibility.

    ERIC Educational Resources Information Center

    Petersen, Erik Lundtang; And Others

    1987-01-01

    Suggests that wind energy for electrification will prove to be an appropriate technology with very positive socioeconomic benefits, especially in developing countries. Provides examples of projects conducted by a Danish wind research laboratory. (TW)

  14. Hoopa Valley Small Scale Hydroelectric Feasibility Project

    SciTech Connect

    Curtis Miller

    2009-03-22

    This study considered assessing the feasibility of developing small scale hydro-electric power from seven major tributaries within the Hoopa Valley Indian Reservation of Northern California (http://www.hoopa-nsn.gov/). This study pursued the assessment of seven major tributaries of the Reservation that flow into the Trinity River. The feasibility of hydropower on the Hoopa Valley Indian Reservation has real potential for development and many alternative options for project locations, designs, operations and financing. In order to realize this opportunity further will require at least 2-3 years of intense data collection focusing on stream flow measurements at multiple locations in order to quantify real power potential. This also includes on the ground stream gradient surveys, road access planning and grid connectivity to PG&E for sale of electricity. Imperative to this effort is the need for negotiations between the Hoopa Tribal Council and PG&E to take place in order to finalize the power rate the Tribe will receive through any wholesale agreement that utilizes the alternative energy generated on the Reservation.

  15. Power control and management of the grid containing largescale wind power systems

    NASA Astrophysics Data System (ADS)

    Aula, Fadhil Toufick

    The ever increasing demand for electricity has driven many countries toward the installation of new generation facilities. However, concerns such as environmental pollution and global warming issues, clean energy sources, high costs associated with installation of new conventional power plants, and fossil fuels depletion have created many interests in finding alternatives to conventional fossil fuels for generating electricity. Wind energy is one of the most rapidly growing renewable power sources and wind power generations have been increasingly demanded as an alternative to the conventional fossil fuels. However, wind power fluctuates due to variation of wind speed. Therefore, large-scale integration of wind energy conversion systems is a threat to the stability and reliability of utility grids containing these systems. They disturb the balance between power generation and consumption, affect the quality of the electricity, and complicate load sharing and load distribution managing and planning. Overall, wind power systems do not help in providing any services such as operating and regulating reserves to the power grid. In order to resolve these issues, research has been conducted in utilizing weather forecasting data to improve the performance of the wind power system, reduce the influence of the fluctuations, and plan power management of the grid containing large-scale wind power systems which consist of doubly-fed induction generator based energy conversion system. The aims of this research, my dissertation, are to provide new methods for: smoothing the output power of the wind power systems and reducing the influence of their fluctuations, power managing and planning of a grid containing these systems and other conventional power plants, and providing a new structure of implementing of latest microprocessor technology for controlling and managing the operation of the wind power system. In this research, in order to reduce and smooth the fluctuations, two

  16. NREL's Wind Powering America Team Helps Indiana Develop Wind Resources (Fact Sheet)

    SciTech Connect

    Not Available

    2010-10-01

    How does a state advance, in just five years, from having no installed wind capacity to having more than 1000 megawatts (MW) of installed capacity? The Wind Powering America (WPA) initiative, based at the National Renewable Energy Laboratory (NREL), employs a state-focused approach that has helped accelerate wind energy deployment in many states. One such state is Indiana, which is now home to the largest wind plant east of the Mississippi.

  17. Equilibrium pricing in electricity markets with wind power

    NASA Astrophysics Data System (ADS)

    Rubin, Ofir David

    Estimates from the World Wind Energy Association assert that world total wind power installed capacity climbed from 18 Gigawatt (GW) to 152 GW from 2000 to 2009. Moreover, according to their predictions, by the end of 2010 global wind power capacity will reach 190 GW. Since electricity is a unique commodity, this remarkable expansion brings forward several key economic questions regarding the integration of significant amount of wind power capacity into deregulated electricity markets. The overall dissertation objective is to develop a comprehensive theoretical framework that enables the modeling of the performance and outcome of wind-integrated electricity markets. This is relevant because the state of knowledge of modeling electricity markets is insufficient for the purpose of wind power considerations. First, there is a need to decide about a consistent representation of deregulated electricity markets. Surprisingly, the related body of literature does not agree on the very economic basics of modeling electricity markets. That is important since we need to capture the fundamentals of electricity markets before we introduce wind power to our study. For example, the structure of the electric industry is a key. If market power is present, the integration of wind power has large consequences on welfare distribution. Since wind power uncertainty changes the dynamics of information it also impacts the ability to manipulate market prices. This is because the quantity supplied by wind energy is not a decision variable. Second, the intermittent spatial nature of wind over a geographical region is important because the market value of wind power capacity is derived from its statistical properties. Once integrated into the market, the distribution of wind will impact the price of electricity produced from conventional sources of energy. Third, although wind power forecasting has improved in recent years, at the time of trading short-term electricity forwards, forecasting

  18. Electric power from offshore wind via synoptic-scale interconnection

    PubMed Central

    Kempton, Willett; Pimenta, Felipe M.; Veron, Dana E.; Colle, Brian A.

    2010-01-01

    World wind power resources are abundant, but their utilization could be limited because wind fluctuates rather than providing steady power. We hypothesize that wind power output could be stabilized if wind generators were located in a meteorologically designed configuration and electrically connected. Based on 5 yr of wind data from 11 meteorological stations, distributed over a 2,500 km extent along the U.S. East Coast, power output for each hour at each site is calculated. Each individual wind power generation site exhibits the expected power ups and downs. But when we simulate a power line connecting them, called here the Atlantic Transmission Grid, the output from the entire set of generators rarely reaches either low or full power, and power changes slowly. Notably, during the 5-yr study period, the amount of power shifted up and down but never stopped. This finding is explained by examining in detail the high and low output periods, using reanalysis data to show the weather phenomena responsible for steady production and for the occasional periods of low power. We conclude with suggested institutions appropriate to create and manage the power system analyzed here. PMID:20368464

  19. Electric power from offshore wind via synoptic-scale interconnection.

    PubMed

    Kempton, Willett; Pimenta, Felipe M; Veron, Dana E; Colle, Brian A

    2010-04-20

    World wind power resources are abundant, but their utilization could be limited because wind fluctuates rather than providing steady power. We hypothesize that wind power output could be stabilized if wind generators were located in a meteorologically designed configuration and electrically connected. Based on 5 yr of wind data from 11 meteorological stations, distributed over a 2,500 km extent along the U.S. East Coast, power output for each hour at each site is calculated. Each individual wind power generation site exhibits the expected power ups and downs. But when we simulate a power line connecting them, called here the Atlantic Transmission Grid, the output from the entire set of generators rarely reaches either low or full power, and power changes slowly. Notably, during the 5-yr study period, the amount of power shifted up and down but never stopped. This finding is explained by examining in detail the high and low output periods, using reanalysis data to show the weather phenomena responsible for steady production and for the occasional periods of low power. We conclude with suggested institutions appropriate to create and manage the power system analyzed here.

  20. Offshore wind speed and wind power characteristics for ten locations in Aegean and Ionian Seas

    NASA Astrophysics Data System (ADS)

    Bagiorgas, Haralambos S.; Mihalakakou, Giouli; Rehman, Shafiqur; Al-Hadhrami, Luai M.

    2012-08-01

    This paper utilizes wind speed data measured at 3 and 10 m above water surface level using buoys at 10 stations in Ionian and Aegean Seas to understand the behaviour of wind and thereafter energy yield at these stations using 5 MW rated power offshore wind turbine. With wind power densities of 971 and 693 W/m2 at 50 m above water surface level, Mykonos and Lesvos were found to be superb and outstanding windy sites with wind class of 7 and 6, respectively. Other locations like Athos, Santorini and Skyros with wind power density of more than 530 W/m2 and wind class of 5 were found to be the excellent sites. Around 15-16% higher winds were observed at 10 m compared to that at 3 m. Lower values of wind speed were found during summer months and higher during winter time in most of the cases reported in the present work. Slightly decreasing (~2% per year) linear trends were observed in annual mean wind speed at Lesvos and Santorini. These trends need to be verified with more data from buoys or from nearby onshore meteorological stations. At Athos and Mykonos, increasing linear trends were estimated. At all the stations the chosen wind turbine could produce energy for more than 70% of the time. The wind speed distribution was found to be well represented by Weibull parameters obtained using Maximum likelihood method compared to WAsP and Method of Moments.

  1. System frequency support of permanent magnet synchronous generator-based wind power plant

    NASA Astrophysics Data System (ADS)

    Wu, Ziping

    on rotor speed control. The proposed control scheme is achieved through the coordinated control between rotor speed and modified pitch angle in accordance with different specified wind speed modes. Fourth, an improved inertial control method based on the maximum power point tracking operation curve is introduced to boost the overall frequency support capability of PMSG-WTGs based on rotor speed control. Fifth, a novel control method based on the torque limit (TLC) is proposed for the purpose of maximizing the wind turbine (WT)'s inertial response. To avoid the SFD caused by the deloaded operation of WT, a small-scale battery energy storage system (BESS) model is established and implemented to eliminate this impact and meanwhile assist the restoration of wind turbine to MPPT mode by means of coordinated control strategy between BESS and PMSG-WTG. Last but not the least, all three types of control strategies are implemented in the CART2-PMSG integrated model based on rotor speed control or active power control respectively to evaluate their impacts on the wind turbine's structural loads during the frequency regulation process. Simulation results demonstrate that all the proposed methods can enhance the overall frequency regulation performance while imposing very slight negative impact on the major mechanical components of the wind turbine.

  2. The Great Plains Wind Power Test Facility

    SciTech Connect

    Schroeder, John

    2014-01-30

    This multi-year, multi-faceted project was focused on the continued development of a nationally-recognized facility for the testing, characterization, and improvement of grid-connected wind turbines, integrated wind-water desalination systems, and related educational and outreach topics. The project involved numerous faculty and graduate students from various engineering departments, as well as others from the departments of Geosciences (in particular the Atmospheric Science Group) and Economics. It was organized through the National Wind Institute (NWI), which serves as an intellectual hub for interdisciplinary and transdisciplinary research, commercialization and education related to wind science, wind energy, wind engineering and wind hazard mitigation at Texas Tech University (TTU). Largely executed by an academic based team, the project resulted in approximately 38 peer-reviewed publications, 99 conference presentations, the development/expansion of several experimental facilities, and two provisional patents.

  3. Estimating maximum global wind power availability and associated climatic consequences

    NASA Astrophysics Data System (ADS)

    Miller, Lee; Gans, Fabian; Kleidon, Axel

    2010-05-01

    Estimating maximum global wind power availability and associated climatic consequences Wind speed reflects the continuous generation of kinetic energy and its dissipation, primarily in the atmospheric boundary layer. When wind turbines extract kinetic wind energy, less kinetic energy remains in the atmosphere in the mean state. While this effect does not play a significant role for a single turbine, it becomes a critical factor for the estimation of large-scale wind power availability. This extraction of kinetic energy by turbines also competes with the natural processes of kinetic energy dissipation, thus setting fundamental limits on extractability that are not considered in previous large-scale studies [1,2,3]. Our simple momentum balance model using ECMWF climate data illustrates a fundamental limit to global wind power extractability and thereby electricity potential (93TW). This is independent of engineering advances in turbine design and wind farm layout. These results are supported by similar results using a global climate model of intermediate complexity. Varying the surface drag coefficient with different simulations allows us to directly relate changes in atmospheric and boundary layer dissipation with resulting climate indices and wind power potential. These new estimates of the maximum power generation by wind turbines are well above the currently installed capacity. Hence, present day installations are unlikely to have a global impact. However, when compared to the current human energy demand of 17TW combined with plans by the US and EU to drastically increase onshore and offshore wind turbine installations [4,5,6], understanding the climatic response and ultimate limitations of wind power as a large-scale renewable energy source is critical. [1] Archer, C., and M.Z. Jacobson, (2005) Evaluation of global wind power, J. Geophys. Res. 110:D12110. [2] Lu, X., M.B. McElroy, and J. Kiviluoma, (2009) Global potential for wind-generated electricity, Proc

  4. Small-scale gradients of charged particles in the heliospheric magnetic field

    SciTech Connect

    Guo, Fan; Giacalone, Joe

    2014-01-01

    Using numerical simulations of charged-particles propagating in the heliospheric magnetic field, we study small-scale gradients, or 'dropouts,' in the intensity of solar energetic particles seen at 1 AU. We use two turbulence models, the foot-point random motion model and the two-component model, to generate fluctuating magnetic fields similar to spacecraft observations at 1 AU. The turbulence models include a Kolmogorov-like magnetic field power spectrum containing a broad range of spatial scales from those that lead to large-scale field-line random walk to small scales leading to resonant pitch-angle scattering of energetic particles. We release energetic protons (20 keV-10 MeV) from a spatially compact and instantaneous source. The trajectories of energetic charged particles in turbulent magnetic fields are numerically integrated. Spacecraft observations are mimicked by collecting particles in small windows when they pass the windows at a distance of 1 AU. We show that small-scale gradients in the intensity of energetic particles and velocity dispersions observed by spacecraft can be reproduced using the foot-point random motion model. However, no dropouts are seen in simulations using the two-component magnetic turbulence model. We also show that particle scattering in the solar wind magnetic field needs to be infrequent for intensity dropouts to form.

  5. Small scale structure on cosmic strings

    NASA Technical Reports Server (NTRS)

    Albrecht, Andreas

    1989-01-01

    The current understanding of cosmic string evolution is discussed, and the focus placed on the question of small scale structure on strings, where most of the disagreements lie. A physical picture designed to put the role of the small scale structure into more intuitive terms is presented. In this picture it can be seen how the small scale structure can feed back in a major way on the overall scaling solution. It is also argued that it is easy for small scale numerical errors to feed back in just such a way. The intuitive discussion presented here may form the basis for an analytic treatment of the small scale structure, which argued in any case would be extremely valuable in filling the gaps in the present understanding of cosmic string evolution.

  6. Control voltage and power fluctuations when connecting wind farms

    NASA Astrophysics Data System (ADS)

    Berinde, Ioan; Bǎlan, Horia; Oros Pop, Teodora Susana

    2015-12-01

    Voltage, frequency, active power and reactive power are very important parameters in terms of power quality. These parameters are followed when connecting any power plant, the more the connection of wind farms. Connecting wind farms to the electricity system must not cause interference outside the limits set by regulations. Modern solutions for fast and automatic voltage control and power fluctuations using electronic control systems of reactive power flows. FACTS (Flexible Alternating Current Transmision System) systems, established on the basis of power electronic circuits ensure control of electrical status quantities to achieve the necessary transfer of power to the power grid. FACTS devices can quickly control parameters and sizes of state power lines, such as impedance line voltages and phase angles of the voltages of the two ends of the line. Their use can lead to improvement in power system operation by increasing the transmission capacity of power lines, power flow control lines, improved static and transient stability reserve.

  7. Control voltage and power fluctuations when connecting wind farms

    SciTech Connect

    Berinde, Ioan Bălan, Horia Oros, Teodora Susana

    2015-12-23

    Voltage, frequency, active power and reactive power are very important parameters in terms of power quality. These parameters are followed when connecting any power plant, the more the connection of wind farms. Connecting wind farms to the electricity system must not cause interference outside the limits set by regulations. Modern solutions for fast and automatic voltage control and power fluctuations using electronic control systems of reactive power flows. FACTS (Flexible Alternating Current Transmision System) systems, established on the basis of power electronic circuits ensure control of electrical status quantities to achieve the necessary transfer of power to the power grid. FACTS devices can quickly control parameters and sizes of state power lines, such as impedance line voltages and phase angles of the voltages of the two ends of the line. Their use can lead to improvement in power system operation by increasing the transmission capacity of power lines, power flow control lines, improved static and transient stability reserve.

  8. COE projection for the modular WARP{trademark} wind power system for wind farms and electric utility power transmission

    SciTech Connect

    Weisbrich, A.L.; Ostrow, S.L.; Padalino, J.

    1995-09-01

    Wind power has emerged as an attractive alternative source of electricity for utilities. Turbine operating experience from wind farms has provided corroborating data of wind power potential for electric utility application. Now, a patented modular wind power technology, the Toroidal Accelerator Rotor Platform (TARP{trademark}) Windframe{trademark}, forms the basis for next generation megawatt scale wind farm and/or distributed wind power plants. When arranged in tall vertically clustered TARP{trademark} module stacks, such power plant units are designated Wind Amplified Rotor Platform (WARP{trademark}) Systems. While heavily building on proven technology, these systems are projected to surpass current technology windmills in terms of performance, user-friendly operation and ease of maintenance. In its unique generation and transmission configuration, the WARP{trademark}-GT System combines both electricity generation through wind energy conversion and electric power transmission. Furthermore, environmental benefits include dramatically less land requirement, architectural appearance, lower noise and EMI/TV interference, and virtual elimination of bird mortality potential. Cost-of-energy (COE) is projected to be from under $0.02/kWh to less than $0.05/kWh in good to moderate wind resource sites.

  9. Design and implementation of power system stabilizers in wind plants

    NASA Astrophysics Data System (ADS)

    Martinez, Carlos

    Wind energy, increasing its share in the generation mix, is intended to replace fossil fuel plants in order to reduce green house gas emissions. However, the replacement of conventional synchronous units by wind generators reduces the number of online Power Systems Stabilizers (PSS) and may therefore deteriorate the damping of critical swing modes, leading to a reduction of the power transfer capacity in transmission corridors. Several reports indicate that angular instability, due to insufficient damping and inadequate tuning or disabling of power system stabilizers, is one of the major events that lead and/or contributed to wide area blackouts. Variable speed wind turbine generators are capable of fast decoupled real and reactive power control. A damping torque can be generated by modulating a fraction of the real and reactive power output of the wind farm. Supplementary active and reactive power control loops are designed and integrated in the wind turbine controls. Operating limits are added to restrict the kinetic energy exchange of the supplementary control loop within a specified turbine speed. An analytical method is developed in order to assess the effectiveness of real and reactive power modulation in damping inter-area oscillations and to justify the use and commissioning of wind based PSS. A wide area measurement based power system stabilizer suitable for wind farms is designed and integrated in the global and local controls of wind turbines. Feedback signals are selected based on an observability index of the selected mode(s). The proposed stabilizer transfer function is derived via a constrained Hinfinity optimization. The controller is tested in time domain simulations using a two area four generators benchmark suffering from interarea oscillatory mode within the range of 0.4-0.6Hz. Testing scenarios show the resiliency and effectiveness of the wind based PSS in damping angular oscillations and stabilizing the power system. The damping contribution

  10. Return time statistic of wind power ramp events

    NASA Astrophysics Data System (ADS)

    Calif, Rudy; Schmitt, François G.

    2015-04-01

    Detection and forecasting of wind power ramp events is a critical issue for the management of power generated by wind turbine and a cluster of wind turbines. The wind power ramp events occur suddenly with larges changes (increases or decreases) of wind power output. In this work, the statistic and the dynamic of wind power ramp events are examined. For that, we analyze several datasets of wind power output with different sampling rate and duration. The data considered are delivered by five wind farms and two single turbines, located at different geographic locations. From these datasets, the return time series τr of wind power ramp events, i.e., the time between two successive ramps above a given threshold Δ p. The return time statistic is investigated plotting the complementary cumulative distribution C(τ_r) in log-log representation. Using a robust method developed by Clauset et al., combining maximum-likelihood fitting methods with goodness-of-fit tests based on the Kolmogorov Smirnov statistic, we show a scaling behavior of the return time statistic, of the form: C(τ_r)˜ kτ_r-α where k is a positive constant and the exponent α called the tail exponent of the distribution. In this study, the value of α ranges from 1.68 to 2.20. This result is a potential information for the estimation risk of wind power generation based on the return time series. Clauset A, Shalizi CR, Newman MEJ. Power-Law distributions in empirical data. SIAM Review 2009;51(4):661-703.

  11. A model to predict the power output from wind farms

    SciTech Connect

    Landberg, L.

    1997-12-31

    This paper will describe a model that can predict the power output from wind farms. To give examples of input the model is applied to a wind farm in Texas. The predictions are generated from forecasts from the NGM model of NCEP. These predictions are made valid at individual sites (wind farms) by applying a matrix calculated by the sub-models of WASP (Wind Atlas Application and Analysis Program). The actual wind farm production is calculated using the Riso PARK model. Because of the preliminary nature of the results, they will not be given. However, similar results from Europe will be given.

  12. Comparison of Wind Power and Load Forecasting Error Distributions: Preprint

    SciTech Connect

    Hodge, B. M.; Florita, A.; Orwig, K.; Lew, D.; Milligan, M.

    2012-07-01

    The introduction of large amounts of variable and uncertain power sources, such as wind power, into the electricity grid presents a number of challenges for system operations. One issue involves the uncertainty associated with scheduling power that wind will supply in future timeframes. However, this is not an entirely new challenge; load is also variable and uncertain, and is strongly influenced by weather patterns. In this work we make a comparison between the day-ahead forecasting errors encountered in wind power forecasting and load forecasting. The study examines the distribution of errors from operational forecasting systems in two different Independent System Operator (ISO) regions for both wind power and load forecasts at the day-ahead timeframe. The day-ahead timescale is critical in power system operations because it serves the unit commitment function for slow-starting conventional generators.

  13. On the causes of spectral enhancements in solar wind power spectra

    NASA Technical Reports Server (NTRS)

    Unti, T.; Russell, C. T.

    1976-01-01

    Enhancements in power spectra of the solar-wind ion flux in the frequency neighborhood of 0.5 Hz had been noted by Unti et al. (1973). It was speculated that these were due to convected small-scale density irregularities. In this paper, 54 flux spectra calculated from OGO 5 data are examined. It is seen that the few prominent spectral peaks which occur were not generated by density irregularities, but were due to several different causes, including convected discontinuities and propagating transverse waves. A superposition of many spectra, however, reveals a moderate enhancement at a frequency corresponding to convected features with a correlation length of a proton gyroradius, consistent with the results of Neugebauer (1975).

  14. Optimization of Power Coefficient of Wind Turbine Using Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Rajakumar, Sappani; Ravindran, Durairaj; Sivakumar, Mahalingam; Venkatachalam, Gopalan; Muthukumar, Shunmugavelu

    2016-06-01

    In the design of a wind turbine, the goal is to attain the highest possible power output under specified atmospheric conditions. The optimization of power coefficient of horizontal axis wind turbine has been carried out by integration of blade element momentum method and genetic algorithm (GA). The design variables considered are wind velocity, angle of attack and tip speed ratio. The objective function is power coefficient of wind turbine. The different combination of design variables are optimized using GA and then the Power coefficient is optimized. The optimized design variables are validated with the experimental results available in the literature. By this optimization work the optimum design variables of wind turbine can be found economically than experimental work. NACA44XX series airfoils are considered for this optimization work.

  15. Fundamental economic issues in the development of small scale hydro

    SciTech Connect

    Not Available

    1980-05-01

    Some basic economic issues involved in the development of small-scale hydroelectric power are addressed. The discussion represents an economist's view of the investment process in this resource. Very little investment has been made in small-scale hydro development and an attempt is made to show that the reason for this may not be that the expected present worth of the returns of the project do not exceed the construction cost by a sufficient amount. Rather, a set of factors in combination impose costs on the project not normally incurred in small businesses. The discussion covers costs, supply, demand, and profitability.

  16. WPA Omnibus Award MT Wind Power Outreach

    SciTech Connect

    Brian Spangler, Manager Energy Planning and Renewables

    2012-01-30

    The objective of this grant was to further the development of Montana's vast wind resources for small, medium, and large scale benefits to Montana and the nation. This was accomplished through collaborative work with wind industry representatives, state and local governments, the agricultural community, and interested citizens. Through these efforts MT Dept Environmental Quality (DEQ) was able to identify development barriers, educate and inform citizens, as well as to participate in regional and national dialogue that will spur the development of wind resources. The scope of DEQ's wind outreach effort evolved over the course of this agreement from the development of the Montana Wind Working Group and traditional outreach efforts, to the current focus on working with the state's university system to deliver a workforce trained to enter the wind industry.

  17. Variable-Speed Wind Power Plant Operating With Reserve Power Capability: Preprint

    SciTech Connect

    Singh, M.; Gevorgian, V.; Muljadi, E.; Ela, E.

    2013-10-01

    As the level of wind penetration increases, wind turbine technology must move from merely generating power from wind to taking a role in supporting the bulk power system. Wind turbines should have the capability to provide inertial response and primary frequency (governor) response. Wind turbine generators with this capability can support the frequency stability of the grid. To provide governorresponse, wind turbines should be able to generate less power than the available wind power and hold the rest in reserves, ready to be accessed as needed. In this paper, we explore several ways to control wind turbine output to enable reserve-holding capability. The focus of this paper is on doubly-fed induction generator (also known as Type 3) and full-converter (also known as Type 4) windturbines.

  18. Wind energy can power a strong recovery.

    PubMed

    Bode, Denise

    2009-01-01

    The U.S. wind industry is a dynamic one that pumps billions of dollars into our economy each year. Wind has gone mainstream and today is the most affordable near-term carbon-free energy source. The U.S. industry experienced a nearly 70 percent increase in total jobs last year-well-paying, family-supporting jobs. But new wind farms now find it hard to secure financing. Thus, the economic stimulus package moving through Congress is critical.

  19. Short-Term Wind Power Forecasts using Doppler Lidar

    NASA Astrophysics Data System (ADS)

    Magerman, Beth

    With a ground-based Doppler lidar on the upwind side of a wind farm in the Tehachapi Pass of California, radial wind velocity measurements were collected for repeating sector sweeps, scanning up to 10 kilometers away. This region consisted of complex terrain, with the scans made between mountains. The dataset was utilized for techniques being studied for short-term forecasting of wind power by correlating changes in energy content and of turbulence intensity by tracking spatial variance, in the wind ahead of a wind farm. A ramp event was also captured and its propagation was tracked. Orthogonal horizontal wind vectors were retrieved from the radial velocity using a sector Velocity Azimuth Display method. Streamlines were plotted to determine the potential sites for a correlation of upstream wind speed with wind speed at downstream locations near the wind farm. A "virtual wind turbine" was "placed" in locations along the streamline by using the time-series velocity data at the location as the input to a modeled wind turbine, to determine the extractable energy content at that location. The relationship between this time-dependent energy content upstream and near the wind farm was studied. By correlating the energy content with each upstream location based on a time shift estimated according to advection at the mean wind speed, several fits were evaluated. A prediction of the downstream energy content was produced by shifting the power output in time and applying the best-fit function. This method made predictions of the power near the wind farm several minutes in advance. Predictions were also made up to an hour in advance for a large ramp event. The Magnitude Absolute Error and Standard Deviation are presented for the predictions based on each selected upstream location.

  20. 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.

  1. The Role of Atmospheric Measurements in Wind Power Statistical Models

    NASA Astrophysics Data System (ADS)

    Wharton, S.; Bulaevskaya, V.; Irons, Z.; Newman, J. F.; Clifton, A.

    2015-12-01

    The simplest wind power generation curves model power only as a function of the wind speed at turbine hub-height. While the latter is an essential predictor of power output, it is widely accepted that wind speed information in other parts of the vertical profile, as well as additional atmospheric variables including atmospheric stability, wind veer, and hub-height turbulence are also important factors. The goal of this work is to determine the gain in predictive ability afforded by adding additional atmospheric measurements to the power prediction model. In particular, we are interested in quantifying any gain in predictive ability afforded by measurements taken from a laser detection and ranging (lidar) instrument, as lidar provides high spatial and temporal resolution measurements of wind speed and direction at 10 or more levels throughout the rotor-disk and at heights well above. Co-located lidar and meteorological tower data as well as SCADA power data from a wind farm in Northern Oklahoma will be used to train a set of statistical models. In practice, most wind farms continue to rely on atmospheric measurements taken from less expensive, in situ instruments mounted on meteorological towers to assess turbine power response to a changing atmospheric environment. Here, we compare a large suite of atmospheric variables derived from tower measurements to those taken from lidar to determine if remote sensing devices add any competitive advantage over tower measurements alone to predict turbine power response.

  2. Performance optimization for doubly fed wind power generation systems

    SciTech Connect

    Bhowmik, S.; Spee, R.; Enslin, J.H.R.

