Space Station laboratory module power loading analysis

NASA Astrophysics Data System (ADS)

Fu, S. J.

1994-07-01

The electrical power system of Space Station Freedom is an isolated electrical power generation and distribution network designed to meet the demands of a large number of electrical loads. An algorithm is developed to determine the power bus loading status under normal operating conditions to ensure the supply meets demand. The probabilities of power availability for payload operations (experiments) are also derived.

40 CFR 1033.140 - Rated power.

Code of Federal Regulations, 2011 CFR

2011-07-01

... value to the nearest whole horsepower. Generally, this will be the brake power of the engine in notch 8... each possible operator demand setpoint or “notch”. See 40 CFR 1065.1001 for the definition of operator... discrete operator demand setpoints, or notches, the nominal power curve would be a series of eight power...

How to introduce demand side resources in the design of low-carbon power systems in China

NASA Astrophysics Data System (ADS)

Zhou, Pengcheng; Liu, Yiqun; Zeng, Ming; Sun, Chenjun

2018-04-01

Nowadays, China's energy demand sustained rapid growth, and the coal-based energy structure has adverse effects on the environment. The flexibility of demand side resource (DSR) will be greatly improved, and DSR can reduce electricity consumption actively and temporarily, and realize energy saving and emission reduction. But there are still some problems to introduce DSR in China. This paper proposes three practices for introducing demand side resources to improve the flexibility of power systems through demand resources.

Modeling Framework and Validation of a Smart Grid and Demand Response System for Wind Power Integration

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

Broeer, Torsten; Fuller, Jason C.; Tuffner, Francis K.

2014-01-31

Electricity generation from wind power and other renewable energy sources is increasing, and their variability introduces new challenges to the power system. The emergence of smart grid technologies in recent years has seen a paradigm shift in redefining the electrical system of the future, in which controlled response of the demand side is used to balance fluctuations and intermittencies from the generation side. This paper presents a modeling framework for an integrated electricity system where loads become an additional resource. The agent-based model represents a smart grid power system integrating generators, transmission, distribution, loads and market. The model incorporates generatormore » and load controllers, allowing suppliers and demanders to bid into a Real-Time Pricing (RTP) electricity market. The modeling framework is applied to represent a physical demonstration project conducted on the Olympic Peninsula, Washington, USA, and validation simulations are performed using actual dynamic data. Wind power is then introduced into the power generation mix illustrating the potential of demand response to mitigate the impact of wind power variability, primarily through thermostatically controlled loads. The results also indicate that effective implementation of Demand Response (DR) to assist integration of variable renewable energy resources requires a diversity of loads to ensure functionality of the overall system.« less

Proceedings of Symposium on Energy Engineering in the 21st Century (SEE 2000). Volume Four

DTIC Science & Technology

2000-01-13

Significantly Varying Demand of Heat and Power 1347 D. Hein and K. Kwanka T2. Thermodynamic Analysis and Sensitivity Studies on Braysson cycle Using...to Volumes 1-4 T. Cycle Analysis 1346 CHENG CYCLE COGENERATION FOR A SIGNIFICANTLY VARYING DEMAND OF HEAT AND POWER Dietmar Hein, Klaus Kwanka...significantly varying demand of heat and power a Cheng Cycle gas turbine cogeneration plant was installed. By injecting steam, produced by the heat

Research on Simulation Requirements and Business Architecture of Automated Demand Response in Power Sales Side Market Liberalization

NASA Astrophysics Data System (ADS)

Liu, Yiqun; Zhou, Pengcheng; Zeng, Ming; Chen, Songsong

2018-01-01

With the gradual reform of the electricity market, the power sale side liberalization has become the focus of attention as the key task of reform. The open power market provides a good environment for DR (Demand Response). It is of great significance to research the simulation requirements and business architecture of ADR (Automatic Demand Response) in power sale side market liberalization. Firstly, this paper analyzes the simulation requirements of ADR. Secondly, it analyzes the influence factors that the business development of ADR from five aspects after power sale side market liberalization. Finally, Based on ADR technology support system, the business architecture of ADR after power sale side market liberalization is constructed.

A Risk Management Method for the Operation of a Supply-Chain without Storage:

NASA Astrophysics Data System (ADS)

Kobayashi, Yasuhiro; Manabe, Yuuji; Nakata, Norimasa; Kusaka, Satoshi

A business risk management method has been developed for a supply-chain without a storage function under demand uncertainty. Power supply players in the deregulated power market face the need to develop the best policies for power supply from self-production and reserved purchases to balance demand, which is predictable with error. The proposed method maximizes profit from the operation of the supply-chain under probabilistic demand uncertainty on the basis of a probabilistic programming approach. Piece-wise linear functions are employed to formulate the impact of under-booked or over-booked purchases on the supply cost, and constraints on over-demand probability are introduced to limit over-demand frequency on the basis of the demand probability distribution. The developed method has been experimentally applied to the supply policy of a power-supply-chain, the operation of which is based on a 3-stage pricing purchase contract and on 28 time zones. The characteristics of the obtained optimal supply policy are successfully captured in the numerical results, which suggest the applicability of the proposed method.

Power Sources for Micro-Autonomous Vehicles- Challenges and Prospects

NASA Technical Reports Server (NTRS)

Narayan, S. R.; Kisor, A.; Valdez, T. I.; Manohara, H.

2009-01-01

Micro-autonomous vehicle systems are expected to have expanded role in military missions by providing full spectrum intelligence, surveillance and reconnaissance support on the battlefield, suppression of enemy defenses, and enabling co-operative (swarm-like) configurations. Of the numerous demanding requirements of autonomy, sensing, navigation, mobility, etc., meeting the requirement of mission duration or endurance is a very challenging one. This requirement is demanding because of the constraints of mass and volume that limit the quantity of energy that can be stored on-board. Energy is required for mobility, payload operation, information processing, and communication. Mobility requirements typically place an extraordinary demand on the specific energy (Wh/kg) and specific power (W/kg) of the power source; the actual distribution of the energy between mobility and other system functions could vary substantially with the mission type. The power requirements for continuous mobility can vary from 100-1000 W/kg depending on the terrain, ground speed and flight speed. Even with the power source accounting for 30% of the mass of the vehicle, the best of rechargeable batteries can provide only up to 1-2 hours of run-time for a continuous power demand at 100W/kg. In the case of micro-aerial vehicles with flight speed requirements in the range of 5-15 m s-1, the mission times rarely exceed 20 minutes [2]. Further, the power required during take-off and hover can be twice or thrice that needed for steady level flight, and thus the number and sequence of such events is also limited by the mass and size of the power source. For operations such as "perch and stare" or "silent watch" the power demand is often only a tenth of that required during continuous flight. Thus, variation in power demand during various phases of the mission importantly affects the power source selection.

Method for predicting water demand for crop uses in New Jersey in 1990, 2000, 2010, and 2020, and for estimating water use for livestock and selected sectors of the food-processing industry in New Jersey in 1987

USGS Publications Warehouse

Clawges, R.M.; Titus, E.O.

1993-01-01

A method was developed to predict water demand for crop uses in New Jersey. A separate method was developed to estimate water use for livestock and selected sectors of the food-processing industry in 1987. Predictions of water demand for field- grown crops in New Jersey were made for 1990, 2000, 2010, and 2020 under three climatological scenarios: (1) wet year, (2) average year, and (3) drought year. These estimates ranged from 4.10 times 10 to the 9th power to 16.82 times 10 to the 9th power gal (gallons). Irrigation amounts calculated for the three climatological scenarios by using a daily water-balance model were multiplied by predicted numbers of irrigated acreage. Irrigated acreage was predicted from historical crop-irrigation data and from predictions of harvested acreage produced by using a statistical model relating population to harvested acreage. Predictions of water demand for cranberries and container-grown nursery crops also were made for 1990, 2000, 2010, and 2020. Predictions of water demand under the three climatological scenarios were made for container- grown nursery crops, but not for cranberries, because water demand for cranberries varies little in response to climatological factors. Water demand for cranberries was predicted to remain constant at 4.43 times 10 to the 9th power gal through the year 2020. Predictions of water demand for container-grown nursery crops ranged from 1.89 times 10 to the 9th power to 3.63 times 10 to the 9th power gal. Water-use for livestock in 1987 was estimated to be 0.78 times 10 to the 9th power gal, and water use for selected sectors of the food-processing industry was estimated to be 3.75 times 10 to the 9th power gal.

What is the Impact of Utility Demand Charges on a DCFC host

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

Francfort, James Edward

The PEV Electric Vehicle Supply Equipment (EVSE) delivered by The EV Project included both AC Level 2 and DCFC units. Over 100 of these dual-port Blink DC fast chargers were deployed by The EV Project. These DCFCs were installed in workplaces and in publicly accessible locations near traffic hubs, retail centers, parking lots, restaurants, and similar locations. The Blink DCFC is capable of charging at power up to 60 kW. Its dual-port design sequences the charge from one port to the other, delivering power to only one of two vehicles connected at a time. The actual power delivered through amore » port is determined by the PEV’s on-board battery management system (BMS). Both the power and the total energy used to recharge a PEV can represent a significant cost for the charging site host. Many electric utilities impose fees for power demand as part of their commercial rate structure. The demand charge incurred by a customer is related to the peak power used during a monthly billing cycle. This is in contrast to the cumulative total energy usage that is the more familiar utility charge seen for most residential services. A demand charge is typically assessed for the highest average power over any 15 minute interval during the monthly billing cycle. One objective of The EV Project was to identify and elucidate the motivations and barriers to potential DCFC site hosts. The application of electric utility demand charges is one such potential barrier. This subject was introduced in the paper: DC Fast Charge - Demand Charge Reduction1. It discussed demand charge impact in general terms in order to focus on potential mitigation actions. This paper identifies specific cases in order to quantify the impact of demand charges on EV Project DCFC hosts.« less

Quantitative habitability.

PubMed

Shock, Everett L; Holland, Melanie E

2007-12-01

A framework is proposed for a quantitative approach to studying habitability. Considerations of environmental supply and organismal demand of energy lead to the conclusions that power units are most appropriate and that the units for habitability become watts per organism. Extreme and plush environments are revealed to be on a habitability continuum, and extreme environments can be quantified as those where power supply only barely exceeds demand. Strategies for laboratory and field experiments are outlined that would quantify power supplies, power demands, and habitability. An example involving a comparison of various metabolisms pursued by halophiles is shown to be well on the way to a quantitative habitability analysis.

The Ames Power Monitoring System

NASA Technical Reports Server (NTRS)

Osetinsky, Leonid; Wang, David

2003-01-01

The Ames Power Monitoring System (APMS) is a centralized system of power meters, computer hardware, and specialpurpose software that collects and stores electrical power data by various facilities at Ames Research Center (ARC). This system is needed because of the large and varying nature of the overall ARC power demand, which has been observed to range from 20 to 200 MW. Large portions of peak demand can be attributed to only three wind tunnels (60, 180, and 100 MW, respectively). The APMS helps ARC avoid or minimize costly demand charges by enabling wind-tunnel operators, test engineers, and the power manager to monitor total demand for center in real time. These persons receive the information they need to manage and schedule energy-intensive research in advance and to adjust loads in real time to ensure that the overall maximum allowable demand is not exceeded. The APMS (see figure) includes a server computer running the Windows NT operating system and can, in principle, include an unlimited number of power meters and client computers. As configured at the time of reporting the information for this article, the APMS includes more than 40 power meters monitoring all the major research facilities, plus 15 Windows-based client personal computers that display real-time and historical data to users via graphical user interfaces (GUIs). The power meters and client computers communicate with the server using Transmission Control Protocol/Internet Protocol (TCP/IP) on Ethernet networks, variously, through dedicated fiber-optic cables or through the pre-existing ARC local-area network (ARCLAN). The APMS has enabled ARC to achieve significant savings ($1.2 million in 2001) in the cost of power and electric energy by helping personnel to maintain total demand below monthly allowable levels, to manage the overall power factor to avoid low power factor penalties, and to use historical system data to identify opportunities for additional energy savings. The APMS also provides power engineers and electricians with the information they need to plan modifications in advance and perform day-to-day maintenance of the ARC electric-power distribution system.

Exploring the Basis for Gender Differences in the Demand-Withdraw Pattern

PubMed Central

Holley, Sarah R.; Sturm, Virginia E.; Levenson, Robert W.

2010-01-01

During marital conflict, wives tend to demand and husbands tend to withdraw. These behaviors were historically thought to stem from essential differences between men and women. An alternative explanation implicates one form of power differences—wives desire more change and therefore demand, whereas husbands desire less change and withdraw to maintain status quo. Studying same-sex as well as cross-sex couples enables an evaluation of both explanations. We examined demand-withdraw behaviors in 63 heterosexual, gay, and lesbian couples. The demand-withdraw pattern was seen regardless of type of couple. Further, for all couples, differences in the amount of change desired in partners during a conflict interaction predicted differences in demand and withdraw behaviors. These results offer further evidence that an oft-observed difference in heterosexual relationships may result from social conventions that afford men greater power and women less power. PMID:20455136

Power Management for Space Advanced Life Support

NASA Technical Reports Server (NTRS)

Jones, Harry

2001-01-01

Space power systems include the power source, storage, and management subsystems. In current crewed spacecraft, solar cells are the power source, batteries provide storage, and the crew performs any required load scheduling. For future crewed planetary surface systems using Advanced Life Support, we assume that plants will be grown to produce much of the crew's food and that nuclear power will be employed. Battery storage is much more costly than nuclear power capacity and so is not likely to be used. We investigate the scheduling of power demands by the crew or automatic control, to reduce the peak power load and the required generating capacity. The peak to average power ratio is a good measure of power use efficiency. We can easily schedule power demands to reduce the peak power from its maximum, but simple scheduling approaches may not find the lowest possible peak to average power ratio. An initial power scheduling example was simple enough for a human to solve, but a more complex example with many intermittent load demands required automatic scheduling. Excess power is a free resource and can be used even for minor benefits.

Compressed air energy storage system

DOEpatents

Ahrens, F.W.; Kartsounes, G.T.

An internal combustion reciprocating engine is operable as a compressor during slack demand periods utilizing excess power from a power grid to charge air into an air storage reservoir and as an expander during peak demand periods to feed power into the power grid utilizing air obtained from the air storage reservoir together with combustion reciprocating engine is operated at high pressure and a low pressure turbine and compressor are also employed for air compression and power generation.

Experimental study of mini SCADA renewable energy management system on microgrid using Raspberry Pi

NASA Astrophysics Data System (ADS)

Tridianto, E.; Permatasari, P. D.; Ali, I. R.

2018-03-01

Renewable Energy Management System (REMS) is a device that can be able to monitor power through a microgrid. The purpose of this system is to optimize power usage that produced from renewable energy with the result that reduces power demand from the grid. To reach the goal this device manage the load power needs fully supplied by renewable energy when the power produced from renewable energy is higher than load demand, besides power surplus will be stored in battery in this way energy stored in battery can be used when it needed. When the power produced from renewable energy can not satisfy the power demand, power will supply by renewable energy and grid. This device uses power meters for record any power flow through microgrid. In order to manage power flow in microgrid this system use relay module. The user can find out energy consumption (consumed by the load) and production (produced by renewable energy) in a period of time so that the user can switch on the load in right time.

75 FR 10833 - In the Matter of Entergy Nuclear Operations; Vermont Yankee Nuclear Power Station; Demand for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-09

... NUCLEAR REGULATORY COMMISSION [Docket No. 05000271; License No. DPR-28; EA-10-034; NRC-2010-0089] In the Matter of Entergy Nuclear Operations; Vermont Yankee Nuclear Power Station; Demand for.... The license authorizes the operation of the Vermont Yankee Nuclear Power Station (Vermont Yankee) in...

Meeting China's electricity needs through clean energy sources: A 2030 low-carbon energy roadmap

NASA Astrophysics Data System (ADS)

Hu, Zheng

China is undergoing rapid economic development that generates significant increase in energy demand, primarily for electricity. Energy supply in China is heavily relying on coal, which leads to high carbon emissions. This dissertation explores opportunities for meeting China's growing power demand through clean energy sources. The utilization of China's clean energy sources as well as demand-side management is still at the initial phase. Therefore, development of clean energy sources would require substantial government support in order to be competitive in the market. One of the widely used means to consider clean energy in power sector supplying is Integrated Resource Strategic Planning, which aims to minimize the long term electricity costs while screening various power supply options for the power supply and demand analysis. The IRSP tool tackles the energy problem from the perspective of power sector regulators, and provides different policy scenarios to quantify the impacts of combined incentives. Through three scenario studies, Business as Usual, High Renewable, and Renewable and Demand Side Management, this dissertation identifies the optimized scenario for China to achieve the clean energy target of 2030. The scenarios are assessed through energy, economics, environment, and equity dimensions.

Social power, product conspicuousness, and the demand for luxury brand counterfeit products.

PubMed

Bian, Xuemei; Haque, Sadia; Smith, Andrew

2015-03-01

The aim of this article is twofold: (1) to achieve a better understanding of the psychological determinants of the demand for luxury brand counterfeit products (LBCP) through exploring the effects of social power; (2) to extend power literature by identifying boundary conditions of the relationship between social power and compensatory consumption identified by Rucker and Galinsky (2008, J. Consum. Res., 35, 257-267) and Rucker and Galinsky (2009, J. Exp. Soc. Psychol., 45, 549-555). Findings from three experiments demonstrate that social power holds key insights into understanding consumers' purchase propensity for LBCP; product conspicuousness moderates the effects of social power on purchase propensity for status products; these moderation effects are only observed when the status products are LBCP but not genuine products. This article, therefore, contributes to the literature regarding the demand for counterfeits as well as the social power and compensatory consumption literature. © 2014 The British Psychological Society.

Phosphoric acid fuel cell platinum use study

NASA Technical Reports Server (NTRS)

Lundblad, H. L.

1983-01-01

The U.S. Department of Energy is promoting the private development of phosphoric acid fuel cell (PAFC) power plants for terrestrial applications. Current PAFC technology utilizes platinum as catalysts in the power electrodes. The possible repercussions that the platinum demand of PAFC power plant commercialization will have on the worldwide supply and price of platinum from the outset of commercialization to the year 2000 are investigated. The platinum demand of PAFC commercialization is estimated by developing forecasts of platinum use per unit of generating capacity and penetration of PAFC power plants into the electric generation market. The ability of the platinum supply market to meet future demands is gauged by assessing the size of platinum reserves and the capability of platinum producers to extract, refine and market sufficient quantities of these reserves. The size and timing of platinum price shifts induced by the added demand of PAFC commercialization are investigated by several analytical methods. Estimates of these price shifts are then used to calculate the subsequent effects on PAFC power plant capital costs.

Phosphoric acid fuel cell platinum use study

NASA Astrophysics Data System (ADS)

Lundblad, H. L.

1983-05-01

The U.S. Department of Energy is promoting the private development of phosphoric acid fuel cell (PAFC) power plants for terrestrial applications. Current PAFC technology utilizes platinum as catalysts in the power electrodes. The possible repercussions that the platinum demand of PAFC power plant commercialization will have on the worldwide supply and price of platinum from the outset of commercialization to the year 2000 are investigated. The platinum demand of PAFC commercialization is estimated by developing forecasts of platinum use per unit of generating capacity and penetration of PAFC power plants into the electric generation market. The ability of the platinum supply market to meet future demands is gauged by assessing the size of platinum reserves and the capability of platinum producers to extract, refine and market sufficient quantities of these reserves. The size and timing of platinum price shifts induced by the added demand of PAFC commercialization are investigated by several analytical methods. Estimates of these price shifts are then used to calculate the subsequent effects on PAFC power plant capital costs.

Potential climate change impacts on water availability and cooling water demand in the Lusatian Lignite Mining Region, Central Europe

NASA Astrophysics Data System (ADS)

Pohle, Ina; Koch, Hagen; Gädeke, Anne; Grünewald, Uwe; Kaltofen, Michael; Redetzky, Michael

2014-05-01

In the catchments of the rivers Schwarze Elster, Spree and Lusatian Neisse, hydrologic and socioeconomic systems are coupled via a complex water management system in which water users, reservoirs and water transfers are included. Lignite mining and electricity production are major water users in the region: To allow for open pit lignite mining, ground water is depleted and released into the river system while cooling water is used in the thermal power plants. In order to assess potential climate change impacts on water availability in the catchments as well as on the water demand of the thermal power plants, a climate change impact assessment was performed using the hydrological model SWIM and the long term water management model WBalMo. The potential impacts of climate change were considered by using three regional climate change scenarios of the statistical regional climate model STAR assuming a further temperature increase of 0, 2 or 3 K by the year 2050 in the region respectively. Furthermore, scenarios assuming decreasing mining activities in terms of a decreasing groundwater depression cone, lower mining water discharges, and reduced cooling water demand of the thermal power plants are considered. In the standard version of the WBalMo model cooling water demand is considered as static with regard to climate variables. However, changes in the future cooling water demand over time according to the plans of the local mining and power plant operator are considered. In order to account for climate change impacts on the cooling water demand of the thermal power plants, a dynamical approach for calculating water demand was implemented in WBalMo. As this approach is based on air temperature and air humidity, the projected air temperature and air humidity of the climate scenarios at the locations of the power plants are included in the calculation. Due to increasing temperature and decreasing precipitation declining natural and managed discharges, and hence a lower water availability in the region, were simulated by SWIM and WBalMo respectively. Next to changing climate conditions, also the different mining scenarios have considerable impacts on natural and managed discharges. Using the dynamic approach for cooling water demand, the simulated water demands are lower in winter, but higher in summer compared to the static approach. As a consequence of changes in the seasonal pattern of the cooling water demand of the power plants, lower summer discharges downstream of the thermal power plants are simulated using the dynamical approach. Due to the complex water management system in the region included in the water management model WBalMo, also the simulation of reservoir releases and volumes is impacted by the choice of either the static or the dynamic approach for calculating the cooling water demand of the thermal power plants.

Demand charge reduction with digester gas

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

Not Available

1985-02-01

This paper examines a rather sophisticated treatment system in the city of Whitewater, Wisconsin. The power generated is used to trim utility peak power loads and demand charges. Power is derived from four Waukesha VHP 3600G engine generator sets with provisions for a fifth as growth requires. The engine is a Waukesha F3521GU spark ignited, six-cylinder gas engine with 9.375 in. x 8.50 bore and stroke driving a Kato 350 kW generator rated at 480/277 volts and 1200 rpm. Normal operation is to reduce the peak demand.

Responses of Lower-Body Power and Match Running Demands Following Long-Haul Travel in International Rugby Sevens Players.

PubMed

Mitchell, John A; Pumpa, Kate L; Pyne, David B

2017-03-01

Mitchell, JA, Pumpa, KL, and Pyne, DB. Responses of lowerbody power and match running demands after long-haul travel in international rugby sevens players. J Strength Cond Res 31(3): 686-695, 2017-This study determined the effect of long-haul (>5 hours) travel on lower-body power and match running demands in international rugby sevens players. Lower-body power was assessed in 22 male international rugby sevens players (age 21.7 ± 2.7 years, mass 89.0 ± 6.7 kg, stature 180.5 ± 6.2 cm; mean ± SD) monitored over 17 rugby sevens tournaments. A countermovement jump was used to monitor lower-body power (peak and mean power) over repeated three week travel and competition periods (pretravel, posttravel, and posttournament). Small decreases were evident in peak power after both short and long-haul travel (-4.0%, ±3.2%; mean, ±90% confidence limits) with further reductions in peak and mean power posttournament (-4.5%, ±2.3% and -3.8%, ±1.5%) culminating in a moderate decrease in peak power overall (-7.4%, ±4.0%). A subset of 12 players (completing a minimum of 8 tournaments) had the effects of match running demands assessed with lower-body power. In this subset, long-haul travel elicited a large decrease in lower-body peak (-9.4%, ±3.5%) and mean power (-5.6%, ±2.9%) over the monitoring period, with a small decrease (-4.3%, ±3.0% and -2.2%, ±1.7%) posttravel and moderate decrease (-5.4%, ±2.5% and -3.5%, ±1.9%) posttournament, respectively. Match running demands were monitored through global positioning system. In long-haul tournaments, the 12 players covered ∼13%, ±13% greater total distance (meter) and ∼11%, ±10% higher average game meters >5 m·s when compared with short-haul (<5 hours) travel. Effective pretravel and posttravel player management strategies are indicated to reduce neuromuscular fatigue and running load demands in rugby sevens tournaments after long-haul travel.

Cyber Physical System Modelling of Distribution Power Systems for Dynamic Demand Response

NASA Astrophysics Data System (ADS)

Chu, Xiaodong; Zhang, Rongxiang; Tang, Maosen; Huang, Haoyi; Zhang, Lei

2018-01-01

Dynamic demand response (DDR) is a package of control methods to enhance power system security. A CPS modelling and simulation platform for DDR in distribution power systems is presented in this paper. CPS modelling requirements of distribution power systems are analyzed. A coupled CPS modelling platform is built for assessing DDR in the distribution power system, which combines seamlessly modelling tools of physical power networks and cyber communication networks. Simulations results of IEEE 13-node test system demonstrate the effectiveness of the modelling and simulation platform.

Compressed air energy storage system

DOEpatents

Ahrens, Frederick W.; Kartsounes, George T.

1981-01-01

An internal combustion reciprocating engine is operable as a compressor during slack demand periods utilizing excess power from a power grid to charge air into an air storage reservoir and as an expander during peak demand periods to feed power into the power grid utilizing air obtained from the air storage reservoir together with combustible fuel. Preferably the internal combustion reciprocating engine is operated at high pressure and a low pressure turbine and compressor are also employed for air compression and power generation.

An adaptive load-following control system for a space nuclear power system

NASA Astrophysics Data System (ADS)

Metzger, John D.; El-Genk, Mohamed S.

An adaptive load-following control system is proposed for a space nuclear power system. The conceptual design of the SP-100 space nuclear power system proposes operating the nuclear reactor at a base thermal power and accommodating changes in the electrical power demand with a shunt regulator. It is necessary to increase the reactor thermal power if the payload electrical demand exceeds the peak system electrical output for the associated reactor power. When it is necessary to change the nuclear reactor power to meet a change in the power demand, the power ascension or descension must be accomplished in a predetermined manner to avoid thermal stresses in the system and to achieve the desired reactor period. The load-following control system described has the ability to adapt to changes in the system and to changes in the satellite environment. The application is proposed of the model reference adaptive control (MRAC). The adaptive control system has the ability to control the dynamic response of nonlinear systems. Three basic subsets of adaptive control are: (1) gain scheduling, (2) self-tuning regulators, and (3) model reference adaptive control.

Water and Climate Impacts on Power System Operations: The Importance of Cooling Systems and Demand Response Measures

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

Macknick, Jordan; Zhou, Ella; O'Connell, Matthew

The U.S. electricity sector is highly dependent upon water resources; changes in water temperatures and water availability can affect operational costs and the reliability of power systems. Despite the importance of water for power system operations, the effects of changes in water characteristics on multiple generators in a system are generally not modeled. Moreover, demand response measures, which can change the magnitude and timing of loads and can have beneficial impacts on power system operations, have not yet been evaluated in the context of water-related power vulnerabilities. This effort provides a first comprehensive vulnerability and cost analysis of water-related impactsmore » on a modeled power system and the potential for demand response measures to address vulnerability and cost concerns. This study uniquely combines outputs and inputs of a water and power plant system model, production cost, model, and relative capacity value model to look at variations in cooling systems, policy-related thermal curtailments, and demand response measures to characterize costs and vulnerability for a test system. Twenty-five scenarios over the course of one year are considered: a baseline scenario as well as a suite of scenarios to evaluate six cooling system combinations, the inclusion or exclusion of policy-related thermal curtailments, and the inclusion or exclusion of demand response measures. A water and power plant system model is utilized to identify changes in power plant efficiencies resulting from ambient conditions, a production cost model operating at an hourly scale is used to calculate generation technology dispatch and costs, and a relative capacity value model is used to evaluate expected loss of carrying capacity for the test system.« less

Scientific Challenges in Sustainable Energy Technology

NASA Astrophysics Data System (ADS)

Lewis, Nathan

2006-03-01

This presentation will describe and evaluate the challenges, both technical, political, and economic, involved with widespread adoption of renewable energy technologies. First, we estimate the available fossil fuel resources and reserves based on data from the World Energy Assessment and World Energy Council. In conjunction with the current and projected global primary power production rates, we then estimate the remaining years of supply of oil, gas, and coal for use in primary power production. We then compare the price per unit of energy of these sources to those of renewable energy technologies (wind, solar thermal, solar electric, biomass, hydroelectric, and geothermal) to evaluate the degree to which supply/demand forces stimulate a transition to renewable energy technologies in the next 20-50 years. Secondly, we evaluate the greenhouse gas buildup limitations on carbon-based power consumption as an unpriced externality to fossil-fuel consumption, considering global population growth, increased global gross domestic product, and increased energy efficiency per unit of globally averaged GDP, as produced by the Intergovernmental Panel on Climate Change (IPCC). A greenhouse gas constraint on total carbon emissions, in conjunction with global population growth, is projected to drive the demand for carbon-free power well beyond that produced by conventional supply/demand pricing tradeoffs, at potentially daunting levels relative to current renewable energy demand levels. Thirdly, we evaluate the level and timescale of R&D investment that is needed to produce the required quantity of carbon-free power by the 2050 timeframe, to support the expected global energy demand for carbon-free power. Fourth, we evaluate the energy potential of various renewable energy resources to ascertain which resources are adequately available globally to support the projected global carbon-free energy demand requirements. Fifth, we evaluate the challenges to the chemical sciences to enable the cost-effective production of carbon-free power on the needed scale by the 2050 timeframe. Finally, we discuss the effects of a change in primary power technology on the energy supply infrastructure and discuss the impact of such a change on the modes of energy consumption by the energy consumer and additional demands on the chemical sciences to support such a transition in energy supply.

High-resolution integration of water, energy, and climate models to assess electricity grid vulnerabilities to climate change

NASA Astrophysics Data System (ADS)

Meng, M.; Macknick, J.; Tidwell, V. C.; Zagona, E. A.; Magee, T. M.; Bennett, K.; Middleton, R. S.

2017-12-01

The U.S. electricity sector depends on large amounts of water for hydropower generation and cooling thermoelectric power plants. Variability in water quantity and temperature due to climate change could reduce the performance and reliability of individual power plants and of the electric grid as a system. While studies have modeled water usage in power systems planning, few have linked grid operations with physical water constraints or with climate-induced changes in water resources to capture the role of the energy-water nexus in power systems flexibility and adequacy. In addition, many hydrologic and hydropower models have a limited representation of power sector water demands and grid interaction opportunities of demand response and ancillary services. A multi-model framework was developed to integrate and harmonize electricity, water, and climate models, allowing for high-resolution simulation of the spatial, temporal, and physical dynamics of these interacting systems. The San Juan River basin in the Southwestern U.S., which contains thermoelectric power plants, hydropower facilities, and multiple non-energy water demands, was chosen as a case study. Downscaled data from three global climate models and predicted regional water demand changes were implemented in the simulations. The Variable Infiltration Capacity hydrologic model was used to project inflows, ambient air temperature, and humidity in the San Juan River Basin. Resulting river operations, water deliveries, water shortage sharing agreements, new water demands, and hydroelectricity generation at the basin-scale were estimated with RiverWare. The impacts of water availability and temperature on electric grid dispatch, curtailment, cooling water usage, and electricity generation cost were modeled in PLEXOS. Lack of water availability resulting from climate, new water demands, and shortage sharing agreements will require thermoelectric generators to drastically decrease power production, as much as 50% during intensifying drought scenarios, which can have broader electricity sector system implications. Results relevant to stakeholder and power provider interests highlight the vulnerabilities in grid operations driven by water shortage agreements and changes in the climate.