    1999-08-01

    Significant variation of the resource kinetic energy, in the form of wind speed, results in substantially reduced energy capture in a fixed-speed wind turbine. In order to increase the wind energy capture in the turbine, variable-speed generation (VSG) strategies have been proposed and implemented. However, that requires an expensive ac/ac power converter, which increases the capital investment significantly. Consequently, doubly fed systems have been proposed to reduce the size of the power converter and, thereby, the associated cost. Additionally, in doubly fed systems, as a fixed operating point (power and speed), power flow can be regulated between the two winding systems on the machine. This feature can by utilized to essentially minimize losses in the machine associated with the given operating point or achieve other desired performance enhancements. In this paper, a brushless doubly fed machine (BDFM) is utilized to develop a VSG wind power generator. The VSG controller employs a wind-speed-estimation-based maximum power point tracker and a heuristic-model-based maximum efficiency point tracker to optimize the power output of the system. The controller has been verified for efficacy on a 1.5-kW laboratory VSG wind generator. The strategy is applicable to all doubly fed configurations, including conventional wound-rotor induction machines, Scherbius cascades, BDFM's and doubly fed reluctance machines.

  3. A unified large/small-scale dynamo in helical turbulence

    NASA Astrophysics Data System (ADS)

    Bhat, Pallavi; Subramanian, Kandaswamy; Brandenburg, Axel

    2016-09-01

    We use high resolution direct numerical simulations (DNS) to show that helical turbulence can generate significant large-scale fields even in the presence of strong small-scale dynamo action. During the kinematic stage, the unified large/small-scale dynamo grows fields with a shape-invariant eigenfunction, with most power peaked at small scales or large k, as in Subramanian & Brandenburg. Nevertheless, the large-scale field can be clearly detected as an excess power at small k in the negatively polarized component of the energy spectrum for a forcing with positively polarized waves. Its strength overline{B}, relative to the total rms field Brms, decreases with increasing magnetic Reynolds number, ReM. However, as the Lorentz force becomes important, the field generated by the unified dynamo orders itself by saturating on successively larger scales. The magnetic integral scale for the positively polarized waves, characterizing the small-scale field, increases significantly from the kinematic stage to saturation. This implies that the small-scale field becomes as coherent as possible for a given forcing scale, which averts the ReM-dependent quenching of overline{B}/B_rms. These results are obtained for 10243 DNS with magnetic Prandtl numbers of PrM = 0.1 and 10. For PrM = 0.1, overline{B}/B_rms grows from about 0.04 to about 0.4 at saturation, aided in the final stages by helicity dissipation. For PrM = 10, overline{B}/B_rms grows from much less than 0.01 to values of the order the 0.2. Our results confirm that there is a unified large/small-scale dynamo in helical turbulence.

  4. Wind speed power spectrum analysis for Bushland, Texas

    SciTech Connect

    Eggleston, E.D.

    1996-12-31

    Numerous papers and publications on wind turbulence have referenced the wind speed spectrum presented by Isaac Van der Hoven in his article entitled Power Spectrum of Horizontal Wind Speed Spectrum in the Frequency Range from 0.0007 to 900 Cycles per Hour. Van der Hoven used data measured at different heights between 91 and 125 meters above the ground, and represented the high frequency end of the spectrum with data from the peak hour of hurricane Connie. These facts suggest we should question the use of his power spectrum in the wind industry. During the USDA - Agricultural Research Service`s investigation of wind/diesel system power storage, using the appropriate wind speed power spectrum became a significant issue. We developed a power spectrum from 13 years of hourly average data, 1 year of 5 minute average data, and 2 particularly gusty day`s 1 second average data all collected at a height of 10 meters. While the general shape is similar to the Van der Hoven spectrum, few of his peaks were found in the Bushland spectrum. While higher average wind speeds tend to suggest higher amplitudes in the high frequency end of the spectrum, this is not always true. Also, the high frequency end of the spectrum is not accurately described by simple wind statistics such as standard deviation and turbulence intensity. 2 refs., 5 figs., 1 tab.

  5. Method and system for small scale pumping

    DOEpatents

    Insepov, Zeke; Hassanein, Ahmed

    2010-01-26

    The present invention relates generally to the field of small scale pumping and, more specifically, to a method and system for very small scale pumping media through microtubes. One preferred embodiment of the invention generally comprises: method for small scale pumping, comprising the following steps: providing one or more media; providing one or more microtubes, the one or more tubes having a first end and a second end, wherein said first end of one or more tubes is in contact with the media; and creating surface waves on the tubes, wherein at least a portion of the media is pumped through the tube.

  6. Characterization of wind power resource and its intermittency

    NASA Astrophysics Data System (ADS)

    Gunturu, U. B.; Schlosser, C. A.

    2011-12-01

    Wind resource in the continental and offshore United States has been calculated and characterized using metrics that describe - apart from abundance - its availability, persistence and intermittency. The Modern Era Retrospective-Analysis for Research and Applications (MERRA) boundary layer flux data has been used to construct wind power density profiles at 50, 80, 100 and 120 m turbine hub heights. The wind power density estimates at 50 m are qualitatively similar to those in the US wind atlas developed by the National Renewable Energy Laboratory (NREL), but quantitatively a class less in some regions, but are within the limits of uncertainty. We also show that for long tailed distributions like those of the wind power density, the mean is an overestimation and median is a more robust metric for summary representation of wind power resource.Generally speaking, the largest and most available wind power density resources are found in off-shore regions of the Atlantic and Pacific coastline, and the largest on-shore resource potential lies in the central United States. However, the intermittency and widespread synchronicity of on-shore wind power density are substantial, and highlights areas where considerable back-up generation technologies will be required. Generation-duration curves are also presented for the independent systems operator (ISO) zones of the U.S. to highlight the regions with the largest capacity factor (MISO, ERCOT, and SWPP) as well as the periods and extent to which all ISOs contain no wind power and the potential benefits of aggregation on wind power intermittency in each region. The impact of raising the wind turbine hub height on metrics of abundance, persistence, variability and intermittency is analyzed. There is a general increase in availability and abundance of wind resource but there is also an increase in intermittency with respect to a 'usable wind power' crossing level in low resource regions. A similar perspective of wind resource for

  7. Final Scientific Report - Wind Powering America State Outreach Project

    SciTech Connect

    Sinclair, Mark; Margolis, Anne

    2012-02-01

    The goal of the Wind Powering America State Outreach Project was to facilitate the adoption of effective state legislation, policy, finance programs, and siting best practices to accelerate public acceptance and development of wind energy. This was accomplished by Clean Energy States Alliance (CESA) through provision of informational tools including reports and webinars as well as the provision of technical assistance to state leaders on wind siting, policy, and finance best practices, identification of strategic federal-state partnership activities for both onshore and offshore wind, and participation in regional wind development collaboratives. The Final Scientific Report - Wind Powering America State Outreach Project provides a summary of the objectives, activities, and outcomes of this project as accomplished by CESA over the period 12/1/2009 - 11/30/2011.

  8. Economical wind powered bioventing systems successfully applied at remote locations

    SciTech Connect

    Graves, D.; Klein, J.; Dillon, T. Jr.; Wilson, B.; Walker, K.

    1996-12-31

    Wind-powered bioventing systems were designed to operate at remote locations in the absence of electrical power. Laboratory measurements of soil respiration under bioventing conditions indicated the biodegradation of up to 25 mg of weathered diesel per kg of site soil per day. Further testing demonstrated the potential for harnessing wind-power to stimulate air movement through vadose zone soil. Several wind-powered bioventing systems were installed near Nome, Alaska. In situ respiration tests, soil gas composition measurements and measurable pressure changes in the soil indicated that the systems were capable of aerating the soil. Diesel range oil measurements indicated contaminant reductions up to 90% after only two treatments seasons. The results demonstrate the effectiveness of wind-powered biovents. The low cost, low maintenance, and simplicity of the biovents make them a very attractive treatment option for windy, remote sites with unsaturated soil impacted by biodegradable contaminants.

  9. Systems and methods for an integrated electrical sub-system powered by wind energy

    DOEpatents

    Liu, Yan; Garces, Luis Jose

    2008-06-24

    Various embodiments relate to systems and methods related to an integrated electrically-powered sub-system and wind power system including a wind power source, an electrically-powered sub-system coupled to and at least partially powered by the wind power source, the electrically-powered sub-system being coupled to the wind power source through power converters, and a supervisory controller coupled to the wind power source and the electrically-powered sub-system to monitor and manage the integrated electrically-powered sub-system and wind power system.

  10. Wind Power Technologies FY 2017 Budget At-A-Glance

    SciTech Connect

    None, None

    2016-03-01

    The Wind Program accelerates U.S. deployment of clean, affordable, and reliable domestic wind power through research, development, and demonstration activities. These advanced technology investments directly contribute to the goals for the United States to generate 80% of the nation’s electricity from clean, carbon-free energy sources by 2035; reduce carbon emissions 26%-28% below 2005 levels by 2025; and reduce carbon emissions 80% by 2050 by reducing costs and increasing performance of wind energy systems.

  11. Global assessment of high-altitude wind power

    NASA Astrophysics Data System (ADS)

    Archer, C. L.; Caldeira, K.

    2008-12-01

    Wind speed generally increases with altitude to the tropopause; hence, the power available in high-altitude winds is enormous, especially near the jet streams. We assess for the first time the available wind power resource worldwide at altitudes between 500 and 12,000 m. The highest wind power densities are found near 10,000 m over Japan and eastern China, the eastern coast of the United States, southern Australia, and north-eastern Africa. Below 1000 m, the best locations are the southern tip of South America, the coasts along the northern Pacific and Atlantic oceans, the central-eastern coast of Africa, and the north-eastern coast of South America. Because jet streams vary locally and seasonally, however, the high-altitude wind power resource is less steady than needed for baseload power. However, dynamically reaching the height with the highest winds, increasing the area covered with high-altitude devices, and using batteries for storage can effectively reduce intermittency. When high-altitude wind power devices are distributed uniformly throughout the entire atmosphere, numerical simulations show negligible effects on the global climate for low densities, but surface cooling, decreased precipitation, and greater sea ice cover for high densities.

  12. Wind power project siting workshop: emerging issues and technologies

    SciTech Connect

    anon.

    2004-12-01

    With wind power development extending more broadly across the various regions of the United States, and with new participants entering the wind development business, AWEA developed a workshop on the various ways in which wind power projects affect--and don't affect--elements of the human and natural environment. Over 180 people gathered in Portland, OR on October 13-14, 2004 to participate in a day and a half of presentations by 20 leading industry specialists. Their presentations covered emerging issues of project siting, such as bat interactions and wildlife survey techniques, and methods of generating local support for wind projects. Workshop topics included: Avian and Bat Research Updates; Wildlife Survey Technologies & Techniques; Technical Issues such as Noise, Aesthetics, and Lighting; National Environmental Policy Act (NEPA) Scenarios and Federal Land Policies; Tribal & Community Relations; Federal & State Permitting Process; and Bureau of Land Management Wind Power Developments.

  13. Small scale structure on cosmic strings

    SciTech Connect

    Albrecht, A.

    1989-10-30

    I discuss our current understanding of cosmic string evolution, and focus on the question of small scale structure on strings, where most of the disagreements lie. I present a physical picture designed to put the role of the small scale structure into more intuitive terms. In this picture one can see how the small scale structure can feed back in a major way on the overall scaling solution. I also argue that it is easy for small scale numerical errors to feed back in just such a way. The intuitive discussion presented here may form the basis for an analytic treatment of the small structure, which I argue in any case would be extremely valuable in filling the gaps in our resent understanding of cosmic string evolution. 24 refs., 8 figs.

  14. Wind Power in Ontario: Its Contribution to the Electricity Grid

    ERIC Educational Resources Information Center

    Rowlands, Ian H.; Jernigan, Carey

    2008-01-01

    The purpose of this article is to investigate wind turbine production, the variability of that production, and the relationship between output and system-wide demand. A review of the literature reveals that a variety of measures (and methods) to explore the variability of wind power production exist. Attention then turns to the province of Ontario…

  15. Understanding Inertial and Frequency Response of Wind Power Plants: Preprint

    SciTech Connect

    Muljadi, E.; Gevorgian, V.; Singh, M.; Santoso, S.

    2012-07-01

    The objective of this paper is to analyze and quantify the inertia and frequency responses of wind power plants with different wind turbine technologies (particularly those of fixed speed, variable slip with rotor-resistance controls, and variable speed with vector controls).

  16. Final Technical Report - Kotzebue Wind Power Project - Volume II

    SciTech Connect

    Rana Zucchi, Global Energy Concepts, LLC; Brad Reeve, Kotzebue Electric Association; DOE Project Officer - Doug Hooker

    2007-10-31

    The Kotzebue Wind Power Project is a joint undertaking of the U.S. Department of Energy (DOE); Kotzebue Electric Association (KEA); and the Alaska Energy Authority (AEA). The goal of the project is to develop, construct, and operate a wind power plant interconnected to a small isolated utility grid in an arctic climate in Northwest Alaska. The primary objective of KEA’s wind energy program is to bring more affordable electricity and jobs to remote Alaskan communities. DOE funding has allowed KEA to develop a multi-faceted approach to meet these objectives that includes wind project planning and development, technology transfer, and community outreach. The first wind turbines were installed in the summer of 1997 and the newest turbines were installed in the spring of 2007. The total installed capacity of the KEA wind power project is 1.16 MW with a total of 17 turbines rated between 65 kW and 100 kW. The operation of the wind power plant has resulted in a wind penetration on the utility system in excess of 35% during periods of low loads. This document and referenced attachments are presented as the final technical report for the U.S. Department of Energy (DOE) grant agreement DE-FG36-97GO10199. Interim deliverables previously submitted are also referenced within this document and where reasonable to do so, specific sections are incorporated in the report or attached as appendices.

  17. Proceedings of National Avian-Wind Power Planning Meeting IV

    SciTech Connect

    NWCC Avian Subcommittee

    2001-05-01

    OAK-B135 The purpose of the fourth meeting was to (1) share research and update research conducted on avian wind interactions (2) identify questions and issues related to the research results, (3) develop conclusions about some avian/wind power issues, and (4) identify questions and issues for future avian research.

  18. Wind Power Curve Modeling in Simple and Complex Terrain

    SciTech Connect

    Bulaevskaya, V.; Wharton, S.; Irons, Z.; Qualley, G.

    2015-02-09

    Our previous work on wind power curve modeling using statistical models focused on a location with a moderately complex terrain in the Altamont Pass region in northern California (CA). The work described here is the follow-up to that work, but at a location with a simple terrain in northern Oklahoma (OK). The goal of the present analysis was to determine the gain in predictive ability afforded by adding information beyond the hub-height wind speed, such as wind speeds at other heights, as well as other atmospheric variables, to the power prediction model at this new location and compare the results to those obtained at the CA site in the previous study. While we reach some of the same conclusions at both sites, many results reported for the CA site do not hold at the OK site. In particular, using the entire vertical profile of wind speeds improves the accuracy of wind power prediction relative to using the hub-height wind speed alone at both sites. However, in contrast to the CA site, the rotor equivalent wind speed (REWS) performs almost as well as the entire profile at the OK site. Another difference is that at the CA site, adding wind veer as a predictor significantly improved the power prediction accuracy. The same was true for that site when air density was added to the model separately instead of using the standard air density adjustment. At the OK site, these additional variables result in no significant benefit for the prediction accuracy.

  19. Electrical Collection and Transmission Systems for Offshore Wind Power: Preprint

    SciTech Connect

    Green, J.; Bowen, A.; Fingersh, L.J.; Wan, Y.

    2007-03-01

    The electrical systems needed for offshore wind farms to collect power from wind turbines--and transmit it to shore--will be a significant cost element of these systems. This paper describes the development of a simplified model of the cost and performance of such systems.

  20. Final Technical Report - Kotzebue Wind Power Porject - Volume I

    SciTech Connect

    Rana Zucchi, Global Energy Concepts, LLC; Brad Reeve, Kotzebue Electric Association; DOE Project Officer - Doug Hooker

    2007-10-26

    The Kotzebue Wind Power Project is a joint undertaking of the U.S. Department of Energy (DOE); Kotzebue Electric Association (KEA); and the Alaska Energy Authority (AEA). The goal of the project is to develop, construct, and operate a wind power plant interconnected to a small isolated utility grid in an arctic climate in Northwest Alaska. The primary objective of KEA’s wind energy program is to bring more affordable electricity and jobs to remote Alaskan communities. DOE funding has allowed KEA to develop a multi-faceted approach to meet these objectives that includes wind project planning and development, technology transfer, and community outreach. The first wind turbines were installed in the summer of 1997 and the newest turbines were installed in the spring of 2007. The total installed capacity of the KEA wind power project is 1.16 MW with a total of 17 turbines rated between 65 kW and 100 kW. The operation of the wind power plant has resulted in a wind penetration on the utility system in excess of 35% during periods of low loads. This document and referenced attachments are presented as the final technical report for the U.S. Department of Energy (DOE) grant agreement DE-FG36-97GO10199. Interim deliverables previously submitted are also referenced within this document and where reasonable to do so, specific sections are incorporated in the report or attached as appendices.

  1. Wind tunnel measurements of wake structure and wind farm power for actuator disk model wind turbines in yaw

    NASA Astrophysics Data System (ADS)

    Howland, Michael; Bossuyt, Juliaan; Kang, Justin; Meyers, Johan; Meneveau, Charles

    2016-11-01

    Reducing wake losses in wind farms by deflecting the wakes through turbine yawing has been shown to be a feasible wind farm control approach. In this work, the deflection and morphology of wakes behind a wind turbine operating in yawed conditions are studied using wind tunnel experiments of a wind turbine modeled as a porous disk in a uniform inflow. First, by measuring velocity distributions at various downstream positions and comparing with prior studies, we confirm that the nonrotating wind turbine model in yaw generates realistic wake deflections. Second, we characterize the wake shape and make observations of what is termed a "curled wake," displaying significant spanwise asymmetry. Through the use of a 100 porous disk micro-wind farm, total wind farm power output is studied for a variety of yaw configurations. Strain gages on the tower of the porous disk models are used to measure the thrust force as a substitute for turbine power. The frequency response of these measurements goes up to the natural frequency of the model and allows studying the spatiotemporal characteristics of the power output under the effects of yawing. This work has been funded by the National Science Foundation (Grants CBET-113380 and IIA-1243482, the WINDINSPIRE project). JB and JM are supported by ERC (ActiveWindFarms, Grant No. 306471).

  2. Assessment of distributed wind-power systems. Final report

    SciTech Connect

    Kaupang, B.M.

    1983-02-01

    A utility-oriented methodology for the purpose of evaluating distributed wind-power systems was developed and tested, utilizing data from three actual utility systems. Conventional utility planning techniques were used, including loss-of-load probability and production-cost-simulation methods in the generation planning area, transmission and distribution (T and D) system expansion models, and loss calculations. Evaluations were based on comparison of total utility-system cost with an without wind-power plants, and wre expressed in terms of wind-power-plant value and cost. Value is measured by the worth of displaced energy and capacity of conventional power plants, of T and D equipmen deferrals, and of T and D loss savings. Cost consists of he capital, and operating and maintenace costs of the wind-power plants. The value of distributed wind-power generation was found to be dominated by the generation energy and capacity value, as opposed to T and D system impacts. The energy value alone did, in two of the three utilities studied, result in a favorable value/cost relationship for the cost assumptions that were used. The problem of voltage fluctuation on distribution feeders from wind turbines due to wind gusts was studied for several sites. In most relaistic applications, the voltage fluctuations would not be a limiting criterion for practical wind-turbine penetration levels. If the wind turbine is connected to the distributionfeeder through a rectifier-inverter, voltage fluctuations become a negligible factor. However, reactive-power compensation of the inverter would most likely be required for this application.

  3. Triboelectric nanogenerator for harvesting wind energy and as self-powered wind vector sensor system.

    PubMed

    Yang, Ya; Zhu, Guang; Zhang, Hulin; Chen, Jun; Zhong, Xiandai; Lin, Zong-Hong; Su, Yuanjie; Bai, Peng; Wen, Xiaonan; Wang, Zhong Lin

    2013-10-22

    We report a triboelectric nanogenerator (TENG) that plays dual roles as a sustainable power source by harvesting wind energy and as a self-powered wind vector sensor system for wind speed and direction detection. By utilizing the wind-induced resonance vibration of a fluorinated ethylene-propylene film between two aluminum foils, the integrated TENGs with dimensions of 2.5 cm × 2.5 cm × 22 cm deliver an output voltage up to 100 V, an output current of 1.6 μA, and a corresponding output power of 0.16 mW under an external load of 100 MΩ, which can be used to directly light up tens of commercial light-emitting diodes. Furthermore, a self-powered wind vector sensor system has been developed based on the rationally designed TENGs, which is capable of detecting the wind direction and speed with a sensitivity of 0.09 μA/(m/s). This work greatly expands the applicability of TENGs as power sources for self-sustained electronics and also self-powered sensor systems for ambient wind detection.

  4. Phase locking of wind turbines leads to intermittent power production

    NASA Astrophysics Data System (ADS)

    Anvari, M.; Wächter, M.; Peinke, J.

    2016-12-01

    Wind energy, inserted into the power grid by wind turbines, is strongly influenced by the turbulent fluctuations of wind speed in the atmospheric layer. Here we investigate the power production of a wind farm and show that due to the presence of large-scale and long-time correlation in wind velocity, turbines interact with each other. This interaction can result in phase locking in pairs of turbines. We show that there are time intervals during which some pairs of turbines are temporally phase locked. This intermediate phase locking leads to the statistical effect that the short-time fluctuations of the cumulative power output of the wind farm become non-Gaussian, i.e., intermittent power production occurs. Contrary to phase-locked states, there are some time intervals where all turbines are phase unlocking and consequently the probability density function of the temporal increment of cumulative power production of the wind farm has almost Gaussian distribution. The phase-locked states, which can be distinct from phase-unlocked states by their dynamical features, are evaluated by reconstructed stochastic differential equations.

  5. Application and performance of remote bioventing systems powered by wind

    SciTech Connect

    Graves, D.; Hague, K.; Wilson, B.; Dillon, T. Jr.; Klein, J.; McLaughlin, J.; Olson, G.

    1995-12-31

    Wind-powered bioventing systems were designed to operate at remote locations in the absence of electrical power. Laboratory measurements of soil respiration under bioventing conditions indicated the biodegradation of up to 25 mg of weathered diesel per kg of site soil per day. Further testing demonstrated the potential for harnessing wind-power to stimulate air movement through vadose zone soil. A 12-in. attic turbine in a 10-mph wind was found to generate 0.025 in. of water vacuum with an airflow of approximately 2.5 ft{sup 3} per min. Two wind-powered bioventing systems were installed near Nome, Alaska. In situ respiration tests and soil gas composition measurements indicated that the systems were capable of aerating the soil. Measurements of diesel-range organics (DRO) taken during installation and at the end of the treatment season show concentration reductions of 29 and 87% at the two sites.

  6. Wind Powering America: Clean Energy for the 21st Century (Revised)

    SciTech Connect

    Not Available

    2004-09-01

    Wind Powering America: Clean Energy for the 21st Century continues to be one of the most popular publications produced by the Wind Powering America team. This latest revision incorporates new wind facts from the American Wind Energy Association, as well as wind FAQs for consumers, updated wind resource maps, and a list of WPA publications.

  7. Federal Incentives for Wind Power (Fact Sheet)

    SciTech Connect

    Not Available

    2013-05-01

    This fact sheet describes the federal incentives available as of April 2013 that encourage increased development and deployment of wind energy technologies, including research grants, tax incentives, and loan programs.

  8. Variability of wind power near Oklahoma City and implications for siting of wind turbines

    SciTech Connect

    Kessler, E.; Eyster, R.

    1987-09-01

    Data from five sites near Oklahoma City were examined to assess wind power availability. Wind turbines of identical manufacture were operated at three of the sites, one of which was also equipped with anemometers on a 100-ft tower. Comprehensive anemometric data were available from the other two sites. The study indicates that the average wind speed varies substantially over Oklahoma's rolling plains, which have often been nominally regarded as flat for purposes of wind power generation. Average wind differences may be as much as 5 mph at 20 ft above ground level, and 7 mph at 100 ft above ground level for elevation differences of about 200 ft above mean sea level, even in the absence of substantial features of local terrain. Local altitude above mean sea level seems to be as influential as the shape of local terrain in determining the average wind speed. The wind turbine used at a meteorologically instrumented site in the study produced the power expected from it for the wind regime in which it was situated. The observed variations of local wind imply variations in annual kWh of as much as a factor of four between identical turbines located at similar heights above ground level in shallow valleys and on hilltops or elevated extended flat areas. 17 refs., 39 figs., 11 tabs.

  9. Rotor equivalent wind speed for power curve measurement - comparative exercise for IEA Wind Annex 32

    NASA Astrophysics Data System (ADS)

    Wagner, R.; Cañadillas, B.; Clifton, A.; Feeney, S.; Nygaard, N.; Poodt, M.; St. Martin, C.; Tüxen, E.; Wagenaar, J. W.

    2014-06-01

    A comparative exercise has been organised within the International Energy Agency (IEA) Wind Annex 32 in order to test the Rotor Equivalent Wind Speed (REWS) method under various conditions of wind shear and measurement techniques. Eight organisations from five countries participated in the exercise. Each member of the group has derived both the power curve based on the wind speed at hub height and the power curve based on the REWS. This yielded results for different wind turbines, located in diverse types of terrain and where the wind speed profile was measured with different instruments (mast or various lidars). The participants carried out two preliminary steps in order to reach consensus on how to implement the REWS method. First, they all derived the REWS for one 10 minute wind speed profile. Secondly, they all derived the power curves for one dataset. The main point requiring consensus was the definition of the segment area used as weighting for the wind speeds measured at the various heights in the calculation of the REWS. This comparative exercise showed that the REWS method results in a significant difference compared to the standard method using the wind speed at hub height in conditions with large shear and low turbulence intensity.

  10. Wind Power predictability a risk factor in the design, construction and operation of Wind Generation Turbines

    NASA Astrophysics Data System (ADS)

    Thiesen, J.; Gulstad, L.; Ristic, I.; Maric, T.

    2010-09-01

    Summit: The wind power predictability is often a forgotten decision and planning factor for most major wind parks, both onshore and offshore. The results of the predictability are presented after having examined a number of European offshore and offshore parks power predictability by using three(3) mesoscale model IRIE_GFS and IRIE_EC and WRF. Full description: It is well known that the potential wind production is changing with latitude and complexity in terrain, but how big are the changes in the predictability and the economic impacts on a project? The concept of meteorological predictability has hitherto to some degree been neglected as a risk factor in the design, construction and operation of wind power plants. Wind power plants are generally built in places where the wind resources are high, but these are often also sites where the predictability of the wind and other weather parameters is comparatively low. This presentation addresses the question of whether higher predictability can outweigh lower average wind speeds with regard to the overall economy of a wind power project. Low predictability also tends to reduce the value of the energy produced. If it is difficult to forecast the wind on a site, it will also be difficult to predict the power production. This, in turn, leads to increased balance costs and a less reduced carbon emission from the renewable source. By investigating the output from three(3) mesoscale models IRIE and WRF, using ECMWF and GFS as boundary data over a forecasting period of 3 months for 25 offshore and onshore wind parks in Europe, the predictability are mapped. Three operational mesoscale models with two different boundary data have been chosen in order to eliminate the uncertainty with one mesoscale model. All mesoscale models are running in a 10 km horizontal resolution. The model output are converted into "day a head" wind turbine generation forecasts by using a well proven advanced physical wind power model. The power models

  11. 78 FR 44150 - Atlantic Wind Lease Sale 1 (ATLW1) Commercial Leasing for Wind Power on the Outer Continental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-23

    ... Bureau of Ocean Energy Management Atlantic Wind Lease Sale 1 (ATLW1) Commercial Leasing for Wind Power on... Management (BOEM), Interior. ACTION: Final Sale Notice for Commercial Leasing for Wind Power on the Outer... commercial wind energy lease on the Outer Continental Shelf (OCS) offshore Virginia, pursuant to...

  12. 77 FR 71621 - Atlantic Wind One (ATLW1) Commercial Leasing for Wind Power on the Outer Continental Shelf...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-03

    ... Bureau of Ocean Energy Management Atlantic Wind One (ATLW1) Commercial Leasing for Wind Power on the... Management (BOEM), Interior. ACTION: Proposed Sale Notice for Commercial Leasing for Wind Power on the Outer... Assessment (EA) and Finding of No Significant Impact (FONSI) for commercial wind lease issuance and...

  13. 77 FR 71612 - Atlantic Wind Lease Sale 2 (ATLW2) Commercial Leasing for Wind Power on the Outer Continental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-03

    ... Bureau of Ocean Energy Management Atlantic Wind Lease Sale 2 (ATLW2) Commercial Leasing for Wind Power on... for wind power on the Outer Continental Shelf offshore Rhode Island and Massachusetts. SUMMARY: This document is the Proposed Sale Notice (PSN) for the sale of commercial wind energy leases on the...