The energy supply of today and tomorrow

NASA Astrophysics Data System (ADS)

Janssen, W.

1980-04-01

The paper examines present worldwide energy demand and compares it with predictions of future demand. Topics discussed include the exhaustible energies, regenerative energies, nuclear energy, electrical power, power plant capacities, safety and the environment, and the necessity and possibilities for energy conservation.

Effects of velocity and weight support on ground reaction forces and metabolic power during running.

PubMed

Grabowski, Alena M; Kram, Rodger

2008-08-01

The biomechanical and metabolic demands of human running are distinctly affected by velocity and body weight. As runners increase velocity, ground reaction forces (GRF) increase, which may increase the risk of an overuse injury, and more metabolic power is required to produce greater rates of muscular force generation. Running with weight support attenuates GRFs, but demands less metabolic power than normal weight running. We used a recently developed device (G-trainer) that uses positive air pressure around the lower body to support body weight during treadmill running. Our scientific goal was to quantify the separate and combined effects of running velocity and weight support on GRFs and metabolic power. After obtaining this basic data set, we identified velocity and weight support combinations that resulted in different peak GRFs, yet demanded the same metabolic power. Ideal combinations of velocity and weight could potentially reduce biomechanical risks by attenuating peak GRFs while maintaining aerobic and neuromuscular benefits. Indeed, we found many combinations that decreased peak vertical GRFs yet demanded the same metabolic power as running slower at normal weight. This approach of manipulating velocity and weight during running may prove effective as a training and/or rehabilitation strategy.

Development of an Advanced Grid-Connected PV-ECS System Considering Solar Energy Estimation

NASA Astrophysics Data System (ADS)

Rahman, Md. Habibur; Yamashiro, Susumu; Nakamura, Koichi

In this paper, the development and the performance of a viable distributed grid-connected power generation system of Photovoltaic-Energy Capacitor System (PV-ECS) considering solar energy estimation have been described. Instead of conventional battery Electric Double Layer Capacitors (EDLC) are used as storage device and Photovoltaic (PV) panel to generate power from solar energy. The system can generate power by PV, store energy when the demand of load is low and finally supply the stored energy to load during the period of peak demand. To realize the load leveling function properly the system will also buy power from grid line when load demand is high. Since, the power taken from grid line depends on the PV output power, a procedure has been suggested to estimate the PV output power by calculating solar radiation. In order to set the optimum value of the buy power, a simulation program has also been developed. Performance of the system has been studied for different load patterns in different weather conditions by using the estimated PV output power with the help of the simulation program.

The Research of Utilization Hours of Coal-Fired Power Generation Units Based on Electric Energy Balance

NASA Astrophysics Data System (ADS)

Liu, Junhui; Yang, Jianlian; Wang, Jiangbo; Yang, Meng; Tian, Chunzheng; He, Xinhui

2018-01-01

With grid-connected scale of clean energy such as wind power and photovoltaic power expanding rapidly and cross-province transmission scale being bigger, utilization hours of coal-fired power generation units become lower and lower in the context of the current slowdown in electricity demand. This paper analyzes the influencing factors from the three aspects of demand, supply and supply and demand balance, and the mathematical model has been constructed based on the electric energy balance. The utilization hours of coal-fired power generation units have been solved considering the relationship among proportion of various types of power installed capacity, the output rate and utilization hours. By carrying out empirical research in Henan Province, the utilization hours of coal-fired units of Henan Province in 2020 has been achieved. The example validates the practicability and the rationality of the model, which can provide a basis for the decision-making for coal-fired power generation enterprises.

Identification of Characterization Factor for Power System Oscillation Based on Multiple Synchronized Phasor Measurements

NASA Astrophysics Data System (ADS)

Hashiguchi, Takuhei; Watanabe, Masayuki; Matsushita, Akihiro; Mitani, Yasunori; Saeki, Osamu; Tsuji, Kiichiro; Hojo, Masahide; Ukai, Hiroyuki

Electric power systems in Japan are composed of remote and distributed location of generators and loads mainly concentrated in large demand areas. The structures having long distance transmission tend to produce heavy power flow with increasing electric power demand. In addition, some independent power producers (IPP) and power producer and suppliers (PPS) are participating in the power generation business, which makes power system dynamics more complex. However, there was little observation as a whole power system. In this paper the authors present a global monitoring system of power system dynamics by using the synchronized phasor measurement of demand side outlets. Phasor Measurement Units (PMU) are synchronized based on the global positioning system (GPS). The purpose of this paper is to show oscillation characteristics and methods for processing original data obtained from PMU after certain power system disturbances triggered by some accidents. This analysis resulted in the observation of the lowest and the second lowest frequency mode. The derivation of eigenvalue with two degree of freedom model brings a monitoring of two oscillation modes. Signal processing based on Wavelet analysis and simulation studies to illustrate the obtained phenomena are demonstrated in detail.

Impact of uncoordinated plug-in electric vehicle charging on residential power demand - supplementary data

DOE Data Explorer

Muratori, Matteo (ORCID:0000000316886742)

2017-06-15

This data set is provided in support of a forthcoming paper: "Impact of uncoordinated plug-in electric vehicle charging on residential power demand," [1]. These files include electricity demand profiles for 200 households randomly selected among the ones available in the 2009 RECS data set for the Midwest region of the United States. The profiles have been generated using the modeling proposed by Muratori et al. [2], [3], that produces realistic patterns of residential power consumption, validated using metered data, with a resolution of 10 minutes. Households vary in size and number of occupants and the profiles represent total electricity use, in watts. The files also include in-home plug-in electric vehicle recharging profiles for 348 vehicles associated with the 200 households assuming both Level 1 (1920 W) and Level 2 (6600 W) residential charging infrastructure. The vehicle recharging profiles have been generated using the modeling proposed by Muratori et al. [4], that produces real-world recharging demand profiles, with a resolution of 10 minutes. [1] M. Muratori, "Impact of uncoordinated plug-in electric vehicle charging on residential power demand." Forthcoming. [2] M. Muratori, M. C. Roberts, R. Sioshansi, V. Marano, and G. Rizzoni, "A highly resolved modeling technique to simulate residential power demand," Applied Energy, vol. 107, no. 0, pp. 465 - 473, 2013. [3] M. Muratori, V. Marano, R. Sioshansi, and G. Rizzoni, "Energy consumption of residential HVAC systems: a simple physically-based model," in 2012 IEEE Power and Energy Society General Meeting. San Diego, CA, USA: IEEE, 22-26 July 2012. [4] M. Muratori, M. J. Moran, E. Serra, and G. Rizzoni, "Highly-resolved modeling of personal transportation energy consumption in the United States," Energy, vol. 58, no. 0, pp. 168-177, 2013.

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

Piette, Mary Ann

California needs new, responsive, demand-side energy technologies to ensure that periods of tight electricity supply on the grid don't turn into power outages. Led by Berkeley Lab's Mary Ann Piette, the California Energy Commission (through its Public Interest Energy Research Program) has established a Demand Response Research Center that addresses two motivations for adopting demand responsiveness: reducing average electricity prices and preventing future electricity crises. The research seeks to understand factors that influence "what works" in Demand Response. Piette's team is investigating the two types of demand response, load response and price response, that may influence and reduce the usemore » of peak electric power through automated controls, peak pricing, advanced communications, and other strategies.« less

Impact of active and break wind spells on the demand-supply balance in wind energy in India

NASA Astrophysics Data System (ADS)

Kulkarni, Sumeet; Deo, M. C.; Ghosh, Subimal

2018-02-01

With an installed capacity of over 19,000 MW, the wind power currently accounts for almost 70% of the total installed capacity among the renewable energy sector in India. The extraction of wind power mainly depends on prevailing meteorology which is strongly influenced by monsoon variability. The monsoon season is characterized by significant fluctuations in between periods of wet and dry spells. During the dry spells, the demand for power from agriculture and cooling equipment increases, whereas during the wet periods, such demand reduces, although, at the same time, the power supply increases because of strong westerly winds contributing to an enhanced production of wind energy. At this backdrop, we aim to assess the impact of intra-seasonal wind variability on the balance of energy supply and demand during monsoon seasons in India. Further, we explore the probable cause of wind variability by relating it to El Nino events. It is observed that the active and break phases in wind significantly impact the overall wind potential output. Although the dry spells are generally found to reduce the overall wind potential, their impact on the potential seems to have declined after the year 2000. The impact of meteorological changes on variations in wind power studied in this work should find applications typically in taking investment decisions on conventional generation facilities, like thermal, which are currently used to maintain the balance of power supply and demand.

Local Politics and the Demand for Public Education.

ERIC Educational Resources Information Center

Colburn, Christopher B.; Horowitz, John B.

2003-01-01

Uses a political fragmentation index to calculate how political power affects educational spending in Virginia. Compares different political voices relative to each other, examines the role of power distribution, and considers political fragmentation across several dimensions. Along with traditional demand variables, interest group pressures…

CALCULATING WATER CONSUMPTION AND WITHDRAWAL FROM POWER PLANTS GLOBALLYUsing machine learning, remote sensing and power plant data from the Power Watch platform

NASA Astrophysics Data System (ADS)

Kressig, A.

2017-12-01

BACKGROUND The Greenhouse Gas Protocol (GHGP), Scope 2 Guidance standardizes how companies measure greenhouse gas emissions from purchased or independently generated electricity (called "scope 2 emissions"). Additionally, the interlinkages between industrial or commercial (nonresidential) energy requirements and water demands have been studied extensively, mostly at the national or provincial scale, focused on industries involved in power generation. However there is little guidance available for companies to systematically and effectively quantify water withdrawals and consumption (herein referred to as "water demand") associated with purchased or acquired electricity(what we call "Scope 2 Water"). This lack of guidance on measuring a company's water demand from electricity use is due to a lack of data on average consumption and withdrawal rates of water associated with purchased electricity. OBJECTIVE There is growing demand from companies in the food, beverage, manufacturing, information communication and technology, and other sectors for a methodology to quantify Scope 2 water demands. By understanding Scope 2 water demands, companies could evaluate their exposure to water-related risks associated with purchased or acquired electricity, and quantify the water benefits of changing to less water-intensive sources of electricity and energy generation such as wind and solar. However, there has never been a way of quantifying Scope 2 Water consumption and withdrawals for a company across its international supply chain. Even with interest in understanding exposure to water related risk and measuring water use reductions, there has been no quantitative way of measuring this information. But WRI's Power Watch provides the necessary data to allow for the Scope 2 Water accounting, because it will provide water withdrawal and consumption rates associated with purchased electricity at the power plant level. By calculating the average consumption and withdrawal rates per unit of electricity produced across a grid region, companies can measure their water demand from facilities in that region. WRI is now developing a global dataset of grid level water consumption rates and developing a guidance for companies to report water demand across their supply chain and measure their reductions.

Comparative life cycle assessment of biogas plant configurations for a demand oriented biogas supply for flexible power generation.

PubMed

Hahn, Henning; Hartmann, Kilian; Bühle, Lutz; Wachendorf, Michael

2015-03-01

The environmental performance of biogas plant configurations for a demand - oriented biogas supply for flexible power generation is comparatively assessed in this study. Those configurations indicate an increased energy demand to operate the operational enhancements compared to conventional biogas plants supplying biogas for baseload power generation. However, findings show that in contrast to an alternative supply of power generators with natural gas, biogas supplied on demand by adapted biogas plant configurations saves greenhouse gas emissions by 54-65 g CO(2-eq) MJ(-1) and primary energy by about 1.17 MJ MJ(-1). In this regard, configurations with flexible biogas production profit from reduced biogas storage requirements and achieve higher savings compared to configurations with continuous biogas production. Using thicker biogas storage sheeting material reduces the methane permeability of up to 6m(3) d(-1) which equals a reduction of 8% of the configuration's total methane emissions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dynamic management of integrated residential energy systems

NASA Astrophysics Data System (ADS)

Muratori, Matteo

This study combines principles of energy systems engineering and statistics to develop integrated models of residential energy use in the United States, to include residential recharging of electric vehicles. These models can be used by government, policymakers, and the utility industry to provide answers and guidance regarding the future of the U.S. energy system. Currently, electric power generation must match the total demand at each instant, following seasonal patterns and instantaneous fluctuations. Thus, one of the biggest drivers of costs and capacity requirement is the electricity demand that occurs during peak periods. These peak periods require utility companies to maintain operational capacity that often is underutilized, outdated, expensive, and inefficient. In light of this, flattening the demand curve has long been recognized as an effective way of cutting the cost of producing electricity and increasing overall efficiency. The problem is exacerbated by expected widespread adoption of non-dispatchable renewable power generation. The intermittent nature of renewable resources and their non-dispatchability substantially limit the ability of electric power generation of adapting to the fluctuating demand. Smart grid technologies and demand response programs are proposed as a technical solution to make the electric power demand more flexible and able to adapt to power generation. Residential demand response programs offer different incentives and benefits to consumers in response to their flexibility in the timing of their electricity consumption. Understanding interactions between new and existing energy technologies, and policy impacts therein, is key to driving sustainable energy use and economic growth. Comprehensive and accurate models of the next-generation power system allow for understanding the effects of new energy technologies on the power system infrastructure, and can be used to guide policy, technology, and economic decisions. This dissertation presents a bottom-up highly resolved model of a generic residential energy eco-system in the United States. The model is able to capture the entire energy footprint of an individual household, to include all appliances, space conditioning systems, in-home charging of plug-in electric vehicles, and any other energy needs, viewing residential and transportation energy needs as an integrated continuum. The residential energy eco-system model is based on a novel bottom-up approach that quantifies consumer energy use behavior. The incorporation of stochastic consumer behaviors allows capturing the electricity consumption of each residential specific end-use, providing an accurate estimation of the actual amount of available controllable resources, and for a better understanding of the potential of residential demand response programs. A dynamic energy management framework is then proposed to manage electricity consumption inside each residential energy eco-system. Objective of the dynamic energy management framework is to optimize the scheduling of all the controllable appliances and in-home charging of plug-in electric vehicles to minimize cost. Such an automated energy management framework is used to simulate residential demand response programs, and evaluate their impact on the electric power infrastructure. For instance, time-varying electricity pricing might lead to synchronization of the individual residential demands, creating pronounced rebound peaks in the aggregate demand that are higher and steeper than the original demand peaks that the time-varying electricity pricing structure intended to eliminate. The modeling tools developed in this study can serve as a virtual laboratory for investigating fundamental economic and policy-related questions regarding the interplay of individual consumers with energy use. The models developed allow for evaluating the impact of different energy policies, technology adoption, and electricity price structures on the total residential electricity demand. In particular, two case studies are reported in this dissertation to illustrate application of the tools developed. The first considers the impact of market penetration of plug-in electric vehicles on the electric power infrastructure. The second provides a quantitative comparison of the impact of different electricity price structures on residential demand response. Simulation results and an electricity price structure, called Multi-TOU, aimed at solving the rebound peak issue, are presented.

Analysis of recent projections of electric power demand

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

Hudson, Jr, D V

1993-08-01

This report reviews the changes and potential changes in the outlook for electric power demand since the publication of Review and Analysis of Electricity Supply Market Projections (B. Swezey, SERI/MR-360-3322, National Renewable Energy Laboratory). Forecasts of the following organizations were reviewed: DOE/Energy Information Administration, DOE/Policy Office, DRI/McGraw-Hill, North American Electric Reliability Council, and Gas Research Institute. Supply uncertainty was briefly reviewed to place the uncertainties of the demand outlook in perspective. Also discussed were opportunities for modular technologies, such as renewable energy technologies, to fill a potential gap in energy demand and supply.

ELECTRICAL LOAD ANTICIPATOR AND RECORDER

DOEpatents

Russell, J.B.; Thomas, R.J.

1961-07-25

A system is descrbied in which an indication of the prevailing energy consumption in an electrical power metering system and a projected Power demand for one demand interval is provided at selected increments of time withm the demand interval. Each watthour meter in the system is provided with an impulse generator that generates two impulses for each revolution of the meter disc. The total pulses received frorn all the meters are continuously totaled and are fed to a plurality of parallel connected gated counters. Each counter has its gate opened at different sub-time intervals during the demand interval. A multiplier is connected to each of the gated counters except the last one and each multiplier is provided with a different multiplier constant so as to provide an estimate of the power to be drawn over the entire demand interval at the end of each of the different sub-time intervals. Means are provided for recording the ontputs from the different circuits in synchronism with the actuation oi each gate circuit.

CO2 Mitigation Measures of Power Sector and Its Integrated Optimization in China

PubMed Central

Dai, Pan; Chen, Guang; Zhou, Hao; Su, Meirong; Bao, Haixia

2012-01-01

Power sector is responsible for about 40% of the total CO2 emissions in the world and plays a leading role in climate change mitigation. In this study, measures that lower CO2 emissions from the supply side, demand side, and power grid are discussed, based on which, an integrated optimization model of CO2 mitigation (IOCM) is proposed. Virtual energy, referring to energy saving capacity in both demand side and the power grid, together with conventional energy in supply side, is unified planning for IOCM. Consequently, the optimal plan of energy distribution, considering both economic benefits and mitigation benefits, is figured out through the application of IOCM. The results indicate that development of demand side management (DSM) and smart grid can make great contributions to CO2 mitigation of power sector in China by reducing the CO2 emissions by 10.02% and 12.59%, respectively, in 2015, and in 2020. PMID:23213305

The Influence of Wheelchair Propulsion Hand Pattern on Upper Extremity Muscle Power and Stress

PubMed Central

Slowik, Jonathan S.; Requejo, Philip S.; Mulroy, Sara J.; Neptune, Richard R.

2016-01-01

The hand pattern (i.e., full-cycle hand path) used during manual wheelchair propulsion is frequently classified as one of four distinct hand pattern types: arc, single loop, double loop and semicircular. Current clinical guidelines recommend the use of the semicircular pattern, which is based on advantageous levels of broad biomechanical metrics implicitly related to the demand placed on the upper extremity (e.g., lower cadence). However, an understanding of the influence of hand pattern on specific measures of upper extremity muscle demand (e.g., muscle power and stress) is needed to help make such recommendations, but these quantities are difficult and impractical to measure experimentally. The purpose of this study was to use musculoskeletal modeling and forward dynamics simulations to investigate the influence of the hand pattern used on specific measures of upper extremity muscle demand. The simulation results suggest that the double loop and semicircular patterns produce the most favorable levels of overall muscle stress and total muscle power. The double loop pattern had the lowest full-cycle and recovery-phase upper extremity demand but required high levels of muscle power during the relatively short contact phase. The semicircular pattern had the second-lowest full-cycle levels of overall muscle stress and total muscle power, and demand was more evenly distributed between the contact and recovery phases. These results suggest that in order to decrease upper extremity demand, manual wheelchair users should use either the double loop or semicircular pattern when propelling their wheelchairs at a self-selected speed on level ground. PMID:27062591

Demand, Energy, and Power Factor

DTIC Science & Technology

1994-08-01

POWER FACTOR DEFINITION I Basically , power factor (pf) is a measure of how effectively the plant uses the electricity it purchases from the utility. It...not be made available by the plant. U 24 This video is relatively short, less than fifteen-minutes, and covers the basics on demand, block extenders...designing, implementing, and evaluation of the resultant project. 1 2. Thumann, Albeit. Plant Engineer and Managers Guide to Energv Conservation, 5th ed

Thermal energy storage heat exchanger: Molten salt heat exchanger design for utility power plants

NASA Technical Reports Server (NTRS)

Ferarra, A.; Yenetchi, G.; Haslett, R.; Kosson, R.

1977-01-01

The use of thermal energy storage (TES) in the latent heat of molten salts as a means of conserving fossil fuels and lowering the cost of electric power was evaluated. Public utility systems provided electric power on demand. This demand is generally maximum during late weekday afternoons, with considerably lower overnight and weekend loads. Typically, the average demand is only 60% to 80% of peak load. As peak load increases, the present practice is to purchase power from other grid facilities or to bring older less efficient fossil-fuel plants on line which increase the cost of electric power. The widespread use of oil-fired boilers, gas turbine and diesel equipment to meet peaking loads depletes our oil-based energy resources. Heat exchangers utilizing molten salts can be used to level the energy consumption curve. The study begins with a demand analysis and the consideration of several existing modern fossil-fuel and nuclear power plants for use as models. Salts are evaluated for thermodynamic, economic, corrosive, and safety characteristics. Heat exchanger concepts are explored and heat exchanger designs are conceived. Finally, the economics of TES conversions in existing plants and new construction is analyzed. The study concluded that TES is feasible in electric power generation. Substantial data are presented for TES design, and reference material for further investigation of techniques is included.

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices

DOEpatents

Chassin, David P [Pasco, WA; Donnelly, Matthew K [Kennewick, WA; Dagle, Jeffery E [Richland, WA

2011-12-06

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices

DOEpatents

Chassin, David P.; Donnelly, Matthew K.; Dagle, Jeffery E.

2006-12-12

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

A Two-Stage Stochastic Mixed-Integer Programming Approach to the Smart House Scheduling Problem

NASA Astrophysics Data System (ADS)

Ozoe, Shunsuke; Tanaka, Yoichi; Fukushima, Masao

A “Smart House” is a highly energy-optimized house equipped with photovoltaic systems (PV systems), electric battery systems, fuel cell cogeneration systems (FC systems), electric vehicles (EVs) and so on. Smart houses are attracting much attention recently thanks to their enhanced ability to save energy by making full use of renewable energy and by achieving power grid stability despite an increased power draw for installed PV systems. Yet running a smart house's power system, with its multiple power sources and power storages, is no simple task. In this paper, we consider the problem of power scheduling for a smart house with a PV system, an FC system and an EV. We formulate the problem as a mixed integer programming problem, and then extend it to a stochastic programming problem involving recourse costs to cope with uncertain electricity demand, heat demand and PV power generation. Using our method, we seek to achieve the optimal power schedule running at the minimum expected operation cost. We present some results of numerical experiments with data on real-life demands and PV power generation to show the effectiveness of our method.

A wavelet-fuzzy logic based energy management strategy for a fuel cell/battery/ultra-capacitor hybrid vehicular power system

NASA Astrophysics Data System (ADS)

Erdinc, O.; Vural, B.; Uzunoglu, M.

Due to increasing concerns on environmental pollution and depleting fossil fuels, fuel cell (FC) vehicle technology has received considerable attention as an alternative to the conventional vehicular systems. However, a FC system combined with an energy storage system (ESS) can display a preferable performance for vehicle propulsion. As the additional ESS can fulfill the transient power demand fluctuations, the fuel cell can be downsized to fit the average power demand without facing peak loads. Besides, braking energy can be recovered by the ESS. This study focuses on a vehicular system powered by a fuel cell and equipped with two secondary energy storage devices: battery and ultra-capacitor (UC). However, an advanced energy management strategy is quite necessary to split the power demand of a vehicle in a suitable way for the on-board power sources in order to maximize the performance while promoting the fuel economy and endurance of hybrid system components. In this study, a wavelet and fuzzy logic based energy management strategy is proposed for the developed hybrid vehicular system. Wavelet transform has great capability for analyzing signals consisting of instantaneous changes like a hybrid electric vehicle (HEV) power demand. Besides, fuzzy logic has a quite suitable structure for the control of hybrid systems. The mathematical and electrical models of the hybrid vehicular system are developed in detail and simulated using MATLAB ®, Simulink ® and SimPowerSystems ® environments.

Demand Response and Energy Storage Integration Study

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

Ma, Ookie; Cheung, Kerry; Olsen, Daniel J.

2016-03-01

Demand response and energy storage resources present potentially important sources of bulk power system services that can aid in integrating variable renewable generation. While renewable integration studies have evaluated many of the challenges associated with deploying large amounts of variable wind and solar generation technologies, integration analyses have not yet fully incorporated demand response and energy storage resources. This report represents an initial effort in analyzing the potential integration value of demand response and energy storage, focusing on the western United States. It evaluates two major aspects of increased deployment of demand response and energy storage: (1) Their operational valuemore » in providing bulk power system services and (2) Market and regulatory issues, including potential barriers to deployment.« less

Demand Response and Energy Storage Integration Study

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

Ma, Ookie; Cheung, Kerry

Demand response and energy storage resources present potentially important sources of bulk power system services that can aid in integrating variable renewable generation. While renewable integration studies have evaluated many of the challenges associated with deploying large amounts of variable wind and solar generation technologies, integration analyses have not yet fully incorporated demand response and energy storage resources. This report represents an initial effort in analyzing the potential integration value of demand response and energy storage, focusing on the western United States. It evaluates two major aspects of increased deployment of demand response and energy storage: (1) Their operational valuemore » in providing bulk power system services and (2) Market and regulatory issues, including potential barriers to deployment.« less

Intelligent and robust optimization frameworks for smart grids

NASA Astrophysics Data System (ADS)

Dhansri, Naren Reddy

A smart grid implies a cyberspace real-time distributed power control system to optimally deliver electricity based on varying consumer characteristics. Although smart grids solve many of the contemporary problems, they give rise to new control and optimization problems with the growing role of renewable energy sources such as wind or solar energy. Under highly dynamic nature of distributed power generation and the varying consumer demand and cost requirements, the total power output of the grid should be controlled such that the load demand is met by giving a higher priority to renewable energy sources. Hence, the power generated from renewable energy sources should be optimized while minimizing the generation from non renewable energy sources. This research develops a demand-based automatic generation control and optimization framework for real-time smart grid operations by integrating conventional and renewable energy sources under varying consumer demand and cost requirements. Focusing on the renewable energy sources, the intelligent and robust control frameworks optimize the power generation by tracking the consumer demand in a closed-loop control framework, yielding superior economic and ecological benefits and circumvent nonlinear model complexities and handles uncertainties for superior real-time operations. The proposed intelligent system framework optimizes the smart grid power generation for maximum economical and ecological benefits under an uncertain renewable wind energy source. The numerical results demonstrate that the proposed framework is a viable approach to integrate various energy sources for real-time smart grid implementations. The robust optimization framework results demonstrate the effectiveness of the robust controllers under bounded power plant model uncertainties and exogenous wind input excitation while maximizing economical and ecological performance objectives. Therefore, the proposed framework offers a new worst-case deterministic optimization algorithm for smart grid automatic generation control.

Preventing Blackouts by Building a Better Power Grid

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

Huang, Henry

America’s power grid is undergoing significant change. New mixes of electricity generation, as well as evolving consumer demand, make it even more challenging to manage. Moment-to-moment changes in electricity supply and demand can vary drastically, challenging power grid operators who must maintain a balance—in real time—to avoid disruptions and blackouts. Enter Senior Power Engineer Zhenyu (Henry) Huang. Henry leads PNNL’s initiative to develop technologies that will shape the future of the power grid, and he’s part of a team that is determined to make our nation’s grid more reliable and secure.

The influence of wheelchair propulsion technique on upper extremity muscle demand: a simulation study.

PubMed

Rankin, Jeffery W; Kwarciak, Andrew M; Richter, W Mark; Neptune, Richard R

2012-11-01

The majority of manual wheelchair users will experience upper extremity injuries or pain, in part due to the high force requirements, repetitive motion and extreme joint postures associated with wheelchair propulsion. Recent studies have identified cadence, contact angle and peak force as important factors for reducing upper extremity demand during propulsion. However, studies often make comparisons between populations (e.g., able-bodied vs. paraplegic) or do not investigate specific measures of upper extremity demand. The purpose of this study was to use a musculoskeletal model and forward dynamics simulations of wheelchair propulsion to investigate how altering cadence, peak force and contact angle influence individual muscle demand. Forward dynamics simulations of wheelchair propulsion were generated to emulate group-averaged experimental data during four conditions: 1) self-selected propulsion technique, and while 2) minimizing cadence, 3) maximizing contact angle, and 4) minimizing peak force using biofeedback. Simulations were used to determine individual muscle mechanical power and stress as measures of muscle demand. Minimizing peak force and cadence had the lowest muscle power requirements. However, minimizing peak force increased cadence and recovery power, while minimizing cadence increased average muscle stress. Maximizing contact angle increased muscle stress and had the highest muscle power requirements. Minimizing cadence appears to have the most potential for reducing muscle demand and fatigue, which could decrease upper extremity injuries and pain. However, altering any of these variables to extreme values appears to be less effective; instead small to moderate changes may better reduce overall muscle demand. Copyright © 2012 Elsevier Ltd. All rights reserved.

Metabolic power demands of rugby league match play.

PubMed

Kempton, Tom; Sirotic, Anita Claire; Rampinini, Ermanno; Coutts, Aaron James

2015-01-01

To describe the metabolic demands of rugby league match play for positional groups and compare match distances obtained from high-speed-running classifications with those derived from high metabolic power. Global positioning system (GPS) data were collected from 25 players from a team competing in the National Rugby League competition over 39 matches. Players were classified into positional groups (adjustables, outside backs, hit-up forwards, and wide-running forwards). The GPS devices provided instantaneous raw velocity data at 5 Hz, which were exported to a customized spreadsheet. The spreadsheet provided calculations for speed-based distances (eg, total distance; high-speed running, >14.4 km/h; and very-high-speed running, >18.1 km/h) and metabolic-power variables (eg, energy expenditure; average metabolic power; and high-power distance, >20 W/kg). The data show that speed-based distances and metabolic power varied between positional groups, although this was largely related to differences in time spent on field. The distance covered at high running speed was lower than that obtained from high-power thresholds for all positional groups; however, the difference between the 2 methods was greatest for hit-up forwards and adjustables. Positional differences existed for all metabolic parameters, although these are at least partially related to time spent on the field. Higher-speed running may underestimate the demands of match play when compared with high-power distance-although the degree of difference between the measures varied by position. The analysis of metabolic power may complement traditional speed-based classifications and improve our understanding of the demands of rugby league match play.

Power management and frequency regulation for microgrid and smart grid: A real-time demand response approach

NASA Astrophysics Data System (ADS)

Pourmousavi Kani, Seyyed Ali

Future power systems (known as smart grid) will experience a high penetration level of variable distributed energy resources to bring abundant, affordable, clean, efficient, and reliable electric power to all consumers. However, it might suffer from the uncertain and variable nature of these generations in terms of reliability and especially providing required balancing reserves. In the current power system structure, balancing reserves (provided by spinning and non-spinning power generation units) usually are provided by conventional fossil-fueled power plants. However, such power plants are not the favorite option for the smart grid because of their low efficiency, high amount of emissions, and expensive capital investments on transmission and distribution facilities, to name a few. Providing regulation services in the presence of variable distributed energy resources would be even more difficult for islanded microgrids. The impact and effectiveness of demand response are still not clear at the distribution and transmission levels. In other words, there is no solid research reported in the literature on the evaluation of the impact of DR on power system dynamic performance. In order to address these issues, a real-time demand response approach along with real-time power management (specifically for microgrids) is proposed in this research. The real-time demand response solution is utilized at the transmission (through load-frequency control model) and distribution level (both in the islanded and grid-tied modes) to provide effective and fast regulation services for the stable operation of the power system. Then, multiple real-time power management algorithms for grid-tied and islanded microgrids are proposed to economically and effectively operate microgrids. Extensive dynamic modeling of generation, storage, and load as well as different controller design are considered and developed throughout this research to provide appropriate models and simulation environment to evaluate the effectiveness of the proposed methodologies. Simulation results revealed the effectiveness of the proposed methods in providing balancing reserves and microgrids' economic and stable operation. The proposed tools and approaches can significantly enhance the application of microgrids and demand response in the smart grid era. They will also help to increase the penetration level of variable distributed generation resources in the smart grid.

Cut Electric Bills by Controlling Demand

ERIC Educational Resources Information Center

Grumman, David L.