  14. A Wind Energy Powered Wireless Temperature Sensor Node

    PubMed Central

    Zhang, Chuang; He, Xue-Feng; Li, Si-Yu; Cheng, Yao-Qing; Rao, Yang

    2015-01-01

    A wireless temperature sensor node composed of a piezoelectric wind energy harvester, a temperature sensor, a microcontroller, a power management circuit and a wireless transmitting module was developed. The wind-induced vibration energy harvester with a cuboid chamber of 62 mm × 19.6 mm × 10 mm converts ambient wind energy into electrical energy to power the sensor node. A TMP102 temperature sensor and the MSP430 microcontroller are used to measure the temperature. The power management module consists of LTC3588-1 and LT3009 units. The measured temperature is transmitted by the nRF24l01 transceiver. Experimental results show that the critical wind speed of the harvester was about 5.4 m/s and the output power of the harvester was about 1.59 mW for the electrical load of 20 kΩ at wind speed of 11.2 m/s, which was sufficient to power the wireless sensor node to measure and transmit the temperature every 13 s. When the wind speed increased from 6 m/s to 11.5 m/s, the self-powered wireless sensor node worked normally. PMID:25734649

  15. A wind energy powered wireless temperature sensor node.

    PubMed

    Zhang, Chuang; He, Xue-Feng; Li, Si-Yu; Cheng, Yao-Qing; Rao, Yang

    2015-02-27

    A wireless temperature sensor node composed of a piezoelectric wind energy harvester, a temperature sensor, a microcontroller, a power management circuit and a wireless transmitting module was developed. The wind-induced vibration energy harvester with a cuboid chamber of 62 mm × 19.6 mm × 10 mm converts ambient wind energy into electrical energy to power the sensor node. A TMP102 temperature sensor and the MSP430 microcontroller are used to measure the temperature. The power management module consists of LTC3588-1 and LT3009 units. The measured temperature is transmitted by the nRF24l01 transceiver. Experimental results show that the critical wind speed of the harvester was about 5.4 m/s and the output power of the harvester was about 1.59 mW for the electrical load of 20 kΩ at wind speed of 11.2 m/s, which was sufficient to power the wireless sensor node to measure and transmit the temperature every 13 s. When the wind speed increased from 6 m/s to 11.5 m/s, the self-powered wireless sensor node worked normally.

  16. Piezoelectric wind turbine

    NASA Astrophysics Data System (ADS)

    Kishore, Ravi Anant; Priya, Shashank

    2013-03-01

    In past few years, there has been significant focus towards developing small scale renewable energy based power sources for powering wireless sensor nodes in remote locations such as highways and bridges to conduct continuous health monitoring. These prior efforts have led to the development of micro-scale solar modules, hydrogen fuel cells and various vibration based energy harvesters. However, the cost effectiveness, reliability, and practicality of these solutions remain a concern. Harvesting the wind energy using micro-to-small scale wind turbines can be an excellent solution in variety of outdoor scenarios provided they can operate at few miles per hour of wind speed. The conventional electromagnetic generator used in the wind mills always has some cogging torque which restricts their operation above certain cut-in wind speed. This study aims to develop a novel piezoelectric wind turbine that utilizes bimorph actuators for electro-mechanical energy conversion. This device utilizes a Savonius rotor that is connected to a disk having magnets at the periphery. The piezoelectric actuators arranged circumferentially around the disk also have magnets at the tip which interacts with the magnetic field of the rotating disk and produces cyclical deflection. The wind tunnel experiments were conducted between 2-12 mph of wind speeds to characterize and optimize the power output of the wind turbine. Further, testing was conducted in the open environment to quantify the response to random wind gusts. An attempt was made towards integration of the piezoelectric wind turbine with the wireless sensor node.

  17. Wind Power Forecasting Error Frequency Analyses for Operational Power System Studies: Preprint

    SciTech Connect

    Florita, A.; Hodge, B. M.; Milligan, M.

    2012-08-01

    The examination of wind power forecasting errors is crucial for optimal unit commitment and economic dispatch of power systems with significant wind power penetrations. This scheduling process includes both renewable and nonrenewable generators, and the incorporation of wind power forecasts will become increasingly important as wind fleets constitute a larger portion of generation portfolios. This research considers the Western Wind and Solar Integration Study database of wind power forecasts and numerical actualizations. This database comprises more than 30,000 locations spread over the western United States, with a total wind power capacity of 960 GW. Error analyses for individual sites and for specific balancing areas are performed using the database, quantifying the fit to theoretical distributions through goodness-of-fit metrics. Insights into wind-power forecasting error distributions are established for various levels of temporal and spatial resolution, contrasts made among the frequency distribution alternatives, and recommendations put forth for harnessing the results. Empirical data are used to produce more realistic site-level forecasts than previously employed, such that higher resolution operational studies are possible. This research feeds into a larger work of renewable integration through the links wind power forecasting has with various operational issues, such as stochastic unit commitment and flexible reserve level determination.

  18. On wind turbine power performance measurements at inclined airflow

    NASA Astrophysics Data System (ADS)

    Pedersen, T. F.

    2004-07-01

    The average airflow inclination in complex terrain may be substantial. The airflow inclination affects wind turbine performance and also affects the cup anemometer being used in power performance measurements. In this article the overall dependence of the power curve on inclined airflow is analysed for its influence on both the wind turbine and the cup anemometer. The wind turbine performance analysis is based on results of measurements and theoretical calculations with the aeroelastic code HAWC coupled to a 3D actuator disc model for varying yaw angle. The cup anemometer analysis at inclined flow is based on an averaging of measured angular characteristics in a wind tunnel with the distribution of airflow inclination angles over time. The relative difference in annual energy production in terrain with inclined airflow compared with flat terrain is simulated for cup anemometers with theoretical optimal angular characteristics for two different definitions of wind speed, as well as for five commercial cup anemometers with measured angular characteristics. Copyright

  19. 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.

  20. Multi-decadal Variability of the Wind Power Output

    NASA Astrophysics Data System (ADS)

    Kirchner Bossi, Nicolas; García-Herrera, Ricardo; Prieto, Luis; Trigo, Ricardo M.

    2014-05-01

    The knowledge of the long-term wind power variability is essential to provide a realistic outlook on the power output during the lifetime of a planned wind power project. In this work, the Power Output (Po) of a market wind turbine is simulated with a daily resolution for the period 1871-2009 at two different locations in Spain, one at the Central Iberian Plateau and another at the Gibraltar Strait Area. This is attained through a statistical downscaling of the daily wind conditions. It implements a Greedy Algorithm as classificator of a geostrophic-based wind predictor, which is derived by considering the SLP daily field from the 56 ensemble members of the longest homogeneous reanalysis available (20CR, 1871-2009). For calibration and validation purposes we use 10 years of wind observations (the predictand) at both sites. As a result, a series of 139 annual wind speed Probability Density Functions (PDF) are obtained, with a good performance in terms of wind speed uncertainty reduction (average daily wind speed MAE=1.48 m/s). The obtained centennial series allow to investigate the multi-decadal variability of wind power from different points of view. Significant periodicities around the 25-yr frequency band, as well as long-term linear trends are detected at both locations. In addition, a negative correlation is found between annual Po at both locations, evidencing the differences in the dynamical mechanisms ruling them (and possible complementary behavior). Furthermore, the impact that the three leading large-scale circulation patterns over Iberia (NAO, EA and SCAND) exert over wind power output is evaluated. Results show distinct (and non-stationary) couplings to these forcings depending on the geographical position and season or month. Moreover, significant non-stationary correlations are observed with the slow varying Atlantic Multidecadal Oscillation (AMO) index for both case studies. Finally, an empirical relationship is explored between the annual Po and the

  1. Integrating energy storage with wind power in weak electricity grids

    NASA Astrophysics Data System (ADS)

    McDowall, Jim

    Energy storage is required to match wind generation to consumption. This time shifting can be accomplished with several hours of storage, but studies have shown that the economic value of such storage systems is unlikely to support their widespread use. This does not mean that the outlook is uniformly bleak for storage with wind power. This paper discusses storage systems ranging from a few seconds of run time to several hours, and provides a rationale for the use of systems with several minutes of run time to support a high penetration of wind power into weak electricity grids.

  2. R & D on Offshore Wind Power Generation System in Japan

    NASA Astrophysics Data System (ADS)

    Oishi, Kazuhito; Fukumoto, Yukinari

    Offshore wind energy has been widely exploited in Europe. Having a long coastline, the offshore wind energy will be the one of the important solutions for the increase of renewable energy in Japan. However, due to the difference in wind and marine condition between Japan and Europe, the safety, the environmental impact and the economical feasibility of the offshore wind power generation system have to be investigated in Japan. According to the data observed offshore, the wind speed is enough higher than that on land and the wind energy is economically feasible. In order to utilize the energy, the design method of the foundation against very high waves in typhoon storm should be established. For shallow offshore coastal area, gravity foundation type has been improved by hydraulic experiment. Additionally, for deeper ocean, floating types such as semi-submersible float and spar-buoy have been researched.

  3. Introduction to Voigt's wind power plant. [energy conversion efficiency

    NASA Technical Reports Server (NTRS)

    Tompkin, J.

    1973-01-01

    The design and operation of a 100 kilowatt wind driven generator are reported. Its high speed three-bladed turbine operates at a height of 50 meters. Blades are rigidly connected to the hub and turbine revolutions change linearly with wind velocity, maintaining a constant speed ratio of blade tip velocity to wind velocity over the full predetermined wind range. Three generators installed in the gondola generate either dc or ac current. Based on local wind conditions, the device has a maximum output of 720 kilowatts at a wind velocity of 16 meters per second. Total electrical capacity is 750 kilowatts, and power output per year is 2,135,000 kilowatt/hours.

  4. Increasing Wind Turbine Power Generation Through Optimized Flow Control Design

    NASA Astrophysics Data System (ADS)

    Cooney, John; Williams, Theodore; Corke, Thomas

    2013-11-01

    A practical, validated methodology is outlined for implementing flow control systems into wind turbine designs to maximize power generation. This approach involves determining optimal flow control strategies to minimize aerodynamic losses for horizontal axis wind turbines during Region II operation. A quantitative design optimization (QDO) process is completed for the wind turbine utilized in the Notre Dame Laboratory for Enhanced Wind Energy Research. QDO utilizes CFD simulations and shape optimization tools to maximize effectiveness of flow control. Here, only flow control schemes that could be retrofitted on the existing turbine were explored. The final geometry is discussed along with accompanying validations of the predicted performance from wind tunnel experiments at full-scale conditions. Field data from the wind energy laboratory is included.

  5. Quadrennial Technology Review 2015: Technology Assessments--Wind Power

    SciTech Connect

    none,

    2015-10-07

    Wind power has become a mainstream power source in the U.S. electricity portfolio, supplying 4.9% of the nation’s electricity demand in 2014. With more than 65 GW installed across 39 states at the end of 2014, utility-scale wind power is a cost-effective source of low-emissions power generation throughout much of the nation. The United States has significant sustainable land-based and offshore wind resource potential, greater than 10 times current total U.S. electricity consumption. A technical wind resource assessment conducted by the Department of Energy (DOE) in 2009 estimated that the land-based wind energy potential for the contiguous United States is equivalent to 10,500 GW capacity at 80 meters (m) hub and 12,000 GW capacity at 100 meters (m) hub heights, assuming a capacity factor of at least 30%. A subsequent 2010 DOE report estimated the technical offshore wind energy potential to be 4,150 GW. The estimate was calculated from the total offshore area within 50 nautical miles of shore in areas where average annual wind speeds are at least 7 m per second at a hub height of 90 m.

  6. Offshore based WARP{trademark} Power Spar buoys for multi-megawatt wind power plants

    SciTech Connect

    Weisbrich, A.L.; Rhodes, A.F.

    1998-12-31

    Since the earliest use of wind as a stationary power source, major consideration and effort has gone into the selection of a location with relatively high wind speed as well as proximity to the place of energy demand. As wind speed increases, collectible energy from the wind increases by the third power. That is, in a location with 20% higher wind speed, it is possible to generate 73% more power. If 50% higher wind velocity is available, 300% more power and energy can be generated. In the ideal, an offshore wind power plant should be easily and relatively inexpensively constructed, and economically sited in any depth water. In addition to these characteristics, if the typically excellent offshore winds could be amplified by as much as 50% to 80% and captured by low cost, highly reliable aircraft propeller sized wind turbines, substantial cost effectiveness and practicality would result. ENECO`s Wind amplified Rotor Platform (WARP{trademark}) Power Spar buoy system design appears to have the features needed to achieve these objectives and is proposed for test and commercialization.

  7. A Nonlinear Dynamics Approach for Incorporating Wind-Speed Patterns into Wind-Power Project Evaluation

    PubMed Central

    Huffaker, Ray; Bittelli, Marco

    2015-01-01

    Wind-energy production may be expanded beyond regions with high-average wind speeds (such as the Midwest U.S.A.) to sites with lower-average speeds (such as the Southeast U.S.A.) by locating favorable regional matches between natural wind-speed and energy-demand patterns. A critical component of wind-power evaluation is to incorporate wind-speed dynamics reflecting documented diurnal and seasonal behavioral patterns. Conventional probabilistic approaches remove patterns from wind-speed data. These patterns must be restored synthetically before they can be matched with energy-demand patterns. How to accurately restore wind-speed patterns is a vexing problem spurring an expanding line of papers. We propose a paradigm shift in wind power evaluation that employs signal-detection and nonlinear-dynamics techniques to empirically diagnose whether synthetic pattern restoration can be avoided altogether. If the complex behavior of observed wind-speed records is due to nonlinear, low-dimensional, and deterministic system dynamics, then nonlinear dynamics techniques can reconstruct wind-speed dynamics from observed wind-speed data without recourse to conventional probabilistic approaches. In the first study of its kind, we test a nonlinear dynamics approach in an application to Sugarland Wind—the first utility-scale wind project proposed in Florida, USA. We find empirical evidence of a low-dimensional and nonlinear wind-speed attractor characterized by strong temporal patterns that match up well with regular daily and seasonal electricity demand patterns. PMID:25617767

  8. Impact of Increasing Distributed Wind Power and Wind Turbine Siting on Rural Distribution Feeder Voltage Profiles: Preprint

    SciTech Connect

    Allen, A.; Zhang, Y. C.; Hodge, B. M.

    2013-09-01

    Many favorable wind energy resources in North America are located in remote locations without direct access to the transmission grid. Building transmission lines to connect remotely-located wind power plants to large load centers has become a barrier to increasing wind power penetration in North America. By connecting utility-sized megawatt-scale wind turbines to the distribution system, wind power supplied to consumers could be increased greatly. However, the impact of including megawatt-scale wind turbines on distribution feeders needs to be studied. The work presented here examined the impact that siting and power output of megawatt-scale wind turbines have on distribution feeder voltage. This is the start of work to present a general guide to megawatt-scale wind turbine impact on the distribution feeder and finding the amount of wind power that can be added without adversely impacting the distribution feeder operation, reliability, and power quality.

  9. Using ensemble NWP wind power forecasts to improve national power system management

    NASA Astrophysics Data System (ADS)

    Cannon, D.; Brayshaw, D.; Methven, J.; Coker, P.; Lenaghan, D.

    2014-12-01

    National power systems are becoming increasingly sensitive to atmospheric variability as generation from wind (and other renewables) increases. As such, the days-ahead predictability of wind power has significant implications for power system management. At this time horizon, power system operators plan transmission line outages for maintenance. In addition, forecast users begin to form backup strategies to account for the uncertainty in wind power predictions. Under-estimating this uncertainty could result in a failure to meet system security standards, or in the worst instance, a shortfall in total electricity supply. On the other hand, overly conservative assumptions about the forecast uncertainty incur costs associated with the unnecessary holding of reserve power. Using the power system of Great Britain (GB) as an example, we construct time series of GB-total wind power output using wind speeds from either reanalyses or global weather forecasts. To validate the accuracy of these data sets, wind power reconstructions using reanalyses and forecast analyses over a recent period are compared to measured GB-total power output. The results are found to be highly correlated on time scales greater than around 6 hours. Results are presented using ensemble wind power forecasts from several national and international forecast centres (obtained through TIGGE). Firstly, the skill with which global ensemble forecasts can represent the uncertainty in the GB-total power output at up to 10 days ahead is quantified. Following this, novel ensemble forecast metrics are developed to improve estimates of forecast uncertainty within the context of power system operations, thus enabling the development of more cost effective strategies. Finally, the predictability of extreme events such as prolonged low wind periods or rapid changes in wind power output are examined in detail. These events, if poorly forecast, induce high stress scenarios that could threaten the security of the power

  10. A Scenario Generation Method for Wind Power Ramp Events Forecasting

    SciTech Connect

    Cui, Ming-Jian; Ke, De-Ping; Sun, Yuan-Zhang; Gan, Di; Zhang, Jie; Hodge, Bri-Mathias

    2015-07-03

    Wind power ramp events (WPREs) have received increasing attention in recent years due to their significant impact on the reliability of power grid operations. In this paper, a novel WPRE forecasting method is proposed which is able to estimate the probability distributions of three important properties of the WPREs. To do so, a neural network (NN) is first proposed to model the wind power generation (WPG) as a stochastic process so that a number of scenarios of the future WPG can be generated (or predicted). Each possible scenario of the future WPG generated in this manner contains the ramping information, and the distributions of the designated WPRE properties can be stochastically derived based on the possible scenarios. Actual data from a wind power plant in the Bonneville Power Administration (BPA) was selected for testing the proposed ramp forecasting method. Results showed that the proposed method effectively forecasted the probability of ramp events.

  11. Detecting and characterising ramp events in wind power time series

    NASA Astrophysics Data System (ADS)

    Gallego, Cristóbal; Cuerva, Álvaro; Costa, Alexandre

    2014-12-01

    In order to implement accurate models for wind power ramp forecasting, ramps need to be previously characterised. This issue has been typically addressed by performing binary ramp/non-ramp classifications based on ad-hoc assessed thresholds. However, recent works question this approach. This paper presents the ramp function, an innovative wavelet- based tool which detects and characterises ramp events in wind power time series. The underlying idea is to assess a continuous index related to the ramp intensity at each time step, which is obtained by considering large power output gradients evaluated under different time scales (up to typical ramp durations). The ramp function overcomes some of the drawbacks shown by the aforementioned binary classification and permits forecasters to easily reveal specific features of the ramp behaviour observed at a wind farm. As an example, the daily profile of the ramp-up and ramp-down intensities are obtained for the case of a wind farm located in Spain.

  12. Wind-assist irrigation and electrical-power generation

    NASA Astrophysics Data System (ADS)

    Nelson, V.; Starcher, K.

    1982-07-01

    A wind turbine is mechanically connected to an existing irrigation well. The system can be operated in three modes: electric motor driving the water turbine pump. Wind assist mode where wind turbine supplements power from the utility line to drive the water turbine pump. At wind speeds of 12 m/s and greater, the wind turbine can pump water (15 kW) and feed power (10 kW) back into the utility grid at the same time. Electrical generation mode where the water pump is disconnected and all power is fed back to the utility grid. The concept is technically viable as the mechanical connection allows for a smooth transfer of power in parallel with an existing power source. Minor problems caused delays and major problems of two rotor failures precluded enough operation time to obtain a good estimation of the economics. Because reliability and maintenance are difficult problems with prototype or limited production wind energy conversion systems, the expense of the demonstration project has exceeded the estimated cost by a large amount.

  13. Wind, Wave, and Tidal Energy Without Power Conditioning

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    2013-01-01

    Most present wind, wave, and tidal energy systems require expensive power conditioning systems that reduce overall efficiency. This new design eliminates power conditioning all, or nearly all, of the time. Wind, wave, and tidal energy systems can transmit their energy to pumps that send high-pressure fluid to a central power production area. The central power production area can consist of a series of hydraulic generators. The hydraulic generators can be variable displacement generators such that the RPM, and thus the voltage, remains constant, eliminating the need for further power conditioning. A series of wind blades is attached to a series of radial piston pumps, which pump fluid to a series of axial piston motors attached to generators. As the wind is reduced, the amount of energy is reduced, and the number of active hydraulic generators can be reduced to maintain a nearly constant RPM. If the axial piston motors have variable displacement, an exact RPM can be maintained for all, or nearly all, wind speeds. Analyses have been performed that show over 20% performance improvements with this technique over conventional wind turbines

  14. Generation Expansion Planning with High Penetration of Wind Power

    NASA Astrophysics Data System (ADS)

    Sharan, Ishan; Balasubramanian, R.

    2016-08-01

    Worldwide thrust is being provided in generation of electricity from wind. Planning for the developmental needs of wind based power has to be consistent with the objective and basic framework of overall resource planning. The operational issues associated with the integration of wind power must be addressed at the planning stage. Lack of co-ordinated planning of wind turbine generators, conventional generating units and expansion of the transmission system may lead to curtailment of wind power due to transmission inadequacy or operational constraints. This paper presents a generation expansion planning model taking into account fuel transportation and power transmission constraints, while addressing the operational issues associated with the high penetration of wind power. For analyzing the operational issues, security constrained unit commitment algorithm is embedded in the integrated generation and transmission expansion planning model. The integrated generation and transmission expansion planning problem has been formulated as a mixed integer linear problem involving both binary and continuous variables in GAMS. The model has been applied to the expansion planning of a real system to illustrate the proposed approach.

  15. Status of Centralized Wind Power Forecasting in North America: May 2009-May 2010

    SciTech Connect

    Porter, K.; Rogers, J.

    2010-04-01

    Report surveys grid wind power forecasts for all wind generators, which are administered by utilities or regional transmission organizations (RTOs), typically with the assistance of one or more wind power forecasting companies.

  16. Examining the Variability of Wind Power Output in the Regulation Time Frame: Preprint

    SciTech Connect

    Hodge, B. M.; Shedd, S.; Florita, A.

    2012-08-01

    This work examines the distribution of changes in wind power for different time scales in the regulation time frame as well as the correlation of changes in power output for individual wind turbines in a wind plant.

  17. Wind power forecasting : state-of-the-art 2009.

    SciTech Connect

    Monteiro, C.; Bessa, R.; Miranda, V.; Botterud, A.; Wang, J.; Conzelmann, G.; Decision and Information Sciences; INESC Porto

    2009-11-20

    Many countries and regions are introducing policies aimed at reducing the environmental footprint from the energy sector and increasing the use of renewable energy. In the United States, a number of initiatives have been taken at the state level, from renewable portfolio standards (RPSs) and renewable energy certificates (RECs), to regional greenhouse gas emission control schemes. Within the U.S. Federal government, new energy and environmental policies and goals are also being crafted, and these are likely to increase the use of renewable energy substantially. The European Union is pursuing implementation of its ambitious 20/20/20 targets, which aim (by 2020) to reduce greenhouse gas emissions by 20% (as compared to 1990), increase the amount of renewable energy to 20% of the energy supply, and reduce the overall energy consumption by 20% through energy efficiency. With the current focus on energy and the environment, efficient integration of renewable energy into the electric power system is becoming increasingly important. In a recent report, the U.S. Department of Energy (DOE) describes a model-based scenario, in which wind energy provides 20% of the U.S. electricity demand in 2030. The report discusses a set of technical and economic challenges that have to be overcome for this scenario to unfold. In Europe, several countries already have a high penetration of wind power (i.e., in the range of 7 to 20% of electricity consumption in countries such as Germany, Spain, Portugal, and Denmark). The rapid growth in installed wind power capacity is expected to continue in the United States as well as in Europe. A large-scale introduction of wind power causes a number of challenges for electricity market and power system operators who will have to deal with the variability and uncertainty in wind power generation when making their scheduling and dispatch decisions. Wind power forecasting (WPF) is frequently identified as an important tool to address the variability and

  18. A proposed national wind power R and D program. [offshore wind power system for electric energy supplies

    NASA Technical Reports Server (NTRS)

    Heronemus, W.

    1973-01-01

    An offshore wind power system is described that consists of wind driven electrical dc generators mounted on floating towers in offshore waters. The output from the generators supplies underwater electrolyzer stations in which water is converted into hydrogen and oxygen. The hydrogen is piped to shore for conversion to electricity in fuel cell stations. It is estimated that this system can produce 159 x 10 to the ninth power kilowatt-hours per year. It is concluded that solar energy - and that includes wind energy - is the only way out of the US energy dilemma in the not too distant future.

  19. Harnessing the Power of Wind Technology

    ERIC Educational Resources Information Center

    Dotson, Tawny M.

    2009-01-01

    "Where the wind comes sweepin' down the plain" is more than just a song lyric for Oklahoma's career and technical education community. It's the acknowledgement of an untapped natural resource that has the potential to translate into both energy independence for the country and jobs for the state. Statewide, technology center instructors…

  20. Wind powered direct drive water pumping systems

    SciTech Connect

    Sadhu, D.

    1983-12-01

    Wind turbine of comparatively large capacities are used exclusively for electricity generation, and so far small multiblade horizontal axis turbines are extensively employed for water pumping with reciprocating piston pumps. However, the advent of wind turbines for irrigation, characterised with large discharge volume pumps, require application of large capacity and efficient ones to make the operation viable. An analysis is made in this paper to find matching pump coupled directly with wind turbine for optimum system operation in variable speed. There exist various type of wind turbines, operating on different principles having characteristics different, dependent not only on the types but also on the design criteria of the individuals. Water pumps are also of various types whose operation characteristics vary with the type, mode of operation and design parameters. A nondimensional analysis is carried out to match the two, to operate at optimum, by superimposing the operating characteristics of the one over the other. The transmission method is also taken in account on the investment analysis of the whole system. Positive displacement pumps are best suited for high starting torque turbines e.g. Savonius or Filippini or multiblade horizontal axis rotors, and consequently are less efficient, though is advantageous for high water lift operation.

  1. The Phenomenology of Small-Scale Turbulence

    NASA Astrophysics Data System (ADS)

    Sreenivasan, K. R.; Antonia, R. A.

    I have sometimes thought that what makes a man's work classic is often just this multiplicity [of interpretations], which invites and at the same time resists our craving for a clear understanding. Wright (1982, p. 34), on Wittgenstein's philosophy Small-scale turbulence has been an area of especially active research in the recent past, and several useful research directions have been pursued. Here, we selectively review this work. The emphasis is on scaling phenomenology and kinematics of small-scale structure. After providing a brief introduction to the classical notions of universality due to Kolmogorov and others, we survey the existing work on intermittency, refined similarity hypotheses, anomalous scaling exponents, derivative statistics, intermittency models, and the structure and kinematics of small-scale structure - the latter aspect coming largely from the direct numerical simulation of homogeneous turbulence in a periodic box.

  2. 75 FR 82130 - WTO Dispute Settlement Proceeding Regarding China-Subsidies on Wind Power Equipment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-29

    ... Proceeding Regarding China--Subsidies on Wind Power Equipment AGENCY: Office of the United States Trade... consultations regarding certain subsidies provided by the People's Republic of China (China) on wind power... Administration of Special Fund for Industrialization of Wind Power Equipment'' (``Wind Power Equipment...

  3. Wind Generation Participation in Power System Frequency Response: Preprint

    SciTech Connect

    Gevorgian, Vahan; Zhang, Yingchen

    2017-01-01

    The electrical frequency of an interconnected power system must be maintained close its nominal level at all times. Excessive under- and overfrequency excursions can lead to load shedding, instability, machine damage, and even blackouts. There is a rising concern in the electric power industry in recent years about the declining amount of inertia and primary frequency response (PFR) in many interconnections. This decline may continue due to increasing penetrations of inverter-coupled generation and the planned retirements of conventional thermal plants. Inverter-coupled variable wind generation is capable of contributing to PFR and inertia with a response that is different from that of conventional generation. It is not yet entirely understood how such a response will affect the system at different wind power penetration levels. The modeling work presented in this paper evaluates the impact of wind generation's provision of these active power control strategies on a large, synchronous interconnection. All simulations were conducted on the U.S. Western Interconnection with different levels of instantaneous wind power penetrations (up to 80%). The ability of wind power plants to provide PFR - and a combination of synthetic inertial response and PFR - significantly improved the frequency response performance of the system.

  4. Wind Turbine Generator System Duration Test Report for the Mariah Power Windspire Wind Turbine

    SciTech Connect

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

    2010-05-01

    This test was conducted as part of the U.S. Department of Energy's (DOE) Independent Testing project to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Wind Technology Center (NWTC) as a part of the first round of this project. Duration testing is one of up to five tests that may be performed on the turbines. Other tests include power performance, safety and function, noise, and power quality tests. NWTC testing results provide manufacturers with reports that may be used to meet part of small wind turbine certification requirements. This duration test report focuses on the Mariah Power Windspire wind turbine.

  5. Geologic utility of small-scale airphotos

    NASA Technical Reports Server (NTRS)

    Clark, M. M.