1974-01-01

Electric bills can be reduced by lowering electric consumption and by controlling demand -- the amount of electricity used at a certain point in time. Gives tips to help reduce electric demand at peak power periods. (Author/DN)

Reservoirs operation and water resources utilization coordination in Hongshuihe basin

NASA Astrophysics Data System (ADS)

Li, Chonghao; Chi, Kaige; Pang, Bo; Tang, Hongbin

2018-06-01

In the recent decade, the demand for water resources has been increasing with the economic development. The reservoirs of cascade hydropower stations in Hongshuihe basin, which are constructed with a main purpose of power generation, are facing more integrated water resources utilization problem. The conflict between power generation of cascade reservoirs and flood control, shipping, environmental protection and water supply has become increasingly prominent. This paper introduces the general situation and integrated water demand of cascade reservoirs in Hongshuihe basin, and it analyses the impact of various types of integrated water demand on power generation and supply. It establishes mathematic models, constrained by various types of integrated water demand, to guide the operation and water resources utilization management of cascade reservoirs in Hongshuihe basin. Integrated water coordination mechanism of Hongshuihe basin is also introduced. It provides a technical and management guide and demonstration for cascade reservoirs operation and integrated water management at home and abroad.

Residential green power demand in the United States

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

Dagher, Leila; Bird, Lori; Heeter, Jenny

This paper investigates the demand determinants of green power in the U.S. residential sector. The data employed were collected by the National Renewable Energy Laboratory and consist of a cross-section of seven utilities observed over 13 years. A series of tests are performed that resulted in estimating a demand equation using the one-way cross-section random effects model. As expected, we find that demand is highly price inelastic. More interestingly though, is that elasticity with respect to number of customers is 0.52 leading to the conclusion that new subscribers tend to purchase less green power on average than the existing customers.more » Another compelling finding is that obtaining accreditation will have a 28.5% positive impact on consumption. Knowing that gaining green accreditation is important to the success of programs, utilities may want to seek certification and highlight it in their advertising campaigns.« less

A low power, on demand electrothermal valve for wireless drug delivery applications

PubMed Central

Li, Po-Ying; Givrad, Tina K.; Sheybani, Roya; Holschneider, Daniel P.; Maarek, Jean-Michel I.

2014-01-01

We present a low power, on demand Parylene MEMS electrothermal valve. A novel Ω-shaped thermal resistive element requires low power (~mW) and enables rapid valve opening (~ms). Using both finite element analysis and valve opening experiments, a robust resistive element design for improved valve opening performance in water was obtained. In addition, a thermistor, as an inrush current limiter, was added into the valve circuit to provide variable current ramping. Wireless activation of the valve using RF inductive power transfer was demonstrated. PMID:20024057

Optimal Sizing of Hybrid Renewable Energy Systems: An Application for Real Demand in Qatar Remote Area

NASA Astrophysics Data System (ADS)

Alyafei, Nora

Renewable energy (RE) sources are becoming popular for power generations due to advances in renewable energy technologies and their ability to reduce the problem of global warming. However, their supply varies in availability (as sun and wind) and the required load demand fluctuates. Thus, to overcome the uncertainty issues of RE power sources, they can be combined with storage devices and conventional energy sources in a Hybrid Power Systems (HPS) to satisfy the demand load at any time. Recently, RE systems received high interest to take advantage of their positive benefits such as renewable availability and CO2 emissions reductions. The optimal design of a hybrid renewable energy system is mostly defined by economic criteria, but there are also technical and environmental criteria to be considered to improve decision making. In this study three main renewable sources of the system: photovoltaic arrays (PV), wind turbine generators (WG) and waste boilers (WB) are integrated with diesel generators and batteries to design a hybrid system that supplies the required demand of a remote area in Qatar using heuristic approach. The method utilizes typical year data to calculate hourly output power of PV, WG and WB throughout the year. Then, different combinations of renewable energy sources with battery storage are proposed to match hourly demand during the year. The design which satisfies the desired level of loss of power supply, CO 2 emissions and minimum costs is considered as best design.

Joint Real-Time Energy and Demand-Response Management using a Hybrid Coalitional-Noncooperative Game

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

He, Fulin; Gu, Yi; Hao, Jun

In order to model the interactions among utility companies, building demands and renewable energy generators (REGs), a hybrid coalitional-noncooperative game framework has been proposed. We formulate a dynamic non-cooperative game to study the energy dispatch within multiple utility companies, while we take a coalitional perspective on REGs and buildings demands through a hedonic coalition formation game approach. In this case, building demands request different power supply from REGs, then the building demands can be organized into an ultimate coalition structure through a distributed hedonic shift algorithm. At the same time, utility companies can also obtain a stable power generation profile.more » In addition, the interactive progress among the utility companies and building demands which cannot be supplied by REGs is implemented by distributed game theoretic algorithms. Numerical results illustrate that the proposed hybrid coalitional-noncooperative game scheme reduces the cost of both building demands and utility companies compared with the initial scene.« less

A study of some economic factors relating to the development and implementation of a satellite power system

NASA Technical Reports Server (NTRS)

1978-01-01

Areas are examined relating to the design, development and implementation of a satellite power system (SPS): an analysis of the effect of energy R&D programs in general and SPS in particular on optimal fossil fuel consumption patterns, a study of alternative uses of SPS technologies, and a study of the electric power market penetration potential for SPS. It is shown that a credible program of R&D on long-range energy alternatives leads to lower optimal prices for fossil fuels, resulting in large short-term benefits accruing to the specific program elements. Several alternative uses of SPS technologies were identified; however the markets for these technologies are generally quite diffuse and difficult to assess. The notable exception is solar array technology which has, potentially, a very large non-SPS market. It is shown that the market for SPS units derives from two components of demand: the demand created by growth in the electrical energy demand which leads to an increased demand for baseload generating capacity, and a demand created by the need to replace retiring capacity.

Study of a conceptual nuclear energy center at Green River, Utah. Power demand, load center assessment and transmission

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

Smith, D.R.; Thaik, A.; Pingel, P.

This document constitutes a segment of a feasibility study investigating the ramification of constructing a nuclear energy center in an arid western region. In this phase of the study. The projected power demands and load center locations were reviewed and assessed. Alternative transmission systems were analysed and a conceptual transmission for bulk power transportation is proposed with potential line routes. Environmental impacts of the proposed transmission were also identified.

[A preliminary evaluation of mental status and an investigation of occupational health knowledge demand in operating and maintenance personnel in wind power plants].

PubMed

Hu, S Q; Zhang, Q; Zhu, X H; Sun, K; Chen, S Z; Liu, A G; Luo, G L; Huang, W

2016-10-20

Objective: To investigate the mental status, level of occupational health knowledge, health behaviors, and occupational health knowledge demand in operating and maintenance personnel in wind power plants, and to provide a basis for formulating protective measures of occupational health for operating and maintenance personnel in wind power plants. Methods: A cluster sampling was performed in regionally representative wind power plants in the wind power industry from May 2014 to June 2015, and the Symptom Checklist-90 (SCL-90) and a self-made evaluation questionnaire were used to investigate the general status, mental health, and occupational health knowledge demand in 160 operating and maintenance workers. Results: Of all respondents, 26.9% had mental health issues. The awareness rate of infectious disease knowledge and preventive measures was 11.9%. Of all workers, 96.5% wanted to know the occupational hazard factors in the workplace, and 96.3% wanted to get the knowledge of the prevention of related diseases. Conclusion: Mental health issues in operating and maintenance personnel in wind power plants cannot be neglected and there is a high demand for occupational health services and related knowledge. Comprehensive intervention measures for health promotion in the workplace should be adopted to improve working environment, enhance individual mental health education, increase the level of occupational health management, and protect the health of workers.

Towards 50% wind electricity in Denmark: Dilemmas and challenges

NASA Astrophysics Data System (ADS)

Bach, Paul-Frederik

2016-05-01

Electricity and heat supply systems are essential contributors to a fossil-free future in Denmark. The combined production of heat and power (CHP) and the production of wind energy are already well developed in Denmark. Combined heat and power covers about 40% of the demand for space heating in Denmark, and the production of wind energy is supposed to exceed 50% of the demand for electricity by 2020. The changing electricity and heat production has some consequences already now: i) Decreasing wholesale prices in Denmark and in other countries. ii) Thermal power plants are closing down. Denmark is no longer self-sufficient with electricity under all conditions. iii) The electricity production pattern does not match the demand pattern. The result is that the neighbouring countries must absorb the variations from wind and solar power. Essential challenges: i) The future of combined heat and power in Denmark is uncertain. ii) Denmark will need new backup capacity for filling the gaps in wind power and solar cell output. iii) Flexible electricity consumers are supposed to contribute to balancing the future power systems. There is still a long way to go before the Smart Grid visions are implemented in large scale. iv) The transformation of the power system will create new risks of power failures.

Development and Simulation of Increased Generation on a Secondary Circuit of a Microgrid

NASA Astrophysics Data System (ADS)

Reyes, Karina

As fossil fuels are depleted and their environmental impacts remain, other sources of energy must be considered to generate power. Renewable sources, for example, are emerging to play a major role in this regard. In parallel, electric vehicle (EV) charging is evolving as a major load demand. To meet reliability and resiliency goals demanded by the electricity market, interest in microgrids are growing as a distributed energy resource (DER). In this thesis, the effects of intermittent renewable power generation and random EV charging on secondary microgrid circuits are analyzed in the presence of a controllable battery in order to characterize and better understand the dynamics associated with intermittent power production and random load demands in the context of the microgrid paradigm. For two reasons, a secondary circuit on the University of California, Irvine (UCI) Microgrid serves as the case study. First, the secondary circuit (UC-9) is heavily loaded and an integral component of a highly characterized and metered microgrid. Second, a unique "next-generation" distributed energy resource has been deployed at the end of the circuit that integrates photovoltaic power generation, battery storage, and EV charging. In order to analyze this system and evaluate the impact of the DER on the secondary circuit, a model was developed to provide a real-time load flow analysis. The research develops a power management system applicable to similarly integrated systems. The model is verified by metered data obtained from a network of high resolution electric meters and estimated load data for the buildings that have unknown demand. An increase in voltage is observed when the amount of photovoltaic power generation is increased. To mitigate this effect, a constant power factor is set. Should the real power change dramatically, the reactive power is changed to mitigate voltage fluctuations.

Essays on Mathematical Optimization for Residential Demand Response in the Energy Sector

NASA Astrophysics Data System (ADS)

Palaparambil Dinesh, Lakshmi

In the electric utility industry, it could be challenging to adjust supply to match demand due to large generator ramp up times, high generation costs and insufficient in-house generation capacity. Demand response (DR) is a technique for adjusting the demand for electric power instead of the supply. Direct Load Control (DLC) is one of the ways to implement DR. DLC program participants sign up for power interruption contracts and are given financial incentives for curtailing electricity usage during peak demand time periods. This dissertation studies a DLC program for residential air conditioners using mathematical optimization models. First, we develop a model that determines what contract parameters to use in designing contracts between the provider and residential customers, when to turn which power unit on or off and how much power to cut during peak demand hours. The model uses information on customer preferences for choice of contract parameters such as DLC financial incentives and energy usage curtailment. In numerical experiments, the proposed model leads to projected cost savings of the order of 20%, compared to a current benchmark model used in practice. We also quantify the impact of factors leading to cost savings and study characteristics of customers picked by different contracts. Second, we study a DLC program in a macro economic environment using a Computable General Equilibrium (CGE) model. A CGE model is used to study the impact of external factors such as policy and technology changes on different economic sectors. Here we differentiate customers based on their preference for DLC programs by using different values for price elasticity of demand for electricity commodity. Consequently, DLC program customers could substitute demand for electricity commodity with other commodities such as transportation sector. Price elasticity of demand is calculated using a novel methodology that incorporates customer preferences for DLC contracts from the first model. The calculation of elasticity based on our methodology is useful since the prices of commodities are not only determined by aggregate demand and supply but also by customers' relative preferences for commodities. In addition to this we quantify the indirect substitution and rebound effects on sectoral activity levels, incomes and prices based on customer differences, when DLC is implemented.

Approaches to Enable Demand Response by Industrial Loads for Ancillary Services Provision

NASA Astrophysics Data System (ADS)

Zhang, Xiao

Demand response has gained significant attention in recent years as it demonstrates potentials to enhance the power system's operational flexibility in a cost-effective way. Industrial loads such as aluminum smelters, steel manufacturers, and cement plants demonstrate advantages in supporting power system operation through demand response programs, because of their intensive power consumption, already existing advanced monitoring and control infrastructure, and the strong economic incentive due to the high energy costs. In this thesis, we study approaches to efficiently integrate each of these types of manufacturing processes as demand response resources. The aluminum smelting process is able to change its power consumption both accurately and quickly by controlling the pots' DC voltage, without affecting the production quality. Hence, an aluminum smelter has both the motivation and the ability to participate in demand response. First, we focus on determining the optimal regulation capacity that such a manufacturing plant should provide. Next, we focus on determining its optimal bidding strategy in the day-ahead energy and ancillary services markets. Electric arc furnaces (EAFs) in steel manufacturing consume a large amount of electric energy. However, a steel plant can take advantage of time-based electricity prices by optimally arranging energy-consuming activities to avoid peak hours. We first propose scheduling methods that incorporate the EAFs' flexibilities to reduce the electricity cost. We then propose methods to make the computations more tractable. Finally, we extend the scheduling formulations to enable the provision of spinning reserve. Cement plants are able to quickly adjust their power consumption rate by switching on/off the crushers. However, switching on/off the loading units only achieves discrete power changes, which restricts the load from offering valuable ancillary services such as regulation and load following, as continuous power changes are required for these services. We propose methods that enable these services with the support of an on-site energy storage device. As demonstrated by the case studies, the proposed approaches are effective and can generate practical production instructions for the industrial loads. This thesis not only provides methods to enable demand response by industrial loads but also potentially encourages industrial loads to be active in electricity markets.

Drought Vulnerability of Thermoelectric Generation using Texas as a Case Study

NASA Astrophysics Data System (ADS)

Scanlon, B. R.; Duncan, I.; Reedy, R. C.

2013-12-01

Increasing extent, frequency, and intensity of droughts raises concerns about the vulnerability of thermoelectricity generation to water-shortages. In this study we evaluated the impact of the 2011 flash drought in Texas on electricity demand and water supply for power plants. The impacts of the drought were greater in sub-humid east Texas than in semiarid west Texas because most power plants are pre-adapted to low water availability in west Texas. This comparison between sub-humid and semiarid regions in Texas serves as a proxy for climatic differences between the eastern and western US. High temperatures with ≥100 days of triple digit temperatures raised annual electricity demands/generation by 6% and peak demands in August by 4% relative to 2010. The corresponding water demands/consumption for 2011 for thermoelectric generation was increased by ~10% relative to 2010. While electricity demand only increased slightly during the drought, water supply decreased markedly with statewide reservoir storage at record lows (58% of capacity). Reductions in reservoir storage would suggest that power plants should be vulnerable to water shortages; however, data show that power plants subjected to water shortages were flexible enough to adapt by switching to less water-intensive technologies. Some power plants switched from once-through cooling to cooling towers with more than an order of magnitude reduction in water withdrawals whereas others switched from steam turbines to combustion turbines (no cooling water requirements) when both were available. Recent increases in natural gas production by an order of magnitude and use in combined cycle plants enhances the robustness of the power-plant fleet to drought by reducing water consumption (~1/3rd of that for steam turbines), allowing plants to operate with (combined cycle generator) or without (combustion turbine generator) water, and as base-load or peaking plants to complement increasing wind generation. Drought vulnerability of the power plant fleet can be further enhanced by reducing demand and/or increasing supplies of water (e.g. use of nontraditional water sources: municipal waste water or brackish water) and increasing supplies of electricity. Our ability to cope with projected increases in droughts would be greatly improved by joint management of water and electricity.

Scientific challenges in sustainable energy technology

NASA Astrophysics Data System (ADS)

Lewis, Nathan

2006-04-01

We describe and evaluate the technical, political, and economic challenges involved with widespread adoption of renewable energy technologies. First, we estimate fossil fuel resources and reserves and, together with the current and projected global primary power production rates, estimate the remaining years of oil, gas, and coal. We then compare the conventional price of fossil energy with that from renewable energy technologies (wind, solar thermal, solar electric, biomass, hydroelectric, and geothermal) to evaluate the potential for a transition to renewable energy in the next 20-50 years. Secondly, we evaluate - per the Intergovernmental Panel on Climate Change - the greenhouse constraint on carbon-based power consumption as an unpriced externality to fossil-fuel use, considering global population growth, increased global gross domestic product, and increased energy efficiency per unit GDP. This constraint is projected to drive the demand for carbon-free power well beyond that produced by conventional supply/demand pricing tradeoffs, to levels far greater than current renewable energy demand. Thirdly, we evaluate the level and timescale of R&D investment needed to produce the required quantity of carbon-free power by the 2050 timeframe. Fourth, we evaluate the energy potential of various renewable energy resources to ascertain which resources are adequately available globally to support the projected demand. Fifth, we evaluate the challenges to the chemical sciences to enable the cost-effective production of carbon-free power required. Finally, we discuss the effects of a change in primary power technology on the energy supply infrastructure and discuss the impact of such a change on the modes of energy consumption by the energy consumer and additional demands on the chemical sciences to support such a transition in energy supply.

Daily Peak Load Forecasting of Next Day using Weather Distribution and Comparison Value of Each Nearby Date Data

NASA Astrophysics Data System (ADS)

Ito, Shigenobu; Yukita, Kazuto; Goto, Yasuyuki; Ichiyanagi, Katsuhiro; Nakano, Hiroyuki

By the development of industry, in recent years; dependence to electric energy is growing year by year. Therefore, reliable electric power supply is in need. However, to stock a huge amount of electric energy is very difficult. Also, there is a necessity to keep balance between the demand and supply, which changes hour after hour. Consequently, to supply the high quality and highly dependable electric power supply, economically, and with high efficiency, there is a need to forecast the movement of the electric power demand carefully in advance. And using that forecast as the source, supply and demand management plan should be made. Thus load forecasting is said to be an important job among demand investment of electric power companies. So far, forecasting method using Fuzzy logic, Neural Net Work, Regression model has been suggested for the development of forecasting accuracy. Those forecasting accuracy is in a high level. But to invest electric power in higher accuracy more economically, a new forecasting method with higher accuracy is needed. In this paper, to develop the forecasting accuracy of the former methods, the daily peak load forecasting method using the weather distribution of highest and lowest temperatures, and comparison value of each nearby date data is suggested.

Water demand for electricity in deep decarbonisation scenarios: a multi-model assessment

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

Mouratiadou, I.; Bevione, M.; Bijl, D. L.

This study assesses the effects of deep electricity decarbonisation and shifts in the choice of power plant cooling technologies on global electricity water demand, using a suite of five integrated assessment models. We find that electricity sector decarbonisation results in co-benefits for water resources primarily due to the phase-out of water-intensive coal-based thermoelectric power generation, although these co-benefits vary substantially across decarbonisation scenarios. Wind and solar photovoltaic power represent a win-win option for both climate and water resources, but further expansion of nuclear or fossil- and biomass-fuelled power plants with carbon capture and storage may result in increased pressures onmore » the water environment. Further to these results, the paper provides insights on the most crucial factors of uncertainty with regards to future estimates of water demand. These estimates varied substantially across models in scenarios where the effects of decarbonisation on the electricity mix were less clear-cut. Future thermal and water efficiency improvements of power generation technologies and demand-side energy efficiency improvements were also identified to be important factors of uncertainty. We conclude that in order to ensure positive effects of decarbonisation on water resources, climate policy should be combined with technology-specific energy and/or water policies.« less

Economics of power plant siting in southeastern New England. Final report

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

Gates, J.M.; Meade, N.F.; Sutinen, J.G.

1974-06-01

The four major topics are discussed, i.e. demand and supply of electrical energy in the SENE region; the economics of expanding supply of and managing demand for electrical energy in SENE; the economics of locating power plants; and the economic implications of fifteen alternative power plant sites. The major sources of demand in the SENE region are Boston and Providence. Fossil fuel expansions in these areas will have to contend with higher fuel prices in the future and strict air quality standards. This will create incentives for fossil fuel facilities in outlying communities and for coastal nuclear plants where adequatemore » cooling water exists. Considerations affecting the choice of sites are: public health and safety; environmental quality and zero emissions; resistance on the part of land owners to sell sites for power plants; and local regulations on transmission lines.« less

Energy storage inherent in large tidal turbine farms

PubMed Central

Vennell, Ross; Adcock, Thomas A. A.

2014-01-01

While wind farms have no inherent storage to supply power in calm conditions, this paper demonstrates that large tidal turbine farms in channels have short-term energy storage. This storage lies in the inertia of the oscillating flow and can be used to exceed the previously published upper limit for power production by currents in a tidal channel, while simultaneously maintaining stronger currents. Inertial storage exploits the ability of large farms to manipulate the phase of the oscillating currents by varying the farm's drag coefficient. This work shows that by optimizing how a large farm's drag coefficient varies during the tidal cycle it is possible to have some flexibility about when power is produced. This flexibility can be used in many ways, e.g. producing more power, or to better meet short predictable peaks in demand. This flexibility also allows trading total power production off against meeting peak demand, or mitigating the flow speed reduction owing to power extraction. The effectiveness of inertial storage is governed by the frictional time scale relative to either the duration of a half tidal cycle or the duration of a peak in power demand, thus has greater benefits in larger channels. PMID:24910516

Energy storage inherent in large tidal turbine farms.

PubMed

Vennell, Ross; Adcock, Thomas A A

2014-06-08

While wind farms have no inherent storage to supply power in calm conditions, this paper demonstrates that large tidal turbine farms in channels have short-term energy storage. This storage lies in the inertia of the oscillating flow and can be used to exceed the previously published upper limit for power production by currents in a tidal channel, while simultaneously maintaining stronger currents. Inertial storage exploits the ability of large farms to manipulate the phase of the oscillating currents by varying the farm's drag coefficient. This work shows that by optimizing how a large farm's drag coefficient varies during the tidal cycle it is possible to have some flexibility about when power is produced. This flexibility can be used in many ways, e.g. producing more power, or to better meet short predictable peaks in demand. This flexibility also allows trading total power production off against meeting peak demand, or mitigating the flow speed reduction owing to power extraction. The effectiveness of inertial storage is governed by the frictional time scale relative to either the duration of a half tidal cycle or the duration of a peak in power demand, thus has greater benefits in larger channels.

Simulation of a microgrid

NASA Astrophysics Data System (ADS)

Dulǎu, Lucian Ioan

2015-12-01

This paper describes the simulation of a microgrid system with storage technologies. The microgrid comprises 6 distributed generators (DGs), 3 loads and a 150 kW storage unit. The installed capacity of the generators is 1100 kW, while the total load demand is 900 kW. The simulation is performed by using a SCADA software, considering the power generation costs, the loads demand and the system's power losses. The generators access the system in order of their power generation cost. The simulation is performed for the entire day.

Photovoltaic village power application: Assessment of the near-term market

NASA Technical Reports Server (NTRS)

Rosenblum, L.; Bifano, W. J.; Poley, W. A.; Scudder, L. R.

1978-01-01

The village power application represents a potential market for photovoltaics. The price of energy for photovoltaic systems was compared to that of utility line extensions and diesel generators. The potential domestic demand was defined in both the government and commercial sectors. The foreign demand and sources of funding for village power systems in the developing countries were also discussed briefly. It was concluded that a near term domestic market of at least 12 MW min and a foreign market of about 10 GW exists.

Modeling and Economic Analysis of Power Grid Operations in a Water Constrained System

NASA Astrophysics Data System (ADS)

Zhou, Z.; Xia, Y.; Veselka, T.; Yan, E.; Betrie, G.; Qiu, F.

2016-12-01

The power sector is the largest water user in the United States. Depending on the cooling technology employed at a facility, steam-electric power stations withdrawal and consume large amounts of water for each megawatt hour of electricity generated. The amounts are dependent on many factors, including ambient air and water temperatures, cooling technology, etc. Water demands from most economic sectors are typically highest during summertime. For most systems, this coincides with peak electricity demand and consequently a high demand for thermal power plant cooling water. Supplies however are sometimes limited due to seasonal precipitation fluctuations including sporadic droughts that lead to water scarcity. When this occurs there is an impact on both unit commitments and the real-time dispatch. In this work, we model the cooling efficiency of several different types of thermal power generation technologies as a function of power output level and daily temperature profiles. Unit specific relationships are then integrated in a power grid operational model that minimizes total grid production cost while reliably meeting hourly loads. Grid operation is subject to power plant physical constraints, transmission limitations, water availability and environmental constraints such as power plant water exit temperature limits. The model is applied to a standard IEEE-118 bus system under various water availability scenarios. Results show that water availability has a significant impact on power grid economics.

Trans-Pecos Photovoltaic Concentration Experiment. Final report for Phase-I system design, 6 June 1978-28 February 1979

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

Marcy, W.M.; Dudek, R.A.

1979-03-30

The Trans-Pecos Photovoltaic Concentrating Experiment is the design of a 200 kWe peak photovoltaic concentrating system applied to deep well irrigation in the Trans-Pecos region of Texas. The site selected is typical of deep well irrigation in arid regions of Texas, New Mexico, and Arizona. The existing well utilizes a 200 horse power, three phase, 480 volt induction motor to lift water 540 feet to irrigate 380 acres. The Trans-Pecos Photovoltaic Concentration (PVC) system employs a two axis (azimuth-elevation) tracking parabolic concentrator module that focuses sunlight at 38X concentration on two strings of actively cooled silicon solar cells. The directmore » current from a field of 102 collector modules is converted by a maximum power point electric power conditioning system to three phase alternating current. The power from the power conditioning system is connected through appropriate switchgear in parallel with the utility grid to the well's induction motor. The operational philosophy of the experiment is to displace daytime utility power with solar generated electric power. The solar system is sized to provide approximately 50 percent of the 24 hour energy demand of the motor. This requires an energy exchange with the utility since peak solar power (200 kWe) generated exceeds the peak motor demand (149.2 kWe). The annual energy production is projected to be 511 Mwh using El Paso, Texas solar TMY data. System electrical power production efficiency is projected to be 7.4 percent at the design point, and 7.0 percent on an annual electrical energy production basis. The system is projected to provide 37.8 percent of the 24 hour energy demand of the motor at the design point of March 10, excluding energy delivered to the grid in excess of motor demand. The total energy produced is projected to be 39.0 percent of the 24 hour energy demand of the motor at the design point of March 10.« less

Travel demand forecasting models: a comparison of EMME/2 and QUR II using a real-world network.

DOT National Transportation Integrated Search

2000-10-01

In order to automate the travel demand forecasting process in urban transportation planning, a number of : commercial computer based travel demand forecasting models have been developed, which have provided : transportation planners with powerful and...

Cost analysis of concepts for a demand oriented biogas supply for flexible power generation.

PubMed

Hahn, Henning; Ganagin, Waldemar; Hartmann, Kilian; Wachendorf, Michael

2014-10-01

With the share of intermittent renewable energies within the electricity system rising, balancing services from dispatchable power plants are of increasing importance. Highlighting the importance of the need to keeping fuel costs for flexible power generation to a minimum, the study aims to identify favourable biogas plant configurations, supplying biogas on demand. A cost analysis of five configurations based on biogas storing and flexible biogas production concepts has been carried out. Results show that additional flexibility costs for a biogas supply of 8h per day range between 2€ and 11€MWh(-1) and for a 72h period without biogas demand from 9€ to 19€MWh(-1). While biogas storage concepts were identified as favourable short term supply configurations, flexible biogas production concepts profit from reduced storage requirements at plants with large biogas production capacities or for periods of several hours without biogas demand. Copyright © 2014 Elsevier Ltd. All rights reserved.

An up-link power control for demand assignment International Business Satellite Communications Network

NASA Astrophysics Data System (ADS)

Nohara, Mitsuo; Takeuchi, Yoshio; Takahata, Fumio

Up-link power control (UPC) is one of the essential technologies to provide efficient satellite communication systems operated at frequency bands above 10 GHz. A simple and cost-effective UPC scheme applicable to a demand assignment international business satellite communications system has been developed. This paper presents the UPC scheme, including the hardware implementation and its performance.

Impacts of Rising Air Temperatures and Emissions Mitigation on Electricity Demand and Supply in the United States. A Multi-Model Comparison

DOE PAGES

McFarland, James; Zhou, Yuyu; Clarke, Leon; ...

2015-06-10

The electric power sector both affects and is affected by climate change. Numerous studies highlight the potential of the power sector to reduce greenhouse gas emissions. Fewer studies have explored the physical impacts of climate change on the power sector. Our present analysis examines how projected rising temperatures affect the demand for and supply of electricity. We apply a common set of temperature projections to three well-known electric sector models in the United States: the US version of the Global Change Assessment Model (GCAM-USA), the Regional Electricity Deployment System model (ReEDS), and the Integrated Planning Model (IPM®). Incorporating the effectsmore » of rising temperatures from a control scenario without emission mitigation into the models raises electricity demand by 1.6 to 6.5 % in 2050 with similar changes in emissions. Moreover, the increase in system costs in the reference scenario to meet this additional demand is comparable to the change in system costs associated with decreasing power sector emissions by approximately 50 % in 2050. This result underscores the importance of adequately incorporating the effects of long-run temperature change in climate policy analysis.« less

Perspectives of the electric power industry amid the transforming global power generation markets

NASA Astrophysics Data System (ADS)

Makarov, A. A.; Mitrova, T. A.; Veselov, F. V.; Galkina, A. A.; Kulagin, V. A.

2017-10-01

A scenario-based prognosis of the evolution of global power generation markets until 2040, which was developed using the Scaner model-and-information complex, was given. The perspective development of fuel markets, vital for the power generation industry, was considered, and an attempt to predict the demand, production, and prices of oil, gas, coal, and noncarbon resources across various regions of the world was made. The anticipated decline in the growth of the global demand for fossil fuels and their sufficiency with relatively low extraction expenses will maintain the fuel prices (the data hereinafter are given as per 2014 prices) lower than their peak values in 2012. The outrunning growth of demand for electric power is shown in comparison with other power resources by regions and large countries in the world. The conditions of interfuel competition in the electric power industry considering the changes in anticipated fuel prices and cost indicators for various power generation technologies were studied. For this purpose, the ratios of discounted costs of electric power production by new gas and coal TPPs and wind and solar power plants were estimated. It was proven that accounting the system effects (operation modes, necessary duplicating and reserving the power of electric power plants using renewable energy sources) notably reduces the competitiveness of the renewable power industry and is not always compensated by the expected lowering of its capital intensity and growth of fuel for TPPs. However, even with a moderate (in relation to other prognoses) growth of the role of power plants using renewable energy sources, they will triple electric power production. In this context, thermal power plants will preserve their leadership covering up to 60% of the global electric power production, approximately half using gas.

Scheduling Non-Preemptible Jobs to Minimize Peak Demand

DOE PAGES

Yaw, Sean; Mumey, Brendan

2017-10-28

Our paper examines an important problem in smart grid energy scheduling; peaks in power demand are proportionally more expensive to generate and provision for. The issue is exacerbated in local microgrids that do not benefit from the aggregate smoothing experienced by large grids. Demand-side scheduling can reduce these peaks by taking advantage of the fact that there is often flexibility in job start times. We then focus attention on the case where the jobs are non-preemptible, meaning once started, they run to completion. The associated optimization problem is called the peak demand minimization problem, and has been previously shown tomore » be NP-hard. These results include an optimal fixed-parameter tractable algorithm, a polynomial-time approximation algorithm, as well as an effective heuristic that can also be used in an online setting of the problem. Simulation results show that these methods can reduce peak demand by up to 50% versus on-demand scheduling for household power jobs.« less

Scheduling Non-Preemptible Jobs to Minimize Peak Demand

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

Yaw, Sean; Mumey, Brendan

Our paper examines an important problem in smart grid energy scheduling; peaks in power demand are proportionally more expensive to generate and provision for. The issue is exacerbated in local microgrids that do not benefit from the aggregate smoothing experienced by large grids. Demand-side scheduling can reduce these peaks by taking advantage of the fact that there is often flexibility in job start times. We then focus attention on the case where the jobs are non-preemptible, meaning once started, they run to completion. The associated optimization problem is called the peak demand minimization problem, and has been previously shown tomore » be NP-hard. These results include an optimal fixed-parameter tractable algorithm, a polynomial-time approximation algorithm, as well as an effective heuristic that can also be used in an online setting of the problem. Simulation results show that these methods can reduce peak demand by up to 50% versus on-demand scheduling for household power jobs.« less

Opportunities for ice storage to provide ancillary services to power grids incorporating wind turbine generation

NASA Astrophysics Data System (ADS)

Finley, Christopher

Power generation using wind turbines increases the electrical system balancing, regulation and ramp rate requirements due to the minute to minute variability in wind speed and the difficulty in accurately forecasting wind speeds. The addition of thermal energy storage, such as ice storage, to a building's space cooling equipment increases the operational flexibility of the equipment by allowing the owner to choose when the chiller is run. The ability of the building owner to increase the power demand from the chiller (e.g. make ice) or to decrease the power demand (e.g. melt ice) to provide electrical system ancillary services was evaluated.

The effect of real-time pricing on load shifting in a highly renewable power system dominated by generation from the renewable sources of wind and photovoltaics

NASA Astrophysics Data System (ADS)

Kies, Alexander; Brown, Tom; Schlachtberger, David; Schramm, Stefan

2017-04-01

The supply-demand imbalance is a major concern in the presence of large shares of highly variable renewable generation from sources like wind and photovoltaics (PV) in power systems. Other than the measures on the generation side, such as flexible backup generation or energy storage, sector coupling or demand side management are the most likely option to counter imbalances, therefore to ease the integration of renewable generation. Demand side management usually refers to load shifting, which comprises the reaction of electricity consumers to price fluctuations. In this work, we derive a novel methodology to model the interplay of load shifting and provided incentives via real-time pricing in highly renewable power systems. We use weather data to simulate generation from the renewable sources of wind and photovoltaics, as well as historical load data, split into different consumption categories, such as, heating, cooling, domestic, etc., to model a simplified power system. Together with renewable power forecast data, a simple market model and approaches to incorporate sector coupling [1] and load shifting [2,3], we model the interplay of incentives and load shifting for different scenarios (e.g., in dependency of the risk-aversion of consumers or the forecast horizon) and demonstrate the practical benefits of load shifting. First, we introduce the novel methodology and compare it with existing approaches. Secondly, we show results of numerical simulations on the effects of load shifting: It supports the integration of PV power by providing a storage, which characteristics can be described as "daily" and provides a significant amount of balancing potential. Lastly, we propose an experimental setup to obtain empirical data on end-consumer load-shifting behaviour in response to price incentives. References [1] Brown, T., Schlachtberger, D., Kies. A., Greiner, M., Sector coupling in a highly renewable European energy system, Proc. of the 15th International Workshop on Large-Scale Integration of Wind Power into Power Systems as well as on Transmission Networks for Offshore Wind Power Plants, Vienna, Austria, 15.-17. November 2016 [2] Kleinhans, D.: Towards a systematic characterization of the potential of demand side management, arXiv preprint arXiv:1401.4121, 2014 [3] Kies, A., Schyska, B. U., von Bremen, L., The Demand Side Management Potential to Balance a Highly Renewable European Power System. Energies, 9(11), 955, 2016

Space-based solar power conversion and delivery systems study

NASA Technical Reports Server (NTRS)

1976-01-01

Even at reduced rates of growth, the demand for electric power is expected to more than triple between now and 1995, and to triple again over the period 1995-2020. Without the development of new power sources and advanced transmission technologies, it may not be possible to supply electric energy at prices that are conductive to generalized economic welfare. Solar power is renewable and its conversion and transmission from space may be advantageous. The goal of this study is to assess the economic merit of space-based photovoltaic systems for power generation and a power relay satellite for power transmission. In this study, satellite solar power generation and transmission systems, as represented by current configurations of the Satellite Solar Station (SSPS) and the Power Relay Satellite (PRS), are compared with current and future terrestrial power generation and transmission systems to determine their technical and economic suitability for meeting power demands in the period of 1990 and beyond while meeting ever-increasing environmental and social constraints.

High-quality recording of bioelectric events. Part 2. Low-noise, low-power multichannel amplifier design.

PubMed

Metting van Rijn, A C; Peper, A; Grimbergen, C A

1991-07-01

A multichannel instrumentation amplifier, developed to be used in a miniature universal eight-channel amplifier module, is described. After discussing the specific properties of a bioelectric recording, the difficulties of meeting the demanded specifications with a design based on operational amplifiers are reviewed. Because it proved impossible to achieve the demanded combination of low noise and low power consumption using commercially available operational amplifiers, an amplifier equipped with an input stage with discrete transistors was developed. A new design concept was used to expand the design to a multichannel version with an equivalent input noise voltage of 0.35 microV RMS in a bandwidth of 0.1-100 Hz and a power consumption of 0.6 mW per channel. The results of this study are applied to miniature, universal, eight-channel amplifier modules, manufactured with thick-film production techniques. The modules can be coupled to satisfy the demand for a multiple of eight channels. The low power consumption enables the modules to be used in all kinds of portable and telemetry measurement systems and simplifies the power supply in stationary measurement systems.

Photovoltaic village power application: assessment of the near-term market

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

Rosenblum, L.; Bifano, W.J.; Poley, W.A.

1978-01-01

A preliminary assessment of the near-term market for photovoltaic village power applications is presented. One of the objectives of the Department of Energy's (DOE) National Photovoltaic Program is to stimulate the demand for photovoltaic power systems so that appropriate markets will be developed in the near-term to support the increasing photovoltaic production capacity also being developed by DOE. The village power application represents such a potential market for photovoltaics. The price of energy for photovoltaic systems is compared to that of utility line extensions and diesel generators. The potential ''domestic''' demand (including the 50 states of the union plus themore » areas under legal control of the U.S. government) is defined in both the goverment and commercial sectors. The foreign demand and sources of funding for village power systems in the developing countries are also discussed briefly. It is concluded that a near-term domestic market of at least 12 MW (peak) and a foreign market of about 10 GW (peak) exists and that significant market penetration should be possible beginning in the 1981--82 period.« less

Coordinated control of micro-grid based on distributed moving horizon control.

PubMed

Ma, Miaomiao; Shao, Liyang; Liu, Xiangjie

2018-05-01

This paper proposed the distributed moving horizon coordinated control scheme for the power balance and economic dispatch problems of micro-grid based on distributed generation. We design the power coordinated controller for each subsystem via moving horizon control by minimizing a suitable objective function. The objective function of distributed moving horizon coordinated controller is chosen based on the principle that wind power subsystem has the priority to generate electricity while photovoltaic power generation coordinates with wind power subsystem and the battery is only activated to meet the load demand when necessary. The simulation results illustrate that the proposed distributed moving horizon coordinated controller can allocate the output power of two generation subsystems reasonably under varying environment conditions, which not only can satisfy the load demand but also limit excessive fluctuations of output power to protect the power generation equipment. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

A Comprehensive Study of the Tocks Island Lake Project and Alternatives. Part A. Chapters I, II, III. Analysis of Service Areas and Resource Needs.

DTIC Science & Technology

1975-06-01

Conventional Hydroelectric and Pumped Storage Power XI- 49 2. Electric Power Demand XI- 53 3. Water Demand by Power Plants XI- 54 4. Fossil and Nuclear ...Systems and Temporary Evacuation XV- 32 12. Upstream Land Use and Agricultural Treatment XV- 32 13. Results and Criteria for Further Analysis XV- 33... resulted in record flows and significant flooding. The August, 1955, flood was a result of Hurricanes Connie and Diane. Northern New Jersey streams have had

Hydrogen use projections and supply options

NASA Technical Reports Server (NTRS)

Manvi, R.; Fujita, T.

1976-01-01

Reference and expanded use projections were developed to estimate future hydrogen demand. The rationale in the development of these projections, which estimate the growth of hydrogen usage of approximately 1 X 10 to the fifteenth power Btu in 1973 to approximately 5.5 X 10 to the fifteenth power for reference use and 22 X 10 to the fifteenth power Btu for expanded use projections in year 2000. Primary energy sources required to produce these demands are discussed in the light of transition from a low merchant to high merchant supply option.

Automated Demand Response Approaches to Household Energy Management in a Smart Grid Environment

NASA Astrophysics Data System (ADS)

Adika, Christopher Otieno

The advancement of renewable energy technologies and the deregulation of the electricity market have seen the emergence of Demand response (DR) programs. Demand response is a cost-effective load management strategy which enables the electricity suppliers to maintain the integrity of the power grid during high peak periods, when the customers' electrical load is high. DR programs are designed to influence electricity users to alter their normal consumption patterns by offering them financial incentives. A well designed incentive-based DR scheme that offer competitive electricity pricing structure can result in numerous benefits to all the players in the electricity market. Lower power consumption during peak periods will significantly enhance the robustness of constrained networks by reducing the level of power of generation and transmission infrastructure needed to provide electric service. Therefore, this will ease the pressure of building new power networks as we avoiding costly energy procurements thereby translating into huge financial savings for the power suppliers. Peak load reduction will also reduce the inconveniences suffered by end users as a result of brownouts or blackouts. Demand response will also drastically lower the price peaks associated with wholesale markets. This will in turn reduce the electricity costs and risks for all the players in the energy market. Additionally, DR is environmentally friendly since it enhances the flexibility of the power grid through accommodation of renewable energy resources. Despite its many benefits, DR has not been embraced by most electricity networks. This can be attributed to the fact that the existing programs do not provide enough incentives to the end users and, therefore, most electricity users are not willing to participate in them. To overcome these challenges, most utilities are coming up with innovative strategies that will be more attractive to their customers. Thus, this dissertation presents various demand response schemes that can be deployed by electricity providers to manage customer loads. This study also addresses the problem of manual demand response by proposing smart systems that will autonomously execute the DR programs without the direct involvement of the customers.

Optimal Coordination of Building Loads and Energy Storage for Power Grid and End User Services

DOE PAGES

Hao, He; Wu, Di; Lian, Jianming; ...

2017-01-18

Demand response and energy storage play a profound role in the smart grid. The focus of this study is to evaluate benefits of coordinating flexible loads and energy storage to provide power grid and end user services. We present a Generalized Battery Model (GBM) to describe the flexibility of building loads and energy storage. An optimization-based approach is proposed to characterize the parameters (power and energy limits) of the GBM for flexible building loads. We then develop optimal coordination algorithms to provide power grid and end user services such as energy arbitrage, frequency regulation, spinning reserve, as well as energymore » cost and demand charge reduction. Several case studies have been performed to demonstrate the efficacy of the GBM and coordination algorithms, and evaluate the benefits of using their flexibility for power grid and end user services. We show that optimal coordination yields significant cost savings and revenue. Moreover, the best option for power grid services is to provide energy arbitrage and frequency regulation. Finally and furthermore, when coordinating flexible loads with energy storage to provide end user services, it is recommended to consider demand charge in addition to time-of-use price in order to flatten the aggregate power profile.« less

18 CFR 1301.55 - Responding to demands.

Code of Federal Regulations, 2010 CFR

2010-04-01

... information to be withheld. (c) Factors to be considered in determining whether requested testimony or records... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Responding to demands... Proceedings § 1301.55 Responding to demands. Generally, authorization to provide the requested material or...

Projected electric power demands for the Potomac Electric Power Company. Volume 1

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

Estomin, S.; Kahal, M.

1984-03-01

This three-volume report presents the results of an econometric forecast of peak and electric power demands for the Potomac Electric Power Company (PEPCO) through the year 2002. Volume I describes the methodology, the results of the econometric estimations, the forecast assumptions and the calculated forecasts of peak demand and energy usage. Separate sets of models were developed for the Maryland Suburbs (Montgomery and Prince George's counties), the District of Columbia and Southern Maryland (served by a wholesale customer of PEPCO). For each of the three jurisdictions, energy equations were estimated for residential and commercial/industrial customers for both summer and wintermore » seasons. For the District of Columbia, summer and winter equations for energy sales to the federal government were also estimated. Equations were also estimated for street lighting and energy losses. Noneconometric techniques were employed to forecast energy sales to the Northern Virginia suburbs, Metrorail and federal government facilities located in Maryland.« less

Analysis of Time-of-Day Energy Demand and Supply in University and Hospital

NASA Astrophysics Data System (ADS)

Shimazaki, Yoichi

The aim of this study was to estimate the time-of-day energy demand in University of Yamanashi. Our University consisted of Kofu campus (Faculty of Education & Human Sciences and Faculty of Engineering) and Faculty of Medicine campus (Faculty of Medicine and University Hospital). The energy data of 4 facilities were classified into hot water, heating, cooling and electric power demands based on electric power consumptions, city gas and heavy oil from 1996 to 2005. For 10 years, primary energy increased 1.2 times in the whole of the university. The amount of electric power consumption was 63% in the fuel classification. The amount of electric power consumption of faculty reacted to the change in temperature greatly. In 2005, it was found that thermoelectric-ratios for 4 facilities, i.e. Education, Engineering, Medicine and Hospital were 2.3, 1.5, 2.0 and 2.7 respectively. These data are very useful for the energy saving and energy management of university.

Systems and methods for energy cost optimization in a building system

DOEpatents

Turney, Robert D.; Wenzel, Michael J.

2016-09-06

Methods and systems to minimize energy cost in response to time-varying energy prices are presented for a variety of different pricing scenarios. A cascaded model predictive control system is disclosed comprising an inner controller and an outer controller. The inner controller controls power use using a derivative of a temperature setpoint and the outer controller controls temperature via a power setpoint or power deferral. An optimization procedure is used to minimize a cost function within a time horizon subject to temperature constraints, equality constraints, and demand charge constraints. Equality constraints are formulated using system model information and system state information whereas demand charge constraints are formulated using system state information and pricing information. A masking procedure is used to invalidate demand charge constraints for inactive pricing periods including peak, partial-peak, off-peak, critical-peak, and real-time.

Electric power supply and demand for the contiguous United States, 1981 - 1990

NASA Astrophysics Data System (ADS)

1981-07-01

The outlook for electric power supply and demand in the United States decade 1981 to 1990 is reviewed from the perspective of reliability and adequacy of service. Electric power supply adequacy as projected for the nine Regional Reliability Council areas of the contiguous United States is reported as well as interruptible load data reported by the Councils. cogeneration is discussed. Each of the 27 electric regions (sub-areas of the nine Council areas) in the contiguous US are studied. A glossary of terms is given. Appendices describe the Council structure, and include a copy of the ERA-411 Manual, which contains all the items to which the Councils were asked to respond. The utilities with included data, the Staff Report, Estimated Electric Demand and Supply for Summer 1981, Contiguous United States dated May 1981 are included.

Power monitoring and control for large scale projects: SKA, a case study

NASA Astrophysics Data System (ADS)

Barbosa, Domingos; Barraca, João. Paulo; Maia, Dalmiro; Carvalho, Bruno; Vieira, Jorge; Swart, Paul; Le Roux, Gerhard; Natarajan, Swaminathan; van Ardenne, Arnold; Seca, Luis

2016-07-01

Large sensor-based science infrastructures for radio astronomy like the SKA will be among the most intensive datadriven projects in the world, facing very high demanding computation, storage, management, and above all power demands. The geographically wide distribution of the SKA and its associated processing requirements in the form of tailored High Performance Computing (HPC) facilities, require a Greener approach towards the Information and Communications Technologies (ICT) adopted for the data processing to enable operational compliance to potentially strict power budgets. Addressing the reduction of electricity costs, improve system power monitoring and the generation and management of electricity at system level is paramount to avoid future inefficiencies and higher costs and enable fulfillments of Key Science Cases. Here we outline major characteristics and innovation approaches to address power efficiency and long-term power sustainability for radio astronomy projects, focusing on Green ICT for science and Smart power monitoring and control.

Power combining of semiconductor lasers: A review

NASA Technical Reports Server (NTRS)

Katz, J.

1982-01-01

Several methods of coherent power combining are described and compared. A comparison is also made between coherent and incoherent power combining, and important operational characteristics are considered. It is found that in communication links with demanding requirements coherent power combining is necessary.

An Economic Evalution of Demand-side Energy Storage Systems by using a Multi-agent based Electricity Market

NASA Astrophysics Data System (ADS)

Furusawa, Ken; Sugihara, Hideharu; Tsuji, Kiichiro

Opened wholesale electric power market in April 2005, deregulation of electric power industry in Japan has faced a new competitive environment. In the new environment, Independent Power Producer (: IPP), Power Producer and Supplier (: PPS), Load Service Entity (: LSE) and electric utility can trade electric energy through both bilateral contracts and single-price auction at the electricity market. In general, the market clearing price (: MCP) is largely changed by amount of total load demand in the market. The influence may cause price spike, and consequently the volatility of MCP will make LSEs and their customers to face a risk of revenue and cost. DSM is attracted as a means of load leveling, and has effect on decreasing MCP at peak load period. Introducing Energy Storage systems (: ES) is one of DSM in order to change demand profile at customer-side. In case that customers decrease their own demand at jumped MCP, a bidding strategy of generating companies may be changed their strategy. As a result, MCP is changed through such complex mechanism. In this paper the authors evaluate MCP by multi-agent. It is considered that customer-side ES has an effect on MCP fluctuation. Through numerical examples, this paper evaluates the influence on MCP by controlling customer-side ES corresponding to variation of MCP.

Drought and the water-energy nexus in Texas

NASA Astrophysics Data System (ADS)

Scanlon, Bridget R.; Duncan, Ian; Reedy, Robert C.

2013-12-01

Texas experienced the most extreme drought on record in 2011 with up to 100 days of triple digit temperatures resulting in record electricity demand and historically low reservoir levels. We quantified water and electricity demand and supply for each power plant during the drought relative to 2010 (baseline). Drought raised electricity demands/generation by 6%, increasing water demands/consumption for electricity by 9%. Reductions in monitored reservoir storage <50% of capacity in 2011 would suggest drought vulnerability, but data show that the power plants were flexible enough at the plant level to adapt by switching to less water-intensive technologies. Natural gas, now ˜50% of power generation in Texas, enhances drought resilience by increasing the flexibility of power plant generators, including gas combustion turbines to complement increasing wind generation and combined cycle generators with ˜30% of cooling water requirements of traditional steam turbine plants. These reductions in water use are projected to continue to 2030 with increased use of natural gas and renewables. Although water use for gas production is controversial, these data show that water saved by using natural gas combined cycle plants relative to coal steam turbine plants is 25-50 times greater than the amount of water used in hydraulic fracturing to extract the gas.

Research on the EDM Technology for Micro-holes at Complex Spatial Locations

NASA Astrophysics Data System (ADS)

Y Liu, J.; Guo, J. M.; Sun, D. J.; Cai, Y. H.; Ding, L. T.; Jiang, H.

2017-12-01

For the demands on machining micro-holes at complex spatial location, several key technical problems are conquered such as micro-Electron Discharge Machining (micro-EDM) power supply system’s development, the host structure’s design and machining process technical. Through developing low-voltage power supply circuit, high-voltage circuit, micro and precision machining circuit and clearance detection system, the narrow pulse and high frequency six-axis EDM machining power supply system is developed to meet the demands on micro-hole discharging machining. With the method of combining the CAD structure design, CAE simulation analysis, modal test, ODS (Operational Deflection Shapes) test and theoretical analysis, the host construction and key axes of the machine tool are optimized to meet the position demands of the micro-holes. Through developing the special deionized water filtration system to make sure that the machining process is stable enough. To verify the machining equipment and processing technical developed in this paper through developing the micro-hole’s processing flow and test on the real machine tool. As shown in the final test results: the efficient micro-EDM machining pulse power supply system, machine tool host system, deionized filtration system and processing method developed in this paper meet the demands on machining micro-holes at complex spatial locations.

Ideology, Economics and Reader Demand in Soviet Publishing

ERIC Educational Resources Information Center

Walker, G. P. M.

1978-01-01

Examines some of the important assumptions and disputes about publishing as an industry: demand and pricing; profit and subsidy; quality, effectiveness and "optimality"; and the power of the reader. (Author)

The design of optimal electric power demand management contracts

NASA Astrophysics Data System (ADS)

Fahrioglu, Murat

1999-11-01

Our society derives a quantifiable benefit from electric power. In particular, forced outages or blackouts have enormous consequences on society, one of which is loss of economic surplus. Electric utilities try to provide reliable supply of electric power to their customers. Maximum customer benefit derives from minimum cost and sufficient supply availability. Customers willing to share in "availability risk" can derive further benefit by participating in controlled outage programs. Specifically, whenever utilities foresee dangerous loading patterns, there is a need for a rapid reduction in demand either system-wide or at specific locations. The utility needs to get relief in order to solve its problems quickly and efficiently. This relief can come from customers who agree to curtail their loads upon request in exchange for an incentive fee. This thesis shows how utilities can get efficient load relief while maximizing their economic benefit. This work also shows how estimated customer cost functions can be calibrated, using existing utility data, to help in designing efficient demand management contracts. In order to design such contracts, optimal mechanism design is adopted from "Game Theory" and applied to the interaction between a utility and its customers. The idea behind mechanism design is to design an incentive structure that encourages customers to sign up for the right contract and reveal their true value of power. If a utility has demand management contracts with customers at critical locations, most operational problems can be solved efficiently. This thesis illustrates how locational attributes of customers incorporated into demand management contract design can have a significant impact in solving system problems. This kind of demand management contracts can also be used by an Independent System Operator (ISO). During times of congestion a loss of economic surplus occurs. When the market is too slow or cannot help relieve congestion, demand management can help solve the problem. Another tool the ISO requires for security purposes is reserves. Even though demand management contracts may not be a good substitute for spinning reserves, they are adequate to augment or replace supplemental and backup reserves.

Integrated power sector efficiency analysis: A case study of Costa Rica

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

Waddle, D.B.; MacDonald, J.M.

1990-03-01

In an effort to analyze and document the potential for power sector efficiency improvements from generation to end-use, the Agency for International Development and the Government of Costa Rica are jointly conducting an integrated power sector efficiency analysis. Potential for energy and cost savings in power plants, transmission and distribution, and demand-side management programs are being evaluated. The product of this study will be an integrated investment plan for the Instituto Costarricense de Electricidad, incorporating both supply and demand side investment options. This paper presents the methodology employed in the study, as well as preliminary estimates of the results ofmore » the study. 14 refs., 2 figs., 5 tabs.« less

Design of demand side response model in energy internet demonstration park

NASA Astrophysics Data System (ADS)

Zhang, Q.; Liu, D. N.

2017-08-01

The implementation of demand side response can bring a lot of benefits to the power system, users and society, but there are still many problems in the actual operation. Firstly, this paper analyses the current situation and problems of demand side response. On this basis, this paper analyses the advantages of implementing demand side response in the energy Internet demonstration park. Finally, the paper designs three kinds of feasible demand side response modes in the energy Internet demonstration park.

Electric power market agent design

NASA Astrophysics Data System (ADS)

Oh, Hyungseon

The electric power industry in many countries has been restructured in the hope of a more economically efficient system. In the restructured system, traditional operating and planning tools based on true marginal cost do not perform well since information required is strictly confidential. For developing a new tool, it is necessary to understand offer behavior. The main objective of this study is to create a new tool for power system planning. For the purpose, this dissertation develops models for a market and market participants. A new model is developed in this work for explaining a supply-side offer curve, and several variables are introduced to characterize the curve. Demand is estimated using a neural network, and a numerical optimization process is used to determine the values of the variables that maximize the profit of the agent. The amount of data required for the optimization is chosen with the aid of nonlinear dynamics. To suggest an optimal demand-side bidding function, two optimization problems are constructed and solved for maximizing consumer satisfaction based on the properties of two different types of demands: price-based demand and must-be-served demand. Several different simulations are performed to test how an agent reacts in various situations. The offer behavior depends on locational benefit as well as the offer strategies of competitors.

A study on economic power dispatch grid connected PV power plant in educational institutes

NASA Astrophysics Data System (ADS)

Singh, Kuldip; Kumar, M. Narendra; Mishra, Satyasis

2018-04-01

India has main concerns on environment and escalation of fuel prices with respect to diminution of fossil fuel reserves and the major focus on renewable Energy sources for power generation to fulfill the present and future energy demand. Installation of PV power plants in the Educational Institutions has grown up drastically throughout India. More PV power plant are integrated with load and grid through net metering. Therefore, this paper is an analysis of the 75kWp PV plant at chosen buses, considering the need of minimum demand from the grid. The case study is carried out for different generation level throughout the day and year w.r.t load and climate changes, load sharing on grid. The economic dispatch model developed for PV plant integrated with Grid.

Water Use in the US Electric Power Sector: Energy Systems ...

EPA Pesticide Factsheets

This presentation reviews the water demands of long-range electricity scenarios. It addresses questions such as: What are the aggregate water requirements of the U.S. electric power sector? How could water requirements evolve under different long-range regional generation mixes? It also looks at research addressing the electricity generation water demand from a life cycle perspective, such as water use for the fuel cycle (natural gas, coal, uranium, etc.) and water use for the materials/equipment/manufacturing of new power plants. The presentation is part of panel session on the Water-Energy Nexus at the World Energy Engineering Congress

Response to the Directorate of Health Care Studies and Clinical Investigations Final Report (Revised) Assessing Power Analysis Approaches for the Fort Bragg Evaluation Project

DTIC Science & Technology

1993-07-28

Below is a summary of Vanderbilt’s response, requested by Health Services Command ( HSC ), to the final report prepared by the Directorate of Health Care...Command’s ( HSC ) demands for client data it sought to use somehow in power analysis (see Appendix F). Dr. Kapadia’s statement is the standard view held...not involve actual data, the results from this method may be entirely misleading and not accurate." When HSC demanded client data for power analysis in

Opportunistic Wireless Charging System Design for an On-Demand Shuttle Service

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

Meintz, Andrew; Doubleday, Kate; Markel, Tony

System right-sizing is critical to the implementation of in-motion wireless power transfer (WPT) for electric vehicles. This study evaluates potential system designs for an on-demand employee shuttle by determining the required battery size based on the rated power at a variable number of charging locations. Vehicle power and state of charge are simulated over the drive cycle, based on position and velocity data at every second from the existing shuttle. Adding just one WPT location can halve the battery size. Many configurations are capable of self-sustaining with WPT, while others benefit from supplemental stationary charging.

Scenarios for Low Carbon and Low Water Electric Power Plant Operations: Implications for Upstream Water Use.

PubMed

Dodder, Rebecca S; Barnwell, Jessica T; Yelverton, William H

2016-11-01

Electric sector water use, in particular for thermoelectric operations, is a critical component of the water-energy nexus. On a life cycle basis per unit of electricity generated, operational (e.g., cooling system) water use is substantially higher than water demands for the fuel cycle (e.g., natural gas and coal) and power plant manufacturing (e.g., equipment and construction). However, could shifting toward low carbon and low water electric power operations create trade-offs across the electricity life cycle? We compare business-as-usual with scenarios of carbon reductions and water constraints using the MARKet ALlocation (MARKAL) energy system model. Our scenarios show that, for water withdrawals, the trade-offs are minimal: operational water use accounts for over 95% of life cycle withdrawals. For water consumption, however, this analysis identifies potential trade-offs under some scenarios. Nationally, water use for the fuel cycle and power plant manufacturing can reach up to 26% of the total life cycle consumption. In the western United States, nonoperational consumption can even exceed operational demands. In particular, water use for biomass feedstock irrigation and manufacturing/construction of solar power facilities could increase with high deployment. As the United States moves toward lower carbon electric power operations, consideration of shifting water demands can help avoid unintended consequences.

Nutrition for power sports: middle-distance running, track cycling, rowing, canoeing/kayaking, and swimming.

PubMed

Stellingwerff, Trent; Maughan, Ronald J; Burke, Louise M

2011-01-01

Contemporary training for power sports involves diverse routines that place a wide array of physiological demands on the athlete. This requires a multi-faceted nutritional strategy to support both general training needs--tailored to specific training phases--as well as the acute demands of competition. Elite power sport athletes have high training intensities and volumes for most of the training season, so energy intake must be sufficient to support recovery and adaptation. Low pre-exercise muscle glycogen reduces high-intensity performance, so daily carbohydrate intake must be emphasized throughout training and competition phases. There is strong evidence to suggest that the timing, type, and amount of protein intake influence post-exercise recovery and adaptation. Most power sports feature demanding competition schedules, which require aggressive nutritional recovery strategies to optimize muscle glycogen resynthesis. Various power sports have different optimum body compositions and body weight requirements, but increasing the power-to-weight ratio during the championship season can lead to significant performance benefits for most athletes. Both intra- and extracellular buffering agents may enhance performance, but more research is needed to examine the potential long-term impact of buffering agents on training adaptation. Interactions between training, desired physiological adaptations, competition, and nutrition require an individual approach and should be continuously adjusted and adapted.

Fuel-cell based power generating system having power conditioning apparatus

DOEpatents

Mazumder, Sudip K.; Pradhan, Sanjaya K.

2010-10-05

A power conditioner includes power converters for supplying power to a load, a set of selection switches corresponding to the power converters for selectively connecting the fuel-cell stack to the power converters, and another set of selection switches corresponding to the power converters for selectively connecting the battery to the power converters. The power conveners output combined power that substantially optimally meets a present demand of the load.

Opportunity for offshore wind to reduce future demand for coal-fired power plants in China with consequent savings in emissions of CO2.

PubMed

Lu, Xi; McElroy, Michael B; Chen, Xinyu; Kang, Chongqing

2014-12-16

Although capacity credits for wind power have been embodied in power systems in the U.S. and Europe, the current planning framework for electricity in China continues to treat wind power as a nondispatchable source with zero contribution to firm capacity. This study adopts a rigorous reliability model for the electric power system evaluating capacity credits that should be recognized for offshore wind resources supplying power demands for Jiangsu, China. Jiangsu is an economic hub located in the Yangtze River delta accounting for 10% of the total electricity consumed in China. Demand for electricity in Jiangsu is projected to increase from 331 TWh in 2009 to 800 TWh by 2030. Given a wind penetration level of 60% for the future additional Jiangsu power supply, wind resources distributed along the offshore region of five coastal provinces in China (Shandong, Jiangsu, Shanghai, Zhejiang, and Fujian) should merit a capacity credit of 12.9%, the fraction of installed wind capacity that should be recognized to displace coal-fired systems without violating the reliability standard. In the high-coal-price scenario, with 60% wind penetration, reductions in CO2 emissions relative to a business as usual reference could be as large as 200.2 million tons of CO2 or 51.8% of the potential addition, with a cost for emissions avoided of $29.0 per ton.

Load-Following Power Timeline Analyses for the International Space Station

NASA Technical Reports Server (NTRS)

Fincannon, James; Delleur, Ann; Green, Robert; Hojnicki, Jeffrey

1996-01-01

Spacecraft are typically complex assemblies of interconnected systems and components that have highly time-varying thermal communications, and power requirements. It is essential that systems designers be able to assess the capability of the spacecraft to meet these requirements which should represent a realistic projection of demand for these resources once the vehicle is on-orbit. To accomplish the assessment from the power standpoint, a computer code called ECAPS has been developed at NASA Lewis Research Center that performs a load-driven analysis of a spacecraft power system given time-varying distributed loading and other mission data. This program is uniquely capable of synthesizing all of the changing spacecraft conditions into a single, seamless analysis for a complete mission. This paper presents example power load timelines with which numerous data are integrated to provide a realistic assessment of the load-following capabilities of the power system. Results of analyses show how well the power system can meet the time-varying power resource demand.

The SCARLET{trademark} array for high power GEO satellites

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

Spence, B.R.; Jones, P.A.; Eskenazi, M.I.