    1969-01-01

    The geologic value of small scale airphotos is emphasized by describing the application of high altitude oblique and 1:120,000 to 1:145,000 scale vertical airphotos to several geologic problems in California. These examples show that small-scale airphotos can be of use to geologists in the following ways: (1) high altitude, high oblique airphotos show vast areas in one view; and (2) vertical airphotos offer the most efficient method of discovering the major topographic features and structural and lithologic characteristics of terrain.

  6. Wake Mitigation Strategies for Optimizing Wind Farm Power Production

    NASA Astrophysics Data System (ADS)

    Dilip, Deepu; Porté-Agel, Fernando

    2016-04-01

    Although wind turbines are designed individually for optimum power production, they are often arranged into groups of closely spaced turbines in a wind farm rather than in isolation. Consequently, most turbines in a wind farm do not operate in unobstructed wind flows, but are affected by the wakes of turbines in front of them. Such wake interference significantly reduces the overall power generation from wind farms and hence, development of effective wake mitigation strategies is critical for improving wind farm efficiency. One approach towards this end is based on the notion that the operation of each turbine in a wind farm at its optimum efficiency might not lead to optimum power generation from the wind farm as a whole. This entails a down regulation of individual turbines from its optimum operating point, which can be achieved through different methods such as pitching the turbine blades, changing the turbine tip speed ratio or yawing of the turbine, to name a few. In this study, large-eddy simulations of a two-turbine arrangement with the second turbine fully in the wake of the first are performed. Different wake mitigation techniques are applied to the upstream turbine, and the effects of these on its wake characteristics are investigated. Results for the combined power from the two turbines for each of these methods are compared to a baseline scenario where no wake mitigation strategies are employed. Analysis of the results shows the potential for improved power production from such wake control methods. It should be noted, however, that the magnitude of the improvement is strongly affected by the level of turbulence in the incoming atmospheric flow.

  7. Performance of a small wind powered water pumping system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lorentz helical pumps (Henstedt-Ulzburg, Germany) have been powered by solar energy for remote water pumping applications for many years, but from October 2005 to March 2008 a Lorentz helical pump was powered by wind energy at the USDA-ARS Conservation and Production Research Laboratory (CPRL) near ...

  8. Livestock water pumping with wind and solar power

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent developments in pumping technologies have allowed for efficient use of renewable energies like wind and solar to power new pumps for remote water pumping. A helical type, positive displacement pump was developed a few years ago and recently modified to accept input from a variable power sourc...

  9. Kolmogorov spectrum of renewable wind and solar power fluctuations

    NASA Astrophysics Data System (ADS)

    Tabar, M. Reza Rahimi; Anvari, M.; Lohmann, G.; Heinemann, D.; Wächter, M.; Milan, P.; Lorenz, E.; Peinke, Joachim

    2014-10-01

    With increasing the contribution of renewable energies in power production, the task of reducing dynamic instability in power grids must also be addressed from the generation side, because the power delivered from such sources is spatiotemporally stochastic in nature. Here we characterize the stochastic properties of the wind and solar energy sources by studying their spectrum and multifractal exponents. The computed power spectrum from high frequency time series of solar irradiance and wind power reveals a power-law behaviour with an exponent ˜ 5/3 (Kolmogorov exponent) for the frequency domain 0.001 Hz < f < 0.05 Hz, which means that the power grid is being fed by turbulent-like sources. Our results bring important evidence on the stochastic and turbulent-like behaviour of renewable power production from wind and solar energies, which can cause instability in power grids. Our statistical analysis also provides important information that must be used as a guideline for an optimal design of power grids that operate under intermittent renewable sources of power.

  10. Ice Accretion Prediction on Wind Turbines and Consequent Power Losses

    NASA Astrophysics Data System (ADS)

    Yirtici, Ozcan; Tuncer, Ismail H.; Ozgen, Serkan

    2016-09-01

    Ice accretion on wind turbine blades modifies the sectional profiles and causes alteration in the aerodynamic characteristic of the blades. The objective of this study is to determine performance losses on wind turbines due to the formation of ice in cold climate regions and mountainous areas where wind energy resources are found. In this study, the Blade Element Momentum method is employed together with an ice accretion prediction tool in order to estimate the ice build-up on wind turbine blades and the energy production for iced and clean blades. The predicted ice shapes of the various airfoil profiles are validated with the experimental data and it is shown that the tool developed is promising to be used in the prediction of power production losses of wind turbines.

  11. Wind Powering America: Goals, Approach, Perspectives, and Prospects; Preprint

    SciTech Connect

    Flowers, L. T.; Dougherty, P. J.

    2002-03-01

    While wind development activity in the United States has dramatically increased over the last 3 years, it has been mainly driven by policy mandates in the investor owned utility community. Also, while significant wind development has and is now occurring in the Northwest, the Great Plains, the Rocky Mountains, Texas, and several eastern states, there remain a number of states that have excellent resources that are essentially undeveloped. Additionally, the U.S. federal agencies represent the largest institutional load in the world, and thus are a potential large market for green (wind) energy. Rural America is economically stressed and traditional agricultural incomes are seriously threatened; wind development in these windy regions offers one of the most promising''crops'' of the 21st century. Public power serves these communities, and local development of wind with low-cost financing appears to be competitive with new conventional fossil energy sources.

  12. Factors driving wind power development in the United States

    SciTech Connect

    Bird, Lori A.; Parsons, Brian; Gagliano, Troy; Brown, Matthew H.; Wiser, Ryan H.; Bolinger, Mark

    2003-05-15

    In the United States, there has been substantial recent growth in wind energy generating capacity, with growth averaging 24 percent annually during the past five years. About 1,700 MW of wind energy capacity was installed in 2001, while another 410 MW became operational in 2002. This year (2003) shows promise of significant growth with more than 1,500 MW planned. With this growth, an increasing number of states are experiencing investment in wind energy projects. Wind installations currently exist in about half of all U.S. states. This paper explores the key factors at play in the states that have achieved a substantial amount of wind energy investment. Some of the factors that are examined include policy drivers, such as renewable portfolio standards (RPS), federal and state financial incentives, and integrated resource planning; as well as market drivers, such as consumer demand for green power, natural gas price volatility, and wholesale market rules.

  13. Transforming intermittent wind energy to a baseload power supply economically

    SciTech Connect

    Cavallo, A.J.

    1996-12-31

    Wind generated electricity can be transformed from an intermittent to a baseload power supply cost-effectively by taking advantage of the fundamental properties of wind and by the efficient utilization of compressed air energy storage (CAES) systems. A utility scale wind-CAES-transmission system can have a 95 percent capacity factor at a cost of delivered electricity that is about 15 percent greater than a conventional wind energy system with a 34 percent capacity factor. This approach has several compelling advantages. It is based on existing technology and makes best use of costly transmission lines. It produces electricity that is the technical equivalent of that from fossil fuel or nuclear power stations. It minimizes greenhouse gas and other fossil fuel pollution, and is an industrial scale system that could cover a significant fraction of total electrical demand in regions such as the US, Mexico, China or Europe.

  14. Detection of Wind Turbine Power Performance Abnormalities Using Eigenvalue Analysis

    DTIC Science & Technology

    2014-12-23

    Detection of Wind Turbine Power Performance Abnormalities Using Eigenvalue Analysis Georgios Alexandros Skrimpas1, Christian Walsted Sweeney2, Kun S...University of Denmark, Lyngby, 2800, Denmark nm@elektro.dtu.dk jh@elektro.dtu.dk ABSTRACT Condition monitoring of wind turbines is a field of continu...ous research and development as new turbine configurations enter into the market and new failure modes appear. Systems utilising well established

  15. Controlled power transfer from wind driven reluctance generator

    SciTech Connect

    Rahim, Y.H.A.; Al-Sabbagh, A.M.L.

    1997-12-01

    The paper describes the dynamic performance of a wind driven reluctance generator connected to an electric network of large capacity. A controller that makes possible the regular flow of power to the network has been considered. Controller parameters that successfully suppress unwanted mechanical and electrical stresses and overshoots due to wind gust, have been estimated. The performance of the controller has also been examined for short-circuit faults at the terminals of the generators.

  16. IAPSA 2 small-scale system specification

    NASA Technical Reports Server (NTRS)

    Cohen, Gerald C.; Torkelson, Thomas C.

    1990-01-01

    The details of a hardware implementation of a representative small scale flight critical system is described using Advanced Information Processing System (AIPS) building block components and simulated sensor/actuator interfaces. The system was used to study application performance and reliability issues during both normal and faulted operation.

  17. Small-scale coronal structure, part 3

    NASA Technical Reports Server (NTRS)

    Webb, David F.

    1986-01-01

    Recent observations and models pertaining specifically to solar coronal bright points (BPs) and generally to small-scale coronal structure are reviewed. Two questions were addressed: What is the degree of correspondence among various alleged signatures of BPs at different levels of atmosphere and what can PBs tell about the emerging flux spectrum of the sun?

  18. Rotor dynamic considerations for large wind power generator systems

    NASA Technical Reports Server (NTRS)

    Ormiston, R. A.

    1973-01-01

    Successful large, reliable, low maintenance wind turbines must be designed with full consideration for minimizing dynamic response to aerodynamic, inertial, and gravitational forces. Much of existing helicopter rotor technology is applicable to this problem. Compared with helicopter rotors, large wind turbines are likely to be relatively less flexible with higher dimensionless natural frequencies. For very large wind turbines, low power output per unit weight and stresses due to gravitational forces are limiting factors. The need to reduce rotor complexity to a minimum favors the use of cantilevered (hingeless) rotor configurations where stresses are relieved by elastic deformations.

  19. Economic analysis of wind-powered crop drying. Final report

    SciTech Connect

    Garling, W.S.; Harper, M.R.; Merchant-Geuder, L.; Welch, M.

    1980-03-01

    Potential applications of wind energy include not only large central turbines that can be utilized by utilities, but also dispersed systems for farms and other applications. The US Departments of Energy (DOE) and Agriculture (USDA) currently are establishing the feasibility of wind energy use in applications where the energy can be used as available, or stored in a simple form. These applications include production of hot water for rural sanitation, heating and cooling of rural structures and products, drying agricultural products, and irrigation. This study, funded by USDA, analyzed the economic feasibility of wind power in crop drying. Drying of corn, soybeans, rice, peanuts, tobacco, and dehydrated alfalfa were addressed.

  20. Power quality control of an autonomous wind-diesel power system based on hybrid intelligent controller.

    PubMed

    Ko, Hee-Sang; Lee, Kwang Y; Kang, Min-Jae; Kim, Ho-Chan

    2008-12-01

    Wind power generation is gaining popularity as the power industry in the world is moving toward more liberalized trade of energy along with public concerns of more environmentally friendly mode of electricity generation. The weakness of wind power generation is its dependence on nature-the power output varies in quite a wide range due to the change of wind speed, which is difficult to model and predict. The excess fluctuation of power output and voltages can influence negatively the quality of electricity in the distribution system connected to the wind power generation plant. In this paper, the authors propose an intelligent adaptive system to control the output of a wind power generation plant to maintain the quality of electricity in the distribution system. The target wind generator is a cost-effective induction generator, while the plant is equipped with a small capacity energy storage based on conventional batteries, heater load for co-generation and braking, and a voltage smoothing device such as a static Var compensator (SVC). Fuzzy logic controller provides a flexible controller covering a wide range of energy/voltage compensation. A neural network inverse model is designed to provide compensating control amount for a system. The system can be optimized to cope with the fluctuating market-based electricity price conditions to lower the cost of electricity consumption or to maximize the power sales opportunities from the wind generation plant.

  1. Toward improved statistical treatments of wind power forecast errors

    NASA Astrophysics Data System (ADS)

    Hart, E.; Jacobson, M. Z.

    2011-12-01

    The ability of renewable resources to reliably supply electric power demand is of considerable interest in the context of growing renewable portfolio standards and the potential for future carbon markets. Toward this end, a number of probabilistic models have been applied to the problem of grid integration of intermittent renewables, such as wind power. Most of these models rely on simple Markov or autoregressive models of wind forecast errors. While these models generally capture the bulk statistics of wind forecast errors, they often fail to reproduce accurate ramp rate distributions and do not accurately describe extreme forecast error events, both of which are of considerable interest to those seeking to comment on system reliability. The problem often lies in characterizing and reproducing not only the magnitude of wind forecast errors, but also the timing or phase errors (ie. when a front passes over a wind farm). Here we compare time series wind power data produced using different forecast error models to determine the best approach for capturing errors in both magnitude and phase. Additionally, new metrics are presented to characterize forecast quality with respect to both considerations.

  2. Key challenges of offshore wind power: Three essays addressing public acceptance, stakeholder conflict, and wildlife impacts

    NASA Astrophysics Data System (ADS)

    Bates, Alison Waterbury

    been proposed. The essay examines how the public considers the societal tradeoffs that are made to develop small-scale, in-view demonstration wind projects instead of larger facilities farther offshore. Results indicate that a strong majority of the public supports near-shore demonstration wind projects in both states. Primary reasons for support include benefits to wildlife, cost of electricity, and job creation, while the primary reasons for opposition include wildlife impacts, aesthetics, tourism, and user conflicts. These factors differ between coastal Delaware and greater Atlantic City and highlight the importance of local, community engagement in the early stages of development. The second essay examines the interaction of a new proposed use of the ocean---offshore wind---and a key existing ocean user group---commercial fishers. A key component of offshore wind planning includes consideration of existing uses of the marine environment in order to optimally site wind projects while minimizing conflicts. Commercial fisheries comprise an important stakeholder group, and may be one of the most impacted stakeholders from offshore renewable energy development. Concern of the fishing industry stems from possible interference with productive fishing grounds and access within wind developments resulting in costs from increased effort or reduction in catch. Success of offshore wind development may in part depend on the acceptance of commercial fishers, who are concerned about loss of access to fishing grounds. Using a quantitative, marine spatial planning approach in the siting of offshore wind projects with respect to commercial fishing in the mid-Atlantic, U.S., this essay develops a spatially explicit representation of potential conflicts and compatibilities between these two industries in the mid-Atlantic region of the United States. Areas that are highly valuable to the wind industry are determined through a spatial suitability model using variable cost per unit

  3. Yaw-Misalignment and its Impact on Wind Turbine Loads and Wind Farm Power Output

    NASA Astrophysics Data System (ADS)

    van Dijk, Mike T.; van Wingerden, Jan-Willem; Ashuri, Turaj; Li, Yaoyu; Rotea, Mario A.

    2016-09-01

    To make wind energy cost competitive with traditional resources, wind turbines are commonly placed in groups. Aerodynamic interaction between the turbines causes sub-optimal energy production. A control strategy to mitigate these losses is by redirecting the wake by yaw misalignment. This paper aims to assess the influence of load variations of the rotor due to partial wake overlap and presents a combined optimization of the power and loads using wake redirection. For this purpose, we design a computational framework which computes the wind farm power production and the wind turbine rotor loads based on the yaw settings. The simulation results show that partial wake overlap can significantly increase asymmetric loading of the rotor disk and that yaw misalignment is beneficial in situations where the wake can be sufficiently directed away from the downstream turbine.

  4. Description of the US Army small-scale 2-meter rotor test system

    NASA Technical Reports Server (NTRS)

    Phelps, Arthur E., III; Berry, John D.

    1987-01-01

    A small-scale powered rotor model was designed for use as a research tool in the exploratory testing of rotors and helicopter models. The model, which consists of a 29 hp rotor drive system, a four-blade fully articulated rotor, and a fuselage, was designed to be simple to operate and maintain in wind tunnels of moderate size and complexity. Two six-component strain-gauge balances are used to provide independent measurement of the rotor and fuselage aerodynamic loads. Commercially available standardized hardware and equipment were used to the maximum extent possible, and specialized parts were designed so that they could be fabricated by normal methods without using highly specialized tooling. The model was used in a hover test of three rotors having different planforms and in a forward flight investigation of a 21-percent-scale model of a U.S. Army scout helicopter equipped with a mast-mounted sight.

  5. Compensation for Harmonic Currents and Reactive Power in Wind Power Generation System using PWM Inverter

    NASA Astrophysics Data System (ADS)

    Shinohara, Katsuji; Shinhatsubo, Kurato; Iimori, Kenichi; Yamamoto, Kichiro; Saruban, Takamichi; Yamaemori, Takahiro

    In recent year, consciousness of environmental problems is enhancing, and the price of the electric power purchased by an electric power company is established expensive for the power plant utilizing the natural energy. So, the introduction of the wind power generation is promoted in Japan. Generally, squirrel-cage induction machines are widely used as a generator in wind power generation system because of its small size, lightweight and low-cost. However, the induction machines do not have a source of excitation. Thus, it causes the inrush currents and the instantaneous voltage drop when the generator is directly connected to a power grid. To reduce the inrush currents, an AC power regulator is used. Wind power generations are frequently connected to and disconnected from the power grid. However, when the inrush currents are reduced, harmonic currents are caused by phase control of the AC power regulator. And the phase control of AC power regulator cannot control the power factor. Therefore, we propose the use of the AC power regulator to compensate for the harmonic currents and reactive power in the wind power generation system, and demonstrate the validity of its system by simulated and experimental results.

  6. Fouling assemblages on offshore wind power plants and adjacent substrata

    NASA Astrophysics Data System (ADS)

    Wilhelmsson, Dan; Malm, Torleif

    2008-09-01

    A significant expansion of offshore wind power is expected in the near future, with thousands of turbines in coastal waters, and various aspects of how this may influence the coastal ecology including disturbance effects from noise, shadows, electromagnetic fields, and changed hydrological conditions are accordingly of concern. Further, wind power plants constitute habitats for a number of organisms, and may locally alter assemblage composition and biomass of invertebrates, algae and fish. In this study, fouling assemblages on offshore wind turbines were compared to adjacent hard substrate. Influences of the structures on the seabed were also investigated. The turbines differed significantly from adjacent boulders in terms of assemblage composition of epibiota and motile invertebrates. Species number and Shannon-Wiener diversity were, also, significantly lower on the wind power plants. It was also indicated that the turbines might have affected assemblages of invertebrates and algae on adjacent boulders. Off shore wind power plant offer atypical substrates for fouling assemblages in terms of orientation, depth range, structure, and surface texture. Some potential ecological implications of the addition of these non-natural habitats for coastal ecology are discussed.

  7. GPP Webinar: Market Outlook and Innovations in Wind and Solar Power

    EPA Pesticide Factsheets

    Green Power Partnership webinar reviewing the state of the renewable energy industry as a whole, with a focus on wind and solar power and exploring recent marketplace innovations in wind and solar power and renewable energy purchases.

  8. Unit commitment with wind power generation: integrating wind forecast uncertainty and stochastic programming.

    SciTech Connect

    Constantinescu, E. M.; Zavala, V. M.; Rocklin, M.; Lee, S.; Anitescu, M.

    2009-10-09

    We present a computational framework for integrating the state-of-the-art Weather Research and Forecasting (WRF) model in stochastic unit commitment/energy dispatch formulations that account for wind power uncertainty. We first enhance the WRF model with adjoint sensitivity analysis capabilities and a sampling technique implemented in a distributed-memory parallel computing architecture. We use these capabilities through an ensemble approach to model the uncertainty of the forecast errors. The wind power realizations are exploited through a closed-loop stochastic unit commitment/energy dispatch formulation. We discuss computational issues arising in the implementation of the framework. In addition, we validate the framework using real wind speed data obtained from a set of meteorological stations. We also build a simulated power system to demonstrate the developments.

  9. Windmills: Ancestors of the wind power generation

    NASA Astrophysics Data System (ADS)

    Rossi, Cesare; Russo, Flavio; Savino, Sergio

    2016-12-01

    A brief description of the windmills from the second millennium BC to the Renaissance is presented. This survey is a part of several studies conducted by the authors on technology in the ancient world. The windmills are the first motor, other than human muscles, and are the ancestors of the modern wind turbines. Some authors' virtual reconstructions of old windmills are also presented. The paper shows that the operating principle of many modern machines had already been conceived in the ancient times by using a technology that was more advanced than expected, but with two main differences, as follows: Similar tasks were accomplished by using much less energy; and the environmental impact was nil or very low. Modern designers should sometimes consider simplicity rather than the use of a large amount of energy.

  10. Using Bayes Model Averaging for Wind Power Forecasts

    NASA Astrophysics Data System (ADS)

    Preede Revheim, Pål; Beyer, Hans Georg

    2014-05-01

    For operational purposes predictions of the forecasts of the lumped output of groups of wind farms spread over larger geographic areas will often be of interest. A naive approach is to make forecasts for each individual site and sum them up to get the group forecast. It is however well documented that a better choice is to use a model that also takes advantage of spatial smoothing effects. It might however be the case that some sites tends to more accurately reflect the total output of the region, either in general or for certain wind directions. It will then be of interest giving these a greater influence over the group forecast. Bayesian model averaging (BMA) is a statistical post-processing method for producing probabilistic forecasts from ensembles. Raftery et al. [1] show how BMA can be used for statistical post processing of forecast ensembles, producing PDFs of future weather quantities. The BMA predictive PDF of a future weather quantity is a weighted average of the ensemble members' PDFs, where the weights can be interpreted as posterior probabilities and reflect the ensemble members' contribution to overall forecasting skill over a training period. In Revheim and Beyer [2] the BMA procedure used in Sloughter, Gneiting and Raftery [3] were found to produce fairly accurate PDFs for the future mean wind speed of a group of sites from the single sites wind speeds. However, when the procedure was attempted applied to wind power it resulted in either problems with the estimation of the parameters (mainly caused by longer consecutive periods of no power production) or severe underestimation (mainly caused by problems with reflecting the power curve). In this paper the problems that arose when applying BMA to wind power forecasting is met through two strategies. First, the BMA procedure is run with a combination of single site wind speeds and single site wind power production as input. This solves the problem with longer consecutive periods where the input data

  11. Water-supported wind actuated power generating assembly

    SciTech Connect

    Hoar, R.A.

    1982-02-23

    A counterweighted elongate buoyant body that floats on the surface of the sea or a lake has at least one sail supporting mast extending upwardly therefrom as well as vanes that tend to maintain the sails substantially normal to the direction of movement of the wind. The buoyant body is by frame means maintained within the confines of a circular series of piles. The counterweight and means for pivoting each sail from a position normal to the direction of the wind to substantially parallel thereto cooperate to impart a transverse rocking motion to the buoyant body that has an eccentric transverse arcuate member depending therefrom that is engaged by a pair of rollers, as the transverse member moves relative to the pair of rollers a bellows is receprocated upwardly and downwardly to draw water into and discharge it from a check valve controlled confined space to a reservoir situated at a substantial distance above the surface of the body of water. Water discharges by gravity from the reservoir to a turbine or the like to power a generator to produce electricity for power purposes. Power means pivot the sails substantially parallel to the direction of the wind after the latter has rolled the buoyant body to a first position. The counterweight then rolls the buoyant body to a second position where upon the power means pivot the sails to positions substantially normal to the direction of the wind to start another power generating cycle.

  12. Air emissions due to wind and solar power.

    PubMed

    Katzenstein, Warren; Apt, Jay

    2009-01-15

    Renewables portfolio standards (RPS) encourage large-scale deployment of wind and solar electric power. Their power output varies rapidly, even when several sites are added together. In many locations, natural gas generators are the lowest cost resource available to compensate for this variability, and must ramp up and down quickly to keep the grid stable, affecting their emissions of NOx and CO2. We model a wind or solar photovoltaic plus gas system using measured 1-min time-resolved emissions and heat rate data from two types of natural gas generators, and power data from four wind plants and one solar plant. Over a wide range of renewable penetration, we find CO2 emissions achieve approximately 80% of the emissions reductions expected if the power fluctuations caused no additional emissions. Using steam injection, gas generators achieve only 30-50% of expected NOx emissions reductions, and with dry control NOx emissions increase substantially. We quantify the interaction between state RPSs and NOx constraints, finding that states with substantial RPSs could see significant upward pressure on NOx permit prices, if the gas turbines we modeled are representative of the plants used to mitigate wind and solar power variability.

  13. Small Scale Equidistribution of Random Eigenbases

    NASA Astrophysics Data System (ADS)

    Han, Xiaolong

    2017-01-01

    We investigate small scale equidistribution of random orthonormal bases of eigenfunctions (i.e., eigenbases) on a compact manifold M. Assume that the group of isometries acts transitively on M and the multiplicity {m_λ} of eigenfrequency {λ} tends to infinity at least logarithmically as {λ to ∞}. We prove that, with respect to the natural probability measure on the space of eigenbases, almost surely a random eigenbasis is equidistributed at small scales; furthermore, the scales depend on the growth rate of {m_λ}. In particular, this implies that almost surely random eigenbases on the sphere S^n ({n ≥ 2}) and the tori T^n ({n ≥ 5}) are equidistributed at polynomial scales.

  14. DOE small scale fuel alcohol plant design

    SciTech Connect

    LaRue, D.M.; Richardson, J.G.

    1980-01-01

    The Department of Energy, in an effort to facilitate the deployment of rural-based ethanol production capability, has undertaken this effort to develop a basic small-scale plant design capable of producing anhydrous ethanol. The design, when completed, will contain all necessary specifications and diagrams sufficient for the construction of a plant. The design concept is modular; that is, sections of the plant can stand alone or be integrated into other designs with comparable throughput rates. The plant design will be easily scaled up or down from the designed flow rate of 25 gallons of ethanol per hour. Conversion factors will be provided with the final design package to explain scale-up and scale-down procedures. The intent of this program is to provide potential small-scale producers with sound information about the size, engineering requirements, costs and level of effort in building such a system.

  15. On the effect of spatial dispersion of wind power plants on the wind energy capacity credit in Greece

    NASA Astrophysics Data System (ADS)

    Caralis, George; Perivolaris, Yiannis; Rados, Konstantinos; Zervos, Arthouros

    2008-01-01

    Wind energy is now a mature technology and can be considered as a significant contributor in reducing CO2 emissions and protecting the environment. To meet the wind energy national targets, effective implementation of massive wind power installed capacity in the power supply system is required. Additionally, capacity credit is an important issue for an unstable power supply system as in Greece. To achieve high and reliable wind energy penetration levels into the system, the effect of spatial dispersion of wind energy installations within a very wide area (e.g. national level) on the power capacity credit should be accounted for. In the present paper, a methodology for estimating the effect of spatial dispersion of wind farm installations on the capacity credit is presented and applied for the power supply system of Greece. The method is based on probability theory and makes use of wind forecasting models to represent the wind energy potential over any candidate area for future wind farm installations in the country. Representative wind power development scenarios are studied and evaluated. Results show that the spatial dispersion of wind power plants contributes beneficially to the wind capacity credit.

  16. Power Control of New Wind Power Generation System with Induction Generator Excited by Voltage Source Converter

    NASA Astrophysics Data System (ADS)

    Morizane, Toshimitsu; Kimura, Noriyuki; Taniguchi, Katsunori

    This paper investigates advantages of new combination of the induction generator for wind power and the power electronic equipment. Induction generator is popularly used for the wind power generation. The disadvantage of it is impossible to generate power at the lower rotor speed than the synchronous speed. To compensate this disadvantage, expensive synchronous generator with the permanent magnets is sometimes used. In proposed scheme, the diode rectifier is used to convert the real power from the induction generator to the intermediate dc voltage, while only the reactive power necessary to excite the induction generator is supplied from the voltage source converter (VSC). This means that the rating of the expensive VSC is minimized and total cost of the wind power generation system is decreased compared to the system with synchronous generator. Simulation study to investigate the control strategy of proposed system is performed. The results show the reduction of the VSC rating is prospective.

  17. An optimal sizing method for energy storage system in wind farms based on the analysis of wind power forecast error

    NASA Astrophysics Data System (ADS)

    Ye, R. L.; Guo, Z. Z.; Liu, R. Y.; Liu, J. N.

    2016-11-01

    Energy storage system (ESS) in a wind farm can effectively compensate the fluctuations of wind power. How to determine the size of ESS in wind farms is an urgent problem to be solved. A novel method is proposed for designing the optimal size of ESS considering wind power uncertainty. This approach uses non-parametric estimation method to analysis the wind power forecast error (WPFE) and the cumulative wind power deviation (CWPD) within the scheduling period. Then a cost-benefit analysis model is established to obtain the optimal size of ESS based on the analysis of WPFE and CWPD. A series of wind farm data in California are used as numerical cases, which presents that the algorithm presented in this paper has good feasibility and performance in optimal ESS sizing in wind farms.