1997-12-31

The GEO satellite market is demanding increasingly capable spacecraft which, in turn, drives commercial spacecraft manufacturers to require significantly higher power solar arrays. As satellite capability increases the demand for high power array systems which are both cost and performance competitive becomes more crucial. Conventional rigid panel planar arrays, although suitable in the past, negatively impact spacecraft competitiveness for these new applications. The Solar Concentrator Array with Refractive Linear Element Technology (SCARLET{trademark}) represents an economically attractive solution for meeting these new high power requirements. When compared to conventional planar arrays, SCARLET provides substantially lower cost and higher deployed stiffness, competitivemore » mass, better producibility, and affordable use of high efficiency multijunction cells. This paper compares cost/performance characteristics of the SCARLET array to conventional planar arrays for high power GEO spacecraft applications. High power SCARLET array configurations are described, and inherent spacecraft and array level cost/performance benefits are presented.« less

The equal load-sharing model of cascade failures in power grids

NASA Astrophysics Data System (ADS)

Scala, Antonio; De Sanctis Lucentini, Pier Giorgio

2016-11-01

Electric power-systems are one of the most important critical infrastructures. In recent years, they have been exposed to extreme stress due to the increasing power demand, the introduction of distributed renewable energy sources, and the development of extensive interconnections. We investigate the phenomenon of abrupt breakdown of an electric power-system under two scenarios: load growth (mimicking the ever-increasing customer demand) and power fluctuations (mimicking the effects of renewable sources). Our results indicate that increasing the system size causes breakdowns to become more abrupt; in fact, mapping the system to a solvable statistical-physics model indicates the occurrence of a first order transition in the large size limit. Such an enhancement for the systemic risk failures (black-outs) with increasing network size is an effect that should be considered in the current projects aiming to integrate national power-grids into ;super-grids;.

Grid-Tied Photovoltaic Power System

NASA Technical Reports Server (NTRS)

Eichenberg, Dennis J.

2011-01-01

A grid-tied photovoltaic (PV) power system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility. Operating costs of a PV power system are low compared to conventional power technologies. This method can displace the highest-cost electricity during times of peak demand in most climatic regions, and thus reduce grid loading. Net metering is often used, in which independent power producers such as PV power systems are connected to the utility grid via the customers main service panels and meters. When the PV power system is generating more power than required at that location, the excess power is provided to the utility grid. The customer pays the net of the power purchased when the on-site power demand is greater than the onsite power production, and the excess power is returned to the utility grid. Power generated by the PV system reduces utility demand, and the surplus power aids the community. Modern PV panels are readily available, reliable, efficient, and economical, with a life expectancy of at least 25 years. Modern electronics have been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy equal to the modern PV panels. The grid-tied PV power system was successfully designed and developed, and this served to validate the basic principles developed, and the theoretical work that was performed. Grid-tied PV power systems are reliable, maintenance- free, long-life power systems, and are of significant value to NASA and the community. Of particular value are the analytical tools and capabilities that have been successfully developed. Performance predictions can be made confidently for grid-tied PV systems of various scales. The work was done under the NASA Hybrid Power Management (HPM) Program, which is the integration of diverse power devices in an optimal configuration for space and terrestrial applications.

Metabolic Power Requirement of Change of Direction Speed in Young Soccer Players: Not All Is What It Seems

PubMed Central

Mendez-Villanueva, Alberto; Palazzi, Dino; Ahmaidi, Saïd

2016-01-01

Purpose The aims of this study were to 1) compare the metabolic power demand of straight-line and change of direction (COD) sprints including 45° or 90°-turns, and 2) examine the relation between estimated metabolic demands and muscular activity throughout the 3 phases of COD-sprints. Methods Twelve highly-trained soccer players performed one 25-m and three 20-m sprints, either in straight-line or with one 45°- or 90°-COD. Sprints were monitored with 2 synchronized 100-Hz laser guns to assess players’ velocities before, during and after the COD. Acceleration and deceleration were derived from changes in speed over time. Metabolic power was estimated based on di Prampero’s approach (2005). Electromyography amplitude (RMS) of 2 lower limb muscles was measured. The expected energy expenditure during time-adjusted straight-line sprints (matching COD sprints time) was also calculated. Results Locomotor-dependant metabolic demand was largely lower with COD (90°, 142.1±13.5 J.kg-1) compared with time-adjusted (effect size, ES = -3.0; 193.2±18.6 J.kg-1) and non-adjusted straight-line sprints (ES = -1.7; 168.4±15.3 J.kg-1). Metabolic power requirement was angle-dependent, moderately lower for 90°-COD vs. 45°-COD sprint (ES = -1.0; 149.5±10.4 J.kg-1). Conversely, the RMS was slightly- (45°, ES = +0.5; +2.1%, 90% confidence limits (±3.6) for vastus lateralis muscle (VL)) to-largely (90°, ES = +1.6; +6.1 (3.3%) for VL) greater for COD-sprints. Metabolic power/RMS ratio was 2 to 4 times lower during deceleration than acceleration phases. Conclusion Present results show that COD-sprints are largely less metabolically demanding than linear sprints. This may be related to the very low metabolic demand associated with the deceleration phase during COD-sprints that may not be compensated by the increased requirement of the reacceleration phase. These results also highlight the dissociation between metabolic and muscle activity demands during COD-sprints, which questions the use of metabolic power as a single measure of running load in soccer. PMID:26930649

75 FR 8895 - Basin Electric Power Cooperative: Deer Creek Station

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-26

.... The purpose of the proposed Project is to help serve increased load demand for electric power in the... Basin Electric Power Cooperative: Deer Creek Station AGENCY: Rural Utilities Service, USDA. ACTION...) and the Western Area Power Administration (Western) have issued a Draft Environmental Impact Statement...

A statistical analysis of energy and power demand for the tractive purposes of an electric vehicle in urban traffic - an analysis of a short and long observation period

NASA Astrophysics Data System (ADS)

Slaski, G.; Ohde, B.

2016-09-01

The article presents the results of a statistical dispersion analysis of an energy and power demand for tractive purposes of a battery electric vehicle. The authors compare data distribution for different values of an average speed in two approaches, namely a short and long period of observation. The short period of observation (generally around several hundred meters) results from a previously proposed macroscopic energy consumption model based on an average speed per road section. This approach yielded high values of standard deviation and coefficient of variation (the ratio between standard deviation and the mean) around 0.7-1.2. The long period of observation (about several kilometers long) is similar in length to standardized speed cycles used in testing a vehicle energy consumption and available range. The data were analysed to determine the impact of observation length on the energy and power demand variation. The analysis was based on a simulation of electric power and energy consumption performed with speed profiles data recorded in Poznan agglomeration.

Contribution of Road Grade to the Energy Use of Modern Automobiles Across Large Datasets of Real-World Drive Cycles: Preprint

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

Wood, E.; Burton, E.; Duran, A.

Understanding the real-world power demand of modern automobiles is of critical importance to engineers using modeling and simulation to inform the intelligent design of increasingly efficient powertrains. Increased use of global positioning system (GPS) devices has made large scale data collection of vehicle speed (and associated power demand) a reality. While the availability of real-world GPS data has improved the industry's understanding of in-use vehicle power demand, relatively little attention has been paid to the incremental power requirements imposed by road grade. This analysis quantifies the incremental efficiency impacts of real-world road grade by appending high fidelity elevation profiles tomore » GPS speed traces and performing a large simulation study. Employing a large real-world dataset from the National Renewable Energy Laboratory's Transportation Secure Data Center, vehicle powertrain simulations are performed with and without road grade under five vehicle models. Aggregate results of this study suggest that road grade could be responsible for 1% to 3% of fuel use in light-duty automobiles.« less

A Multiagent Energy Management System for a Small Microgrid Equipped with Power Sources and Energy Storage Units

NASA Astrophysics Data System (ADS)

Radziszewska, Weronika; Nahorski, Zbigniew

An Energy Management System (EMS) for a small microgrid is presented, with both demand and production side management. The microgrid is equipped with renewable and controllable power sources (like a micro gas turbine), energy storage units (batteries and flywheels). Energy load is partially scheduled to avoid extreme peaks of power demand and to possibly match forecasted energy supply from the renewable power sources. To balance the energy in the network on line, a multiagent system is used. Intelligent agents of each device are proactively acting towards balancing the energy in the network, and at the same time optimizing the cost of operation of the whole system. A semi-market mechanism is used to match a demand and a production of the energy. Simulations show that the time of reaching a balanced state does not exceed 1 s, which is fast enough to let execute proper balancing actions, e.g. change an operating point of a controllable energy source. Simulators of sources and consumption devices were implemented in order to carry out exhaustive tests.

Demand Response For Power System Reliability: FAQ

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

Kirby, Brendan J

2006-12-01

Demand response is the most underutilized power system reliability resource in North America. Technological advances now make it possible to tap this resource to both reduce costs and improve. Misconceptions concerning response capabilities tend to force loads to provide responses that they are less able to provide and often prohibit them from providing the most valuable reliability services. Fortunately this is beginning to change with some ISOs making more extensive use of load response. This report is structured as a series of short questions and answers that address load response capabilities and power system reliability needs. Its objective is tomore » further the use of responsive load as a bulk power system reliability resource in providing the fastest and most valuable ancillary services.« less

Analysis of power sector efficiency improvements for an integrated utility planning process in Costa Rica

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

Waddle, D.B.; MacDonald, J.M.

1990-01-01

In an effort to analyze and document the potential for power sector efficiency improvements from generation to end-use, the Agency for International Development and the Government of Costa Rica are jointly conducting an integrated power sector efficiency analysis. Potential for energy and cost savings in power plants, transmission and distribution, and demand-side management programs are being evaluated. The product of this study will be an integrated investment plan for the Instituto Costarricense de Electricidad, incorporating both supply and demand side investment options. This paper presents the methodology employed in the study, as well as preliminary estimates of the results ofmore » the study. 14 refs., 4 figs., 5 tabs.« less

Short-term electric power demand forecasting based on economic-electricity transmission model

NASA Astrophysics Data System (ADS)

Li, Wenfeng; Bai, Hongkun; Liu, Wei; Liu, Yongmin; Wang, Yubin Mao; Wang, Jiangbo; He, Dandan

2018-04-01

Short-term electricity demand forecasting is the basic work to ensure safe operation of the power system. In this paper, a practical economic electricity transmission model (EETM) is built. With the intelligent adaptive modeling capabilities of Prognoz Platform 7.2, the econometric model consists of three industrial added value and income levels is firstly built, the electricity demand transmission model is also built. By multiple regression, moving averages and seasonal decomposition, the problem of multiple correlations between variables is effectively overcome in EETM. The validity of EETM is proved by comparison with the actual value of Henan Province. Finally, EETM model is used to forecast the electricity consumption of the 1-4 quarter of 2018.

Major challenges loom for natural gas industry, study says

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

O'Driscoll, M.

The 1994 edition of Natural Gas Trends, the annual joint study by Cambridge Energy Research Associates and Arthur Anderson Co., says that new oil-to-gas competition, price risks and the prospect of unbundling for local distribution companies loom as major challenges for the natural gas industry. With a tighter supply-demand balance in the past two years compounded by the fall in oil prices, gas is in head-to-head competition with oil for marginal markets, the report states. And with higher gas prices in 1993, industrial demand growth slowed while utility demand for gas fell. Some of this was related to fuel switching,more » particularly in the electric utility sector. Total electric power demand for gas has risen slightly due to the growth in industrial power generation, but there has yet to be a pronounced surge in gas use during the 1990s - a decade in which many had expected gas to make major inroads into the electric power sector, the report states. And while utilities still have plans to add between 40,000 and 45,000 megawatts of gas-fired generating capacity, gas actually has lost ground in the utility market to coal and nuclear power: In 1993, electricity output from coal and nuclear rose, while gas-fired generation fell to an estimated 250 billion kilowatt-hours - the lowest level since 1986, when gas generated 246 billion kwh.« less

The capacity credit of grid-connected photovoltaic systems

NASA Astrophysics Data System (ADS)

Alsema, E. A.; van Wijk, A. J. M.; Turkenburg, W. C.

The capacity credit due photovoltaic (PV) power plants if integrated into the Netherlands grid was investigated, together with an estimate of the total allowable penetration. An hourly simulation was performed based on meteorological data from five stations and considering tilted surfaces, the current grid load pattern, and the load pattern after PV-power augmentation. The reliability of the grid was assessed in terms of a loss of load probability analysis, assuming power drops were limited to 1 GW. A projected tolerance for 2.5 GW of PV power was calculated. Peak demands were determined to be highest in winter, contrary to highest insolation levels; however, daily insolation levels coincided with daily peak demands. Combining the PV input with an equal amount of wind turbine power production was found to augment the capacity credit for both at aggregate outputs of 2-4 GW.

Opportunities for Automated Demand Response in California Wastewater Treatment Facilities

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

Aghajanzadeh, Arian; Wray, Craig; McKane, Aimee

Previous research over a period of six years has identified wastewater treatment facilities as good candidates for demand response (DR), automated demand response (Auto-­DR), and Energy Efficiency (EE) measures. This report summarizes that work, including the characteristics of wastewater treatment facilities, the nature of the wastewater stream, energy used and demand, as well as details of the wastewater treatment process. It also discusses control systems and automated demand response opportunities. Furthermore, this report summarizes the DR potential of three wastewater treatment facilities. In particular, Lawrence Berkeley National Laboratory (LBNL) has collected data at these facilities from control systems, submetered processmore » equipment, utility electricity demand records, and governmental weather stations. The collected data were then used to generate a summary of wastewater power demand, factors affecting that demand, and demand response capabilities. These case studies show that facilities that have implemented energy efficiency measures and that have centralized control systems are well suited to shed or shift electrical loads in response to financial incentives, utility bill savings, and/or opportunities to enhance reliability of service. In summary, municipal wastewater treatment energy demand in California is large, and energy-­intensive equipment offers significant potential for automated demand response. In particular, large load reductions were achieved by targeting effluent pumps and centrifuges. One of the limiting factors to implementing demand response is the reaction of effluent turbidity to reduced aeration at an earlier stage of the process. Another limiting factor is that cogeneration capabilities of municipal facilities, including existing power purchase agreements and utility receptiveness to purchasing electricity from cogeneration facilities, limit a facility’s potential to participate in other DR activities.« less

Design of an Input-Parallel Output-Parallel LLC Resonant DC-DC Converter System for DC Microgrids

NASA Astrophysics Data System (ADS)

Juan, Y. L.; Chen, T. R.; Chang, H. M.; Wei, S. E.

2017-11-01

Compared with the centralized power system, the distributed modularized power system is composed of several power modules with lower power capacity to provide a totally enough power capacity for the load demand. Therefore, the current stress of the power components in each module can then be reduced, and the flexibility of system setup is also enhanced. However, the parallel-connected power modules in the conventional system are usually controlled to equally share the power flow which would result in lower efficiency in low loading condition. In this study, a modular power conversion system for DC micro grid is developed with 48 V dc low voltage input and 380 V dc high voltage output. However, in the developed system control strategy, the numbers of power modules enabled to share the power flow is decided according to the output power at lower load demand. Finally, three 350 W power modules are constructed and parallel-connected to setup a modular power conversion system. From the experimental results, compared with the conventional system, the efficiency of the developed power system in the light loading condition is greatly improved. The modularized design of the power system can also decrease the power loss ratio to the system capacity.

Calibrating Physical Parameters in House Models Using Aggregate AC Power Demand

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

Sun, Yannan; Stevens, Andrew J.; Lian, Jianming

For residential houses, the air conditioning (AC) units are one of the major resources that can provide significant flexibility in energy use for the purpose of demand response. To quantify the flexibility, the characteristics of all the houses need to be accurately estimated, so that certain house models can be used to predict the dynamics of the house temperatures in order to adjust the setpoints accordingly to provide demand response while maintaining the same comfort levels. In this paper, we propose an approach using the Reverse Monte Carlo modeling method and aggregate house models to calibrate the distribution parameters ofmore » the house models for a population of residential houses. Given the aggregate AC power demand for the population, the approach can successfully estimate the distribution parameters for the sensitive physical parameters based on our previous uncertainty quantification study, such as the mean of the floor areas of the houses.« less

Fuel cell energy storage for Space Station enhancement

NASA Technical Reports Server (NTRS)

Stedman, J. K.

1990-01-01

Viewgraphs on fuel cell energy storage for space station enhancement are presented. Topics covered include: power profile; solar dynamic power system; photovoltaic battery; space station energy demands; orbiter fuel cell power plant; space station energy storage; fuel cell system modularity; energy storage system development; and survival power supply.

Wind-Driven Ecological Flow Regimes Downstream from Hydropower Dams

NASA Astrophysics Data System (ADS)

Kern, J.; Characklis, G. W.

2012-12-01

Conventional hydropower can be turned on and off quicker and less expensively than thermal generation (coal, nuclear, or natural gas). These advantages enable hydropower utilities to respond to rapid fluctuations in energy supply and demand. More recently, a growing renewable energy sector has underlined the need for flexible generation capacity that can complement intermittent renewable resources such as wind power. While wind power entails lower variable costs than other types of generation, incorporating it into electric power systems can be problematic. Due to variable and unpredictable wind speeds, wind power is difficult to schedule and must be used when available. As a result, integrating large amounts of wind power into the grid may result in atypical, swiftly changing demand patterns for other forms of generation, placing a premium on sources that can be rapidly ramped up and down. Moreover, uncertainty in wind power forecasts will stipulate increased levels of 'reserve' generation capacity that can respond quickly if real-time wind supply is less than expected. These changes could create new hourly price dynamics for energy and reserves, altering the short-term financial signals that hydroelectric dam operators use to schedule water releases. Traditionally, hourly stream flow patterns below hydropower dams have corresponded in a very predictable manner to electricity demand, whose primary factors are weather (hourly temperature) and economic activity (workday hours). Wind power integration has the potential to yield more variable, less predictable flows at hydro dams, flows that at times could resemble reciprocal wind patterns. An existing body of research explores the impacts of standard, demand-following hydroelectric dams on downstream ecological flows; but weighing the benefits of increased reliance on wind power against further impacts to ecological flows may be a novel challenge for the environmental community. As a preliminary step in meeting this challenge, the following study was designed to investigate the potential for wind power integration to alter riparian flow regimes below hydroelectric dams. A hydrological model of a three-dam cascade in the Roanoke River basin (Virginia, USA) is interfaced with a simulated electricity market (i.e. a unit commitment problem) representing the Dominion Zone of PJM Interconnection. Incorporating forecasts of electricity demand, hydro capacity and wind availability, a mixed-integer optimization program minimizes the system cost of meeting hourly demand and reserve requirements by means of a diverse generation portfolio (e.g. nuclear, fossil, hydro, and biomass). A secondary 'balancing' energy market is executed if real-time wind generation is less than the day-ahead forecast, calling upon reserved generation resources to meet the supply shortfall. Hydropower release schedules are determined across a range of wind development scenarios (varying wind's fraction of total installed generating capacity, as well as its geographical source region). Flow regimes for each wind development scenario are compared against both historical and simulated flows under current operations (negligible wind power), as well as simulated natural flows (dam removal), in terms of ecologically relevant flow metrics. Results quantify the ability of wind power development to alter within-week stream flows downstream from hydropower dams.

Dispatchable Renewable Energy Model for Microgrid Power System

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

Chiou, Fred; Gentle, Jake P.; McJunkin, Timothy R.

2017-04-01

Over the years, many research projects have been performed and focused on finding out the effective ways to balance the power demands and supply on the utility grid. The causes of the imbalance could be the increasing demands from the end users, the loss of power generation (generators down), faults on the transmission lines, power tripped due to overload, and weather conditions, etc. An efficient Load Frequency Control (LFC) can assure the desired electricity quality provided to the residential, commercial and industrial end users. A simulation model is built in this project to investigate the contribution of the modeling ofmore » dispatchable energy such as solar energy, wind power, hydro power and energy storage to the balance of the microgrid power system. An analysis of simplified feedback control system with proportional, integral, and derivative (PID) controller was performed. The purpose of this research is to investigate a simulation model that achieves certain degree of the resilient control for the microgrid.« less

Heat pipe cooling of power processing magnetics

NASA Technical Reports Server (NTRS)

Hansen, I. G.; Chester, M.

1979-01-01

The constant demand for increased power and reduced mass has raised the internal temperature of conventionally cooled power magnetics toward the upper limit of acceptability. The conflicting demands of electrical isolation, mechanical integrity, and thermal conductivity preclude significant further advancements using conventional approaches. However, the size and mass of multikilowatt power processing systems may be further reduced by the incorporation of heat pipe cooling directly into the power magnetics. Additionally, by maintaining lower more constant temperatures, the life and reliability of the magnetic devices will be improved. A heat pipe cooled transformer and input filter have been developed for the 2.4 kW beam supply of a 30-cm ion thruster system. This development yielded a mass reduction of 40% (1.76 kg) and lower mean winding temperature (20 C lower). While these improvements are significant, preliminary designs predict even greater benefits to be realized at higher power. This paper presents the design details along with the results of thermal vacuum operation and the component performance in a 3 kW breadboard power processor.

Market Evolution: Wholesale Electricity Market Design for 21st Century Power Systems

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

Cochran, Jaquelin; Miller, Mackay; Milligan, Michael

2013-10-01

Demand for affordable, reliable, domestically sourced, and low-carbon electricity is on the rise. This growing demand is driven in part by evolving public policy priorities, especially reducing the health and environmental impacts of electricity service and expanding energy access to under-served customers. Consequently, variable renewable energy resources comprise an increasing share ofelectricity generation globally. At the same time, new opportunities for addressing the variability of renewables are being strengthened through advances in smart grids, communications, and technologies that enable dispatchable demand response and distributed generation to extend to the mass market. A key challenge of merging these opportunities is marketmore » design -- determining how to createincentives and compensate providers justly for attributes and performance that ensure a reliable and secure grid -- in a context that fully realizes the potential of a broad array of sources of flexibility in both the wholesale power and retail markets. This report reviews the suite of wholesale power market designs in use and under consideration to ensure adequacy, security, and flexibilityin a landscape of significant variable renewable energy. It also examines considerations needed to ensure that wholesale market designs are inclusive of emerging technologies, such as demand response, distributed generation, and storage.« less

Decentral Smart Grid Control

NASA Astrophysics Data System (ADS)

Schäfer, Benjamin; Matthiae, Moritz; Timme, Marc; Witthaut, Dirk

2015-01-01

Stable operation of complex flow and transportation networks requires balanced supply and demand. For the operation of electric power grids—due to their increasing fraction of renewable energy sources—a pressing challenge is to fit the fluctuations in decentralized supply to the distributed and temporally varying demands. To achieve this goal, common smart grid concepts suggest to collect consumer demand data, centrally evaluate them given current supply and send price information back to customers for them to decide about usage. Besides restrictions regarding cyber security, privacy protection and large required investments, it remains unclear how such central smart grid options guarantee overall stability. Here we propose a Decentral Smart Grid Control, where the price is directly linked to the local grid frequency at each customer. The grid frequency provides all necessary information about the current power balance such that it is sufficient to match supply and demand without the need for a centralized IT infrastructure. We analyze the performance and the dynamical stability of the power grid with such a control system. Our results suggest that the proposed Decentral Smart Grid Control is feasible independent of effective measurement delays, if frequencies are averaged over sufficiently large time intervals.

Balancing autonomy and utilization of solar power and battery storage for demand based microgrids

NASA Astrophysics Data System (ADS)

Lawder, Matthew T.; Viswanathan, Vilayanur; Subramanian, Venkat R.

2015-04-01

The growth of intermittent solar power has developed a need for energy storage systems in order to decouple generation and supply of energy. Microgrid (MG) systems comprising of solar arrays with battery energy storage studied in this paper desire high levels of autonomy, seeking to meet desired demand at all times. Large energy storage capacity is required for high levels of autonomy, but much of this expensive capacity goes unused for a majority of the year due to seasonal fluctuations of solar generation. In this paper, a model-based study of MGs comprised of solar generation and battery storage shows the relationship between system autonomy and battery utilization applied to multiple demand cases using a single particle battery model (SPM). The SPM allows for more accurate state-of-charge and utilization estimation of the battery than previous studies of renewably powered systems that have used empirical models. The increased accuracy of battery state estimation produces a better assessment of system performance. Battery utilization will depend on the amount of variation in solar insolation as well as the type of demand required by the MG. Consumers must balance autonomy and desired battery utilization of a system within the needs of their grid.

An EOQ Model with Two-Parameter Weibull Distribution Deterioration and Price-Dependent Demand

ERIC Educational Resources Information Center

Mukhopadhyay, Sushanta; Mukherjee, R. N.; Chaudhuri, K. S.

2005-01-01

An inventory replenishment policy is developed for a deteriorating item and price-dependent demand. The rate of deterioration is taken to be time-proportional and the time to deterioration is assumed to follow a two-parameter Weibull distribution. A power law form of the price dependence of demand is considered. The model is solved analytically…

The Impact of Technological Change on Manpower and Skill Demand: Case-Study Data and Policy Implications.

ERIC Educational Resources Information Center

Crossman, Edward R. F. W.; Laner, Stephen

To prove or disprove the hypothesis that automation and technological change impose increased skill demands on manufacturing and service industries, case studies were made of a bank and a steel and air products company, and of two oil companies, airlines, and electric power companies. The basic conceptual tool used to measure skill demands was the…

Electricity decision-making: New techniques for calculating statewide economic impacts from new power supply and demand-side management programs

NASA Astrophysics Data System (ADS)

Tegen, Suzanne Isabel Helmholz

This dissertation introduces new techniques for calculating and comparing statewide economic impacts from new coal, natural gas and wind power plants, as well as from demand-side management programs. The impetus for this work was two-fold. First, reviews of current literature and projects revealed that there was no standard way to estimate statewide economic impacts from new supply- and demand-side electricity options. Second, decision-makers who were interviewed stated that they were overwhelmed with data in general, but also lacked enough specific information about economic development impacts to their states from electricity, to make informed choices. This dissertation includes chapters on electricity decision-making and on economic impacts from supply and demand. The supply chapter compares different electricity options in three states which vary in natural resource content: Arizona, Colorado and Michigan. To account for differing capacity factors, resources are compared on a per-megawatt-hour basis. The calculations of economic impacts from new supply include: materials and labor for construction, operations, maintenance, fuel extraction, fuel transport, as well as property tax, financing and landowner revenues. The demand-side chapter compares residential, commercial and industrial programs in Iowa. Impact calculations include: incremental labor and materials for program planning, installation and operations, as well as sales taxes and electricity saved. Results from supply-side calculations in the three states analyzed indicate that adding new wind power can have a greater impact to a state's economy than adding new gas or coal power due to resource location, taxes and infrastructure. Additionally, demand-side management programs have a higher relative percentage of in-state dollar flow than supply-side solutions, though demand-side programs typically involve fewer MWh and dollars than supply-side generation. Methods for this dissertation include researching existing models and data, gathering new data and interviews with industry representatives and policy makers. The new techniques are important for decision-makers, utilities, energy advocates and others who are concerned with economic development and in-state dollar flows from new electricity decisions.

Alpha power increases in right parietal cortex reflects focused internal attention

PubMed Central

Benedek, Mathias; Schickel, Rainer J.; Jauk, Emanuel; Fink, Andreas; Neubauer, Aljoscha C.

2014-01-01

This study investigated the functional significance of EEG alpha power increases, a finding that is consistently observed in various memory tasks and specifically during divergent thinking. It was previously shown that alpha power is increased when tasks are performed in mind—e.g., when bottom-up processing is prevented. This study aimed to examine the effect of task-immanent differences in bottom-up processing demands by comparing two divergent thinking tasks, one intrinsically relying on bottom-up processing (sensory-intake task) and one that is not (sensory-independence task). In both tasks, stimuli were masked in half of the trials to establish conditions of higher and lower internal processing demands. In line with the hypotheses, internal processing affected performance and led to increases in alpha power only in the sensory-intake task, whereas the sensory-independence task showed high levels of task-related alpha power in both conditions. Interestingly, conditions involving focused internal attention showed a clear lateralization with higher alpha power in parietal regions of the right hemisphere. Considering evidence from fMRI studies, right-parietal alpha power increases may correspond to a deactivation of the right temporoparietal junction, reflecting an inhibition of the ventral attention network. Inhibition of this region is thought to prevent reorienting to irrelevant stimulation during goal-driven, top-down behavior, which may serve the executive function of task shielding during demanding cognitive tasks such as idea generation and mental imagery. PMID:24561034

Distributed control system for demand response by servers

NASA Astrophysics Data System (ADS)

Hall, Joseph Edward

Within the broad topical designation of smart grid, research in demand response, or demand-side management, focuses on investigating possibilities for electrically powered devices to adapt their power consumption patterns to better match generation and more efficiently integrate intermittent renewable energy sources, especially wind. Devices such as battery chargers, heating and cooling systems, and computers can be controlled to change the time, duration, and magnitude of their power consumption while still meeting workload constraints such as deadlines and rate of throughput. This thesis presents a system by which a computer server, or multiple servers in a data center, can estimate the power imbalance on the electrical grid and use that information to dynamically change the power consumption as a service to the grid. Implementation on a testbed demonstrates the system with a hypothetical but realistic usage case scenario of an online video streaming service in which there are workloads with deadlines (high-priority) and workloads without deadlines (low-priority). The testbed is implemented with real servers, estimates the power imbalance from the grid frequency with real-time measurements of the live outlet, and uses a distributed, real-time algorithm to dynamically adjust the power consumption of the servers based on the frequency estimate and the throughput of video transcoder workloads. Analysis of the system explains and justifies multiple design choices, compares the significance of the system in relation to similar publications in the literature, and explores the potential impact of the system.

Reserve valuation in electric power systems

NASA Astrophysics Data System (ADS)

Ruiz, Pablo Ariel

Operational reliability is provided in part by scheduling capacity in excess of the load forecast. This reserve capacity balances the uncertain power demand with the supply in real time and provides for equipment outages. Traditionally, reserve scheduling has been ensured by enforcing reserve requirements in the operations planning. An alternate approach is to employ a stochastic formulation, which allows the explicit modeling of the sources of uncertainty. This thesis compares stochastic and reserve methods and evaluates the benefits of a combined approach for the efficient management of uncertainty in the unit commitment problem. Numerical studies show that the unit commitment solutions obtained for the combined approach are robust and superior with respect to the traditional approach. These robust solutions are especially valuable in areas with a high proportion of wind power, as their built-in flexibility allows the dispatch of practically all the available wind power while minimizing the costs of operation. The scheduled reserve has an economic value since it reduces the outage costs. In several electricity markets, reserve demand functions have been implemented to take into account the value of reserve in the market clearing process. These often take the form of a step-down function at the reserve requirement level, and as such they may not appropriately represent the reserve value. The value of reserve is impacted by the reliability, dynamic and stochastic characteristics of system components, the system operation policies, and the economic aspects such as the risk preferences of the demand. In this thesis, these aspects are taken into account to approximate the reserve value and construct reserve demand functions. Illustrative examples show that the demand functions constructed have similarities with those implemented in some markets.

Including Energy Efficiency and Renewable Energy Policies in Electricity Demand Projections

EPA Pesticide Factsheets

Find more information on how state and local air agencies can identify on-the-books EE/RE policies, develop a methodology for projecting a jurisdiction's energy demand, and estimate the change in power sector emissions.

Advanced Technology Display House. Volume 1: Project Summary and Procedures

NASA Technical Reports Server (NTRS)

Maund, D. H.

1981-01-01

The Advanced Technology Display House (ATDH) project is described. Tasks are defined in the areas of energy demand, water demand, sewage treatment, electric power, plumbing, lighting, heating, and air conditioning. Energy, water, and sewage systems are defined.

Tritium leak triggers reactor shutdown in the US

NASA Astrophysics Data System (ADS)

Gwynne, Peter

2010-04-01

A US state has voted against renewing the operating licence for its only working nuclear reactor after a leak of tritium was found in the 38-year-old power plant. The decision in late February by Vermont's senate to close the 650 MW Vermont Yankee reactor has cast a shadow over the Obama administration's plans to encourage the construction of more nuclear power plants to meet the country's increasing electricity demands. The plant currently provides one-third of the state's electricity demands.

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

NASA Astrophysics Data System (ADS)

Altin, Necmi; Eyimaya, Süleyman Emre

2018-03-01

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

Thermal energy storage for power generation applications

NASA Astrophysics Data System (ADS)

Drost, M. K.; Antoniak, Zen I.; Brown, D. R.

1990-03-01

Studies strongly indicate that the United States will face widespread electrical power constraints in the 1990s. In many cases, the demand for increased power will occur during peak and intermediate demand periods. While natural gas is currently plentiful and economically attractive for meeting peak and intermediate loads, the development of a coal-fired peaking option would give utilities insurance against unexpected supply shortages or cost increases. This paper discusses a conceptual evaluation of using thermal energy storage (TES) to improve the economics of coal-fired peak and intermediate load power generation. The use of TES can substantially improve the economic attractiveness of meeting peak and intermediate loads with coal-fired power generation. In this case, conventional pulverized coal combustion equipment is continuously operated to heat molten nitrate salt, which is then stored. During peak demand periods, hot salt is withdrawn from storage and used to generate steam for a Rankine steam power cycle. This allows the coal-fired salt heater to be approximately one-third the size of a coal-fired boiler in a conventional cycling plant. The general impact is to decouple the generation of thermal energy from its conversion to electricity. The present study compares a conventional cycling pulverized coal-fired power plant to a pulverized coal-fired plant using nitrate salt TES. The study demonstrates that a coal-fired salt heater is technically feasible and should be less expensive than a similar coal-fired boiler. The results show the use of nitrate salt TES reduced the levelized cost of power by between 5 and 24 percent, depending on the operating schedule.

Solid oxide fuel cell systems for residential micro-combined heat and power in the UK: Key economic drivers

NASA Astrophysics Data System (ADS)

Hawkes, Adam; Leach, Matthew

The ability of combined heat and power (CHP) to meet residential heat and power demands efficiently offers potentially significant financial and environmental advantages over centralised power generation and heat-provision through natural-gas fired boilers. A solid oxide fuel cell (SOFC) can operate at high overall efficiencies (heat and power) of 80-90%, offering an improvement over centralised generation, which is often unable to utilise waste heat. This paper applies an equivalent annual cost (EAC) minimisation model to a residential solid oxide fuel cell CHP system to determine what the driving factors are behind investment in this technology. We explore the performance of a hypothetical SOFC system—representing expectations of near to medium term technology development—under present UK market conditions. We find that households with small to average energy demands do not benefit from installation of a SOFC micro-CHP system, but larger energy demands do benefit under these conditions. However, this result is sensitive to a number of factors including stack capital cost, energy import and export prices, and plant lifetime. The results for small and average dwellings are shown to reverse under an observed change in energy import prices, an increase in electricity export price, a decrease in stack capital costs, or an improvement in stack lifetime.

A future Demand Side Management (DSM) opportunity for utility as variable renewable penetrate scale up using agriculture.

NASA Astrophysics Data System (ADS)

Ines, A.; Bhattacharjee, A.; Modi, V.; Robertson, A. W.; Lall, U.; Kocaman Ayse, S.; Chaudhary, S.; Kumar, A.; Ganapathy, A.; Kumar, A.; Mishra, V.

2015-12-01

Energy demand management, also known as demand side management (DSM), is the modification of consumer demand for energy through various methods such as smart metering, incentive based schemes, payments for turning off loads or rescheduling loads. Usually, the goal of demand side management is to encourage the consumer to use less power during periods of peak demand, or to move the time of energy use to off-peak times. Peak demand management does not necessarily decrease total energy consumption, but could be expected to reduce the need for investments in networks and/or power plants for meeting peak demands. Electricity use can vary dramatically on short and medium time frames, and the pricing system may not reflect the instantaneous cost as additional higher-cost that are brought on-line. In addition, the capacity or willingness of electricity consumers to adjust to prices by altering elasticity of demand may be low, particularly over short time frames. In the scenario of Indian grid setup, the retail customers do not follow real-time pricing and it is difficult to incentivize the utility companies for continuing the peak demand supply. A question for the future is how deeper penetration of renewable will be handled? This is a challenging problem since one has to deal with high variability, while managing loss of load probabilities. In the case of managing the peak demand using agriculture, in the future as smart metering matures with automatic turn on/off for a pump, it will become possible to provide an ensured amount of water or energy to the farmer while keeping the grid energized for 24 hours. Supply scenarios will include the possibility of much larger penetration of solar and wind into the grid. While, in absolute terms these sources are small contributors, their role will inevitably grow but DSM using agriculture could help reduce the capital cost. The other option is of advancing or delaying pump operating cycle even by several hours, will still ensure soil moisture requirements met while, balancing the overall system load with generation, reducing critical power mismatches. Through this presentation the author will describe different techniques and results from field experiments in India.

NREL Establishes New Center for Distributed Power

Science.gov Websites

Establishes New Center for Distributed Power Changing Electricity Market Demands Greater , smaller-scale generation facilities. That concept, known as "distributed power," will be Energy Laboratory (NREL). The Distributed Energy Resources Center at NREL will conduct research and

Biopower generation from kitchen wastewater using a bioreactor.

PubMed

Khan, Abdul M; Naz, Shamsa

2014-01-01

This research provides a comparative study of the power output from mediator-less and mediator microbial fuel cells (MFCs) under aerobic and partially anaerobic conditions using kitchen wastewater (KWW) as a renewable energy source. The wastewater sample was subjected to different physical, chemical, biochemical, and microbial analysis. The chemical oxygen demand (COD), biochemical oxygen demand (BOD), and power output values were greater for the fermented samples than the non-fermented samples. The power output of samples was compared through the development of MFCs by using sand-salt bridge and agar-salt bridge. The H2 that was produced was converted to atomic hydrogen by using the nickel-coated zinc electrode. In addition, the power output was further enhanced by introducing air into the cathodic chamber, where oxygen reacts with the protons to form pure H2O. The study showed that the power output was increased with the increase in COD and BOD values.

Abruptness of Cascade Failures in Power Grids

NASA Astrophysics Data System (ADS)

Pahwa, Sakshi; Scoglio, Caterina; Scala, Antonio

2014-01-01

Electric power-systems are one of the most important critical infrastructures. In recent years, they have been exposed to extreme stress due to the increasing demand, the introduction of distributed renewable energy sources, and the development of extensive interconnections. We investigate the phenomenon of abrupt breakdown of an electric power-system under two scenarios: load growth (mimicking the ever-increasing customer demand) and power fluctuations (mimicking the effects of renewable sources). Our results on real, realistic and synthetic networks indicate that increasing the system size causes breakdowns to become more abrupt; in fact, mapping the system to a solvable statistical-physics model indicates the occurrence of a first order transition in the large size limit. Such an enhancement for the systemic risk failures (black-outs) with increasing network size is an effect that should be considered in the current projects aiming to integrate national power-grids into ``super-grids''.

Abruptness of cascade failures in power grids.

PubMed

Pahwa, Sakshi; Scoglio, Caterina; Scala, Antonio

2014-01-15

Electric power-systems are one of the most important critical infrastructures. In recent years, they have been exposed to extreme stress due to the increasing demand, the introduction of distributed renewable energy sources, and the development of extensive interconnections. We investigate the phenomenon of abrupt breakdown of an electric power-system under two scenarios: load growth (mimicking the ever-increasing customer demand) and power fluctuations (mimicking the effects of renewable sources). Our results on real, realistic and synthetic networks indicate that increasing the system size causes breakdowns to become more abrupt; in fact, mapping the system to a solvable statistical-physics model indicates the occurrence of a first order transition in the large size limit. Such an enhancement for the systemic risk failures (black-outs) with increasing network size is an effect that should be considered in the current projects aiming to integrate national power-grids into "super-grids".

Abruptness of Cascade Failures in Power Grids

PubMed Central

Pahwa, Sakshi; Scoglio, Caterina; Scala, Antonio

2014-01-01

Electric power-systems are one of the most important critical infrastructures. In recent years, they have been exposed to extreme stress due to the increasing demand, the introduction of distributed renewable energy sources, and the development of extensive interconnections. We investigate the phenomenon of abrupt breakdown of an electric power-system under two scenarios: load growth (mimicking the ever-increasing customer demand) and power fluctuations (mimicking the effects of renewable sources). Our results on real, realistic and synthetic networks indicate that increasing the system size causes breakdowns to become more abrupt; in fact, mapping the system to a solvable statistical-physics model indicates the occurrence of a first order transition in the large size limit. Such an enhancement for the systemic risk failures (black-outs) with increasing network size is an effect that should be considered in the current projects aiming to integrate national power-grids into “super-grids”. PMID:24424239

Energetic contribution potential of building-integrated photovoltaics on airports in warm climates

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

Ruether, Ricardo; LABSOLAR - Laboratorio de Energia Solar, UFSC - Universidade Federal de Santa Catarina, Caixa Postal 476, Florianopolis, SC 88040-900; Braun, Priscila

2009-10-15

Especially in warm climates, a considerable fraction of the electricity demand in commercial buildings is due to the intensive use of air-conditioning systems. Airport buildings in sunny and warm regions present a perfect match between energy demand and solar resource availability. Airport buildings are also typically large and horizontal, isolated and free of shading, and have a great potential for the integration of solar photovoltaic (PV) systems. In this work, we assess the potential impact in energy demand reduction at the Florianopolis International Airport in Brazil (27 S, 48 W) with the use of building-integrated photovoltaic (BIPV) systems. We analysemore » the building's hourly energy consumption and solar irradiation data, to assess the match between energy demand and potential generation, and we estimate the PV power necessary to supply both the total amount and fractions of the annual energy demand. Our results show that the integration of PV systems on airport buildings in warm climates can supply the entire electric power consumption of an airport complex, in line with the general concept of a zero-energy building (ZEB). (author)« less

Analyzing Power Supply and Demand on the ISS

NASA Technical Reports Server (NTRS)

Thomas, Justin; Pham, Tho; Halyard, Raymond; Conwell, Steve

2006-01-01

Station Power and Energy Evaluation Determiner (SPEED) is a Java application program for analyzing the supply and demand aspects of the electrical power system of the International Space Station (ISS). SPEED can be executed on any computer that supports version 1.4 or a subsequent version of the Java Runtime Environment. SPEED includes an analysis module, denoted the Simplified Battery Solar Array Model, which is a simplified engineering model of the ISS primary power system. This simplified model makes it possible to perform analyses quickly. SPEED also includes a user-friendly graphical-interface module, an input file system, a parameter-configuration module, an analysis-configuration-management subsystem, and an output subsystem. SPEED responds to input information on trajectory, shadowing, attitude, and pointing in either a state-of-charge mode or a power-availability mode. In the state-of-charge mode, SPEED calculates battery state-of-charge profiles, given a time-varying power-load profile. In the power-availability mode, SPEED determines the time-varying total available solar array and/or battery power output, given a minimum allowable battery state of charge.

Demand Response Resource Quantification with Detailed Building Energy Models

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

Hale, Elaine; Horsey, Henry; Merket, Noel

Demand response is a broad suite of technologies that enables changes in electrical load operations in support of power system reliability and efficiency. Although demand response is not a new concept, there is new appetite for comprehensively evaluating its technical potential in the context of renewable energy integration. The complexity of demand response makes this task difficult -- we present new methods for capturing the heterogeneity of potential responses from buildings, their time-varying nature, and metrics such as thermal comfort that help quantify likely acceptability of specific demand response actions. Computed with an automated software framework, the methods are scalable.

A simulated field trip: "The visual aspects of power plant sitings"

Treesearch

Bill Bottomly; Alex Young

1979-01-01

The growth of our economy is demanding construction of a variety of power plants to generate electricity which is having a significant impact on the visual environment. These power plants will consist of conventional thermal (fossil fuel and nuclear), geothermal, wind and solar power plants. There are several areas where solutions to the visual impacts of these power...

Utilizing Climate Forecasts for Improving Water and Power Systems Coordination

NASA Astrophysics Data System (ADS)

Arumugam, S.; Queiroz, A.; Patskoski, J.; Mahinthakumar, K.; DeCarolis, J.

2016-12-01

Climate forecasts, typically monthly-to-seasonal precipitation forecasts, are commonly used to develop streamflow forecasts for improving reservoir management. Irrespective of their high skill in forecasting, temperature forecasts in developing power demand forecasts are not often considered along with streamflow forecasts for improving water and power systems coordination. In this study, we consider a prototype system to analyze the utility of climate forecasts, both precipitation and temperature, for improving water and power systems coordination. The prototype system, a unit-commitment model that schedules power generation from various sources, is considered and its performance is compared with an energy system model having an equivalent reservoir representation. Different skill sets of streamflow forecasts and power demand forecasts are forced on both water and power systems representations for understanding the level of model complexity required for utilizing monthly-to-seasonal climate forecasts to improve coordination between these two systems. The analyses also identify various decision-making strategies - forward purchasing of fuel stocks, scheduled maintenance of various power systems and tradeoff on water appropriation between hydropower and other uses - in the context of various water and power systems configurations. Potential application of such analyses for integrating large power systems with multiple river basins is also discussed.

Key Residential Building Equipment Technologies for Control and Grid Support PART I (Residential)

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

Starke, Michael R; Onar, Omer C; DeVault, Robert C

2011-09-01

Electrical energy consumption of the residential sector is a crucial area of research that has in the past primarily focused on increasing the efficiency of household devices such as water heaters, dishwashers, air conditioners, and clothes washer and dryer units. However, the focus of this research is shifting as objectives such as developing the smart grid and ensuring that the power system remains reliable come to the fore, along with the increasing need to reduce energy use and costs. Load research has started to focus on mechanisms to support the power system through demand reduction and/or reliability services. The powermore » system relies on matching generation and load, and day-ahead and real-time energy markets capture most of this need. However, a separate set of grid services exist to address the discrepancies in load and generation arising from contingencies and operational mismatches, and to ensure that the transmission system is available for delivery of power from generation to load. Currently, these grid services are mostly provided by generation resources. The addition of renewable resources with their inherent variability can complicate the issue of power system reliability and lead to the increased need for grid services. Using load as a resource, through demand response programs, can fill the additional need for flexible resources and even reduce costly energy peaks. Loads have been shown to have response that is equal to or better than generation in some cases. Furthermore, price-incentivized demand response programs have been shown to reduce the peak energy requirements, thereby affecting the wholesale market efficiency and overall energy prices. The residential sector is not only the largest consumer of electrical energy in the United States, but also has the highest potential to provide demand reduction and power system support, as technological advancements in load control, sensor technologies, and communication are made. The prevailing loads based on the largest electrical energy consumers in the residential sector are space heating and cooling, washer and dryer, water heating, lighting, computers and electronics, dishwasher and range, and refrigeration. As the largest loads, these loads provide the highest potential for delivering demand response and reliability services. Many residential loads have inherent flexibility that is related to the purpose of the load. Depending on the load type, electric power consumption levels can either be ramped, changed in a step-change fashion, or completely removed. Loads with only on-off capability (such as clothes washers and dryers) provide less flexibility than resources that can be ramped or step-changed. Add-on devices may be able to provide extra demand response capabilities. Still, operating residential loads effectively requires awareness of the delicate balance of occupants health and comfort and electrical energy consumption. This report is Phase I of a series of reports aimed at identifying gaps in automated home energy management systems for incorporation of building appliances, vehicles, and renewable adoption into a smart grid, specifically with the intent of examining demand response and load factor control for power system support. The objective is to capture existing gaps in load control, energy management systems, and sensor technology with consideration of PHEV and renewable technologies to establish areas of research for the Department of Energy. In this report, (1) data is collected and examined from state of the art homes to characterize the primary residential loads as well as PHEVs and photovoltaic for potential adoption into energy management control strategies; and (2) demand response rules and requirements across the various demand response programs are examined for potential participation of residential loads. This report will be followed by a Phase II report aimed at identifying the current state of technology of energy management systems, sensors, and communication technologies for demand response and load factor control applications for the residential sector. The purpose is to cover the gaps that exist in the information captured by the sensors for energy management system to be able to provide demand response and load factor control. The vision is the development of an energy management system or other controlling enterprise hardware and software that is not only able to control loads, PHEVs, and renewable generation for demand response and load factor control, but also to do so with consumer comforts in mind and in an optimal fashion.« less

Investigating the water consumption for electricity generation at Turkish power plants

NASA Astrophysics Data System (ADS)

El-Khozondar, Balkess; Aydinalp Koksal, Merih

2017-11-01

The water-energy intertwined relationship has recently gained more importance due to the high water consumption in the energy sector and to the limited availability of the water resources. The energy and electricity demand of Turkey is increasing rapidly in the last two decades. More thermal power plants are expected to be built in the near future to supply the rapidly increasing demand in Turkey which will put pressure on water availability. In this study, the water consumption for electricity generation at Turkish power plants is investigated. The main objectives of this study are to identify the amount of water consumed to generate 1 kWh of electricity for each generation technology currently used in Turkey and to investigate ways to reduce the water consumption at power plants expected to be built in the near future to supply the increasing demand. The various electricity generation technology mixture scenarios are analyzed to determine the future total and per generation water consumption, and water savings based on changes of cooling systems used for each technology. The Long-range Energy Alternatives Planning (LEAP) program is used to determine the minimum water consuming electricity generation technology mixtures using optimization approaches between 2017 and 2035.

Integrated thermal and energy management of plug-in hybrid electric vehicles

NASA Astrophysics Data System (ADS)

Shams-Zahraei, Mojtaba; Kouzani, Abbas Z.; Kutter, Steffen; Bäker, Bernard

2012-10-01

In plug-in hybrid electric vehicles (PHEVs), the engine temperature declines due to reduced engine load and extended engine off period. It is proven that the engine efficiency and emissions depend on the engine temperature. Also, temperature influences the vehicle air-conditioner and the cabin heater loads. Particularly, while the engine is cold, the power demand of the cabin heater needs to be provided by the batteries instead of the waste heat of engine coolant. The existing energy management strategies (EMS) of PHEVs focus on the improvement of fuel efficiency based on hot engine characteristics neglecting the effect of temperature on the engine performance and the vehicle power demand. This paper presents a new EMS incorporating an engine thermal management method which derives the global optimal battery charge depletion trajectories. A dynamic programming-based algorithm is developed to enforce the charge depletion boundaries, while optimizing a fuel consumption cost function by controlling the engine power. The optimal control problem formulates the cost function based on two state variables: battery charge and engine internal temperature. Simulation results demonstrate that temperature and the cabin heater/air-conditioner power demand can significantly influence the optimal solution for the EMS, and accordingly fuel efficiency and emissions of PHEVs.

Supply-demand balance in outward-directed networks and Kleiber's law

PubMed Central

Painter, Page R

2005-01-01

Background Recent theories have attempted to derive the value of the exponent α in the allometric formula for scaling of basal metabolic rate from the properties of distribution network models for arteries and capillaries. It has recently been stated that a basic theorem relating the sum of nutrient currents to the specific nutrient uptake rate, together with a relationship claimed to be required in order to match nutrient supply to nutrient demand in 3-dimensional outward-directed networks, leads to Kleiber's law (b = 3/4). Methods The validity of the supply-demand matching principle and the assumptions required to prove the basic theorem are assessed. The supply-demand principle is evaluated by examining the supply term and the demand term in outward-directed lattice models of nutrient and water distribution systems and by applying the principle to fractal-like models of mammalian arterial systems. Results Application of the supply-demand principle to bifurcating fractal-like networks that are outward-directed does not predict 3/4-power scaling, and evaluation of water distribution system models shows that the matching principle does not match supply to demand in such systems. Furthermore, proof of the basic theorem is shown to require that the covariance of nutrient uptake and current path length is 0, an assumption unlikely to be true in mammalian arterial systems. Conclusion The supply-demand matching principle does not lead to a satisfactory explanation for the approximately 3/4-power scaling of mammalian basal metabolic rate. PMID:16283939

Supply-demand balance in outward-directed networks and Kleiber's law.

PubMed

Painter, Page R

2005-11-10

Recent theories have attempted to derive the value of the exponent alpha in the allometric formula for scaling of basal metabolic rate from the properties of distribution network models for arteries and capillaries. It has recently been stated that a basic theorem relating the sum of nutrient currents to the specific nutrient uptake rate, together with a relationship claimed to be required in order to match nutrient supply to nutrient demand in 3-dimensional outward-directed networks, leads to Kleiber's law (b = 3/4). The validity of the supply-demand matching principle and the assumptions required to prove the basic theorem are assessed. The supply-demand principle is evaluated by examining the supply term and the demand term in outward-directed lattice models of nutrient and water distribution systems and by applying the principle to fractal-like models of mammalian arterial systems. Application of the supply-demand principle to bifurcating fractal-like networks that are outward-directed does not predict 3/4-power scaling, and evaluation of water distribution system models shows that the matching principle does not match supply to demand in such systems. Furthermore, proof of the basic theorem is shown to require that the covariance of nutrient uptake and current path length is 0, an assumption unlikely to be true in mammalian arterial systems. The supply-demand matching principle does not lead to a satisfactory explanation for the approximately 3/4-power scaling of mammalian basal metabolic rate.

A probabilistic assessment of large scale wind power development for long-term energy resource planning

NASA Astrophysics Data System (ADS)

Kennedy, Scott Warren

A steady decline in the cost of wind turbines and increased experience in their successful operation have brought this technology to the forefront of viable alternatives for large-scale power generation. Methodologies for understanding the costs and benefits of large-scale wind power development, however, are currently limited. In this thesis, a new and widely applicable technique for estimating the social benefit of large-scale wind power production is presented. The social benefit is based upon wind power's energy and capacity services and the avoidance of environmental damages. The approach uses probabilistic modeling techniques to account for the stochastic interaction between wind power availability, electricity demand, and conventional generator dispatch. A method for including the spatial smoothing effect of geographically dispersed wind farms is also introduced. The model has been used to analyze potential offshore wind power development to the south of Long Island, NY. If natural gas combined cycle (NGCC) and integrated gasifier combined cycle (IGCC) are the alternative generation sources, wind power exhibits a negative social benefit due to its high capacity cost and the relatively low emissions of these advanced fossil-fuel technologies. Environmental benefits increase significantly if charges for CO2 emissions are included. Results also reveal a diminishing social benefit as wind power penetration increases. The dependence of wind power benefits on natural gas and coal prices is also discussed. In power systems with a high penetration of wind generated electricity, the intermittent availability of wind power may influence hourly spot prices. A price responsive electricity demand model is introduced that shows a small increase in wind power value when consumers react to hourly spot prices. The effectiveness of this mechanism depends heavily on estimates of the own- and cross-price elasticities of aggregate electricity demand. This work makes a valuable contribution by synthesizing information from research in power market economics, power system reliability, and environmental impact assessment, to develop a comprehensive methodology for analyzing wind power in the context of long-term energy planning.

Water-Constrained Electric Sector Capacity Expansion Modeling Under Climate Change Scenarios

NASA Astrophysics Data System (ADS)

Cohen, S. M.; Macknick, J.; Miara, A.; Vorosmarty, C. J.; Averyt, K.; Meldrum, J.; Corsi, F.; Prousevitch, A.; Rangwala, I.

2015-12-01

Over 80% of U.S. electricity generation uses a thermoelectric process, which requires significant quantities of water for power plant cooling. This water requirement exposes the electric sector to vulnerabilities related to shifts in water availability driven by climate change as well as reductions in power plant efficiencies. Electricity demand is also sensitive to climate change, which in most of the United States leads to warming temperatures that increase total cooling-degree days. The resulting demand increase is typically greater for peak demand periods. This work examines the sensitivity of the development and operations of the U.S. electric sector to the impacts of climate change using an electric sector capacity expansion model that endogenously represents seasonal and local water resource availability as well as climate impacts on water availability, electricity demand, and electricity system performance. Capacity expansion portfolios and water resource implications from 2010 to 2050 are shown at high spatial resolution under a series of climate scenarios. Results demonstrate the importance of water availability for future electric sector capacity planning and operations, especially under more extreme hotter and drier climate scenarios. In addition, region-specific changes in electricity demand and water resources require region-specific responses that depend on local renewable resource availability and electricity market conditions. Climate change and the associated impacts on water availability and temperature can affect the types of power plants that are built, their location, and their impact on regional water resources.

Trends of Training Courses Conducted in the Human Resources Development Center of the National Institute for Quantum and Radiological Science and Technology After the Fukushima Dai-Ichi Nuclear Power Plant Accident.

PubMed

Shimizu, Yuko; Iida, Haruzo; Nenoi, Mitsuru

2017-07-01

Environmental contamination with radioactive materials caused by the Fukushima Dai-ichi Nuclear Power Plant (NPP) accident in 2011 raised a serious health concern among residents in Japan, and the demand for radiation experts who can handle the radiation-associated problems has increased. The Human Resources Development Center (HRDC) of the National Institute of for Quantum and Radiological Science and Technology in Japan has offered a variety of training programs covering a wide range of technologies associated with radiation since 1959. In this study, the time-course change in the number and age of the applicants for training programs regularly scheduled at HRDC were analyzed to characterize the demand after the NPP accident. The results suggested that the demand for the training of industrial radiation experts elevated sharply after the NPP accident followed by a prompt decrease, and that young people were likely stimulated to learn the basics of radiation. The demand for the training of medical radiation experts was kept high regardless of the NPP accident. The demand for the training of radiation emergency experts fluctuated apparently with three components: a terminating demand after the criticality accident that occurred in 1999, an urgent demand for handling of the NPP accident, and a sustained demand from local governments that undertook reinforcement of their nuclear disaster prevention program. The demand for the training of school students appeared to be increasing after the NPP accident. It could be foreseen that the demand for training programs targeting young people and medical radiation experts would be elevated in future.

What Can China Do? China's Best Alternative Outcome for Energy Efficiency and CO2 Emissions

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

G. Fridley, David; Zheng, Nina; T. Aden, Nathaniel

After rapid growth in economic development and energy demand over the last three decades, China has undertaken energy efficiency improvement efforts to reduce its energy intensity under the 11th Five Year Plan (FYP). Since becoming the world's largest annual CO{sub 2} emitter in 2007, China has set reduction targets for energy and carbon intensities and committed to meeting 15% of its total 2020 energy demand with non-fossil fuel. Despite having achieved important savings in 11th FYP efficiency programs, rising per capita income and the continued economic importance of trade will drive demand for transport activity and fuel use. At themore » same time, an increasingly 'electrified' economy will drive rapid power demand growth. Greater analysis is therefore needed to understand the underlying drivers, possible trajectories and mitigation potential in the growing industrial, transport and power sectors. This study uses scenario analysis to understand the likely trajectory of China's energy and carbon emissions to 2030 in light of the current and planned portfolio of programs, policies and technology development and ongoing urbanization and demographic trends. It evaluates the potential impacts of alternative transportation and power sector development using two key scenarios, Continued Improvement Scenario (CIS) and Accelerated Improvement Scenario (AIS). CIS represents the most likely path of growth based on continuation of current policies and meeting announced targets and goals, including meeting planned appliance efficiency standard revisions, fuel economy standards, and industrial targets and moderate phase-out of subcritical coal-fired generation with additional non-fossil generation. AIS represents a more aggressive trajectory of accelerated improvement in energy intensity and decarbonized power and transport sectors. A range of sensitivity analysis and power technology scenarios are tested to evaluate the impact of additional actions such as carbon capture and sequestration (CCS) and integrated mine-mouth generation. The CIS and AIS results are also contextualized and compared to model scenarios in other published studies. The results of this study show that China's energy and CO{sub 2} emissions will not likely peak before 2030, although growth is expected to slow after 2020. Moreover, China will be able to meet its 2020 carbon intensity reduction target of 40 to 45% under both CIS and AIS, but only meet its 15% non-fossil fuel target by 2020 under AIS. Under both scenarios, efficiency remains a key resource and has the same, if not greater, mitigation potential as new technologies in transport and power sectors. In the transport sector, electrification will be closely linked the degree of decarbonization in the power sector and EV deployment has little or no impact on China's crude oil import demand. Rather, power generation improvements have the largest sector potential for overall emission mitigation while mine-mouth power generation and CCS have limited mitigation potential compared to fuel switching and efficiency improvements. Comparisons of this study's results with other published studies reveal that CIS and AIS are within the range of other national energy projections but alternative studies rely much more heavily on CCS for carbon reduction. The McKinsey study, in particular, has more optimistic assumptions for reductions in crude oil imports and coal demand in its abatement scenario and has much higher gasoline reduction potential for the same level of EV deployment. Despite these differences, this study's scenario analysis of both transport and power sectors illustrate the necessity for continued efficiency improvements and aggressive power sector decarbonization in flattening China's CO{sub 2} emissions.« less

Optical interconnects for satellite payloads: overview of the state-of-the-art

NASA Astrophysics Data System (ADS)

Vervaeke, Michael; Debaes, Christof; Van Erps, Jürgen; Karppinen, Mikko; Tanskanen, Antti; Aalto, Timo; Harjanne, Mikko; Thienpont, Hugo

2010-05-01

The increased demand of broadband communication services like High Definition Television, Video On Demand, Triple Play, fuels the technologies to enhance the bandwidth of individual users towards service providers and hence the increase of aggregate bandwidths on terrestial networks. Optical solutions clearly leverage the bandwidth appetite easily whereas electrical interconnection schemes require an ever-increasing effort to counteract signal distortions at higher bitrates. Dense wavelength division multiplexing and all-optical signal regeneration and switching solve the bandwidth demands of network trunks. Fiber-to-the-home, and fiber-to-the-desk are trends towards providing individual users with greatly increased bandwidth. Operators in the satellite telecommunication sector face similar challenges fuelled by the same demands as for their terrestial counterparts. Moreover, the limited number of orbital positions for new satellites set the trend for an increase in payload datacommunication capacity using an ever-increasing number of complex multi-beam active antennas and a larger aggregate bandwidth. Only satellites with very large capacity, high computational density and flexible, transparent fully digital payload solutions achieve affordable communication prices. To keep pace with the bandwidth and flexibility requirements, designers have to come up with systems requiring a total digital througput of a few Tb/s resulting in a high power consuming satellite payload. An estimated 90 % of the total power consumption per chip is used for the off-chip communication lines. We have undertaken a study to assess the viability of optical datacommunication solutions to alleviate the demands regarding power consumption and aggregate bandwidth imposed on future satellite communication payloads. The review on optical interconnects given here is especially focussed on the demands of the satellite communication business and the particular environment in which the optics have to perform their functionality: space.