  18. Short term fluctuations of wind and solar power systems

    NASA Astrophysics Data System (ADS)

    Anvari, M.; Lohmann, G.; Wächter, M.; Milan, P.; Lorenz, E.; Heinemann, D.; Rahimi Tabar, M. Reza; Peinke, Joachim

    2016-06-01

    Wind and solar power are known to be highly influenced by weather events and may ramp up or down abruptly. Such events in the power production influence not only the availability of energy, but also the stability of the entire power grid. By analysing significant amounts of data from several regions around the world with resolutions of seconds to minutes, we provide strong evidence that renewable wind and solar sources exhibit multiple types of variability and nonlinearity in the time scale of seconds and characterise their stochastic properties. In contrast to previous findings, we show that only the jumpy characteristic of renewable sources decreases when increasing the spatial size over which the renewable energies are harvested. Otherwise, the strong non-Gaussian, intermittent behaviour in the cumulative power of the total field survives even for a country-wide distribution of the systems. The strong fluctuating behaviour of renewable wind and solar sources can be well characterised by Kolmogorov-like power spectra and q-exponential probability density functions. Using the estimated potential shape of power time series, we quantify the jumpy or diffusive dynamic of the power. Finally we propose a time delayed feedback technique as a control algorithm to suppress the observed short term non-Gaussian statistics in spatially strong correlated and intermittent renewable sources.

  19. Small Scale Water Disinfection for Military Purposes

    DTIC Science & Technology

    1990-01-01

    AD-A268 654 Small scale water disinfection for military purposes. Gary Thomson DSTO DoGC Materials Research Laboratory ELECTE P.O. Box 147 m...Scottsdale AUG 2 4 •9 3 1. SUMTasmania 7260 E When a military force is in the field, it is impossible to apply at all times the normal practices of water ...purification such as coagulation, flocculation, sedimentation, filtration and chlorination used for a municipal water supply. For personnel who are

  20. Development and testing of improved statistical wind power forecasting methods.

    SciTech Connect

    Mendes, J.; Bessa, R.J.; Keko, H.; Sumaili, J.; Miranda, V.; Ferreira, C.; Gama, J.; Botterud, A.; Zhou, Z.; Wang, J.

    2011-12-06

    Wind power forecasting (WPF) provides important inputs to power system operators and electricity market participants. It is therefore not surprising that WPF has attracted increasing interest within the electric power industry. In this report, we document our research on improving statistical WPF algorithms for point, uncertainty, and ramp forecasting. Below, we provide a brief introduction to the research presented in the following chapters. For a detailed overview of the state-of-the-art in wind power forecasting, we refer to [1]. Our related work on the application of WPF in operational decisions is documented in [2]. Point forecasts of wind power are highly dependent on the training criteria used in the statistical algorithms that are used to convert weather forecasts and observational data to a power forecast. In Chapter 2, we explore the application of information theoretic learning (ITL) as opposed to the classical minimum square error (MSE) criterion for point forecasting. In contrast to the MSE criterion, ITL criteria do not assume a Gaussian distribution of the forecasting errors. We investigate to what extent ITL criteria yield better results. In addition, we analyze time-adaptive training algorithms and how they enable WPF algorithms to cope with non-stationary data and, thus, to adapt to new situations without requiring additional offline training of the model. We test the new point forecasting algorithms on two wind farms located in the U.S. Midwest. Although there have been advancements in deterministic WPF, a single-valued forecast cannot provide information on the dispersion of observations around the predicted value. We argue that it is essential to generate, together with (or as an alternative to) point forecasts, a representation of the wind power uncertainty. Wind power uncertainty representation can take the form of probabilistic forecasts (e.g., probability density function, quantiles), risk indices (e.g., prediction risk index) or scenarios

  1. Effect of accuracy of wind power prediction on power system operator

    NASA Technical Reports Server (NTRS)

    Schlueter, R. A.; Sigari, G.; Costi, T.

    1985-01-01

    This research project proposed a modified unit commitment that schedules connection and disconnection of generating units in response to load. A modified generation control is also proposed that controls steam units under automatic generation control, fast responding diesels, gas turbines and hydro units under a feedforward control, and wind turbine array output under a closed loop array control. This modified generation control and unit commitment require prediction of trend wind power variation one hour ahead and the prediction of error in this trend wind power prediction one half hour ahead. An improved meter for predicting trend wind speed variation is developed. Methods for accurately simulating the wind array power from a limited number of wind speed prediction records was developed. Finally, two methods for predicting the error in the trend wind power prediction were developed. This research provides a foundation for testing and evaluating the modified unit commitment and generation control that was developed to maintain operating reliability at a greatly reduced overall production cost for utilities with wind generation capacity.

  2. Estimation of power in low velocity vertical axis wind turbine

    NASA Astrophysics Data System (ADS)

    Sampath, S. S.; Shetty, Sawan; Chithirai Pon Selvan, M.

    2015-06-01

    The present work involves in the construction of a vertical axis wind turbine and the determination of power. Various different types of turbine blades are considered and the optimum blade is selected. Mechanical components of the entire setup are built to obtain maximum rotation per minute. The mechanical energy is converted into the electrical energy by coupling coaxially between the shaft and the generator. This setup produces sufficient power for consumption of household purposes which is economic and easily available.

  3. Wind Power Project Repowering: History, Economics, and Demand (Presentation)

    SciTech Connect

    Lantz, E.

    2015-01-01

    This presentation summarizes a related NREL technical report and seeks to capture the current status of wind power project repowering in the U.S. and globally, analyze the economic and financial decision drivers that surround repowering, and to quantify the level and timing of demand for new turbine equipment to supply the repowering market.

  4. Control of wind turbine generators connected to power systems

    NASA Technical Reports Server (NTRS)

    Hwang, H. H.; Mozeico, H. V.; Gilbert, L. J.

    1978-01-01

    A unique simulation model based on a Mode-O wind turbine is developed for simulating both speed and power control. An analytical representation for a wind turbine that employs blade pitch angle feedback control is presented, and a mathematical model is formulated. For Mode-O serving as a practical case study, results of a computer simulation of the model as applied to the problems of synchronization and dynamic stability are provided. It is shown that the speed and output of a wind turbine can be satisfactorily controlled within reasonable limits by employing the existing blade pitch control system under specified conditions. For power control, an additional excitation control is required so that the terminal voltage, output power factor, and armature current can be held within narrow limits. As a result, the variation of torque angle is limited even if speed control is not implemented simultaneously with power control. Design features of the ERDA/NASA 100-kW Mode-O wind turbine are included.

  5. Wind turbine power curve prediction with consideration of rotational augmentation effects

    NASA Astrophysics Data System (ADS)

    Tang, X.; Huang, X.; Sun, S.; Peng, R.

    2016-11-01

    Wind turbine power curve expresses the relationship between the rotor power and the hub wind speed. Wind turbine power curve prediction is of vital importance for power control and wind energy management. To predict power curve, the Blade Element Moment (BEM) method is used in both academic and industrial communities. Due to the limited range of angles of attack measured in wind tunnel testing and the three-dimensional (3D) rotational augmentation effects in rotating turbines, wind turbine power curve prediction remains a challenge especially at high wind speeds. This paper presents an investigation of considering the rotational augmentation effects using characterized lift and drag coefficients from 3D computational fluid dynamics (CFD) simulations coupled in the BEM method. A Matlab code was developed to implement the numerical calculation. The predicted power outputs were compared with the NREL Phase VI wind turbine measurements. The results demonstrate that the coupled method improves the wind turbine power curve prediction.

  6. EMERGENCE OF THE KENNICUTT-SCHMIDT RELATION FROM THE SMALL-SCALE SFR-DENSITY RELATION

    SciTech Connect

    Gnedin, Nickolay Y.; Tasker, Elizabeth J.; Fujimoto, Yusuke

    2014-05-20

    We use simulations of isolated galaxies with a few parsec resolution to explore the connection between the small-scale star formation rate (SFR)-gas density relation and the induced large-scale correlation between the SFR surface density and the surface density of the molecular gas (the Kennicutt-Schmidt relation). We find that, in the simulations, a power-law small-scale ''star formation law'' directly translates into an identical power-law Kennicutt-Schmidt relation. If this conclusion holds in the reality as well, it implies that the observed approximately linear Kennicutt-Schmidt relation must reflect the approximately linear small-scale ''star formation law''.

  7. Wind Farm Monitoring at Storm Lake I Wind Power Project -- Equipment Only: Cooperative Research and Development Final Report, CRADA Number CRD-10-369

    SciTech Connect

    Gevorgian, Vahan

    2015-07-09

    Long-term, high-resolution wind turbine and wind power plant output data are important to assess the impact of wind power on grid operations and to derive meaningful statistics for better understanding of the variability of wind power. These data are used for many research and analysis activities consistent with the Wind Program mission.

  8. Satellite observations of the small-scale cyclonic eddies in the western South China Sea

    NASA Astrophysics Data System (ADS)

    Liu, F.; Tang, S.; Chen, C.

    2015-01-01

    High-resolution ocean color observations offer an opportunity to investigate the oceanic small-scale processes. In this study, the Medium Resolution Imaging Spectrometer (MERIS) daily 300 m data were used to study small-scale processes in the western South China Sea. It is indicated that the cyclonic eddies with horizontal scales of 10 km are frequently observed during the upwelling season of each year over the 2004-2009 period. These small-scale eddies were generated in the vicinity of the southern front of the cold tongue, and then propagated eastward with a speed of approximately 12 cm s-1. This propagation speed was consistent with the velocity of the western boundary current. As a result, the small-scale eddies kept the high levels of phytoplankton rotating away from the coastal areas, resulting in the accumulation of phytoplankton in the interior of the eddies. The generation of the small-scale eddies may be associated with strengthening of the relative movement between the rotation speed of the anticyclonic mesoscale eddies and the offshore transport. With the increases of the normalized rotation speed of the anticyclonic mesoscale eddies relative to the offshore transport, the offshore current became a meander under the impacts of the anticyclonic mesoscale eddies. The meandered cold tongue and instability front may stimulate the generation of the small-scale eddies. Unidirectional uniform wind along the cold tongue may also contribute to the formation of the small-scale eddies.

  9. Network Wind Power Over the Pacific Northwest. Progress Report, October 1979-September 1980.

    SciTech Connect

    Baker, Robert W.; Hewson, E. Wendell

    1980-10-01

    The research in FY80 is composed of six primary tasks. These tasks include data collection and analysis, wind flow studies around an operational wind turbine generator (WTG), kite anemometer calibration, wind flow analysis and prediction, the Klickitat County small wind energy conversion system (SWECS) program, and network wind power analysis. The data collection and analysis task consists of four sections, three of which deal with wind flow site surveys and the fourth with collecting and analyzing wind data from existing data stations. This report also includes an appendix which contains mean monthly wind speed data summaries, wind spectrum summaries, time series analysis plots, and high wind summaries.

  10. Research on unit commitment with large-scale wind power connected power system

    NASA Astrophysics Data System (ADS)

    Jiao, Ran; Zhang, Baoqun; Chi, Zhongjun; Gong, Cheng; Ma, Longfei; Yang, Bing

    2017-01-01

    Large-scale integration of wind power generators into power grid brings severe challenges to power system economic dispatch due to its stochastic volatility. Unit commitment including wind farm is analyzed from the two parts of modeling and solving methods. The structures and characteristics can be summarized after classification has been done according to different objective function and constraints. Finally, the issues to be solved and possible directions of research and development in the future are discussed, which can adapt to the requirements of the electricity market, energy-saving power generation dispatching and smart grid, even providing reference for research and practice of researchers and workers in this field.

  11. A Magnetar Wind Nebula: the Spin-down-Powered Wind is not Enough

    NASA Astrophysics Data System (ADS)

    Gill, Ramandeep; Granot, Jonathan; Baring, Matthew G.; Gelfand, Joseph; Younes, George A.; Kargaltsev, Oleg; Kust Harding, Alice; Kouveliotou, Chryssa; Huppenkothen, Daniela

    2016-04-01

    Magnetars are a small class of slowly-rotating (P~2-12 s) highly magnetized (surface dipole fields ~10^{14}-10^{15} G) that show a variety of bursting activity, powered by the decay of their super-strong magnetic field. While many rotation-powered pulsars are surrounded by a pulsar wind nebula (PWN) powered by their spin-down MHD wind (the prime example being the Crab nebula), only now has the first magnetar wind nebula (MWN) been discovered in X-rays, around Swift J1834.9-0846. We have analyzed this system in detail to see what can be learned from it. We find good evidence that unlike normal PWNe, this MWN cannot be powered by its spin-down MHD wind alone. A considerable contribution to the MWN energy should come from a different source, most likely sporadic outflows associated with the magnetar's bursting activity. This suggests that the MWN may serve as a calorimeter, and provide a new and robust estimate for the magnetar's long-term mean energy output rate in outflows. We also discuss other interesting aspects of this system.

  12. French wind power generation programme EOLE 2005 - first results

    SciTech Connect

    Laali, A.R.; Benard, M.

    1997-12-31

    EOLE 2005 has been launched in July 1996 by the French Ministry of Industry, Electricite de France and ADEME (Agency for Environment and Energy Management). The Ministries of Research and Environment are participating also in this programme. The purpose is to create an initial market in France for wind power generation in order to evaluate the cost-effectiveness and the competitiveness of the wind energy compared to other energy sources by 2005. The installed capacity will reach at least 250 MW and possibly 500 MW.

  13. Performance and flow analysis of vortex wind power turbines

    SciTech Connect

    Rangwalla, A.A.; Hsu, C.T.

    1982-10-01

    The theoretical study presented investigates some possible vortex flow solutions in the tornado-type wind energy system and evaluates the power coefficient that can be obtained theoretically. The actuator disc concept is applied to the vortex wind turbine configuration. The Burgers vortex model is then introduced and the performance of a turbine using it is derived. A generalized analytical solution of the model is given, followed by a numerical solution of the complete equations. The stability of a Burgers vortex is discussed. (LEW)

  14. Quantifying the Hurricane Risk to Offshore Wind Power (Invited)

    NASA Astrophysics Data System (ADS)

    Apt, J.; Rose, S.; Jaramillo, P.; Small, M.

    2013-12-01

    The U.S. Department of Energy has estimated that over 50 GW of offshore wind power will be required for the United States to generate 20% of its electricity from wind. Developers are actively planning offshore wind farms along the U.S. Atlantic and Gulf coasts and several leases have been signed for offshore sites. These planned projects are in areas that are sometimes struck by hurricanes. Whether that risk will grow as a result of climate change is uncertain. Recent years have seen an increase in hurricane activity in the Atlantic basin (1) and, all else being equal, warmer sea surface temperatures can be expected to lead to increased storm intensity. We have developed a method to estimate the catastrophe risk to offshore wind power using simulated hurricanes (2). In Texas, the most vulnerable region we studied, 10% of offshore wind power could be offline simultaneously due to hurricane damage with a 100-year return period and 6% could be destroyed in any 10-year period. Much of the hurricane risk to offshore wind turbines can be mitigated by designing turbines for higher maximum wind speeds, ensuring that turbine nacelles can turn quickly to track the wind direction even when grid power is lost, and building in areas with lower risk. 1. Iris Grossmann and M. Granger Morgan, "Tropical Cyclones, Climate Change, and Scientific Uncertainty: What do we know, what does it mean, and what should be done?," Climatic Change, 108, pp 543-579, 2011. 2. Carnegie Mellon Electricity Industry Center Working Paper CEIC-13-07, http://wpweb2.tepper.cmu.edu/electricity/papers/ceic-13-07.asp This work was supported in part by the EPA STAR fellowship program, a grant from the Alfred P. Sloan Foundation and EPRI to the Carnegie Mellon Electricity Industry Center, and by the Doris Duke Charitable Foundation, the R.K. Mellon Foundation and the Heinz Endowments for support of the RenewElec program at Carnegie Mellon University. This research was also supported in part by the Climate and

  15. Security, protection, and control of power systems with large-scale wind power penetration

    NASA Astrophysics Data System (ADS)

    Acharya, Naresh

    As the number of wind generation facilities in the utility system is fast increasing, many issues associated with their integration into the power system are beginning to emerge. Of the various issues, this dissertation deals with the development of new concepts and computational methods to handle the transmission issues and voltage issues caused by large-scale integration of wind turbines. This dissertation also formulates a probabilistic framework for the steady-state security assessment of wind power incorporating the forecast uncertainty and correlation. Transmission issues are mainly related to the overloading of transmission lines, when all the wind power generated cannot be delivered in full due to prior outage conditions. To deal with this problem, a method to curtail the wind turbine outputs through Energy Management System facilities in the on-line operational environment is proposed. The proposed method, which is based on linear optimization, sends the calculated control signals via the Supervisory Control and Data Acquisition system to wind farm controllers. The necessary ramping of the wind farm outputs is implemented either by the appropriate blade pitch angle control at the turbine level or by switching a certain number of turbines. The curtailment strategy is tested with an equivalent system model of MidAmerican Energy Company. The results show that the line overload in high wind areas can be alleviated by controlling the outputs of the wind farms step-by-step over an allowable period of time. A low voltage event during a system fault can cause a large number of wind turbines to trip, depending on voltages at the wind turbine terminals during the fault and the under-voltage protection setting of wind turbines. As a result, an N-1 contingency may evolve into an N-(K+1) contingency, where K is the number of wind farms tripped due to low voltage conditions. Losing a large amount of wind power following a line contingency might lead to system

  16. Decentralized robust frequency control for power systems subject to wind power variability

    NASA Astrophysics Data System (ADS)

    Liu, Juhua

    As the penetration of wind energy generation increases in electric power systems, the frequency performance degrades mainly for two reasons. First, the intermittency of wind power introduces additional generation-load imbalance in the system, causing frequency to deviate from nominal values. Second, modern wind turbine generators are often decoupled from the grid by power electronics, making the wind turbines contribute no inertia to the grid. When more conventional generation is displaced by such wind generation, the total system inertia will decrease and the grid is more susceptible to generation-load imbalance. Therefore, frequency control must be revisited and enhanced in order to accommodate large-scale integration of wind energy. This dissertation mainly concerns the re-design of generator compensators to improve frequency performance of power systems when the penetration of wind power is high. Hinfinity methods can be used to synthesize controllers to achieve stability and robust performance in the presence disturbances. However, standard Hinfinity methods tend to produce complex controllers when the order of the system is high. Furthermore, when standard Hinfinity methods are continued with a naive decentralized control design, the resulting decentralized controllers may compete against each other and lead to instability. Therefore, we develop a passivity-based decentralized control framework for power system frequency control. A storage function is derived from the entropy of individual generators. Tellegen's theorem is invoked to derive the storage function for the entire power network. With this storage function, the power network is shown to be passive with respect to a supply rate, which is the sum of decentralized input-output products. Stability can then be assured when passive controllers are connected in negative feedback interconnection to the system. Proportional-integral-derivative (PID) controllers with positive gains are passive controllers

  17. Small-scale physics of the ocean

    NASA Technical Reports Server (NTRS)

    Caldwell, Douglas R.

    1987-01-01

    Observations and theoretical models of small-scale phenomena in the oceans are reviewed, with a focus on progress during the period 1983-1986. Topics examined include surface layers, equatorial turbulence, off-equator mixed layers, the scaling of mixing, turbulence concepts, laboratory results, internal waves and mixing, rings, the nature of the bottom layer, double diffusion and intrusions, salt fingers, and biological interactions. Also discussed are developments in instrumentation (fast sampling profilers with upward-profiling capability, deep profilers, ship-motion correction, horizontal samplers, small submersibles, submarines, towed packages, conductivity sensors, dissolved-oxygen sensors, and acoustic Doppler current profilers) and goals for future research.

  18. Wind Power: A Renewable Energy Source for Mars Transit Vehicle

    NASA Technical Reports Server (NTRS)

    Flynn, Michael; Kohout, Lisa; Kliss, Mark (Technical Monitor)

    1998-01-01

    The Martian environment presents significant design challenges for the development of power generation systems. Nuclear-based systems may not be available due to political and safety concerns. The output of photovoltaics are limited by a solar intensity of 580 W/sqm as compared to 1353 W/sqm on Earth. The presence of dust particles in the Mars atmosphere will further reduce the photovoltaic output. Also, energy storage for a 12-hour night period must be provided. In this challenging environment, wind power generation capabilities may provide a viable option as a Martian power generation system. This paper provides an analysis of the feasibility of such a system.

  19. A short-term ensemble wind speed forecasting system for wind power applications

    NASA Astrophysics Data System (ADS)

    Baidya Roy, S.; Traiteur, J. J.; Callicutt, D.; Smith, M.

    2011-12-01

    This study develops an adaptive, blended forecasting system to provide accurate wind speed forecasts 1 hour ahead of time for wind power applications. The system consists of an ensemble of 21 forecasts with different configurations of the Weather Research and Forecasting Single Column Model (WRFSCM) and a persistence model. The ensemble is calibrated against observations for a 2 month period (June-July, 2008) at a potential wind farm site in Illinois using the Bayesian Model Averaging (BMA) technique. The forecasting system is evaluated against observations for August 2008 at the same site. The calibrated ensemble forecasts significantly outperform the forecasts from the uncalibrated ensemble while significantly reducing forecast uncertainty under all environmental stability conditions. The system also generates significantly better forecasts than persistence, autoregressive (AR) and autoregressive moving average (ARMA) models during the morning transition and the diurnal convective regimes. This forecasting system is computationally more efficient than traditional numerical weather prediction models and can generate a calibrated forecast, including model runs and calibration, in approximately 1 minute. Currently, hour-ahead wind speed forecasts are almost exclusively produced using statistical models. However, numerical models have several distinct advantages over statistical models including the potential to provide turbulence forecasts. Hence, there is an urgent need to explore the role of numerical models in short-term wind speed forecasting. This work is a step in that direction and is likely to trigger a debate within the wind speed forecasting community.

  20. Experimental verification of a real-time power curve for downregulated offshore wind power plants

    NASA Astrophysics Data System (ADS)

    Giebel, Gregor; Göcmen Bozkurt, Tuhfe; Sørensen, Poul; Rajczyk Skjelmose, Mads; Runge Kristoffersen, Jesper

    2015-04-01

    Wind farm scale experiments with wakes under downregulation have been initiated in Horns Rev wind farm in the frame of the PossPOW project (see posspow.dtu.dk). The experiments will be compared with the results of the calibrated GCLarsen wake model for real-time which is used not only to obtain real-time power curve but also to estimate the available power in wind farm level. Available (or Possible) Power is the power that a down-regulated (or curtailed) turbine or a wind power plant would produce if it were to operate in normal operational conditions and it is becoming more of particular interest due to increasing number of curtailment periods. Currently, the Transmission System Operators (TSOs) have no real way to determine exactly the available power of a down-regulated wind farm and the PossPOW project is addressing that need. What makes available power calculation interesting at the wind farm level is the change in the wake characteristics for different operational states. Even though the single turbine level available power is easily estimated, the sum of those signals from all turbines in a wind farm overestimates the power since the wake losses significantly decrease during curtailment. In order to calculate that effect, the turbine wind speed is estimated real-time from the produced power, the pitch angle and the rotor speed using a proximate Cp curve. A real-time wake estimation of normal operation is then performed and advected to the next downstream turbine, and so on until the entire wind farm is calculated. The estimation of the rotor effective wind speed, the parameterization of the GCLarsen wake model for real-time use (i.e., 1-sec data from Horns Rev and Thanet) and the details of the advection are the topic can be found in Göcmen et al. [1] Here we plan to describe the experiments using the Horns Rev wind farm and hopefully present the first validation results. Assuming similarity of the wind speeds between neighbouring rows of turbines, the

  1. Annual Report on U.S. Wind Power Installation, Cost, and Performance Trends: 2007 (Revised)

    SciTech Connect

    Wiser, R.; Bolinger, M.

    2008-05-01

    This report focuses on key trends in the U.S. wind power market, with an emphasis on the latest year, and presents a wealth of data, some of which has not historically been mined by wind power analysts.

  2. Role of third party power producer in wind energy

    SciTech Connect

    Van Dyck, W.K.

    1982-06-01

    Windfarm's recent experiences as a ''third party'' entrepeneur in the development of large scale wind energy projects is reviewed. Two large scale wind turbine generators--the MOD 2 and the MOD 5A--have been demonstrated. As a third party developer Windfarms packages the technology in a way that eliminates risk for the utility and puts that risk on outside institutional and venture capital investors. First, windfarm sites must be identified. An 80,000 kilowatt project has begun at Kahuku Point, Oahu, and another 4,000Kw site on Hawaii. A 350,000 kilowatt windfarm 30 miles northeast of San Francisco has been contracted. Government cuts in the 1982 R and D wind power budget, and a threat of the withdrawal of alternative energy tax credits, have been a major challenge. Windfarms is currently developing ideas to fund additional R and D, in lieu of a $ million DOE cutback.

  3. Proposal for a new design of wind power generator

    NASA Astrophysics Data System (ADS)

    Rosenbrock, H. H.

    A wind turbine design which reduces the size of the actuator disk normally required for a given output from a wind turbine (WT) is presented. An annular enclosure is built around the WT. The annulus features stationary, radial, airfoil blades on the outer radius to provide a hollow cylinder of air with a low pressure center, into which the WT discharges. The WT essentially receives the wind power of a rotor with an actuator disk the size of the intake of the annular space. An example is a 16 m diam rotor running at 300 rpm, surrounded by a 100 m o.d. annulus producing 100 MW between 15-50 m/sec. Fewer fluctuating stresses would be imparted to the blades. Analytical justification for the projections is made through application of the Bernoulli theorem.

  4. Accessing Wind Tunnels From NASA's Information Power Grid

    NASA Technical Reports Server (NTRS)

    Becker, Jeff; Biegel, Bryan (Technical Monitor)

    2002-01-01

    The NASA Ames wind tunnel customers are one of the first users of the Information Power Grid (IPG) storage system at the NASA Advanced Supercomputing Division. We wanted to be able to store their data on the IPG so that it could be accessed remotely in a secure but timely fashion. In addition, incorporation into the IPG allows future use of grid computational resources, e.g., for post-processing of data, or to do side-by-side CFD validation. In this paper, we describe the integration of grid data access mechanisms with the existing DARWIN web-based system that is used to access wind tunnel test data. We also show that the combined system has reasonable performance: wind tunnel data may be retrieved at 50Mbits/s over a 100 base T network connected to the IPG storage server.

  5. 78 FR 33897 - Atlantic Wind Lease Sale 2 (ATLW2) Commercial Leasing for Wind Power on the Outer Continental...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... the Interior Bureau of Ocean Energy Management Atlantic Wind Lease Sale 2 (ATLW2) Commercial Leasing for Wind Power on the Outer Continental Shelf Offshore Rhode Island and Massachusetts-- Final Sale Notice and Commercial Wind Lease Issuance and Site Assessment Activities on the Atlantic...

  6. Structural analysis of wind turbine rotors for NSF-NASA Mod-0 wind power system

    NASA Technical Reports Server (NTRS)

    Spera, D. A.

    1975-01-01

    Preliminary estimates of vibratory loads and stresses in hingeless and teetering rotors for the proposed 100-kW wind power system are presented. Stresses in the shank areas of the 19-m (62.5-ft) blades are given for static, rated, and overload conditions. The teetering rotor has substantial advantages over the hingeless rotor with respect to shank stresses, fatigue life, and tower loading. A teetering rotor will probably be required in order to achieve a long service life in a large wind turbine exposed to periodic overload conditions.

  7. Expanded Small-Scale Shock Reactivity Test

    NASA Astrophysics Data System (ADS)

    Granholm, Richard

    2005-07-01

    Explosives react from a strong shock, even in quantities too small for detonation. The potential for a new material to be an explosive can be evaluated from this shock reactivity. The recently developed small-scale shock reactivity test (SSRT)ootnotetextH. W. Sandusky, R. H. Granholm, D. G. Bohl, ``Small-Scale Shock Reactivity Test,'' NSWC Technical Report (in publication), Naval Surface Warfare Center, Indian Head, MD 20640 uses very high confinement to allow prompt reactions to occur in less than half-gram samples well below critical diameter, with the reactions quantified by a dent in a soft aluminum witness block. This test has been expanded to simultaneously measure both early and late-time reactions from a single sample subjected to the output from an RP-80 detonator. The sample apparatus is further confined within a small chamber instrumented with a pressure gage for internal air blast. This provides a measure of late-time reactions, such as from fuel/air combustion. Results are shown from several simultaneous early- and late-reaction measurements.

  8. Small-scale ethanol-production demonstration

    SciTech Connect

    Adcock, L.E. II; Eley, M.H.; Schroer, B.J.