Bulk electric system reliability evaluation incorporating wind power and demand side management

NASA Astrophysics Data System (ADS)

Huang, Dange

Electric power systems are experiencing dramatic changes with respect to structure, operation and regulation and are facing increasing pressure due to environmental and societal constraints. Bulk electric system reliability is an important consideration in power system planning, design and operation particularly in the new competitive environment. A wide range of methods have been developed to perform bulk electric system reliability evaluation. Theoretically, sequential Monte Carlo simulation can include all aspects and contingencies in a power system and can be used to produce an informative set of reliability indices. It has become a practical and viable tool for large system reliability assessment technique due to the development of computing power and is used in the studies described in this thesis. The well-being approach used in this research provides the opportunity to integrate an accepted deterministic criterion into a probabilistic framework. This research work includes the investigation of important factors that impact bulk electric system adequacy evaluation and security constrained adequacy assessment using the well-being analysis framework. Load forecast uncertainty is an important consideration in an electrical power system. This research includes load forecast uncertainty considerations in bulk electric system reliability assessment and the effects on system, load point and well-being indices and reliability index probability distributions are examined. There has been increasing worldwide interest in the utilization of wind power as a renewable energy source over the last two decades due to enhanced public awareness of the environment. Increasing penetration of wind power has significant impacts on power system reliability, and security analyses become more uncertain due to the unpredictable nature of wind power. The effects of wind power additions in generating and bulk electric system reliability assessment considering site wind speed correlations and the interactive effects of wind power and load forecast uncertainty on system reliability are examined. The concept of the security cost associated with operating in the marginal state in the well-being framework is incorporated in the economic analyses associated with system expansion planning including wind power and load forecast uncertainty. Overall reliability cost/worth analyses including security cost concepts are applied to select an optimal wind power injection strategy in a bulk electric system. The effects of the various demand side management measures on system reliability are illustrated using the system, load point, and well-being indices, and the reliability index probability distributions. The reliability effects of demand side management procedures in a bulk electric system including wind power and load forecast uncertainty considerations are also investigated. The system reliability effects due to specific demand side management programs are quantified and examined in terms of their reliability benefits.

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

Komiyama, Ryoichi; Marnay, Chris; Stadler, Michael

In this analysis, the authors projected Japan's energy demand/supply and energy-related CO{sub 2} emissions to 2050. Their analysis of various scenarios indicated that Japan's CO{sub 2} emissions in 2050 could be potentially reduced by 26-58% from the current level (FY 2005). These results suggest that Japan could set a CO{sub 2} emission reduction target for 2050 at between 30% and 60%. In order to reduce CO{sub 2} emissions by 60% in 2050 from the present level, Japan will have to strongly promote energy conservation at the same pace as an annual rate of 1.9% after the oil crises (to cutmore » primary energy demand per GDP (TPES/GDP) in 2050 by 60% from 2005) and expand the share of non-fossil energy sources in total primary energy supply in 2050 to 50% (to reduce CO{sub 2} emissions per primary energy demand (CO{sub 2}/TPES) in 2050 by 40% from 2005). Concerning power generation mix in 2050, nuclear power will account for 60%, solar and other renewable energy sources for 20%, hydro power for 10% and fossil-fired generation for 10%, indicating substantial shift away from fossil fuel in electric power supply. Among the mitigation measures in the case of reducing CO{sub 2} emissions by 60% in 2050, energy conservation will make the greatest contribution to the emission reduction, being followed by solar power, nuclear power and other renewable energy sources. In order to realize this massive CO{sub 2} abatement, however, Japan will have to overcome technological and economic challenges including the large-scale deployment of nuclear power and renewable technologies.« less

Low Power Operation of Temperature-Modulated Metal Oxide Semiconductor Gas Sensors.

PubMed

Burgués, Javier; Marco, Santiago

2018-01-25

Mobile applications based on gas sensing present new opportunities for low-cost air quality monitoring, safety, and healthcare. Metal oxide semiconductor (MOX) gas sensors represent the most prominent technology for integration into portable devices, such as smartphones and wearables. Traditionally, MOX sensors have been continuously powered to increase the stability of the sensing layer. However, continuous power is not feasible in many battery-operated applications due to power consumption limitations or the intended intermittent device operation. This work benchmarks two low-power, duty-cycling, and on-demand modes against the continuous power one. The duty-cycling mode periodically turns the sensors on and off and represents a trade-off between power consumption and stability. On-demand operation achieves the lowest power consumption by powering the sensors only while taking a measurement. Twelve thermally modulated SB-500-12 (FIS Inc. Jacksonville, FL, USA) sensors were exposed to low concentrations of carbon monoxide (0-9 ppm) with environmental conditions, such as ambient humidity (15-75% relative humidity) and temperature (21-27 °C), varying within the indicated ranges. Partial Least Squares (PLS) models were built using calibration data, and the prediction error in external validation samples was evaluated during the two weeks following calibration. We found that on-demand operation produced a deformation of the sensor conductance patterns, which led to an increase in the prediction error by almost a factor of 5 as compared to continuous operation (2.2 versus 0.45 ppm). Applying a 10% duty-cycling operation of 10-min periods reduced this prediction error to a factor of 2 (0.9 versus 0.45 ppm). The proposed duty-cycling powering scheme saved up to 90% energy as compared to the continuous operating mode. This low-power mode may be advantageous for applications that do not require continuous and periodic measurements, and which can tolerate slightly higher prediction errors.

Heuristic approaches for energy-efficient shared restoration in WDM networks

NASA Astrophysics Data System (ADS)

Alilou, Shahab

In recent years, there has been ongoing research on the design of energy-efficient Wavelength Division Multiplexing (WDM) networks. The explosive growth of Internet traffic has led to increased power consumption of network components. Network survivability has also been a relevant research topic, as it plays a crucial role in assuring continuity of service with no disruption, regardless of network component failure. Network survivability mechanisms tend to utilize considerable resources such as spare capacity in order to protect and restore information. This thesis investigates techniques for reducing energy demand and enhancing energy efficiency in the context of network survivability. We propose two novel heuristic energy-efficient shared protection approaches for WDM networks. These approaches intend to save energy by setting on sleep mode devices that are not being used while providing shared backup paths to satisfy network survivability. The first approach exploits properties of a math series in order to assign weight to the network links. It aims at reducing power consumption at the network indirectly by aggregating traffic on a set of nodes and links with high traffic load level. Routing traffic on links and nodes that are already under utilization makes it possible for the links and nodes with no load to be set on sleep mode. The second approach is intended to dynamically route traffic through nodes and links with high traffic load level. Similar to the first approach, this approach computes a pair of paths for every newly arrived demand. It computes these paths for every new demand by comparing the power consumption of nodes and links in the network before the demand arrives with their potential power consumption if they are chosen along the paths of this demand. Simulations of two different networks were used to compare the total network power consumption obtained using the proposed techniques against a standard shared-path restoration scheme. Shared-path restoration is a network survivability method in which a link-disjoint backup path and wavelength is reserved at the time of call setup for a working path. However, in order to reduce spare capacity consumption, this reserved backup path and wavelength may be shared with other backup paths. Pool Sharing Scheme (PSS) is employed to implement shared-path restoration scheme [1]. In an optical network, the failure of a single link leads to the failure of all the lightpaths that pass through that particular link. PSS ensures that the amount of backup bandwidth required on a link to restore the failed connections will not be more than the total amount of reserved backup bandwidth on that link. Simulation results indicate that the proposed approaches lead to up to 35% power savings in WDM networks when traffic load is low. However, power saving decreases to 14% at high traffic load level. Furthermore, in terms of the total capacity consumption for working paths, PSS outperforms the two proposed approaches, as expected. In terms of total capacity consumption all the approaches behave similarly. In general, at low traffic load level, the two proposed approaches behave similar to PSS in terms of average link load, and the ratio of block demands. Nevertheless, at high traffic load, the proposed approaches result in higher ratio of blocked demands than PSS. They also lead to higher average link load than PSS for the equal number of generated demands.

U.S. Electric System Operating Data

EIA Publications

EIA provides hourly electricity operating data, including actual and forecast demand, net generation, and the power flowing between electric systems. EIA's new U.S. Electric System Operating Data tool provides nearly real-time demand data, plus analysis and visualizations of hourly, daily, and weekly electricity supply and demand on a national and regional level for all of the 66 electric system balancing authorities that make up the U.S. electric grid.

Impact of warmer weather on electricity sector emissions due to building energy use

NASA Astrophysics Data System (ADS)

Meier, Paul; Holloway, Tracey; Patz, Jonathan; Harkey, Monica; Ahl, Doug; Abel, David; Schuetter, Scott; Hackel, Scott

2017-06-01

Most US energy consumption occurs in buildings, with cooling demands anticipated to increase net building electricity use under warmer conditions. The electricity generation units that respond to this demand are major contributors to sulfur dioxide (SO2) and nitrogen oxides (NOx), both of which have direct impacts on public health, and contribute to the formation of secondary pollutants including ozone and fine particulate matter. This study quantifies temperature-driven changes in power plant emissions due to increased use of building air conditioning. We compare an ambient temperature baseline for the Eastern US to a model-calculated mid-century scenario with summer-average temperature increases ranging from 1 C to 5 C across the domain. We find a 7% increase in summer electricity demand and a 32% increase in non-coincident peak demand. Power sector modeling, assuming only limited changes to current generation resources, calculated a 16% increase in emissions of NOx and an 18% increase in emissions of SO2. There is a high level of regional variance in the response of building energy use to climate, and the response of emissions to associated demand. The East North Central census region exhibited the greatest sensitivity of energy demand and associated emissions to climate.

Cross-layer Joint Relay Selection and Power Allocation Scheme for Cooperative Relaying System

NASA Astrophysics Data System (ADS)

Zhi, Hui; He, Mengmeng; Wang, Feiyue; Huang, Ziju

2018-03-01

A novel cross-layer joint relay selection and power allocation (CL-JRSPA) scheme over physical layer and data-link layer is proposed for cooperative relaying system in this paper. Our goal is finding the optimal relay selection and power allocation scheme to maximize system achievable rate when satisfying total transmit power constraint in physical layer and statistical delay quality-of-service (QoS) demand in data-link layer. Using the concept of effective capacity (EC), our goal can be formulated into an optimal joint relay selection and power allocation (JRSPA) problem to maximize the EC when satisfying total transmit power limitation. We first solving optimal power allocation (PA) problem with Lagrange multiplier approach, and then solving optimal relay selection (RS) problem. Simulation results demonstrate that CL-JRSPA scheme gets larger EC than other schemes when satisfying delay QoS demand. In addition, the proposed CL-JRSPA scheme achieves the maximal EC when relay located approximately halfway between source and destination, and EC becomes smaller when the QoS exponent becomes larger.

Importance of hard coal in electricity generation in Poland

NASA Astrophysics Data System (ADS)

Plewa, Franciszek; Strozik, Grzegorz

2017-11-01

Polish energy sector is facing a number of challenges, in particular as regards the reconstruction of production potential, diversification of energy sources, environmental issues, adequate fuels supplies and other. Mandatory implementation of Europe 2020 strategy in terms of “3x20” targets (20% reduction of greenhouse gases, 20% of energy from renewable sources, and 20% increase of efficiency in energy production) requires fast decision, which have to be coordinated with energetic safety issues, increasing demands for electric energy, and other factors. In Poland almost 80% of power is installed in coal fired power plants and energy from hard coals is relatively less expensive than from other sources, especially renewable. The most of renewable energy sources power plants are unable to generate power in amounts which can be competitive with coal fires power stations and are highly expensive, what leads o high prices of electric energy. Alternatively, new generation of coal fired coal power plants is able to significantly increase efficiency, reduce carbon dioxide emission, and generate less expensive electric power in amounts adequate to the demands of a country.

Optimal Operation and Value Evaluation of Pumped Storage Power Plants Considering Spot Market Trading and Uncertainty of Bilateral Demand

NASA Astrophysics Data System (ADS)

Takahashi, Kenta; Hara, Ryoichi; Kita, Hiroyuki; Hasegawa, Jun

In recent years, as the deregulation in electric power industry has advanced in many countries, a spot market trading of electricity has been done. Generation companies are allowed to purchase the electricity through the electric power market and supply electric power for their bilateral customers. Under this circumstance, it is important for the generation companies to procure the required electricity with cheaper cost to increase their profit. The market price is volatile since it is determined by bidding between buyer and seller. The pumped storage power plant, one of the storage facilities is promising against such volatile market price since it can produce a profit by purchasing electricity with lower-price and selling it with higher-price. This paper discusses the optimal operation of the pumped storage power plants considering bidding strategy to an uncertain spot market. The volatilities in market price and demand are represented by the Vasicek model in our estimation. This paper also discusses the allocation of operational reserve to the pumped storage power plant.

Real-Time Load-Side Control of Electric Power Systems

NASA Astrophysics Data System (ADS)

Zhao, Changhong

Two trends are emerging from modern electric power systems: the growth of renewable (e.g., solar and wind) generation, and the integration of information technologies and advanced power electronics. The former introduces large, rapid, and random fluctuations in power supply, demand, frequency, and voltage, which become a major challenge for real-time operation of power systems. The latter creates a tremendous number of controllable intelligent endpoints such as smart buildings and appliances, electric vehicles, energy storage devices, and power electronic devices that can sense, compute, communicate, and actuate. Most of these endpoints are distributed on the load side of power systems, in contrast to traditional control resources such as centralized bulk generators. This thesis focuses on controlling power systems in real time, using these load side resources. Specifically, it studies two problems. (1) Distributed load-side frequency control: We establish a mathematical framework to design distributed frequency control algorithms for flexible electric loads. In this framework, we formulate a category of optimization problems, called optimal load control (OLC), to incorporate the goals of frequency control, such as balancing power supply and demand, restoring frequency to its nominal value, restoring inter-area power flows, etc., in a way that minimizes total disutility for the loads to participate in frequency control by deviating from their nominal power usage. By exploiting distributed algorithms to solve OLC and analyzing convergence of these algorithms, we design distributed load-side controllers and prove stability of closed-loop power systems governed by these controllers. This general framework is adapted and applied to different types of power systems described by different models, or to achieve different levels of control goals under different operation scenarios. We first consider a dynamically coherent power system which can be equivalently modeled with a single synchronous machine. We then extend our framework to a multi-machine power network, where we consider primary and secondary frequency controls, linear and nonlinear power flow models, and the interactions between generator dynamics and load control. (2) Two-timescale voltage control: The voltage of a power distribution system must be maintained closely around its nominal value in real time, even in the presence of highly volatile power supply or demand. For this purpose, we jointly control two types of reactive power sources: a capacitor operating at a slow timescale, and a power electronic device, such as a smart inverter or a D-STATCOM, operating at a fast timescale. Their control actions are solved from optimal power flow problems at two timescales. Specifically, the slow-timescale problem is a chance-constrained optimization, which minimizes power loss and regulates the voltage at the current time instant while limiting the probability of future voltage violations due to stochastic changes in power supply or demand. This control framework forms the basis of an optimal sizing problem, which determines the installation capacities of the control devices by minimizing the sum of power loss and capital cost. We develop computationally efficient heuristics to solve the optimal sizing problem and implement real-time control. Numerical experiments show that the proposed sizing and control schemes significantly improve the reliability of voltage control with a moderate increase in cost.

Closeup view of a general electric company demand meter which ...

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

Close-up view of a general electric company demand meter which formerly monitored railroad power usage obtained from Philadelphia Electric Company sources. - Thirtieth Street Station, Load Dispatch Center, Thirtieth & Market Streets, Railroad Station, Amtrak (formerly Pennsylvania Railroad Station), Philadelphia, Philadelphia County, PA

The Oak Ridge Competitive Electricity Dispatch (ORCED) Model Version 9

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

Hadley, Stanton W.; Baek, Young Sun

The Oak Ridge Competitive Electricity Dispatch (ORCED) model dispatches power plants in a region to meet the electricity demands for any single given year up to 2030. It uses publicly available sources of data describing electric power units such as the National Energy Modeling System and hourly demands from utility submittals to the Federal Energy Regulatory Commission that are projected to a future year. The model simulates a single region of the country for a given year, matching generation to demands and predefined net exports from the region, assuming no transmission constraints within the region. ORCED can calculate a numbermore » of key financial and operating parameters for generating units and regional market outputs including average and marginal prices, air emissions, and generation adequacy. By running the model with and without changes such as generation plants, fuel prices, emission costs, plug-in hybrid electric vehicles, distributed generation, or demand response, the marginal impact of these changes can be found.« less

Charge scheduling of an energy storage system under time-of-use pricing and a demand charge.

PubMed

Yoon, Yourim; Kim, Yong-Hyuk

2014-01-01

A real-coded genetic algorithm is used to schedule the charging of an energy storage system (ESS), operated in tandem with renewable power by an electricity consumer who is subject to time-of-use pricing and a demand charge. Simulations based on load and generation profiles of typical residential customers show that an ESS scheduled by our algorithm can reduce electricity costs by approximately 17%, compared to a system without an ESS and by 8% compared to a scheduling algorithm based on net power.

Charge Scheduling of an Energy Storage System under Time-of-Use Pricing and a Demand Charge

PubMed Central

Yoon, Yourim

2014-01-01

A real-coded genetic algorithm is used to schedule the charging of an energy storage system (ESS), operated in tandem with renewable power by an electricity consumer who is subject to time-of-use pricing and a demand charge. Simulations based on load and generation profiles of typical residential customers show that an ESS scheduled by our algorithm can reduce electricity costs by approximately 17%, compared to a system without an ESS and by 8% compared to a scheduling algorithm based on net power. PMID:25197720

Capillary electrophoresis-high resolution sector field inductively coupled plasma mass spectrometry.

PubMed

Sonke, Jeroen E; Salters, Vincent J M

2007-08-03

The background and applications of high resolution sector field inductively coupled plasma mass spectrometry (HR-ICP-MS) as a detector for capillary (CE) and gel electrophoretic separations are reviewed. Notable progress has been made in the fields of bioinorganic and environmental (geo-) chemistry. Metallomics, the study of metal species interactions and functions in biological systems, puts substantial technical demands on speciation analysis. The combination of high species resolving power (CE) and high sensitivity-high mass resolving power (HR-ICP-MS) provides a solid base to meet such demands.

Process Developed for Fabricating Engineered Pore Structures for High- Fuel-Utilization Solid Oxide Fuel Cells

NASA Technical Reports Server (NTRS)

Sofie, Stephen W.; Cable, Thomas L.; Salamone, Sam M.

2005-01-01

Solid oxide fuel cells (SOFCs) have tremendous commercial potential because of their high efficiency, high energy density, and flexible fuel capability (ability to use fossil fuels). The drive for high-power-utilizing, ultrathin electrolytes (less than 10 microns), has placed an increased demand on the anode to provide structural support, yet allow sufficient fuel entry for sustained power generation. Concentration polarization, a condition where the fuel demand exceeds the supply, is evident in all commercial-based anode-supported cells, and it presents a significant roadblock to SOFC commercialization.

Essays in market power mitigation and supply function equilibrium

NASA Astrophysics Data System (ADS)

Subramainam, Thiagarajah Natchie

Market power mitigation has been an integral part of wholesale electricity markets since deregulation. In wholesale electricity markets, different regions in the US take different approaches to regulating market power. While the exercise of market power has received considerable attention in the literature, the issue of market power mitigation has attracted scant attention. In the first chapter, I examine the market power mitigation rules used in New York ISO (Independent System Operator) and California ISO (CAISO) with respect to day-ahead and real-time energy markets. I test whether markups associated with New York in-city generators would be lower with an alternative approach to mitigation, the CAISO approach. Results indicate the difference in markups between these two mitigation rules is driven by the shape of residual demand curves for suppliers. Analysis of residual demand curves faced by New York in-city suppliers show similar markups under both mitigation rules when no one supplier is necessary to meet the demand (i.e., when no supplier is pivotal). However, when some supplier is crucial for the market to clear, the mitigation rule adopted by the NYISO consistently leads to higher markups than would the CAISO rule. This result suggest that market power episodes in New York is confined to periods where some supplier is pivotal. As a result, I find that applying the CAISOs' mitigation rules to the New York market could lower wholesale electricity prices by 18%. The second chapter of my dissertation focuses on supply function equilibrium. In power markets, suppliers submit offer curves in auctions, indicating their willingness to supply at different price levels. Although firms are allowed to submit different offer curves for different time periods, surprisingly many firms stick to a single offer curve for the entire day. This essentially means that firms are submitting a single offer curve for multiple demand realizations. A suitable framework to analyze such oligopolistic competition between power market suppliers is supply function equilibrium models. Using detailed bidding data, I develop equilibrium in supply functions by restricting supplier offers to a class of supply functions. By collating equilibrium supply functions corresponding to different realizations of demand, I obtain a single optimal supply function for the entire day. Then I compare the resulting supply function with actual day-ahead offers in New York. In addition to supply function equilibrium, I also develop a conservative bidding approach in which each firm assumes that rivals bid at marginal costs. Results show that the supply functions derived from equilibrium bidding model in this paper is not consistent with actual bidding in New York. This result is mainly driven by the class of supply functions used in this study to generate the equilibrium. Further, actual offers do not resemble offers generated by the conservative bidding algorithm.

Dynamic linear modeling of monthly electricity demand in Japan: Time variation of electricity conservation effect

PubMed Central

Shiraki, Hiroto; Ashina, Shuichi

2018-01-01

After the severe nuclear disaster in Fukushima, which was triggered by the Great East Japan earthquake in March 2011, nuclear power plants in Japan were temporarily shut down for mandatory inspections. To prevent large-scale blackouts, the Japanese government requested companies and households to reduce electricity consumption in summer and winter. It is reported that the domestic electricity demand had a structural decrease because of the electricity conservation effect (ECE). However, quantitative analysis of the ECE is not sufficient, and especially time variation of the ECE remains unclear. Understanding the ECE is important because Japan’s NDC (nationally determined contribution) assumes the reduction of CO2 emissions through aggressive energy conservation. In this study, we develop a time series model of monthly electricity demand in Japan and estimate time variation of the ECE. Moreover, we evaluate the impact of electricity conservation on CO2 emissions from power plants. The dynamic linear model is used to separate the ECE from the effects of other irrelevant factors (e.g. air temperature, economic production, and electricity price). Our result clearly shows that consumers’ electricity conservation behavior after the earthquake was not temporary but became established as a habit. Between March 2011 and March 2016, the ECE on industrial electricity demand ranged from 3.9% to 5.4%, and the ECE on residential electricity demand ranged from 1.6% to 7.6%. The ECE on the total electricity demand was estimated at 3.2%–6.0%. We found a seasonal pattern that the residential ECE in summer is higher than that in winter. The emissions increase from the shutdown of nuclear power plants was mitigated by electricity conservation. The emissions reduction effect was estimated at 0.82 MtCO2–2.26 MtCO2 (−4.5% on average compared to the zero-ECE case). The time-varying ECE is necessary for predicting Japan’s electricity demand and CO2 emissions after the earthquake. PMID:29708988

Dynamic linear modeling of monthly electricity demand in Japan: Time variation of electricity conservation effect.

PubMed

Honjo, Keita; Shiraki, Hiroto; Ashina, Shuichi

2018-01-01

After the severe nuclear disaster in Fukushima, which was triggered by the Great East Japan earthquake in March 2011, nuclear power plants in Japan were temporarily shut down for mandatory inspections. To prevent large-scale blackouts, the Japanese government requested companies and households to reduce electricity consumption in summer and winter. It is reported that the domestic electricity demand had a structural decrease because of the electricity conservation effect (ECE). However, quantitative analysis of the ECE is not sufficient, and especially time variation of the ECE remains unclear. Understanding the ECE is important because Japan's NDC (nationally determined contribution) assumes the reduction of CO2 emissions through aggressive energy conservation. In this study, we develop a time series model of monthly electricity demand in Japan and estimate time variation of the ECE. Moreover, we evaluate the impact of electricity conservation on CO2 emissions from power plants. The dynamic linear model is used to separate the ECE from the effects of other irrelevant factors (e.g. air temperature, economic production, and electricity price). Our result clearly shows that consumers' electricity conservation behavior after the earthquake was not temporary but became established as a habit. Between March 2011 and March 2016, the ECE on industrial electricity demand ranged from 3.9% to 5.4%, and the ECE on residential electricity demand ranged from 1.6% to 7.6%. The ECE on the total electricity demand was estimated at 3.2%-6.0%. We found a seasonal pattern that the residential ECE in summer is higher than that in winter. The emissions increase from the shutdown of nuclear power plants was mitigated by electricity conservation. The emissions reduction effect was estimated at 0.82 MtCO2-2.26 MtCO2 (-4.5% on average compared to the zero-ECE case). The time-varying ECE is necessary for predicting Japan's electricity demand and CO2 emissions after the earthquake.

Power and Violence: The Relation between Communication Patterns, Power Discrepancies, and Domestic Violence.

ERIC Educational Resources Information Center

Babcock, Julia C.; And Others

1993-01-01

Examined discrepancies in economic status, decision-making power, communication patterns, and communication skill in three groups of spouses (n=95): domestically violent, maritally distressed/nonviolent, and maritally happy/nonviolent. Domestically violent couples were more likely than nonviolent groups to engage in husband-demand/wife-withdraw…

Feasibility study for the Swaziland/Mozambique interconnector. Final report. Export trade information

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

NONE

1997-11-01

This study, conducted by Black & Veatch, was funded by the U.S. Trade and Development Agency. The report, produced for the Ministry of National Resources, Energy and Environment (MNRE) of Swaziland, determines the least cost capacity expansion option to meet the future power demand and system reliability criteria of Swaziland, with particular emphasis on the proposed interconnector between Swaziland and Mozambique. Volume 2, the Final Report, contains the following sections: (1.0) Introduction; (2.0) Review of SEB Power System; (3.0) SEB Load Forecast and Review; (4.0) SEB Load Forecast Revision; (5.0) The SEB Need for Power; (6.0) SEB System Development Planmore » Review; (7.0) Southern Mozambique EdM power System Review; (8.0) Southern Mozambique EdM Energy and Demand; (9.0) Supply Side Capacity Options for Swaziland and Mozambique; (10.0) SEB Expansion Plan Development; (11.0) EdM Expansion Plan Development; (12.0) Cost Sharing of the Interconnector; (13.0) Enviroinmental Evaluation of Interconnector Options; (14.0) Generation/Transmission Trade Offs; (15.0) Draft Interconnection Agreement and Contract Packages; (16.0) Transmission System Study; (17.0) Automatic General Control; (18.0) Automatic Startup and Shutdown of Hydro Electric Power Plants; (19.0) Communications and Metering; (20.0) Conclusions and Recommendations; Appendix A: Demand Side Management Primer; Appendix B. PURPA and Avoided Cost Calculations.« less

A coupled nuclear reactor thermal energy storage system for enhanced load following operation

NASA Astrophysics Data System (ADS)

Alameri, Saeed A.

Nuclear power plants usually provide base-load electric power and operate most economically at a constant power level. In an energy grid with a high fraction of renewable energy sources, future nuclear reactors may be subject to significantly variable power demands. These variable power demands can negatively impact the effective capacity factor of the reactor and result in severe economic penalties. Coupling the reactor to a large Thermal Energy Storage (TES) block will allow the reactor to better respond to variable power demands. In the system described in this thesis, a Prismatic-core Advanced High Temperature Reactor (PAHTR) operates at constant power with heat provided to a TES block that supplies power as needed to a secondary energy conversion system. The PAHTR is designed to have a power rating of 300 MW th, with 19.75 wt% enriched Tri-Structural-Isotropic UO 2 fuel and a five year operating cycle. The passive molten salt TES system will operate in the latent heat region with an energy storage capacity of 150 MWd. Multiple smaller TES blocks are used instead of one large block to enhance the efficiency and maintenance complexity of the system. A transient model of the coupled reactor/TES system is developed to study the behavior of the system in response to varying load demands. The model uses six-delayed group point kinetics and decay heat models coupled to thermal-hydraulic and heat transfer models of the reactor and TES system. Based on the transient results, the preferred TES design consists of 1000 blocks, each containing 11000 LiCl phase change material tubes. A safety assessment of major reactor events demonstrates the inherent safety of the coupled system. The loss of forced circulation study determined the minimum required air convection heat removal rate from the reactor core and the lowest possible reduced primary flow rate that can maintain the reactor in a safe condition. The loss of ultimate heat sink study demonstrated the ability of the TES to absorb the decay heat of the reactor fuel while cooling the PAHTR after an emergency shutdown. The simulated reactivity insertion accident assessment determined the maximum allowable reactivity insertion to the PAHTR as a function of shutdown response times.

Martin Drake power plant

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

Schimmoller, B.K.

2005-08-01

The relatively old Martin Drake coal-fired plant at Colorado Springs is facing challenges to meet environmental requirements whilst satisfying power demands and remaining competition. The article describes measures taken and planned to tackle these challenges. 2 photos.

Analysis of Emergency Diesel Generators Failure Incidents in Nuclear Power Plants

NASA Astrophysics Data System (ADS)

Hunt, Ronderio LaDavis

In early years of operation, emergency diesel generators have had a minimal rate of demand failures. Emergency diesel generators are designed to operate as a backup when the main source of electricity has been disrupted. As of late, EDGs (emergency diesel generators) have been failing at NPPs (nuclear power plants) around the United States causing either station blackouts or loss of onsite and offsite power. These failures occurred from a specific type called demand failures. This thesis evaluated the current problem that raised concern in the nuclear industry which was averaging 1 EDG demand failure/year in 1997 to having an excessive event of 4 EDG demand failure year which occurred in 2011. To determine the next occurrence of the extreme event and possible cause to an event of such happening, two analyses were conducted, the statistical and root cause analysis. Considering the statistical analysis in which an extreme event probability approach was applied to determine the next occurrence year of an excessive event as well as, the probability of that excessive event occurring. Using the root cause analysis in which the potential causes of the excessive event occurred by evaluating, the EDG manufacturers, aging, policy changes/ maintenance practices and failure components. The root cause analysis investigated the correlation between demand failure data and historical data. Final results from the statistical analysis showed expectations of an excessive event occurring in a fixed range of probability and a wider range of probability from the extreme event probability approach. The root-cause analysis of the demand failure data followed historical statistics for the EDG manufacturer, aging and policy changes/ maintenance practices but, indicated a possible cause regarding the excessive event with the failure components. Conclusions showed the next excessive demand failure year, prediction of the probability and the next occurrence year of such failures, with an acceptable confidence level, was difficult but, it was likely that this type of failure will not be a 100 year event. It was noticeable to see that the majority of the EDG demand failures occurred within the main components as of 2005. The overall analysis of this study provided from percentages, indicated that it would be appropriate to make the statement that the excessive event was caused by the overall age (wear and tear) of the Emergency Diesel Generators in Nuclear Power Plants. Future Work will be to better determine the return period of the excessive event once the occurrence has happened for a second time by implementing the extreme event probability approach.

Nuclear option

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

Olson, P.S.

The energy demand complexion of this country is always changing and promises to change in the future. The nuclear industry is responding to changing energy demands through standards writing activities. Since the oil embargo of 1973, there has been a change in the mix of fuels contributing to energy growth in this country; virtually all of the energy growth has come from coal and nuclear power. The predicted expansion of coal use by 1985, over 1977 level, is 37%, while the use of oil is expected to decline by 17%. Use of nuclear power is expected to increase 62% frommore » the 1977 level. The feasibility of using nuclear energy to meet the needs of the USA for electric power is discussed.« less

An Opportunistic Wireless Charging System Design for an On-Demand Shuttle Service: Preprint

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

Doubleday, Kate; Meintz, Andrew; Markel, Tony

System right-sizing is critical to implementation of in-motion wireless power transfer (WPT) for electric vehicles. This study introduces a modeling tool, WPTSim, which uses one-second speed, location, and road grade data from an on-demand employee shuttle in operation to simulate the incorporation of WPT at fine granularity. Vehicle power and state of charge are simulated over the drive cycle to evaluate potential system designs. The required battery capacity is determined based on the rated power at a variable number of charging locations. Adding just one WPT location can more than halve the battery capacity needed. Many configurations are capable ofmore » being self sustaining with WPT, while others benefit from supplemental stationary charging.« less

Integrating Demand-Side Resources into the Electric Grid: Economic and Environmental Considerations

NASA Astrophysics Data System (ADS)

Fisher, Michael J.