    1981-09-01

    The Johnson Environmental and Energy Center with assistance from the Madison County Farm Bureau Association received a grant from the US Department of Energy to design, fabricate, and evaluate a small scale continuous ethanol plant. The scope of the study was to satisfy four specific objectives. The first objective was to design a small scale continuous distillation unit capable of producing 10 to 15 gallons per hour of 170 to 190 proof ethanol. A second objective was to economically fabricate the distillation unit. A third objective was to thoroughly evaluate the unit with emphasis on production potential, operation considerations, and energy balance. The fourth objective was to work with the Farm Bureau in identifying an organization that would place the unit in a production environment. The results of the study indicate that the distillation unit is capable of producing an average of 9 to 14 gallons per hour (based on alcohol percent in beer) of 174 proof ethanol. The energy ratio for distillation is a positive 3:1. Once the unit has reached steady state very little operator attention is required with the exception of periodically refluxing. Material cost of the plate column is approximately $5000. The unit could be built by an individual provided he is trained in welding and has the necessary shop equipment. The report also contains 7 appendices entitled: Principles of ethanol production; pump manufacturer specifications; boiler manufacturer specifications, water treatment manufacturer specifications; tank specifications; test results; and boiler efficiency data sheets. 39 figures, 112 tables.

  9. Design of a miniature wind turbine for powering wireless sensors

    NASA Astrophysics Data System (ADS)

    Xu, F. J.; Yuan, F. G.; Hu, J. Z.; Qiu, Y. P.

    2010-04-01

    In this paper, a miniature wind turbine (MWT) system composed of commercially available off-the-shelf components was designed and tested for harvesting energy from ambient airflow to power wireless sensors. To make MWT operate at very low air flow rates, a 7.6 cm thorgren plastic Propeller blade was adopted as the wind turbine blade. A sub watt brushless DC motor was used as generator. To predict the performance of the MWT, an equivalent circuit model was employed for analyzing the output power and the net efficiency of the MWT system. In theory, the maximum net efficiency 14.8% of the MWT system was predicted. Experimental output power of the MWT versus resistive loads ranging from 5 ohms to 500 ohms under wind speeds from 3 m/s to 4.5 m/s correlates well with those from the predicted model, which means that the equivalent circuit model provides a guideline for optimizing the performance of the MWT and can be used for fulfilling the design requirements by selecting specific components for powering wireless sensors.

  10. Wind tunnel measurements of the power output variability and unsteady loading in a micro wind farm model

    NASA Astrophysics Data System (ADS)

    Bossuyt, Juliaan; Howland, Michael; Meneveau, Charles; Meyers, Johan

    2015-11-01

    To optimize wind farm layouts for a maximum power output and wind turbine lifetime, mean power output measurements in wind tunnel studies are not sufficient. Instead, detailed temporal information about the power output and unsteady loading from every single wind turbine in the wind farm is needed. A very small porous disc model with a realistic thrust coefficient of 0.75 - 0.85, was designed. The model is instrumented with a strain gage, allowing measurements of the thrust force, incoming velocity and power output with a frequency response up to the natural frequency of the model. This is shown by reproducing the -5/3 spectrum from the incoming flow. Thanks to its small size and compact instrumentation, the model allows wind tunnel studies of large wind turbine arrays with detailed temporal information from every wind turbine. Translating to field conditions with a length-scale ratio of 1:3,000 the frequencies studied from the data reach from 10-4 Hz up to about 6 .10-2 Hz. The model's capabilities are demonstrated with a large wind farm measurement consisting of close to 100 instrumented models. A high correlation is found between the power outputs of stream wise aligned wind turbines, which is in good agreement with results from prior LES simulations. Work supported by ERC (ActiveWindFarms, grant no. 306471) and by NSF (grants CBET-113380 and IIA-1243482, the WINDINSPIRE project).

  11. Small-Scale Magnetic Reconnection at Equatorial Coronal Hole Boundaries

    NASA Astrophysics Data System (ADS)

    Lamb, Derek; DeForest, C. E.

    2011-05-01

    Coronal holes have long been known to be the source of the fast solar wind at both high and low latitudes. The equatorial extensions of polar coronal holes have long been assumed to have substantial magnetic reconnection at their boundaries, because they rotate more rigidly than the underlying photosphere. However, evidence for this reconnection has been sparse until very recently. We present some evidence that reconnection due to the evolution of small-scale magnetic fields may be sufficient to drive coronal hole boundary evolution. We hypothesize that a bias in the direction of that reconnection is sufficient to give equatorial coronal holes their rigid rotation. We discuss the prospects for investigating this using FLUX, a reconnection-controlled coronal MHD simulation framework. This work was funded by the NASA SHP-GI program.

  12. Powerful, Rotating Disk Winds from Stellar-mass Black Holes

    NASA Astrophysics Data System (ADS)

    Miller, J. M.; Fabian, A. C.; Kaastra, J.; Kallman, T.; King, A. L.; Proga, D.; Raymond, J.; Reynolds, C. S.

    2015-12-01

    We present an analysis of ionized X-ray disk winds found in the Fe K band of four stellar-mass black holes observed with Chandra, including 4U 1630-47, GRO J1655-40, H 1743-322, and GRS 1915+105. High-resolution photoionization grids were generated in order to model the data. Third-order gratings spectra were used to resolve complex absorption profiles into atomic effects and multiple velocity components. The Fe xxv line is found to be shaped by contributions from the intercombination line (in absorption), and the Fe xxvi line is detected as a spin-orbit doublet. The data require 2-3 absorption zones, depending on the source. The fastest components have velocities approaching or exceeding 0.01c, increasing mass outflow rates and wind kinetic power by orders of magnitude over prior single-zone models. The first-order spectra require re-emission from the wind, broadened by a degree that is loosely consistent with Keplerian orbital velocities at the photoionization radius. This suggests that disk winds are rotating with the orbital velocity of the underlying disk, and provides a new means of estimating launching radii—crucial to understanding wind driving mechanisms. Some aspects of the wind velocities and radii correspond well to the broad-line region in active galactic nuclei (AGNs), suggesting a physical connection. We discuss these results in terms of prevalent models for disk wind production and disk accretion itself, and implications for massive black holes in AGNs.

  13. Monitoring Wind Turbine Loading Using Power Converter Signals

    NASA Astrophysics Data System (ADS)

    Rieg, C. A.; Smith, C. J.; Crabtree, C. J.

    2016-09-01

    The ability to detect faults and predict loads on a wind turbine drivetrain's mechanical components cost-effectively is critical to making the cost of wind energy competitive. In order to investigate whether this is possible using the readily available power converter current signals, an existing permanent magnet synchronous generator based wind energy conversion system computer model was modified to include a grid-side converter (GSC) for an improved converter model and a gearbox. The GSC maintains a constant DC link voltage via vector control. The gearbox was modelled as a 3-mass model to allow faults to be included. Gusts and gearbox faults were introduced to investigate the ability of the machine side converter (MSC) current (I q) to detect and quantify loads on the mechanical components. In this model, gearbox faults were not detectable in the I q signal due to shaft stiffness and damping interaction. However, a model that predicts the load change on mechanical wind turbine components using I q was developed and verified using synthetic and real wind data.

  14. Overlooked Role of Mesoscale Winds in Powering Ocean Diapycnal Mixing

    PubMed Central

    Jing, Zhao; Wu, Lixin; Ma, Xiaohui; Chang, Ping

    2016-01-01

    Diapycnal mixing affects the uptake of heat and carbon by the ocean as well as plays an important role in global ocean circulations and climate. In the thermocline, winds provide an important energy source for furnishing diapycnal mixing primarily through the generation of near-inertial internal waves. However, this contribution is largely missing in the current generation of climate models. In this study, it is found that mesoscale winds at scales of a few hundred kilometers account for more than 65% of near-inertial energy flux into the North Pacific basin and 55% of turbulent kinetic dissipation rate in the thermocline, suggesting their dominance in powering diapycnal mixing in the thermocline. Furthermore, a new parameterization of wind-driven diapycnal mixing in the ocean interior for climate models is proposed, which, for the first time, successfully captures both temporal and spatial variations of wind-driven diapycnal mixing in the thermocline. It is suggested that as mesoscale winds are not resolved by the climate models participated in the Coupled Model Intercomparison Project Phase 5 (CMIP5) due to insufficient resolutions, the diapycnal mixing is likely poorly represented, raising concerns about the accuracy and robustness of climate change simulations and projections. PMID:27849059

  15. Overlooked Role of Mesoscale Winds in Powering Ocean Diapycnal Mixing

    NASA Astrophysics Data System (ADS)

    Jing, Zhao; Wu, Lixin; Ma, Xiaohui; Chang, Ping

    2016-11-01

    Diapycnal mixing affects the uptake of heat and carbon by the ocean as well as plays an important role in global ocean circulations and climate. In the thermocline, winds provide an important energy source for furnishing diapycnal mixing primarily through the generation of near-inertial internal waves. However, this contribution is largely missing in the current generation of climate models. In this study, it is found that mesoscale winds at scales of a few hundred kilometers account for more than 65% of near-inertial energy flux into the North Pacific basin and 55% of turbulent kinetic dissipation rate in the thermocline, suggesting their dominance in powering diapycnal mixing in the thermocline. Furthermore, a new parameterization of wind-driven diapycnal mixing in the ocean interior for climate models is proposed, which, for the first time, successfully captures both temporal and spatial variations of wind-driven diapycnal mixing in the thermocline. It is suggested that as mesoscale winds are not resolved by the climate models participated in the Coupled Model Intercomparison Project Phase 5 (CMIP5) due to insufficient resolutions, the diapycnal mixing is likely poorly represented, raising concerns about the accuracy and robustness of climate change simulations and projections.

  16. Building 865 Hypersonic Wind Tunnel Power System Analysis

    SciTech Connect

    Schneider, Larry X.

    2015-02-01

    This report documents the characterization and analysis of a high current power supply for the building 865 Hypersonic Wind Tunnel at Sandia National Laboratories. The system described in this report became operational in 2013, replacing the original 1968 system which employed an induction voltage regulator. This analysis and testing was completed to help the parent organization understand why an updated and redesigned power system was not delivering adequate power to resistive heater elements in the HWT. This analysis led to an improved understanding of the design and operation of the revised 2013 power supply system and identifies several reasons the revised system failed to achieve the performance of the original power supply installation. Design modifications to improve the performance of this system are discussed.

  17. Design and Study of a Low-Cost Laboratory Model Digital Wind Power Meter

    ERIC Educational Resources Information Center

    Radhakrishnan, Rugmini; Karthika, S.

    2010-01-01

    A vane-type low-cost laboratory model anemometer cum power meter is designed and constructed for measuring low wind energy created from accelerating fluids. The constructed anemometer is a device which records the electrical power obtained by the conversion of wind power using a wind sensor coupled to a DC motor. It is designed for its…

  18. Measurement campaign for wind power potential in west Greenland

    NASA Astrophysics Data System (ADS)

    Rønnow Jakobsen, Kasper

    2013-04-01

    Experiences and results from a wind resource exploring campaign 2003- in west Greenland. Like many other countries, Greenland is trying to reduce its dependency of fossil fuel by implementing renewable energy. The main challenge is that the people live on the coast in scattered settlements, without power infrastructure. Based on this a wind power potential project was established in 2002, funded by the Greenlandic government and the Technical University of Denmark. We present results and experiences of the campaign. 1 Field campaign There were only a few climate stations in or close to settlements and due to their positioning and instrumentation, they were not usable for wind resource estimation. To establish met stations in Arctic areas with complex topography, there are some challenges to face; mast positioning in complex terrain, severe weather conditions, instrumentation, data handling, installation and maintenance budget. The terrain in the ice free and populated part, mainly consists of mountains of different heights and shapes, separated by deep fjords going from the ice cap to the sea. With a generally low wind resource the focus was on the most exposed positions close to the settlements. Data from the nearest existing climate stations was studied for background estimations of predominant wind directions and extreme wind speeds, and based on that the first 10m masts were erected in 2003. 2 Instruments The first installations used standard NRG systems with low cost NRG instruments. For most of the sites this low cost setup did a good job, but there were some problems with the first design, including instrument and boom strains. In subsequent years, the systems were updated several times to be able to operate in the extreme conditions. Different types of instruments, data logger and boom systems were tested to get better data quality and reliability. Today 11 stations with heights ranging from 10-50m are installed and equipped according to the IEC standard

  19. Short-term load forecasting study of wind power based on Elman neural network

    NASA Astrophysics Data System (ADS)

    Tian, Xinran; Yu, Jing; Long, Teng; Liu, Jicheng

    2017-01-01

    Since wind power has intermittent, irregular and volatility nature, improving load forecasting accuracy of wind power has significant influence on controlling wind system and guarantees stable operation of power grids. This paper constructed the wind farm loading forecasting in short-term based on Elman neural network, and made a numerical example analysis. . Examples show that, using input delayed of feedback Elman neural network, can reflect the inherent laws of wind load operation better, so as to present a new idea for short-term load forecasting of wind power.

  20. Analysis of energy-saving dispatch based on energy efficiency for power system with large scale wind power integration

    NASA Astrophysics Data System (ADS)

    Zou, Lanqing; Zhou, Peng; Li, Shitong; Lin, Li

    2017-01-01

    With the increasing of wind generators and the scale of wind farm, the utilization rate of wind power decreases continually, it is essential to develop an energy-saving dispatching model for the purpose of energy conservation and emission reduction. Firstly, considering some main factors, such as generator operating costs, start-up unit costs, shutdown unit costs, oil consumption and pollutant emission, establish an energy efficiency model. Then, based on the principle of energy-saving dispatch, a model is established which objective is maximizing the energy efficiency. Moreover, in order to realize the priority dispatching of wind power, another model is established which objective is minimizing the wind power shedding. Finally, under the conditions of different installed wind power capacities being integrated into a real region grid, two models are compared and analyzed from perspectives of the society, thermal power enterprise and wind power enterprise.

  1. Energy harvesting to power sensing hardware onboard wind turbine blade

    SciTech Connect

    Carlson, Clinton P; Schichting, Alexander D; Quellette, Scott; Farinholt, Kevin M; Park, Gyuhae

    2009-10-05

    Wind turbines are becoming a larger source of renewable energy in the United States. However, most of the designs are geared toward the weather conditions seen in Europe. Also, in the United States, manufacturers have been increasing the length of the turbine blades, often made of composite materials, to maximize power output. As a result of the more severe loading conditions in the United States and the material level flaws in composite structures, blade failure has been a more common occurrence in the U.S. than in Europe. Therefore, it is imperative that a structural health monitoring system be incorporated into the design of the wind turbines in order to monitor flaws before they lead to a catastrophic failure. Due to the rotation of the turbine and issues related to lightning strikes, the best way to implement a structural health monitoring system would be to use a network of wireless sensor nodes. In order to provide power to these sensor nodes, piezoelectric, thermoelectric and photovoltaic energy harvesting techniques are examined on a cross section of a CX-100 wind turbine blade in order to determine the feasibility of powering individual nodes that would compose the sensor network.

  2. A small-scale turbulence model

    NASA Technical Reports Server (NTRS)

    Lundgren, T. S.

    1992-01-01

    A model for the small-scale structure of turbulence is reformulated in such a way that it may be conveniently computed. The model is an ensemble of randomly oriented structured two dimensional vortices stretched by an axially symmetric strain flow. The energy spectrum of the resulting flow may be expressed as a time integral involving only the enstrophy spectrum of the time evolving two-dimensional cross section flow, which may be obtained numerically. Examples are given in which a k(exp -5/3) spectrum is obtained by this method without using large wave number asymptotic analysis. The k(exp -5/3) inertial range spectrum is shown to be related to the existence of a self-similar enstrophy preserving range in the two-dimensional enstrophy spectrum. The results are insensitive to time dependence of the strain-rate, including even intermittent on-or-off strains.

  3. Energetics in robotic flight at small scales.

    PubMed

    Karydis, Konstantinos; Kumar, Vijay

    2017-02-06

    Recent advances in design, sensing and control have led to aerial robots that offer great promise in a range of real-world applications. However, one critical open question centres on how to improve the energetic efficiency of aerial robots so that they can be useful in practical situations. This review paper provides a survey on small-scale aerial robots (i.e. less than 1 m(2) area foot print, and less than 3 kg weight) from the point of view of energetics. The paper discusses methods to improve the efficiency of aerial vehicles, and reports on recent findings by the authors and other groups on modelling the impact of aerodynamics for the purpose of building energy-aware motion planners and controllers.

  4. Practical small-scale explosive seam welding

    NASA Technical Reports Server (NTRS)

    Bement, L. J.

    1983-01-01

    A small-scale explosive seam welding process has been developed that can significantly contribute to remote metal joining operations under hazardous or inaccessible conditions, such as nuclear reactor repair and assembly of structure in space. This paper describes this explosive seam welding process in terms of joining principles, variables, types of joints created, capabilities, and applications. Very small quantities of explosive in a ribbon configuration are used to create narrow (less than 0.5 inch), long-length, uniform, hermetically sealed joints that exhibit parent metal properties in a wide variety of metals, alloys, and combinations. The practicality of this process has been demonstrated by its current acceptance, as well as its capabilities that are superior in many applications to the universally accepted joining processes, such as mechanical fasteners, fusion and resistance welding, and adhesives. Previously announced in STAR as N83-24896

  5. Models of Small-Scale Patchiness

    NASA Technical Reports Server (NTRS)

    McGillicuddy Dennis J., Jr.

    2001-01-01

    Patchiness is perhaps the most salient characteristic of plankton populations in the ocean. The scale of this heterogeneity spans many orders of magnitude in its spatial extent, ranging from planetary down to microscale. It has been argued that patchiness plays a fundamental role in the functioning of marine ecosystems, insofar as the mean conditions may not reflect the environment to which organisms are adapted. For example, the fact that some abundant predators cannot thrive on the mean concentration of their prey in the ocean implies that they are somehow capable of exploiting small-scale patches of prey whose concentrations are much larger than the mean. Understanding the nature of this patchiness is thus one of the major challenges of oceanographic ecology. Additional information is contained in the original extended abstract.

  6. Small-Scale Features in Pulsating Aurora

    NASA Technical Reports Server (NTRS)

    Jones, Sarah; Jaynes, Allison N.; Knudsen, David J.; Trondsen, Trond; Lessard, Marc

    2011-01-01

    A field study was conducted from March 12-16, 2002 using a narrow-field intensified CCD camera installed at Churchill, Manitoba. The camera was oriented along the local magnetic zenith where small-scale black auroral forms are often visible. This analysis focuses on such forms occurring within a region of pulsating aurora. The observations show black forms with irregular shape and nonuniform drift with respect to the relatively stationary pulsating patches. The pulsating patches occur within a diffuse auroral background as a modulation of the auroral brightness in a localized region. The images analyzed show a decrease in the brightness of the diffuse background in the region of the pulsating patch at the beginning of the offphase of the modulation. Throughout the off phase the brightness of the diffuse aurora gradually increases back to the average intensity. The time constant for this increase is measured as the first step toward determining the physical process.

  7. Practical small-scale explosive seam welding

    NASA Technical Reports Server (NTRS)

    Bement, L. J.

    1983-01-01

    A small-scale explosive seam welding process has been developed that can significantly contribute to remote metal joining operations under hazardous or inaccessible conditions, such as nuclear reactor repair and assembly of structure in space. This paper describes this explosive seam welding process in terms of joining principles, variables, types of joints created, capabilities, and applications. Very small quantities of explosive in a ribbon configuration are used to create narrow (less than 0.5 inch), long-length, uniform, hermetically sealed joints that exhibit parent metal properties in a wide variety of metals, alloys, and combinations. The practicality of this process has been demonstrated by its current acceptance, as well as its capabilities that are superior in many applications to the universally accepted joining processes, such as mechanical fasteners, fusion and resistance welding, and adhesives.

  8. Small-scale Features in Pulsating Aurora

    NASA Astrophysics Data System (ADS)

    Jones, S.; Jaynes, A. N.; Knudsen, D. J.; Trondsen, T.; Lessard, M.

    2011-12-01

    A field study was conducted from March 12-16, 2002 using a narrow-field intensified CCD camera installed at Churchill, Manitoba. The camera was oriented along the local magnetic zenith where small-scale black auroral forms are often visible. This analysis focuses on such forms occurring within a region of pulsating aurora. The observations show black forms with irregular shape and nonuniform drift with respect to the relatively stationary pulsating patches. The pulsating patches occur within a diffuse auroral background as a modulation of the auroral brightness in a localized region. The images analyzed show a decrease in the brightness of the diffuse background in the region of the pulsating patch at the beginning of the 'off' phase of the modulation. Throughout the off phase the brightness of the diffuse aurora gradually increases back to the average intensity. The time constant for this increase is measured as the first step toward determining the physical process.

  9. Effects of thermal inflation on small scale density perturbations

    SciTech Connect

    Hong, Sungwook E.; Lee, Hyung-Joo; Lee, Young Jae; Stewart, Ewan D.; Zoe, Heeseung E-mail: ohsk111@kaist.ac.kr E-mail: jcap@profstewart.org

    2015-06-01

    In cosmological scenarios with thermal inflation, extra eras of moduli matter domination, thermal inflation and flaton matter domination exist between primordial inflation and the radiation domination of Big Bang nucleosynthesis. During these eras, cosmological perturbations on small scales can enter and re-exit the horizon, modifying the power spectrum on those scales. The largest modified scale, k{sub b}, touches the horizon size when the expansion changes from deflation to inflation at the transition from moduli domination to thermal inflation. We analytically calculate the evolution of perturbations from moduli domination through thermal inflation and evaluate the curvature perturbation on the constant radiation density hypersurface at the end of thermal inflation to determine the late time curvature perturbation. Our resulting transfer function suppresses the power spectrum by a factor 0∼ 5 at k >> k{sub b}, with k{sub b} corresponding to anywhere from megaparsec to subparsec scales depending on the parameters of thermal inflation. Thus, thermal inflation might be constrained or detected by small scale observations such as CMB distortions or 21cm hydrogen line observations.

  10. A view from Minnesota: A changing climate for wind power

    SciTech Connect

    Noble, M.T.

    1997-12-31

    The author describes a program begun in Minnesota to address the problem of climate change and possible global warming. This projects aims at increasing understanding and appreciation of changes being seen in the US weather patterns and possible correlations with greenhouse gas emissions. Minnesota has taken a stance on mandating support for renewable power sources as a part of their electric utility mix. The author urges the business and industrial sectors of our economy to consider the impact on the US and its citizens of not supporting programs which are directed at reducing greenhouse gas emissions, including support for wind power projects.

  11. Wind Powering America Anemometer Loan Program: A Retrospective

    SciTech Connect

    Jimenez, T.

    2013-05-01

    This white paper details the history, mechanics, status, and impact of the Native American Anemometer Loan Program (ALP) conducted by the U.S. Department of Energy's Wind Powering America (WPA) initiative. Originally conceived in 2000 and terminated (as a WPA activity) at the end of FY 2011, the ALP has resulted in the installation of anemometers at 90 locations. In addition, the ALP provided support for the installation of anemometers at 38 additional locations under a related ALP administered by the Western Area Power Administration.

  12. Design and Operation of Power Systems with Large Amounts of Wind Power: Final Summary Report, IEA WIND Task 25, Phase Three 2012-2014

    SciTech Connect

    Holttinen, Hannele; Kiviluoma, Juha; Forcione, Alain; Milligan, Michael; Smith, Charles J.; Dillon, Jody; Dobschinski, Jan; van Roon, Serafin; Cutululis, Nicolaos; Orths, Antje; Eriksen, Peter Borre; Carlini, Enrico Maria; Estanqueiro, Ana; Bessa, Ricardo; Soder, Lennart; Farahmand, Hossein; Torres, Jose Rueda; Jianhua, Bai; Kondoh, Junji; Pineda, Ivan; Strbac, Goran

    2016-06-01

    This report summarizes recent findings on wind integration from the 16 countries participating in the International Energy Agency (IEA) Wind collaboration research Task 25 in 2012-2014. Both real experience and studies are reported. The national case studies address several impacts of wind power on electric power systems. In this report, they are grouped under long-term planning issues and short-term operational impacts. Long-term planning issues include grid planning and capacity adequacy. Short-term operational impacts include reliability, stability, reserves, and maximizing the value in operational timescales (balancing related issues). The first section presents variability and uncertainty of power system-wide wind power, and the last section presents recent wind integration studies for higher shares of wind power. Appendix 1 provides a summary of ongoing research in the national projects contributing to Task 25 in 2015-2017.

  13. Analysis of source-grid-load contribution to wind power accommodation

    NASA Astrophysics Data System (ADS)

    Li, Nan; Zhang, Jinfang; Zhang, Fuqiang

    2017-01-01

    In recent years, China’s wind power is developing rapidly, but wind electricity curtailment becomes a serious problem. This paper evaluates wind power penetration limit from peak regulation, analyses relevant technical elements that impact wind power accommodation, coving the source side, the transmission side and the load side. By taking certain measures around the three aspects, for example, reducing the minimum technical output of conventional units, increasing outbound transmission capacity, or increasing the valley load, wind electricity curtailment will be effectively reduced. This paper quantitatively analyses wind power penetration limit under certain conditions and the source-grid-load contribution to wind power accommodation, and explores the important technical factors that affect wind power accommodation.

  14. Ramp Forecasting Performance from Improved Short-Term Wind Power Forecasting: Preprint

    SciTech Connect

    Zhang, J.; Florita, A.; Hodge, B. M.; Freedman, J.

    2014-05-01

    The variable and uncertain nature of wind generation presents a new concern to power system operators. One of the biggest concerns associated with integrating a large amount of wind power into the grid is the ability to handle large ramps in wind power output. Large ramps can significantly influence system economics and reliability, on which power system operators place primary emphasis. The Wind Forecasting Improvement Project (WFIP) was performed to improve wind power forecasts and determine the value of these improvements to grid operators. This paper evaluates the performance of improved short-term wind power ramp forecasting. The study is performed for the Electric Reliability Council of Texas (ERCOT) by comparing the experimental WFIP forecast to the current short-term wind power forecast (STWPF). Four types of significant wind power ramps are employed in the study; these are based on the power change magnitude, direction, and duration. The swinging door algorithm is adopted to extract ramp events from actual and forecasted wind power time series. The results show that the experimental short-term wind power forecasts improve the accuracy of the wind power ramp forecasting, especially during the summer.

  15. Estimated changes in wind speed and wind power density over the western High Plains, 1971-2000

    NASA Astrophysics Data System (ADS)

    Greene, J. Scott; Chatelain, Matthew; Morrissey, Mark; Stadler, Steve

    2012-08-01

    This manuscript presents the results of research on the temporal patterns in wind speed and wind power density from 1971 to 2000. The study area is across the western High Plains states east of the Rocky Mountains in an area which has a proven wind power resource. Policies and economic analyses involving the rapidly expanding wind power industry have often assumed a constant in the wind resource; however, any temporal pattern or trend in wind speeds can have a meaningful impact on the reliability of wind power as an energy resource. Using data provided by the North American Regional Climate Change Assessment Program (NARCCAP) to analyze decadal and seasonal trends of wind data, this study shows that from 1971 to 2000 there were some notable changes in the NARCCAP simulated wind velocities over the study region. Wind speed trends across the central High Plains of the USA were most notable across the western portion of the study area along the higher terrain near the front range of the Rocky Mountains. The most significant changes occurred during winter and spring when a large portion of the study area experienced the most substantial decrease in wind speed, with a 20% reduction in wind power density during spring across the western portion of the study area. During summer and fall, the trends are less noticeable, with only very small changes in the summer. Fall was the only season that saw widespread increased values of wind power density from the 1970s to 1990s, with increases of nearly 10% in some southern areas of the study area. Based upon the analysis of the data and previous literature, it is theorized that these changes could be the result of changing synoptic patterns across the study region.

  16. Integration of Wind Energy Systems into Power Engineering Education Program at UW-Madison

    SciTech Connect

    Venkataramanan, Giri; Lesieutre, Bernard; Jahns, Thomas; Desai, Ankur R

    2012-09-01

    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 as 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.

  17. Value of Improved Wind Power Forecasting in the Western Interconnection (Poster)

    SciTech Connect

    Hodge, B.

    2013-12-01

    Wind power forecasting is a necessary and important technology for incorporating wind power into the unit commitment and dispatch process. It is expected to become increasingly important with higher renewable energy penetration rates and progress toward the smart grid. There is consensus that wind power forecasting can help utility operations with increasing wind power penetration; however, there is far from a consensus about the economic value of improved forecasts. This work explores the value of improved wind power forecasting in the Western Interconnection of the United States.

  18. Preliminary estimates of wind power potential at the Nevada test site

    NASA Astrophysics Data System (ADS)

    Booth, H. G.

    1981-07-01

    An assessment of the potential for the useful conversion of wind power to electrical power is given for a Nevada test site. Annual wind power availability was estimated to be sufficient. The percentage of low wind hours was found to be high, and the persistence of favorably strong winds for periods of several days at a time was low. There was a pronounced diurnal cycle in wind power availability. It is concluded that baseload electrical power requirements would require alternate energy sources. Cost effectiveness of this configuration would have to be determined.

  19. Atmospheric Stability Impacts on Power Curves of Tall Wind Turbines - An Analysis of a West Coast North American Wind Farm

    SciTech Connect

    Wharton, S; Lundquist, J K

    2010-02-22

    Tall wind turbines, with hub heights at 80 m or above, can extract large amounts of energy from the atmosphere because they are likely to encounter higher wind speeds, but they face challenges given the complex nature of wind flow and turbulence at these heights in the boundary layer. Depending on whether the boundary layer is stable, neutral, or convective, the mean wind speed, direction, and turbulence properties may vary greatly across the tall turbine swept area (40 to 120 m AGL). This variability can cause tall turbines to produce difference amounts of power during time periods with identical hub height wind speeds. Using meteorological and power generation data from a West Coast North American wind farm over a one-year period, our study synthesizes standard wind park observations, such as wind speed from turbine nacelles and sparse meteorological tower observations, with high-resolution profiles of wind speed and turbulence from a remote sensing platform, to quantify the impact of atmospheric stability on power output. We first compare approaches to defining atmospheric stability. The standard, limited, wind farm operations enable the calculation only of a wind shear exponent ({alpha}) or turbulence intensity (I{sub U}) from cup anemometers, while the presence at this wind farm of a SODAR enables the direct observation of turbulent kinetic energy (TKE) throughout the turbine rotor disk. Additionally, a nearby research meteorological station provided observations of the Obukhov length, L, a direct measure of atmospheric stability. In general, the stability parameters {alpha}, I{sub U}, and TKE are in high agreement with the more physically-robust L, with TKE exhibiting the best agreement with L. Using these metrics, data periods are segregated by stability class to investigate power performance dependencies. Power output at this wind farm is highly correlated with atmospheric stability during the spring and summer months, while atmospheric stability exerts

  20. Wind-powered asynchronous AC/DC/AC converter system. [for electric power supply regulation

    NASA Technical Reports Server (NTRS)

    Reitan, D. K.

    1973-01-01

    Two asynchronous ac/dc/ac systems are modelled that utilize wind power to drive a variable or constant hertz alternator. The first system employs a high power 60-hertz inverter tie to the large backup supply of the power company to either supplement them from wind energy, storage, or from a combination of both at a preset desired current; rectifier and inverter are identical and operate in either mode depending on the silicon control rectifier firing angle. The second system employs the same rectification but from a 60-hertz alternator arrangement; it provides mainly dc output, some sinusoidal 60-hertz from the wind bus and some high harmonic content 60-hertz from an 800-watt inverter.

  1. Wind power in Eritrea, Africa: A preliminary resource assessment

    SciTech Connect

    Garbesi, K.; Rosen, K.; Van Buskirk, R.

    1997-12-31

    The authors preliminary assessment of Eritrean wind energy potential identified two promising regions: (1) the southeastern Red Sea coast and (2) the mountain passes that channel winds between the coastal lowlands and the interior highlands. The coastal site, near the port city of Aseb, has an exceptionally good resource, with estimated average annual wind speeds at 10-m height above 9 m/s at the airport and 7 m/s in the port. Furthermore, the southern 200 km of coastline has offshore WS{sub aa} > 6 m/s. This area has strong potential for development, having a local 20 MW grid and unmet demand for the fishing industry and development. Although the highland sites contain only marginal wind resources ({approximately} 5 m/s), they warrant further investigation because of their proximity to the capital city, Asmera, which has the largest unmet demand and a larger power grid (40 MW with an additional 80 MW planned) to absorb an intermittent source without storage.

  2. Impacts of Large Amounts of Wind Power on Design and Operation of Power Systems, Results of IEA Collaboration

    SciTech Connect

    Holttinen, H.; Meibom, P.; Orths, A.; O'Malley, M.; Ummels, B. C.; Tande, J. O.; Estanqueiro, A.; Gomez, E.; Smith, J. C.; Ela, E.

    2008-01-01

    There are a multitude of studies completed and ongoing related to the cost of wind integration. However, the results are not easy to compare. An international forum for exchange of knowledge of power system impacts of wind power has been formed under the IEA Implementing Agreement on Wind Energy. IEA WIND R and D Task 25 on 'Design and Operation of Power Systems with Large Amounts of Wind Power' produced a state-of-the-art report in October 2007, where the most relevant wind-power grid integration studies were analyzed, especially regarding methodologies and input data. This paper summarizes the results from 18 case studies, with discussion on differences in methodology as well as issues that have been identified to impact the cost of wind integration.

  3. Power Performance Verification of a Wind Farm Using the Friedman’s Test

    PubMed Central

    Hernandez, Wilmar; López-Presa, José Luis; Maldonado-Correa, Jorge L.

    2016-01-01

    In this paper, a method of verification of the power performance of a wind farm is presented. This method is based on the Friedman’s test, which is a nonparametric statistical inference technique, and it uses the information that is collected by the SCADA system from the sensors embedded in the wind turbines in order to carry out the power performance verification of a wind farm. Here, the guaranteed power curve of the wind turbines is used as one more wind turbine of the wind farm under assessment, and a multiple comparison method is used to investigate differences between pairs of wind turbines with respect to their power performance. The proposed method says whether the power performance of the specific wind farm under assessment differs significantly from what would be expected, and it also allows wind farm owners to know whether their wind farm has either a perfect power performance or an acceptable power performance. Finally, the power performance verification of an actual wind farm is carried out. The results of the application of the proposed method showed that the power performance of the specific wind farm under assessment was acceptable. PMID:27271628

  4. Probability density function characterization for aggregated large-scale wind power based on Weibull mixtures

    DOE PAGES

    Gomez-Lazaro, Emilio; Bueso, Maria C.; Kessler, Mathieu; ...

    2016-02-02

    Here, the Weibull probability distribution has been widely applied to characterize wind speeds for wind energy resources. Wind power generation modeling is different, however, due in particular to power curve limitations, wind turbine control methods, and transmission system operation requirements. These differences are even greater for aggregated wind power generation in power systems with high wind penetration. Consequently, models based on one-Weibull component can provide poor characterizations for aggregated wind power generation. With this aim, the present paper focuses on discussing Weibull mixtures to characterize the probability density function (PDF) for aggregated wind power generation. PDFs of wind power datamore » are firstly classified attending to hourly and seasonal patterns. The selection of the number of components in the mixture is analyzed through two well-known different criteria: the Akaike information criterion (AIC) and the Bayesian information criterion (BIC). Finally, the optimal number of Weibull components for maximum likelihood is explored for the defined patterns, including the estimated weight, scale, and shape parameters. Results show that multi-Weibull models are more suitable to characterize aggregated wind power data due to the impact of distributed generation, variety of wind speed values and wind power curtailment.« less

  5. Power Performance Verification of a Wind Farm Using the Friedman's Test.

    PubMed

    Hernandez, Wilmar; López-Presa, José Luis; Maldonado-Correa, Jorge L

    2016-06-03

    In this paper, a method of verification of the power performance of a wind farm is presented. This method is based on the Friedman's test, which is a nonparametric statistical inference technique, and it uses the information that is collected by the SCADA system from the sensors embedded in the wind turbines in order to carry out the power performance verification of a wind farm. Here, the guaranteed power curve of the wind turbines is used as one more wind turbine of the wind farm under assessment, and a multiple comparison method is used to investigate differences between pairs of wind turbines with respect to their power performance. The proposed method says whether the power performance of the specific wind farm under assessment differs significantly from what would be expected, and it also allows wind farm owners to know whether their wind farm has either a perfect power performance or an acceptable power performance. Finally, the power performance verification of an actual wind farm is carried out. The results of the application of the proposed method showed that the power performance of the specific wind farm under assessment was acceptable.

  6. Probability density function characterization for aggregated large-scale wind power based on Weibull mixtures

    SciTech Connect

    Gomez-Lazaro, Emilio; Bueso, Maria C.; Kessler, Mathieu; Martin-Martinez, Sergio; Zhang, Jie; Hodge, Bri -Mathias; Molina-Garcia, Angel

    2016-02-02

    Here, the Weibull probability distribution has been widely applied to characterize wind speeds for wind energy resources. Wind power generation modeling is different, however, due in particular to power curve limitations, wind turbine control methods, and transmission system operation requirements. These differences are even greater for aggregated wind power generation in power systems with high wind penetration. Consequently, models based on one-Weibull component can provide poor characterizations for aggregated wind power generation. With this aim, the present paper focuses on discussing Weibull mixtures to characterize the probability density function (PDF) for aggregated wind power generation. PDFs of wind power data are firstly classified attending to hourly and seasonal patterns. The selection of the number of components in the mixture is analyzed through two well-known different criteria: the Akaike information criterion (AIC) and the Bayesian information criterion (BIC). Finally, the optimal number of Weibull components for maximum likelihood is explored for the defined patterns, including the estimated weight, scale, and shape parameters. Results show that multi-Weibull models are more suitable to characterize aggregated wind power data due to the impact of distributed generation, variety of wind speed values and wind power curtailment.

  7. Smoothing of wind farm output power using prediction based flywheel energy storage system

    NASA Astrophysics Data System (ADS)

    Islam, Farzana

    Being socially beneficial, economically competitive and environment friendly, wind energy is now considered to be the world's fastest growing renewable energy source. However, the stochastic nature of wind imposes a considerable challenge in the optimal management and operation of wind power system. Wind speed prediction is critical for wind energy conversion system since it greatly influences the issues related to effective energy management, dynamic control of wind turbine, and improvement of the overall efficiency of the power generation system. This thesis focuses on integration of energy storage system with wind farm, considering wind speed prediction in the control scheme to overcome the problems associated with wind power fluctuations. In this thesis, flywheel energy storage system (FESS) with adjustable speed rotary machine has been considered for smoothing of output power in a wind farm composed of a fixed speed wind turbine generator (FSWTG). Since FESS has both active and reactive power compensation ability, it enhances the stability of the system effectively. An efficient energy management system combined with supervisory control unit (SCU) for FESS and wind speed prediction has been developed to improve the smoothing of the wind farm output effectively. Wind speed prediction model is developed by artificial neural network (ANN) which has advantages over the conventional prediction scheme including data error tolerance and ease in adaptability. The model for prediction with ANN is developed in MATLAB/Simulink and interfaced with PSCAD/EMTDC. Effectiveness of the proposed control system is illustrated using real wind speed data in various operating conditions.

  8. Nationwide assessment of potential output from wind-powered generators

    NASA Technical Reports Server (NTRS)

    Justus, C. G.; Hargraves, W. R.; Yalcin, A.

    1976-01-01

    A method for computing the actual expected power for a wind-powered generator from a given observed speed distribution is described and applied to estimate the potential output for different locations in the continental U.S. A contour map of generator capacity factor values (fraction of the rated output realizable) is obtained for wind-powered generator systems with a cut-in speed of 3.6 m/sec and a rated speed of 8.0 m/sec, and for a unit with hypothetical values for the 1 MW class (cut-in speed, 6.7 m/sec; rated speed, 13.4 m/sec). Results indicate that in the central U.S. and in certain areas of the New England coast at a height of 61 m, over 60% of the rated output power could be obtained on an annual average. In these areas capacity factors of over 20% could be obtained with the 1MW system.

  9. Induction generator-induction motor wind-powered pumping system

    SciTech Connect

    Miranda, M.S.; Lyra, R.O.C.; Silva, S.R.

    1997-12-31

    The energy storage matter plays an important role in wind-electric conversion systems for isolated applications. Having that in mind, two different approaches can be basically considered: either the immediate conversion of the generated electric energy, as in a water pumping system or electric energy storage for later use, as in a battery charging system. Due to some features such as no need of an external reactive power source and, sometimes, a gearbox, permanent-magnet synchronous generators have been broadly used in low rated power isolated systems. Despite that, system performance can be affected when the generator is feeding an inductive load (e.g., an induction motor) under variable-speed-variable-frequency operational conditions. Since there is no effective flux control, motor overload may occur at high wind speeds. Thus, good system performance can be obtained through additional control devices which may increase system cost. Although being rugged and cheap, induction machines always work as a reactive power drain; therefore, they demand an external reactive power source. Considering that, reactive static compensators appear as an attractive alternative to the cost x performance problem. In addition to that, different control strategies can be used so that system performance can be improved.

  10. Modified power law equations for vertical wind profiles. [in investigation of windpower plant siting

    NASA Technical Reports Server (NTRS)

    Spera, D. A.; Richards, T. R.

    1979-01-01

    In an investigation of windpower plant siting, equations are presented and evaluated for a wind profile model which incorporates both roughness and wind speed effects, while retaining the basic simplicity of the Hellman power law. These equations recognize the statistical nature of wind profiles and are compatible with existing analytical models and recent wind profile data. Predictions of energy output based on the proposed profile equations are 10% to 20% higher than those made with the 1/7 power law. In addition, correlation between calculated and observed blade loads is significantly better at higher wind speeds when the proposed wind profile model is used than when a constant power model is used.

  11. Small-Scale Variability of Large Cloud Drops

    NASA Technical Reports Server (NTRS)

    Marshak, Alexander; Knyazikhin, Y.; Wiscombe, Warren

    2004-01-01

    Cloud droplet size distribution is one of the most fundamental subjects in cloud physics. Understanding of spatial distribution and small-scale fluctuations of cloud droplets is essential for both cloud physics and atmospheric radiation. For cloud physics, it relates to the coalescence growth of raindrops while for radiation, it has a strong impact on a cloud's radiative properties. Most of the existing cloud radiation and precipitation formation models assume that the mean number of drops with a given radius varies proportionally to volume. The analysis of microphysical data on liquid water drop sizes shows that, for sufficiently small volumes, the number is proportional to the drop size dependent power of the volume. For abundant small drops present, the exponent is 1 as assumed in the conventional approach. However, for rarer large drops, the exponents fall below unity. At small scales, therefore, the mean number of large drops decreases with volume at a slower rate than the conventional approach assumes, suggesting more large drops at these scales than conventional models account for; their impact is consequently underestimated. Size dependent models of spatial distribution of cloud drops that simulate the observed power laws show strong drop clustering, the more so the larger the drops. The degree of clustering is determined by the observed exponents. The strong clustering of large drops arises naturally from the observed power-law statistics. Current theories of photon-cloud interaction and warm rain formation will need radical revision in order to produce these statistics; their underlying equations are unable to yield the observed power law.

  12. International wind power market: The US/ECRE

    SciTech Connect

    Lilley, A.

    1995-12-31

    Today, wind power is in its infancy, comprising less than .1% of the world`s total energy mix. However, the world installed base of wind turbines doubled in the period 1989 to 1994, from 1.7 GW to over 3.6 GW. More than 85% of this growth occurred outside the US. In a study commissioned by AWEA for the period 1994 to 2000, market growth in 10 target countries is projected to be from 2 GW to 3.5 GW. The World Energy Council projects a total installed base of nearly 10 GW by the year 2000. Much of this growth is expected to come in developing countries. Driven by market related factors, the US industry has recently turned its attention to the international arena. AWEA, US/ECRE, and their partners in government can play a critical supporting role to industry as they make the transition from a domestically focused industry to one that is globally focused.

  13. Power and Frequency Control as it Relates to Wind-Powered Generation

    SciTech Connect

    Lacommare, Kristina S H

    2010-12-20

    This report is a part of an investigation of the ability of the U.S. power system to accommodate large scale additions of wind generation. The objectives of this report are to describe principles by which large multi-area power systems are controlled and to anticipate how the introduction of large amounts of wind power production might require control protocols to be changed. The operation of a power system is described in terms of primary and secondary control actions. Primary control is fast, autonomous, and provides the first-line corrective action in disturbances; secondary control takes place on a follow-up time scale and manages the deployment of resources to ensure reliable and economic operation. This report anticipates that the present fundamental primary and secondary control protocols will be satisfactory as wind power provides an increasing fraction of the total production, provided that appropriate attention is paid to the timing of primary control response, to short term wind forecasting, and to management of reserves for control action.

  14. Small-Scale Smart Grid Construction and Analysis

    NASA Astrophysics Data System (ADS)

    Surface, Nicholas James

    The smart grid (SG) is a commonly used catch-phrase in the energy industry yet there is no universally accepted definition. The objectives and most useful concepts have been investigated extensively in economic, environmental and engineering research by applying statistical knowledge and established theories to develop simulations without constructing physical models. In this study, a small-scale version (SSSG) is constructed to physically represent these ideas so they can be evaluated. Results of construction show data acquisition three times more expensive than the grid itself although mainly due to the incapability to downsize 70% of data acquisition costs to small-scale. Experimentation on the fully assembled grid exposes the limitations of low cost modified sine wave power, significant enough to recommend pure sine wave investment in future SSSG iterations. Findings can be projected to full-size SG at a ratio of 1:10, based on the appliance representing average US household peak daily load. However this exposes disproportionalities in the SSSG compared with previous SG investigations and recommended changes for future iterations are established to remedy this issue. Also discussed are other ideas investigated in the literature and their suitability for SSSG incorporation. It is highly recommended to develop a user-friendly bidirectional charger to more accurately represent vehicle-to-grid (V2G) infrastructure. Smart homes, BEV swap stations and pumped hydroelectric storage can also be researched on future iterations of the SSSG.

  15. Quantifying the Geographic Diversity Needed to Reduce Wind Power Variability

    NASA Astrophysics Data System (ADS)

    St Martin, C.; Handschy, M.; Lundquist, J. K.

    2014-12-01

    The variability in wind-generated electricity complicates its integration into the electrical grid at higher penetrations. This variability can be reduced by interconnecting wind farms across large regions. We investigate the effectiveness of this aggregation with two extensive data sets. The first consists of 44 years of hourly 10-m wind speeds from 117 stations spanning distances of 5000 km across Canada from the National Climate Data Archive of Environment Canada. The second dataset consists of four years of 5-minute averaged wind speeds from stations across 350 km of the northwestern US from the Bonneville Power Administration. This study seeks to quantify how time scale affects the drop-off of correlation with distance, and hence statistical independence and the degree of geographic diversity needed to provide smoothing on various time scales. To eliminate non-stationarities, we filter both datasets to remove diurnal cycles and seasonal trends, after which we digitally high-pass filter the data on 0.25-2000 hour timescales relevant to power grid management. The wind speed data are then correlated between stations for each high-pass filter cut-off. In both datasets, the correlations between stations fall to zero with increasing station separation distance. Differences in inter-station azimuthal bearing account for a small but distinct fraction of the wide scatter in correlation vs. distance for the Canadian data set, with stations separated along a line 10° North of East-West being systematically less correlated than those perpendicular to that line. Similarities between these two datasets reveal behavior that, if universal, could be particularly useful for grid management. Both datasets exhibit a correlation length that varies as l = l0(1+25/T)-2, where l0 is the correlation length without high-pass filtering and T is the high-pass cut-off (in hours). Since the inter-site separation needed for statistical independence falls for time scales shorter than 25

  16. Analysis of Variability and Uncertainty in Wind Power Forecasting: An International Comparison (Presentation)

    SciTech Connect

    Zhang, J.; Hodge, B.; Miettinen, J.; Holttinen, H.; Gomez-Lozaro, E.; Cutululis, N.; Litong-Palima, M.; Sorensen, P.; Lovholm, A.; Berge, E.; Dobschinski, J.

    2013-10-01

    This presentation summarizes the work to investigate the uncertainty in wind forecasting at different times of year and compare wind forecast errors in different power systems using large-scale wind power prediction data from six countries: the United States, Finland, Spain, Denmark, Norway, and Germany.

  17. Policies to Support Wind Power Deployment: Key Considerations and Good Practices

    SciTech Connect

    Cox, Sadie; Tegen, Suzanne; Baring-Gould, Ian; Oteri, Frank A.; Esterly, Sean; Forsyth, Trudy; Baranowski, Ruth

    2015-05-19

    Policies have played an important role in scaling up wind deployment and increasing its economic viability while also supporting country-specific economic, social, and environmental development goals. Although wind power has become cost-competitive in several contexts, challenges to wind power deployment remain. Within the context of country-specific goals and challenges, policymakers are seeking

  18. 75 FR 61414 - Basin Electric Power Cooperative: South Dakota PrairieWinds Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ... Rural Utilities Service Basin Electric Power Cooperative: South Dakota PrairieWinds Project AGENCY...) for the Environmental Impact Statement (EIS) for the proposed South Dakota PrairieWind Project...-megawatt wind-powered generation facility. ADDRESSES: To obtain copies of the ROD, or for...

  19. Opportunities for Wind Power In Low- and Mid-Quality Resource Regions

    SciTech Connect

    Lantz, Eric; Mai, Trieu; Heimiller, Donna; Ho, Jonathan; Stehly, Tyler

    2016-05-25

    In this presentation for American Wind Energy Association (AWEA) WINDPOWER 2016 conference, the authors discuss wind power today in low and mid-quality resource regions, the anticipated role of wind power in the future electric sector, market potential in low and mid-quality resource regions, and anticipated innovations to capture that market potential.

  20. A small-scale turbulence model

    NASA Technical Reports Server (NTRS)

    Lundgren, T. S.

    1993-01-01

    A previously derived analytical model for the small-scale structure of turbulence is reformulated in such a way that the energy spectrum may be computed. The model is an ensemble of two-dimensional (2D) vortices with internal spiral structure, each stretched by an axially symmetric strain flow. Stretching and differential rotation produce an energy cascade to smaller scales in which the stretching represents the effect of instabilities and the spiral structure is the source of dissipation at the end of the cascade. The energy spectrum of the resulting flow may be expressed as a time integration involving only the enstrophy spectrum of the time evolving 2D cross section flow, which may be obtained numerically. Examples are given in which a k exp -5/3 spectrum is obtained by this method. The k exp -5/3 inertial range spectrum is shown to be related to the existence of a self-similar enstrophy preserving range in the 2D enstrophy spectrum. The results are found to be insensitive to time dependence of the strain rate, including even intermittent on-or-off strains.

  1. TURBULENT SMALL-SCALE DYNAMO ACTION IN SOLAR SURFACE SIMULATIONS

    SciTech Connect

    Graham, Jonathan Pietarila; Cameron, Robert; Schuessler, Manfred

    2010-05-10

    We demonstrate that a magneto-convection simulation incorporating essential physical processes governing solar surface convection exhibits turbulent small-scale dynamo action. By presenting a derivation of the energy balance equation and transfer functions for compressible magnetohydrodynamics, we quantify the source of magnetic energy on a scale-by-scale basis. We rule out the two alternative mechanisms for the generation of the small-scale magnetic field in the simulations: the tangling of magnetic field lines associated with the turbulent cascade and Alfvenization of small-scale velocity fluctuations ('turbulent induction'). Instead, we find that the dominant source of small-scale magnetic energy is stretching by inertial-range fluid motions of small-scale magnetic field lines against the magnetic tension force to produce (against Ohmic dissipation) more small-scale magnetic field. The scales involved become smaller with increasing Reynolds number, which identifies the dynamo as a small-scale turbulent dynamo.

  2. Impacts of Large Amounts of Wind Power on Design and Operation of Power Systems; Results of IEA Collaboration

    SciTech Connect

    Parsons, B.; Ela, E.; Holttinen, H.; Meibom, P.; Orths, A.; O'Malley, M.; Ummels, B. C.; Tande, J.; Estanqueiro, A.; Gomez, E.; Smith, J. C.

    2008-06-01

    There are a multitude of studies completed and ongoing related to the cost of wind integration. However, the results are not easy to compare. An international forum for exchange of knowledge of power system impacts of wind power has been formed under the IEA Implementing Agreement on Wind Energy. IEA WIND R&D Task 25 on “Design and Operation of Power Systems with Large Amounts of Wind Power” produced a state-of-the-art report in October 2007, where the most relevant wind-power grid integration studies were analyzed, especially regarding methodologies and input data. This paper summarizes the results from 18 case studies, with discussion on differences in methodology as well as issues that have been identified to impact the cost of wind integration.

  3. Understanding Dynamic Model Validation of a Wind Turbine Generator and a Wind Power Plant: Preprint

    SciTech Connect

    Muljadi, Eduard; Zhang, Ying Chen; Gevorgian, Vahan; Kosterev, Dmitry

    2016-09-01

    Regional reliability organizations require power plants to validate the dynamic models that represent them to ensure that power systems studies are performed to the best representation of the components installed. In the process of validating a wind power plant (WPP), one must be cognizant of the parameter settings of the wind turbine generators (WTGs) and the operational settings of the WPP. Validating the dynamic model of a WPP is required to be performed periodically. This is because the control parameters of the WTGs and the other supporting components within a WPP may be modified to comply with new grid codes or upgrades to the WTG controller with new capabilities developed by the turbine manufacturers or requested by the plant owners or operators. The diversity within a WPP affects the way we represent it in a model. Diversity within a WPP may be found in the way the WTGs are controlled, the wind resource, the layout of the WPP (electrical diversity), and the type of WTGs used. Each group of WTGs constitutes a significant portion of the output power of the WPP, and their unique and salient behaviors should be represented individually. The objective of this paper is to illustrate the process of dynamic model validations of WTGs and WPPs, the available data recorded that must be screened before it is used for the dynamic validations, and the assumptions made in the dynamic models of the WTG and WPP that must be understood. Without understanding the correct process, the validations may lead to the wrong representations of the WTG and WPP modeled.

  4. Investigating the Correlation Between Wind and Solar Power Forecast Errors in the Western Interconnection: Preprint

    SciTech Connect

    Zhang, J.; Hodge, B. M.; Florita, A.

    2013-05-01

    Wind and solar power generations differ from conventional energy generation because of the variable and uncertain nature of their power output. This variability and uncertainty can have significant impacts on grid operations. Thus, short-term forecasting of wind and solar generation is uniquely helpful for power system operations to balance supply and demand in an electricity system. This paper investigates the correlation between wind and solar power forecasting errors.

  5. Reference Manual for the System Advisor Model's Wind Power Performance Model

    SciTech Connect

    Freeman, J.; Jorgenson, J.; Gilman, P.; Ferguson, T.

    2014-08-01

    This manual describes the National Renewable Energy Laboratory's System Advisor Model (SAM) wind power performance model. The model calculates the hourly electrical output of a single wind turbine or of a wind farm. The wind power performance model requires information about the wind resource, wind turbine specifications, wind farm layout (if applicable), and costs. In SAM, the performance model can be coupled to one of the financial models to calculate economic metrics for residential, commercial, or utility-scale wind projects. This manual describes the algorithms used by the wind power performance model, which is available in the SAM user interface and as part of the SAM Simulation Core (SSC) library, and is intended to supplement the user documentation that comes with the software.

  6. Impacts of Improved Day-Ahead Wind Forecasts on Power Grid Operations: September 2011

    SciTech Connect

    Piwko, R.; Jordan, G.

    2011-11-01

    This study analyzed the potential benefits of improving the accuracy (reducing the error) of day-ahead wind forecasts on power system operations, assuming that wind forecasts were used for day ahead security constrained unit commitment.

  7. Wind and Water Power Modeling and Simulation at the NWTC (Fact Sheet)

    SciTech Connect

    Not Available

    2015-02-01

    Researchers and engineers at the National Wind Technology Center have developed a wide range of computer modeling and simulation tools to support the wind and water power industries with state-of-the-art design and analysis capabilities.

  8. Wind Power Siting: Public Acceptance and Land Use; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    Tegen, Suzanne

    2015-06-17

    Suzanne Tegen presented this information as part of the June 17, 2015 WINDExchange webinar: Overcoming Wind Siting Challenges III: Public Acceptance and Land Use. This presentation provides an overview of current NREL research related to wind energy deployment considerations, the DOE Wind Vision as it relates to public acceptance and land use, why public acceptance of wind power matters, where the U.S. wind resource is best, and how those rich resource areas overlay with population centers.

  9. Power coefficient of tornado-type wind turbines

    SciTech Connect

    Rangwalla, A.A.; Hsu, C.T.

    1983-11-01

    In a tornado-type wind turbine the wind collecting tower is equipped with adjustable vanes that can be opened on the windward side and closed on the leeward side. The wind enters the tower tangentially through these open vanes and exits from the top. As a result, a vortex is formed inside the tower. A vertical axis turbine which is located underneath the tower floor admits air vertically and exhausts it into the vortex core. The pressure drop in the vortex core can be high, depending upon the vortex concentration, thus enhancing manyfold the total pressure drop across the turbine. The power coefficient C /SUB p/ of this system depends mainly on how low a pressure can be created in the vortex core. A maximum C /SUB p/ of about 2.5 was obtained by Yen for a spiral shaped tower. This is about 6.25 times the C /SUB p/ of conventional windmills. Analytical studies have been carried out by several investigators to study the C /SUB p/ of this vortex machine. Loth considered the conservation of angular momentum and obtained a C /SUB p/ based on the tower frontal area, which is not impressive.

  10. Optimized Swinging Door Algorithm for Wind Power Ramp Event Detection: Preprint

    SciTech Connect

    Cui, Mingjian; Zhang, Jie; Florita, Anthony R.; Hodge, Bri-Mathias; Ke, Deping; Sun, Yuanzhang

    2015-08-06

    Significant wind power ramp events (WPREs) are those that influence the integration of wind power, and they are a concern to the continued reliable operation of the power grid. As wind power penetration has increased in recent years, so has the importance of wind power ramps. In this paper, an optimized swinging door algorithm (SDA) is developed to improve ramp detection performance. Wind power time series data are segmented by the original SDA, and then all significant ramps are detected and merged through a dynamic programming algorithm. An application of the optimized SDA is provided to ascertain the optimal parameter of the original SDA. Measured wind power data from the Electric Reliability Council of Texas (ERCOT) are used to evaluate the proposed optimized SDA.

  11. Soft-stall control versus furling control for small wind turbine power regulation

    SciTech Connect

    Muljadi, E; Forsyth, T; Butterfield, C P

    1998-07-01

    Many small wind turbines are designed to furl (turn) in high winds to regulate power and provide overspeed protection. Furling control results in poor energy capture at high wind speeds. This paper proposes an alternative control strategy for small wind turbines -- the soft-stall control method. The furling and soft-stall control strategies are compared using steady state analysis and dynamic simulation analysis. The soft-stall method is found to offer several advantages: increased energy production at high wind speeds, energy production which tracks the maximum power coefficient at low to medium wind speeds, reducing furling noise, and reduced thrust.

  12. Soft-Stall Control versus Furling Control for Small Wind Turbine Power Regulation

    SciTech Connect

    Muljadi, E.; Forsyth, T.; Butterfield, C. P.

    1998-07-01

    Many small wind turbines are designed to furl (turn) in high winds to regulate power and provide overspeed protection. Furling control results in poor energy capture at high wind speeds. This paper proposes an alternative control strategy for small wind turbines -- the soft-stall method. The furling and soft-stall control strategies are compared using steady state analysis and dynamic simulation analysis. The soft-stall method is found to offer several advantages: increased energy production at high wind speeds, energy production which tracks the maximum power coefficient at low to medium wind speeds, reduced furling noise, and reduced thrust.

  13. Social Acceptance of Wind Power in the United States: Evaluating Stakeholder Perspectives (Poster)

    SciTech Connect

    Tegen, S.; Lantz, E.

    2009-05-01

    As the wind industry strives to achieve 20% wind energy by 2030, maintaining high levels of social acceptance for wind energy will become increasingly important. Wind Powering America is currently researching stakeholder perspectives in the U.S. market and reviewing findings from wind energy projects around the world to better understand social acceptance barriers. Results from European studies show that acceptance varies widely depending on local community values. A preliminary survey shows similar results in the United States. Further research will be conducted to refine our understanding of key social acceptance barriers and evaluate the best ways to mitigate negative perspectives on wind power.

  14. Baseload, industrial-scale wind power: An alternative to coal in China

    SciTech Connect

    Lew, D.J.; Williams, R.H.; Xie Shaoxiong; Zhang Shihui

    1996-12-31

    This report presents a novel strategy for developing wind power on an industrial-scale in China. Oversized wind farms, large-scale electrical storage and long-distance transmission lines are integrated to deliver {open_quotes}baseload wind power{close_quotes} to distant electricity demand centers. The prospective costs for this approach to developing wind power are illustrated by modeling an oversized wind farm at Huitengxile, Inner Mongolia. Although storage adds to the total capital investment, it does not necessarily increase the cost of the delivered electricity. Storage makes it possible to increase the capacity factor of the electric transmission system, so that the unit cost for long-distance transmission is reduced. Moreover, baseload wind power is typically more valuable to the electric utility than intermittent wind power, so that storage can be economically attractive even in instances where the cost per kWh is somewhat higher than without storage. 9 refs., 3 figs., 2 tabs.

  15. The influence of large-scale wind power on global climate

    PubMed Central

    Keith, David W.; DeCarolis, Joseph F.; Denkenberger, David C.; Lenschow, Donald H.; Malyshev, Sergey L.; Pacala, Stephen; Rasch, Philip J.

    2004-01-01

    Large-scale use of wind power can alter local and global climate by extracting kinetic energy and altering turbulent transport in the atmospheric boundary layer. We report climate-model simulations that address the possible climatic impacts of wind power at regional to global scales by using two general circulation models and several parameterizations of the interaction of wind turbines with the boundary layer. We find that very large amounts of wind power can produce nonnegligible climatic change at continental scales. Although large-scale effects are observed, wind power has a negligible effect on global-mean surface temperature, and it would deliver enormous global benefits by reducing emissions of CO2 and air pollutants. Our results may enable a comparison between the climate impacts due to wind power and the reduction in climatic impacts achieved by the substitution of wind for fossil fuels. PMID:15536131

  16. The influence of large-scale wind power on global climate.

    PubMed

    Keith, David W; Decarolis, Joseph F; Denkenberger, David C; Lenschow, Donald H; Malyshev, Sergey L; Pacala, Stephen; Rasch, Philip J

    2004-11-16

    Large-scale use of wind power can alter local and global climate by extracting kinetic energy and altering turbulent transport in the atmospheric boundary layer. We report climate-model simulations that address the possible climatic impacts of wind power at regional to global scales by using two general circulation models and several parameterizations of the interaction of wind turbines with the boundary layer. We find that very large amounts of wind power can produce nonnegligible climatic change at continental scales. Although large-scale effects are observed, wind power has a negligible effect on global-mean surface temperature, and it would deliver enormous global benefits by reducing emissions of CO(2) and air pollutants. Our results may enable a comparison between the climate impacts due to wind power and the reduction in climatic impacts achieved by the substitution of wind for fossil fuels.

  17. Wind Power Across Native America: Opportunities, Challenges, and Status (Poster)

    SciTech Connect

    Jimenez, A.; Gough, R.; Flowers, L.; Taylor, R.

    2009-05-01

    Wind projects on tribal lands are differennt, and this poster outlines the ways in which these projects differ, a summary of existing and pending Native American Wind Projects (50 kW and larger), and tribal wind opportunities and issues.

  18. Solar power. [comparison of costs to wind, nuclear, coal, oil and gas

    NASA Technical Reports Server (NTRS)

    Walton, A. L.; Hall, Darwin C.

    1990-01-01

    This paper describes categories of solar technologies and identifies those that are economic. It compares the private costs of power from solar, wind, nuclear, coal, oil, and gas generators. In the southern United States, the private costs of building and generating electricity from new solar and wind power plants are less than the private cost of electricity from a new nuclear power plant. Solar power is more valuable than nuclear power since all solar power is available during peak and midpeak periods. Half of the power from nuclear generators is off-peak power and therefore is less valuable. Reliability is important in determining the value of wind and nuclear power. Damage from air pollution, when factored into the cost of power from fossil fuels, alters the cost comparison in favor of solar and wind power. Some policies are more effective at encouraging alternative energy technologies that pollute less and improve national security.

  19. Analyzing Effects of Turbulence on Power Generation Using Wind Plant Monitoring Data: Preprint

    SciTech Connect

    Zhang, J.; Chowdhury, S.; Hodge, B. M.

    2014-01-01

    In this paper, a methodology is developed to analyze how ambient and wake turbulence affects the power generation of a single wind turbine within an array of turbines. Using monitoring data from a wind power plant, we selected two sets of wind and power data for turbines on the edge of the wind plant that resemble (i) an out-of-wake scenario (i.e., when the turbine directly faces incoming winds) and (ii) an in-wake scenario (i.e., when the turbine is under the wake of other turbines). For each set of data, two surrogate models were then developed to represent the turbine power generation (i) as a function of the wind speed; and (ii) as a function of the wind speed and turbulence intensity. Support vector regression was adopted for the development of the surrogate models. Three types of uncertainties in the turbine power generation were also investigated: (i) the uncertainty in power generation with respect to the published/reported power curve, (ii) the uncertainty in power generation with respect to the estimated power response that accounts for only mean wind speed; and (iii) the uncertainty in power generation with respect to the estimated power response that accounts for both mean wind speed and turbulence intensity. Results show that (i) under the same wind conditions, the turbine generates different power between the in-wake and out-of-wake scenarios, (ii) a turbine generally produces more power under the in-wake scenario than under the out-of-wake scenario, (iii) the power generation is sensitive to turbulence intensity even when the wind speed is greater than the turbine rated speed, and (iv) there is relatively more uncertainty in the power generation under the in-wake scenario than under the out-of-wake scenario.

  20. Design and Operation of Power Systems with Large Amounts of Wind Power, First Results of IEA Collaboration

    SciTech Connect

    Holttinen, H.; Meibom, P.; Orths, A.; Van Hulle, F.; Ensslin, C.; Hofmann, L.; McCann, J.; Pierik, J.; Tande, J. O.; Estanqueiro, A.; Soder, L.; Strbac, G.; Parsons, B.; Smith, J. C.; Lemstrom, B.

    2006-01-01

    An international forum for exchange of knowledge of power system impacts of wind power has been formed under the IEA Implementing Agreement on Wind Energy. The task 'Design and Operation of Power Systems with Large Amounts of Wind Power' will analyse existing case studies from different power systems. There are a multitude of studies made and ongoing related to cost of wind integration. However, the results are not easy to compare. This paper summarizes the results from 10 countries and outlines the studies made at European Wind Energy Association and the European system operators UCTE and ETSO. A more in-depth review of the studies is needed to draw conclusions on the range of integration costs for wind power. A state-of-the art review process of the new IEA collaboration will seek reasons behind the wide range of results for costs of wind integration - definitions for wind penetration, reserves and costs; different power system and load characteristics and operational rules; underlying assumptions on variability and uncertainty of wind, etc.

  1. Quantifying wind resource assessment and grid integration challenges for Delaware offshore wind power utilizing mesoscale modeling techniques

    NASA Astrophysics Data System (ADS)

    Brodie, Joseph F.

    Offshore wind in the United States continues to be a focused area of research as our society grapples with the Earth's changing climate and our ongoing and increasing demand for electricity. While the first offshore wind project in the U.S. is expected to be operational soon, much still remains to be done to help improve viability of offshore wind in additional locations. This dissertation discusses three studies conducted to improve the understanding of and expectations from developing wind energy in the Delaware Wind Energy Area off the Delaware coast. The first study examines the capabilities of the Weather Research and Forecasting (WRF) model to account for variations in wind farm array geometries in an idealized set-up of the model, and determines features of those array geometries that can positively influence the energy production of an offshore farm. The second study investigates the impacts that the misprediction of wind ramp events would have on the interaction of an offshore wind farm with the electricity grid, quantifying some of these impacts and discussing factors which contribute to grid instability. The third study combines the knowledge gained in the first two studies to evaluate potential wind farm array geometries in a regional study of the Delaware Wind Energy Area using WRF along with a selection of case study dates selected to examine the impacts of the synoptic variability of the region throughout the year. These studies demonstrate that careful consideration of the meteorology and climatology of a region when determining the layout of an offshore wind array can improve the power production of the farm, thereby improving wind farm viability. It is shown that using a mesoscale model that incorporates a wind farm parameterization can improve resource assessment by allowing the assessment to evaluate the wind farm's interactions with the weather and climate in the Delaware Wind Energy Area. Furthermore, it is shown that while certain synoptic

  2. An estimation method of the fault wind turbine power generation loss based on correlation analysis

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; Zhu, Shourang; Wang, Wei

    2017-01-01

    A method for estimating the power generation loss of a fault wind turbine is proposed in this paper. In this method, the wind speed is estimated and the estimated value of the loss of power generation is given by combining the actual output power characteristic curve of the wind turbine. In the wind speed estimation, the correlation analysis is used, and the normal operation of the wind speed of the fault wind turbine is selected, and the regression analysis method is used to obtain the estimated value of the wind speed. Based on the estimation method, this paper presents an implementation of the method in the monitoring system of the wind turbine, and verifies the effectiveness of the proposed method.

  3. Atmospheric Impacts on Power Curves of Multi-Megawatt Offshore Wind Turbines

    NASA Astrophysics Data System (ADS)

    Dörenkämper, M.; Tambke, J.; Steinfeld, G.; Heinemann, D.; Kühn, M.

    2014-12-01

    Power curves for offshore wind turbines within the German offshore wind farm alpha ventus were derived based on the IEC standard. Binning in groups of shear and turbulence intensity as measures of atmospheric stability were performed. The derived power curves show a strong dependency on these two parameters. Differences of up to 15% in power output between unstable and stable stratification in the non-wake case occur. For wind turbines within the wake of others the effects are even more pronounced. Here, the differences in power production between the stability classes approach 20%. This dependency of the power curves on stability can cause significant miscalculations of instantaneous power production, long-term energy yield and loads. Parameters other than the hub height wind speed are often not taken into account in state-of-the-art wind power forecasts. This can lead to substantial over- or underestimation of the resulting power.

  4. Short-Term Forecasting of Loads and Wind Power for Latvian Power System: Accuracy and Capacity of the Developed Tools

    NASA Astrophysics Data System (ADS)

    Radziukynas, V.; Klementavičius, A.

    2016-04-01

    The paper analyses the performance results of the recently developed short-term forecasting suit for the Latvian power system. The system load and wind power are forecasted using ANN and ARIMA models, respectively, and the forecasting accuracy is evaluated in terms of errors, mean absolute errors and mean absolute percentage errors. The investigation of influence of additional input variables on load forecasting errors is performed. The interplay of hourly loads and wind power forecasting errors is also evaluated for the Latvian power system with historical loads (the year 2011) and planned wind power capacities (the year 2023).

  5. A data-driven method to characterize turbulence-caused uncertainty in wind power generation

    SciTech Connect

    Zhang, Jie; Jain, Rishabh; Hodge, Bri-Mathias

    2016-10-01

    A data-driven methodology is developed to analyze how ambient and wake turbulence affect the power generation of wind turbine(s). Using supervisory control and data acquisition (SCADA) data from a wind plant, we select two sets of wind velocity and power data for turbines on the edge of the plant that resemble (i) an out-of-wake scenario and (ii) an in-wake scenario. For each set of data, two surrogate models are developed to represent the turbine(s) power generation as a function of (i) the wind speed and (ii) the wind speed and turbulence intensity. Three types of uncertainties in turbine(s) power generation are investigated: (i) the uncertainty in power generation with respect to the reported power curve; (ii) the uncertainty in power generation with respect to the estimated power response that accounts for only mean wind speed; and (iii) the uncertainty in power generation with respect to the estimated power response that accounts for both mean wind speed and turbulence intensity. Results show that (i) the turbine(s) generally produce more power under the in-wake scenario than under the out-of-wake scenario with the same wind speed; and (ii) there is relatively more uncertainty in the power generation under the in-wake scenario than under the out-of-wake scenario.

  6. How Many Model Evaluations Are Required To Predict The AEP Of A Wind Power Plant?

    NASA Astrophysics Data System (ADS)

    Murcia, J. P.; Réthoré, P. E.; Natarajan, A.; Sørensen, J. D.

    2015-06-01

    Wind farm flow models have advanced considerably with the use of large eddy simulations (LES) and Reynolds averaged Navier-Stokes (RANS) computations. The main limitation of these techniques is their high computational time requirements; which makes their use for wind farm annual energy production (AEP) predictions expensive. The objective of the present paper is to minimize the number of model evaluations required to capture the wind power plant's AEP using stationary wind farm flow models. Polynomial chaos techniques are proposed based on arbitrary Weibull distributed wind speed and Von Misses distributed wind direction. The correlation between wind direction and wind speed are captured by defining Weibull-parameters as functions of wind direction. In order to evaluate the accuracy of these methods the expectation and variance of the wind farm power distributions are compared against the traditional binning method with trapezoidal and Simpson's integration rules. The wind farm flow model used in this study is the semi-empirical wake model developed by Larsen [1]. Three test cases are studied: a single turbine, a simple and a real offshore wind power plant. A reduced number of model evaluations for a general wind power plant is proposed based on the convergence of the present method for each case.

  7. Outlooks for Wind Power in the United States: Drivers and Trends under a 2016 Policy Environment

    SciTech Connect

    Mai, Trieu; Lantz, Eric; Ho, Jonathan; Stehly, Tyler; Heimiller, Donna

    2016-12-01

    Over the past decade, wind power has become one of the fastest growing electricity generation sources in the United States. Despite this growth, the U.S. wind industry continues to experience year-to-year fluctuations across the manufacturing and supply chain as a result of dynamic market conditions and changing policy landscapes. Moreover, with advancing wind technologies, ever-changing fossil fuel prices, and evolving energy policies, the long-term future for wind power is highly uncertain. In this report, we present multiple outlooks for wind power in the United States, to explore the possibilities of future wind deployment. The future wind power outlooks presented rely on high-resolution wind resource data and advanced electric sector modeling capabilities to evaluate an array of potential scenarios of the U.S. electricity system. Scenario analysis is used to explore drivers, trends, and implications for wind power deployment over multiple periods through 2050. Specifically, we model 16 scenarios of wind deployment in the contiguous United States. These scenarios span a wide range of wind technology costs, natural gas prices, and future transmission expansion. We identify conditions with more consistent wind deployment after the production tax credit expires as well as drivers for more robust wind growth in the long run. Conversely, we highlight challenges to future wind deployment. We find that the degree to which wind technology costs decline can play an important role in future wind deployment, electric sector CO2 emissions, and lowering allowance prices for the Clean Power Plan.

  8. Brief communication "Spatial and temporal variation of wind power at hub height over Europe"

    NASA Astrophysics Data System (ADS)

    Gisinger, S.; Mayr, G. J.; Messner, J. W.; Stauffer, R.

    2013-05-01

    Wind power over Europe computed from two years of the new 100 m wind product from ECMWF at 16 km horizontal resolution is 20% of maximum capacity of an exemplary wind turbine power curve. This is five percent of maximum capacity less than extrapolated from 10 m winds using model roughness in the logarithmic law, but eight percent more than multiplying 10 m winds by a constant factor of 1.28 as in a previous study. The result from the new data set happens to be very close to the actual capacity factor of 21% for European wind turbines (Boccard, 2009). The capacity factor in high power regions between 50 and 58° N and most of northernmost Africa is almost 30%. The aggregation of wind power over Europe smooths onshore day-to-day fluctuations to at most 7 percentage points during 80% of the year.

  9. Test Cases for Wind Power Plant Dynamic Models on Real-Time Digital Simulator: Preprint

    SciTech Connect

    Singh, M.; Muljadi, E.; Gevorgian, V.

    2012-06-01

    The objective of this paper is to present test cases for wind turbine generator and wind power plant models commonly used during commissioning of wind power plants to ensure grid integration compatibility. In this paper, different types of wind power plant models based on the Western Electricity Coordinating Council Wind Generator Modeling Group's standardization efforts are implemented on a real-time digital simulator, and different test cases are used to gauge their grid integration capability. The low-voltage ride through and reactive power support capability and limitations of wind turbine generators under different grid conditions are explored. Several types of transient events (e.g., symmetrical and unsymmetrical faults, frequency dips) are included in the test cases. The differences in responses from different types of wind turbine are discussed in detail.

  10. Seasonal and annual variability of the global onshore and offshore wind power resource at 100 m

    NASA Astrophysics Data System (ADS)

    Archer, C. L.; Jacobson, M. Z.

    2010-12-01

    We present the results of numerical simulations of the global wind power potential over land and offshore with a coupled climate-meteorological-air pollution model, GATOR-GCMOM, that dynamically calculates wind power at the 100-m hub height of a modern 5 MW wind turbine at each time step. The model was run at various horizontal resolutions (4x5, 2x2.5, and 1.5x1.5 degrees of latitude and longitude) and with various initial conditions (summer or winter) for at least four years each. The global delivered wind power potential at 100 m at fast-wind locations (≥7 m/s) over land, excluding both polar regions, is found to be 138-150 TW (TW=1012 Watts) on average. This result further supports previous observation-based estimates of 72 TW at 80 m and model-based estimates of 79-126 TW at 100 m. Seasonal variations are however significant, with values as low as 94-102 TW in June-July-August (JJA) to 218-246 TW in December-January-February (DJF), with minima in September and maxima in January in all simulations. Global wind power over land at fast-wind locations during DJF is 1.6-2.5 times greater than that during JJA on average. Furthermore, the average wind power over land in the Northern Hemisphere (NH) is ˜126 TW, over 5 times greater than the Southern Hemisphere (SH) average (˜24 TW). In December, the NH wind power over land is up to 32 times greater than that in the SH. This suggests that the two hemispheres have different wind resources, driven by the different distributions of land and ocean areas. The offshore delivered wind power potential (excluding polar regions) is 15-23 TW at 100 m on average, consistent with previous estimates of 18-21 TW, varying between 16-17 and 19-31 TW from JJA to DJF. Wind power over land and near shore in fast-wind locations (which are 7-8% of the total land excluding polar regions) represents 7-10% of the theoretical global wind power over land plus ocean at all wind speeds of ˜1700 TW. Available wind power over land and near shore

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

    SciTech Connect

    U.S. Department of Energy

    2015-03-12

    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.

  12. Energy Storage and Reactive Power Compensator in a Large Wind Farm: Preprint

    SciTech Connect

    Muljadi, E.; Butterfield, C. P.; Yinger, R.; Romanowitz, H.

    2003-10-01

    The size of wind farm power systems is increasing, and so is the number of wind farms contributing to the power systems network. The size of wind turbines is also increasing--from less than 1 MW a few years ago to the 2- to 3-MW machines being installed today and the 5-MW machines under development. The interaction of the wind farm, energy storage, reactive power compensation, and the power system network is being investigated. Because the loads and the wind farms' output fluctuate during the day, the use of energy storage and reactive power compensation is ideal for the power system network. Energy storage and reactive power compensation can minimize real/reactive power imbalances that can affect the surrounding power system. In this paper, we will show how the contribution of wind farms affects the power distribution network and how the power distribution network, energy storage, and reactive power compensation interact when the wind changes. We will also investigate the size of the components in relation to each other and to the power system.

  13. Speckle imaging of solar small scale structure. 2: Study of small scale structure in active regions

    NASA Astrophysics Data System (ADS)

    von der Luehe, O.

    1994-01-01

    The speckle imaging technique which is described in the first paper of this series (von der Luehe 1993) was used to analyze time series of high angular resolution images of solar small scale structure at a wavelength of 585 nm in active regions with the 76 cm diameter vacuum tower telescope at National Solar Observatory (NSO)/Sac Peak. Two sets of reconstructed images with a field of 4 by 4 arcsec which cover a period of 36 min and 83 min were generated and analyzed. The image reconstructions are supplemented with simultaneous large field photographs taken within a 15 A passband centered on the Ca II K (3933) line. The prime objective of the observing program was the study of the structure and the dynamics of the continuum wavelength counterpart of facular points which appear with high contrast in the Ca pictures, i.e., continuum bright points (CBPs). In addition to CBPs, the reconstructions allow studying other small scale phenomena. Results of the studies are given.

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

    SciTech Connect

    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.

  15. Particle Acceleration At Small-Scale Flux Ropes In The Heliosphere

    NASA Astrophysics Data System (ADS)

    Zank, G. P.; Hunana, P.; Mostafavi, P.; le Roux, J. A.; Li, G.; Webb, G. M.; Khabarova, O.; Cummings, A. C.; Stone, E. C.; Decker, R. B.

    2015-12-01

    An emerging paradigm for the dissipation of magnetic turbulence in the supersonic solar wind is via localized small-scale reconnection processes, essentially between quasi-2D interacting magnetic islands or flux roped. Charged particles trapped in merging magnetic islands can be accelerated by the electric field generated by magnetic island merging and the contraction of magnetic islands. We discuss the basic physics of particle acceleration by single magnetic islands and describe how to incorporate these ideas in a distributed "sea of magnetic islands". We describe briefly some observations, selected simulations, and then introduce a transport approach for describing particle acceleration at small-scale flux ropes. We discuss particle acceleration in the supersonic solar wind and extend these ideas to particle acceleration at shock waves. These models are appropriate to the acceleration of both electrons and ions. We describe model predictions and supporting observations.

  16. Prevalence of small-scale jets from the networks of the solar transition region and chromosphere.

    PubMed

    Tian, H; DeLuca, E E; Cranmer, S R; De Pontieu, B; Peter, H; Martínez-Sykora, J; Golub, L; McKillop, S; Reeves, K K; Miralles, M P; McCauley, P; Saar, S; Testa, P; Weber, M; Murphy, N; Lemen, J; Title, A; Boerner, P; Hurlburt, N; Tarbell, T D; Wuelser, J P; Kleint, L; Kankelborg, C; Jaeggli, S; Carlsson, M; Hansteen, V; McIntosh, S W

    2014-10-17

    As the interface between the Sun's photosphere and corona, the chromosphere and transition region play a key role in the formation and acceleration of the solar wind. Observations from the Interface Region Imaging Spectrograph reveal the prevalence of intermittent small-scale jets with speeds of 80 to 250 kilometers per second from the narrow bright network lanes of this interface region. These jets have lifetimes of 20 to 80 seconds and widths of ≤300 kilometers. They originate from small-scale bright regions, often preceded by footpoint brightenings and accompanied by transverse waves with amplitudes of ~20 kilometers per second. Many jets reach temperatures of at least ~10(5) kelvin and constitute an important element of the transition region structures. They are likely an intermittent but persistent source of mass and energy for the solar wind.

  17. XMM-Newton, powerful AGN winds and galaxy feedback

    NASA Astrophysics Data System (ADS)

    Pounds, K.; King, A.

    2016-06-01

    The discovery that ultra-fast ionized winds - sufficiently powerful to disrupt growth of the host galaxy - are a common feature of luminous AGN is major scientific breakthrough led by XMM-Newton. An extended observation in 2014 of the prototype UFO, PG1211+143, has revealed an unusually complex outflow, with distinct and persisting velocities detected in both hard and soft X-ray spectra. While the general properties of UFOs are consistent with being launched - at the local escape velocity - from the inner disc where the accretion rate is modestly super-Eddington (King and Pounds, Ann Rev Astron Astro- phys 2015), these more complex flows have raised questions about the outflow geometry and the importance of shocks and enhanced cooling. XMM-Newton seems likely to remain the best Observatory to study UFOs prior to Athena, and further extended observations, of PG1211+143 and other bright AGN, have the exciting potential to establish the typical wind dynamics, while providing new insights on the accretion geometry and continuum source structure. An emphasis on such large, coordinated observing programmes with XMM-Newton over the next decade will continue the successful philosophy pioneered by EXOSAT, while helping to inform the optimum planning for Athena

  18. Power Flow Simulations of a More Renewable California Grid Utilizing Wind and Solar Insolation Forecasting

    NASA Astrophysics Data System (ADS)

    Hart, E. K.; Jacobson, M. Z.; Dvorak, M. J.

    2008-12-01

    Time series power flow analyses of the California electricity grid are performed with extensive addition of intermittent renewable power. The study focuses on the effects of replacing non-renewable and imported (out-of-state) electricity with wind and solar power on the reliability of the transmission grid. Simulations are performed for specific days chosen throughout the year to capture seasonal fluctuations in load, wind, and insolation. Wind farm expansions and new wind farms are proposed based on regional wind resources and time-dependent wind power output is calculated using a meteorological model and the power curves of specific wind turbines. Solar power is incorporated both as centralized and distributed generation. Concentrating solar thermal plants are modeled using local insolation data and the efficiencies of pre-existing plants. Distributed generation from rooftop PV systems is included using regional insolation data, efficiencies of common PV systems, and census data. The additional power output of these technologies offsets power from large natural gas plants and is balanced for the purposes of load matching largely with hydroelectric power and by curtailment when necessary. A quantitative analysis of the effects of this significant shift in the electricity portfolio of the state of California on power availability and transmission line congestion, using a transmission load-flow model, is presented. A sensitivity analysis is also performed to determine the effects of forecasting errors in wind and insolation on load-matching and transmission line congestion.

  19. Trajectories of concentrating photovoltaics (CPV) in market space based on comparisons with offshore wind power

    NASA Astrophysics Data System (ADS)

    Leutz, Ralf

    2012-10-01

    Concentrating photovoltaics (CPV) are for solar photovoltaics what offshore wind power is for wind power; this is the hypothesis of this work. In analogy to offshore wind cumulative global CPV installations of approximately 3-7 GW are predicted for the year 2020. Scenarios are based on paths for CPV following offshore wind in shape, but with a delay of ten years which is approximately the time lag the first larger offshore wind farms were built earlier than the first large CPV plants of 2011.

  20. Small scale adaptive optics experiment systems engineering

    NASA Technical Reports Server (NTRS)

    Boykin, William H.

    1993-01-01

    Assessment of the current technology relating to the laser power beaming system which in full scale is called the Beam Transmission Optical System (BTOS). Evaluation of system integration efforts are being conducted by the various government agencies and industry. Concepts are being developed for prototypes of adaptive optics for a BTOS.