Demand-side resources are taking an increasingly prominent role in providing essential grid services once provided by thermal power plants. This thesis considers the economic feasibility and environmental effects of integrating demand-side resources into the electric grid with consideration given to the diversity of market and environmental conditions that can affect their behavior. Chapter 2 explores the private economics and system-level carbon dioxide reduction when using demand response for spinning reserve. Steady end uses like lighting are more than twice as profitable as seasonal end uses because spinning reserve is needed year-round. Avoided carbon emission damages from using demand response instead of fossil fuel generation for spinning reserve are sufficient to justify incentives for demand response resources. Chapter 3 quantifies the system-level net emissions rate and private economics of behind-the-meter energy storage. Net emission rates are lower than marginal emission rates for power plants and in-line with estimates of net emission rates from grid-level storage. The economics are favorable for many buildings in regions with high demand charges like California and New York, even without subsidies. Future penetration into regions with average charges like Pennsylvania will depend greatly on installation cost reductions and wholesale prices for ancillary services. Chapter 4 outlines a novel econometric model to quantify potential revenues from energy storage that reduces demand charges. The model is based on a novel predictive metric that is derived from the building's load profile. Normalized revenue estimates are independent of the power capacity of the battery holding other performance characteristics equal, which can be used to calculate the profit-maximizing storage size. Chapter 5 analyzes the economic feasibility of flow batteries in the commercial and industrial market. Flow batteries at a 4-hour duration must be less expensive on a dollar per installed kWh basis, often by 20-30%, to break even with shorter duration li-ion or lead-acid despite allowing for deeper depth of discharge and superior cycle life. These results are robust to assumptions of tariff rates, battery round-trip efficiencies, amount of solar generation and whether the battery can participate in the wholesale energy and ancillary services markets.

Reactive Power Compensation Using an Energy Management System

DTIC Science & Technology

2014-09-01

bulk power grid or independent of the grid in islanded mode using various DG sources ( photovoltaic panels, fuel cells, gas generators, batteries...developed in order to forecast the system’s response to both capacitive and inductive power demands on the grid. The process was then confirmed in a...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited REACTIVE POWER

Static and dynamic crystalline lens accommodation evaluated using quantitative 3-D OCT.

PubMed

Gambra, Enrique; Ortiz, Sergio; Perez-Merino, Pablo; Gora, Michalina; Wojtkowski, Maciej; Marcos, Susana

2013-01-01

Custom high-resolution high-speed anterior segment spectral domain Optical Coherence Tomography (OCT) provided with automatic quantification and distortion correction algorithms was used to characterize three-dimensionally (3-D) the human crystalline lens in vivo in four subjects, for accommodative demands between 0 to 6 D in 1 D steps. Anterior and posterior lens radii of curvature decreased with accommodative demand at rates of 0.73 and 0.20 mm/D, resulting in an increase of the estimated optical power of the eye of 0.62 D per diopter of accommodative demand. Dynamic fluctuations in crystalline lens radii of curvature, anterior chamber depth and lens thickness were also estimated from dynamic 2-D OCT images (14 Hz), acquired during 5-s of steady fixation, for different accommodative demands. Estimates of the eye power from dynamical geometrical measurements revealed an increase of the fluctuations of the accommodative response from 0.07 D to 0.47 D between 0 and 6 D (0.044 D per D of accommodative demand). A sensitivity analysis showed that the fluctuations of accommodation were driven by dynamic changes in the lens surfaces, particularly in the posterior lens surface.

Static and dynamic crystalline lens accommodation evaluated using quantitative 3-D OCT

PubMed Central

Gambra, Enrique; Ortiz, Sergio; Perez-Merino, Pablo; Gora, Michalina; Wojtkowski, Maciej; Marcos, Susana

2013-01-01

Custom high-resolution high-speed anterior segment spectral domain Optical Coherence Tomography (OCT) provided with automatic quantification and distortion correction algorithms was used to characterize three-dimensionally (3-D) the human crystalline lens in vivo in four subjects, for accommodative demands between 0 to 6 D in 1 D steps. Anterior and posterior lens radii of curvature decreased with accommodative demand at rates of 0.73 and 0.20 mm/D, resulting in an increase of the estimated optical power of the eye of 0.62 D per diopter of accommodative demand. Dynamic fluctuations in crystalline lens radii of curvature, anterior chamber depth and lens thickness were also estimated from dynamic 2-D OCT images (14 Hz), acquired during 5-s of steady fixation, for different accommodative demands. Estimates of the eye power from dynamical geometrical measurements revealed an increase of the fluctuations of the accommodative response from 0.07 D to 0.47 D between 0 and 6 D (0.044 D per D of accommodative demand). A sensitivity analysis showed that the fluctuations of accommodation were driven by dynamic changes in the lens surfaces, particularly in the posterior lens surface. PMID:24049680

Sourcing of Steam and Electricity for Carbon Capture Retrofits.

PubMed

Supekar, Sarang D; Skerlos, Steven J

2017-11-07

This paper compares different steam and electricity sources for carbon capture and sequestration (CCS) retrofits of pulverized coal (PC) and natural gas combined cycle (NGCC) power plants. Analytical expressions for the thermal efficiency of these power plants are derived under 16 different CCS retrofit scenarios for the purpose of illustrating their environmental and economic characteristics. The scenarios emerge from combinations of steam and electricity sources, fuel used in each source, steam generation equipment and process details, and the extent of CO 2 capture. Comparing these scenarios reveals distinct trade-offs between thermal efficiency, net power output, levelized cost, profit, and net CO 2 reduction. Despite causing the highest loss in useful power output, bleeding steam and extracting electric power from the main power plant to meet the CCS plant's electricity and steam demand maximizes plant efficiency and profit while minimizing emissions and levelized cost when wholesale electricity prices are below 4.5 and 5.2 US¢/kWh for PC-CCS and NGCC-CCS plants, respectively. At prices higher than these higher profits for operating CCS retrofits can be obtained by meeting 100% of the CCS plant's electric power demand using an auxiliary natural gas turbine-based combined heat and power plant.

Impacts of demand response and renewable generation in electricity power market

NASA Astrophysics Data System (ADS)

Zhao, Zhechong

This thesis presents the objective of the research which is to analyze the impacts of uncertain wind power and demand response on power systems operation and power market clearing. First, in order to effectively utilize available wind generation, it is usually given the highest priority by assigning zero or negative energy bidding prices when clearing the day-ahead electric power market. However, when congestion occurs, negative wind bidding prices would aggravate locational marginal prices (LMPs) to be negative in certain locations. A load shifting model is explored to alleviate possible congestions and enhance the utilization of wind generation, by shifting proper amount of load from peak hours to off peaks. The problem is to determine proper amount of load to be shifted, for enhancing the utilization of wind generation, alleviating transmission congestions, and making LMPs to be non-negative values. The second piece of work considered the price-based demand response (DR) program which is a mechanism for electricity consumers to dynamically manage their energy consumption in response to time-varying electricity prices. It encourages consumers to reduce their energy consumption when electricity prices are high, and thereby reduce the peak electricity demand and alleviate the pressure to power systems. However, it brings additional dynamics and new challenges on the real-time supply and demand balance. Specifically, price-sensitive DR load levels are constantly changing in response to dynamic real-time electricity prices, which will impact the economic dispatch (ED) schedule and in turn affect electricity market clearing prices. This thesis adopts two methods for examining the impacts of different DR price elasticity characteristics on the stability performance: a closed-loop iterative simulation method and a non-iterative method based on the contraction mapping theorem. This thesis also analyzes the financial stability of DR load consumers, by incorporating explicit LMP formulations and consumer payment requirements into the network-constrained unit commitment (NCUC) problem. The proposed model determines the proper amount of DR loads to be shifted from peak hours to off-peaks under ISO's direct load control, for reducing the operation cost and ensuring that consumer payments of DR loads will not deteriorate significantly after load shifting. Both MINLP and MILP models are discussed, and improved formulation strategies are presented.

Optimal Multi-scale Demand-side Management for Continuous Power-Intensive Processes

NASA Astrophysics Data System (ADS)

Mitra, Sumit

With the advent of deregulation in electricity markets and an increasing share of intermittent power generation sources, the profitability of industrial consumers that operate power-intensive processes has become directly linked to the variability in energy prices. Thus, for industrial consumers that are able to adjust to the fluctuations, time-sensitive electricity prices (as part of so-called Demand-Side Management (DSM) in the smart grid) offer potential economical incentives. In this thesis, we introduce optimization models and decomposition strategies for the multi-scale Demand-Side Management of continuous power-intensive processes. On an operational level, we derive a mode formulation for scheduling under time-sensitive electricity prices. The formulation is applied to air separation plants and cement plants to minimize the operating cost. We also describe how a mode formulation can be used for industrial combined heat and power plants that are co-located at integrated chemical sites to increase operating profit by adjusting their steam and electricity production according to their inherent flexibility. Furthermore, a robust optimization formulation is developed to address the uncertainty in electricity prices by accounting for correlations and multiple ranges in the realization of the random variables. On a strategic level, we introduce a multi-scale model that provides an understanding of the value of flexibility of the current plant configuration and the value of additional flexibility in terms of retrofits for Demand-Side Management under product demand uncertainty. The integration of multiple time scales leads to large-scale two-stage stochastic programming problems, for which we need to apply decomposition strategies in order to obtain a good solution within a reasonable amount of time. Hence, we describe two decomposition schemes that can be applied to solve two-stage stochastic programming problems: First, a hybrid bi-level decomposition scheme with novel Lagrangean-type and subset-type cuts to strengthen the relaxation. Second, an enhanced cross-decomposition scheme that integrates Benders decomposition and Lagrangean decomposition on a scenario basis. To demonstrate the effectiveness of our developed methodology, we provide several industrial case studies throughout the thesis.

Smart Grid Risk Management

NASA Astrophysics Data System (ADS)

Abad Lopez, Carlos Adrian

Current electricity infrastructure is being stressed from several directions -- high demand, unreliable supply, extreme weather conditions, accidents, among others. Infrastructure planners have, traditionally, focused on only the cost of the system; today, resilience and sustainability are increasingly becoming more important. In this dissertation, we develop computational tools for efficiently managing electricity resources to help create a more reliable and sustainable electrical grid. The tools we present in this work will help electric utilities coordinate demand to allow the smooth and large scale integration of renewable sources of energy into traditional grids, as well as provide infrastructure planners and operators in developing countries a framework for making informed planning and control decisions in the presence of uncertainty. Demand-side management is considered as the most viable solution for maintaining grid stability as generation from intermittent renewable sources increases. Demand-side management, particularly demand response (DR) programs that attempt to alter the energy consumption of customers either by using price-based incentives or up-front power interruption contracts, is more cost-effective and sustainable in addressing short-term supply-demand imbalances when compared with the alternative that involves increasing fossil fuel-based fast spinning reserves. An essential step in compensating participating customers and benchmarking the effectiveness of DR programs is to be able to independently detect the load reduction from observed meter data. Electric utilities implementing automated DR programs through direct load control switches are also interested in detecting the reduction in demand to efficiently pinpoint non-functioning devices to reduce maintenance costs. We develop sparse optimization methods for detecting a small change in the demand for electricity of a customer in response to a price change or signal from the utility, dynamic learning methods for scheduling the maintenance of direct load control switches whose operating state is not directly observable and can only be inferred from the metered electricity consumption, and machine learning methods for accurately forecasting the load of hundreds of thousands of residential, commercial and industrial customers. These algorithms have been implemented in the software system provided by AutoGrid, Inc., and this system has helped several utilities in the Pacific Northwest, Oklahoma, California and Texas, provide more reliable power to their customers at significantly reduced prices. Providing power to widely spread out communities in developing countries using the conventional power grid is not economically feasible. The most attractive alternative source of affordable energy for these communities is solar micro-grids. We discuss risk-aware robust methods to optimally size and operate solar micro-grids in the presence of uncertain demand and uncertain renewable generation. These algorithms help system operators to increase their revenue while making their systems more resilient to inclement weather conditions.

NREL Integrate: RCS-4-42326

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

Hudgins, Andrew P.; Waight, Jim; Grover, Shailendra

OMNETRIC Corp., Duke Energy, CPS Energy, and the University of Texas at San Antonio (UTSA) created a project team to execute the project 'OpenFMB Reference Architecture Demonstration.' The project included development and demonstration of concepts that will enable the electric utility grid to host larger penetrations of renewable resources. The project concept calls for the aggregation of renewable resources and loads into microgrids and the control of these microgrids with an implementation of the OpenFMB Reference Architecture. The production of power from the renewable resources that are appearing on the grid today is very closely linked to the weather. Themore » difficulty of forecasting the weather, which is well understood, leads to difficulty in forecasting the production of renewable resources. The current state of the art in forecasting the power production from renewables (solar PV and wind) are accuracies in the range of 12-25 percent NMAE. In contrast the demand for electricity aggregated to the system level, is easier to predict. The state of the art of demand forecasting done, 24 hours ahead, is about 2-3% MAPE. Forecasting the load to be supplied from conventional resources (demand minus generation from renewable resources) is thus very hard to forecast. This means that even a few hours before the time of consumption, there can be considerable uncertainty over what must be done to balance supply and demand. Adding to the problem of difficulty of forecasting, is the reality of the variability of the actual production of power from renewables. Due to the variability of wind speeds and solar insolation, the actual output of power from renewable resources can vary significantly over a short period of time. Gusts of winds result is variation of power output of wind turbines. The shadows of clouds moving over solar PV arrays result in the variation of power production of the array. This compounds the problem of balancing supply and demand in real time. Establishing a control system that can manage distribution systems with large penetrations of renewable resources is difficult due to two major issues: (1) the lack of standardization and interoperability between the vast array of equipment in operation and on the market, most of which use different and proprietary means of communication and (2) the magnitude of the network and the information it generates and consumes. The objective of this project is to provide the industry with a design concept and tools that will enable the electric power grid to overcome these barriers and support a larger penetration of clean energy from renewable resources.« less

The impact of predicted demand on energy production

NASA Astrophysics Data System (ADS)

El kafazi, I.; Bannari, R.; Aboutafail, My. O.

2018-05-01

Energy is crucial for human life, a secure and accessible supply of power is essential for the sustainability of societies. Economic development and demographic progression increase energy demand, prompting countries to conduct research and studies on energy demand and production. Although, increasing in energy demand in the future requires a correct determination of the amount of energy supplied. Our article studies the impact of demand on energy production to find the relationship between the two latter and managing properly the production between the different energy sources. Historical data of demand and energy production since 2000 are used. The data are processed by the regression model to study the impact of demand on production. The obtained results indicate that demand has a positive and significant impact on production (high impact). Production is also increasing but at a slower pace. In this work, Morocco is considered as a case study.

History of Power Transmission Technologies and Future Prospects of Power System of Chubu Electric Power Company

NASA Astrophysics Data System (ADS)

Takagi, Hirotaka; Sugiyama, Tomonari; Zashibo, Toshihito

Since its foundation, the power system of Chubu Electric Power Company (hereinafter CEPCO) has developed through power source and transmission facility formation to meet electricity demand increases. This development has been accompanied by progress in transmission technologies including capacity scale-up, compactification and power system stabilization to operate complex power systems. Now, changes in business situation due to electricity market liberalizatin may bring new challenges to future facility formation. This paper reviews CEPCO's history of power system formation and progress in transmission technologies, and describes future challenges.

Electrification Opportunities in the Transportation Sector and Impact of Residential Charging

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

Muratori, Matteo

This presentation provides an overview of electrification opportunities in the transportation sector and present results of a study assessing the impact of residential charging on residential power demand and electric power distribution infrastructure.

Engine Would Recover Exhaust Energy More Efficiently

NASA Technical Reports Server (NTRS)

Dimpelfeld, Philip M.

1993-01-01

Exhaust energy used for supercharging and extra shaft power. Flow of exhaust apportioned by waste gate to meet demand of turbocharger, and portion not fed to turbocharger sent to power-recovery turbine. Expected to increase fuel efficiency.

14 CFR 135.4 - Applicability of rules for eligible on-demand operations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... minimum of 500 hours. (ii) For multi-engine turbine-powered fixed-wing and powered-lift aircraft, the... runway to be used has water, snow, slush, ice, or similar contamination that may adversely affect...

Electricity generation from bio-treatment of sewage sludge with microbial fuel cell.

PubMed

Jiang, Junqiu; Zhao, Qingliang; Zhang, Jinna; Zhang, Guodong; Lee, Duu-Jong

2009-12-01

A two-chambered microbial fuel cell (MFC) with potassium ferricyanide as its electron acceptor was utilized to degrade excess sewage sludge and to generate electricity. Stable electrical power was produced continuously during operation for 250 h. Total chemical oxygen demand (TCOD) of sludge was reduced by 46.4% when an initial TCOD was 10,850 mg/l. The MFC power output did not significantly depend on process parameters such as substrate concentration, cathode catholyte concentration, and anodic pH. However, the MFC produced power was in close correlation with the soluble chemical oxygen demand (SCOD) of sludge. Furthermore, ultrasonic pretreatment of sludge accelerated organic matter dissolution and, hence, TCOD removal rate in the MFC was increased, but power output was insignificantly enhanced. This study demonstrates that this MFC can generate electricity from sewage sludge over a wide range of process parameters.

State participation in the creation of fuel-cell-based power plants to meet civilian demand in Russia

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

Pekhota, F.N.

1996-04-01

At present, up to 70% of Russian territory is not covered by central electrical distribution systems. In the field of fuel cell power plants, Russia is at parity with the leading foreign countries with respect to both technical and economic performance and the level of research being conducted. Civilian use of these generating systems on a broad scale, however, demands that a number of problems be solved, particularly those relating to the need for longer plant service life, lower unit cost of electricity, etc. The Ministry of Science and technical Policy of the Russian Federation issued a decree creating amore » new are of concentration, `Fuel Cell Based Power Plants for Civilian Needs,` in the GNTPR `Environmentally Clean Power Industry,` which will form the basis for financial support in this area out of the federal budget.« less

EPPRD: An Efficient Privacy-Preserving Power Requirement and Distribution Aggregation Scheme for a Smart Grid.

PubMed

Zhang, Lei; Zhang, Jing

2017-08-07

A Smart Grid (SG) facilitates bidirectional demand-response communication between individual users and power providers with high computation and communication performance but also brings about the risk of leaking users' private information. Therefore, improving the individual power requirement and distribution efficiency to ensure communication reliability while preserving user privacy is a new challenge for SG. Based on this issue, we propose an efficient and privacy-preserving power requirement and distribution aggregation scheme (EPPRD) based on a hierarchical communication architecture. In the proposed scheme, an efficient encryption and authentication mechanism is proposed for better fit to each individual demand-response situation. Through extensive analysis and experiment, we demonstrate how the EPPRD resists various security threats and preserves user privacy while satisfying the individual requirement in a semi-honest model; it involves less communication overhead and computation time than the existing competing schemes.

An integrated power/attitude control system /IPACS/ for space vehicle application

NASA Technical Reports Server (NTRS)

Anderson, W. W.; Keckler, C. R.

1973-01-01

An integrated power and attitude control system (IPACS) concept with potential application to a broad class of space missions is discussed. The concept involves the storage and supply on demand of electrical energy in rotating flywheels while simultaneously providing control torques by controlled precession of the flywheels. The system is thus an alternative to the storage batteries used on present spacecraft while providing similar capability for attitude control as that represented by a control moment gyroscope (CMG) system. Potential IPACS configurations discussed include single- and double-rotor double-gimbal IPACS units. Typical sets of control laws which would manage the momentum and energy exchange between the IPACS and a typical space vehicle are discussed. Discussion of a simulation of a typical potential IPACS configuration and candidate mission concerned with pointing capability, power supply and demand flow, and discussion of the interactions between stabilization and control requirements and power flow requirements are presented.

EPPRD: An Efficient Privacy-Preserving Power Requirement and Distribution Aggregation Scheme for a Smart Grid

PubMed Central

Zhang, Lei; Zhang, Jing

2017-01-01

A Smart Grid (SG) facilitates bidirectional demand-response communication between individual users and power providers with high computation and communication performance but also brings about the risk of leaking users’ private information. Therefore, improving the individual power requirement and distribution efficiency to ensure communication reliability while preserving user privacy is a new challenge for SG. Based on this issue, we propose an efficient and privacy-preserving power requirement and distribution aggregation scheme (EPPRD) based on a hierarchical communication architecture. In the proposed scheme, an efficient encryption and authentication mechanism is proposed for better fit to each individual demand-response situation. Through extensive analysis and experiment, we demonstrate how the EPPRD resists various security threats and preserves user privacy while satisfying the individual requirement in a semi-honest model; it involves less communication overhead and computation time than the existing competing schemes. PMID:28783122

Electric energy demand and supply prospects for California

NASA Technical Reports Server (NTRS)

Jones, H. G. M.

1978-01-01

A recent history of electricity forecasting in California is given. Dealing with forecasts and regulatory uncertainty is discussed. Graphs are presented for: (1) Los Angeles Department of Water and Power and Pacific Gas and Electric present and projected reserve margins; (2) California electricity peak demand forecast; and (3) California electricity production.

DEMONSTRATION OF THE ENVIRONMENTAL AND DEMAND-SIDE MANAGEMENT BENEFITS OF GRID-CONNECTED PHOTOVOLTAIC POWER SYSTEMS

EPA Science Inventory

This study investigated the pollutant emission reduction and demand-side management potential of 16 photovoltaic (PV) systems installed across the U.S. in 1993 and 1994. The project was sponsored by the U.S. Environmental Protection Agency (EPA) and 11 electric utilities. This ar...

The Quest for Powerful Learning Environments in Higher Education

ERIC Educational Resources Information Center

Slabbert, J. A.; Gouws, D. G.

2006-01-01

An introductory course in on tertiary level inadvertently sets the scene for the demands of the corresponding profession. Unfortunately, it seems as though these courses do not prepare learners adequately to acquire the demanding professional competences required for professional success. This problem has been a subject of contention especially in…

Control of Teacher Certification in the United States

ERIC Educational Resources Information Center

Tobin, Kerri

2012-01-01

Teacher certification trends in the United States since World War II paint a complicated picture of powerful interests at different levels making demands and trying to institute disparate reforms. These patterns have varied over time, often because of teacher supply and demand. The federal government initiated its involvement when education…

Demand Response Advanced Controls Framework and Assessment of Enabling Technology Costs

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

Potter, Jennifer; Cappers, Peter

The Demand Response Advanced Controls Framework and Assessment of Enabling Technology Costs research describe a variety of DR opportunities and the various bulk power system services they can provide. The bulk power system services are mapped to a generalized taxonomy of DR “service types”, which allows us to discuss DR opportunities and bulk power system services in fewer yet broader categories that share similar technological requirements which mainly drive DR enablement costs. The research presents a framework for the costs to automate DR and provides descriptions of the various elements that drive enablement costs. The report introduces the various DRmore » enabling technologies and end-uses, identifies the various services that each can provide to the grid and provides the cost assessment for each enabling technology. In addition to a report, this research includes a Demand Response Advanced Controls Database and User Manual. They are intended to provide users with the data that underlies this research and instructions for how to use that database more effectively and efficiently.« less

Reducing lighting energy use in retail display windows

NASA Astrophysics Data System (ADS)

Freyssinier, Jean Paul; Frering, Daniel; Taylor, Jennifer; Narendran, Nadarajah; Rizzo, Patricia

2006-08-01

A field study was conducted at three clothing stores to validate previous laboratory findings indicating that colored LEDs used as background display lighting could: 1) lower the power demand of accent lighting by up to 50 percent; and 2) provide greater attention capture and visual appeal than current lighting practice. Blue LEDs provided a colored background for window mannequins by illuminating white backdrops. Eliminating fluorescent general lighting and reducing the number and wattage of halogen accent lamps in the display windows reduced the lighting power demand by up to 50 percent. During an eight-week period, more than 700 shoppers rated the attractiveness, eye-catching ability, comfort, and visibility of four different lighting conditions. The results of this field study showed that by introducing color contrast between the displayed objects and the background, the power demand of the accent lighting could be reduced by up to 50 percent without sacrificing visual appeal, visibility, ability to capture the attention of shoppers, and the ability to see the colors of the objects on display. Furthermore, the sales of the products on display were not affected by the 50 percent reduction in lighting.

Evaluating the impacts of real-time pricing on the usage of wind generation

DOE PAGES

Sioshansi, Ramteen; Short, Walter

2009-02-13

One of the impediments to large-scale use of wind generation within power systems is its nondispatchability and variable and uncertain real-time availability. Operating constraints on conventional generators such as minimum generation points, forbidden zones, and ramping limits as well as system constraints such as power flow limits and ancillary service requirements may force a system operator to curtail wind generation in order to ensure feasibility. Furthermore, the pattern of wind availability and electricity demand may not allow wind generation to be fully utilized in all hours. One solution to these issues, which could reduce these inflexibilities, is the use ofmore » real-time pricing (RTP) tariffs which can both smooth-out the diurnal load pattern in order to reduce the impact of binding unit operating and system constraints on wind utilization, and allow demand to increase in response to the availability of costless wind generation. As a result, we use and analyze a detailed unit commitment model of the Texas power system with different estimates of demand elasticities to demonstrate the potential increases in wind generation from implementing RTP.« less

Compounded effects of heat waves and droughts over the Western Electricity Grid: spatio-temporal scales of impacts and predictability toward mitigation and adaptation.

NASA Astrophysics Data System (ADS)

Voisin, N.; Kintner-Meyer, M.; Skaggs, R.; Xie, Y.; Wu, D.; Nguyen, T. B.; Fu, T.; Zhou, T.

2016-12-01

Heat waves and droughts are projected to be more frequent and intense. We have seen in the past the effects of each of those extreme climate events on electricity demand and constrained electricity generation, challenging power system operations. Our aim here is to understand the compounding effects under historical conditions. We present a benchmark of Western US grid performance under 55 years of historical climate, and including droughts, using 2010-level of water demand and water management infrastructure, and 2010-level of electricity grid infrastructure and operations. We leverage CMIP5 historical hydrology simulations and force a large scale river routing- reservoir model with 2010-level sectoral water demands. The regulated flow at each water-dependent generating plants is processed to adjust water-dependent electricity generation parameterization in a production cost model, that represents 2010-level power system operations with hourly energy demand of 2010. The resulting benchmark includes a risk distribution of several grid performance metrics (unserved energy, production cost, carbon emission) as a function of inter-annual variability in regional water availability and predictability using large scale climate oscillations. In the second part of the presentation, we describe an approach to map historical heat waves onto this benchmark grid performance using a building energy demand model. The impact of the heat waves, combined with the impact of droughts, is explored at multiple scales to understand the compounding effects. Vulnerabilities of the power generation and transmission systems are highlighted to guide future adaptation.

2014 Wind Technologies Market Report

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

Wiser, Ryan; Bolinger, Mark; Barbose, Galen

Wind power capacity additions in the United States rebounded in 2014, and continued growth through 2016 is anticipated. Recent and projected near-term growth is supported by the industry’s primary federal incentive—the production tax credit (PTC)—which is available for projects that began construction by the end of 2014. Wind additions are also being driven by recent improvements in the cost and performance of wind power technologies, which have resulted in the lowest power sales prices ever seen in the U.S. wind sector. Growing corporate demand for wind energy and state-level policies play important roles as well. Expectations for continued technological advancementsmore » and cost reductions may further boost future growth. At the same time, the prospects for growth beyond 2016 are uncertain. The PTC has expired, and its renewal remains in question. Continued low natural gas prices, modest electricity demand growth, and limited near-term demand from state renewables portfolio standards (RPS) have also put a damper on growth expectations. These trends, in combination with increasingly global supply chains, have limited the growth of domestic manufacturing of wind equipment. What they mean for wind power additions through the end of the decade and beyond will be dictated in part by future natural gas prices, fossil plant retirements, and policy decisions.« less

Microsoft Producer: A Software Tool for Creating Multimedia PowerPoint[R] Presentations

ERIC Educational Resources Information Center

Leffingwell, Thad R.; Thomas, David G.; Elliott, William H.

2007-01-01

Microsoft[R] Producer[R] is a powerful yet user-friendly PowerPoint companion tool for creating on-demand multimedia presentations. Instructors can easily distribute these presentations via compact disc or streaming media over the Internet. We describe the features of the software, system requirements, and other required hardware. We also describe…

Energy, A Crisis in Power.

ERIC Educational Resources Information Center

Holdren, John; Herrera, Philip

The demand of Americans for more and more power, particularly electric power, contrasted by the deep and growing concern for the environment and a desire by private citizens to participate in the public decisions that affect the environment is the dilemma explored in this book. Part One by John Holdren, offers a scientist's overview of the energy…

TLBO based Voltage Stable Environment Friendly Economic Dispatch Considering Real and Reactive Power Constraints

NASA Astrophysics Data System (ADS)

Verma, H. K.; Mafidar, P.

2013-09-01

In view of growing concern towards environment, power system engineers are forced to generate quality green energy. Hence the economic dispatch (ED) aims at the power generation to meet the load demand at minimum fuel cost with environmental and voltage constraints along with essential constraints on real and reactive power. The emission control which reduces the negative impact on environment is achieved by including the additional constraints in ED problem. Presently, the power system mostly operates near its stability limits, therefore with increased demand the system faces voltage problem. The bus voltages are brought within limit in the present work by placement of static var compensator (SVC) at weak bus which is identified from bus participation factor. The optimal size of SVC is determined by univariate search method. This paper presents the use of Teaching Learning based Optimization (TLBO) algorithm for voltage stable environment friendly ED problem with real and reactive power constraints. The computational effectiveness of TLBO is established through test results over particle swarm optimization (PSO) and Big Bang-Big Crunch (BB-BC) algorithms for the ED problem.

Superconducting Magnetic Energy Storage (SMES) Program

NASA Astrophysics Data System (ADS)

Rogers, J. D.

1985-05-01

The 30 MJ, 10 MW superconducting magnetic energy storage (SMES) system was devised to interact in the Western US Power System as an alternate means to damp unstable oscillations at 0.35 Hz on the Pacific HVAC Interites. The operating limits of the 30 MJ SMES unit were established, and different means of controlling real and reactive power were tested. The unit can follow a sinusoidal power demand signal with an amplitude of up to 8.6 MW with the converter working in a 12 pulse mode. When the converter operates in the constant VAR mode, a time varying real power demand signal of up to 5 MW can be met. It was shown that the Pacific ac Interite has current and reactive power variations of the same frequency as the modulating frequency of the SMES device. The reliability of the SMES subsystems with a narrow band noise input was assessed. Parameters of the ac power system were determined. Converter short circuit tests, load tests under various control conditions, dc breaker tests for coil current interruption, and converter failure mode tests were conducted. The experimental operation of the SMES system is concluded.

Commercialization of LLNL Zinc Air Fuel Cell Technology For Stationary And Mobile Applications And Electromechanical Battery For Mobile Applications Final Report CRADA No. TC-1420-97

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

Tokarz, F. J.; Cooper, J. F.; Haley, D.

Utility deregulation is occurring throughout the world. Energy storage, peak demand leveling and power quality are becoming increasingly important. New, innovative costeffective methods are critical to the financial success or failure of utility companies in the new free market environment. The implementation of energy storage gives a utility the ability to better utilize existing generating capacity. Energy is stored in the periods of low overall demand and then the stored energy is connected to the power grid during peak demand periods. Storing energy in this manner will lead to significant economic benefits to utilities as well as their customers. Furthermore,more » because the utility's system is operated more efficiently there is a direct reduction in atmospheric pollutants including greenhouse gases.« less

Potential for deserts to supply reliable renewable electric power

NASA Astrophysics Data System (ADS)

Labordena, Mercè; Lilliestam, Johan

2015-04-01

To avoid dangerous climate change, the electricity systems must be decarbonized by mid-century. The world has sufficient renewable electricity resources for complete power sector decarbonization, but an expansion of renewables poses several challenges for the electricity systems. First, wind and solar PV power are intermittent and supply-controlled, making it difficult to securely integrate this fluctuating generation into the power systems. Consequently, power sources that are both renewable and dispatchable, such as biomass, hydro and concentrating solar power (CSP), are particularly important. Second, renewable power has a low power density and needs vast areas of land, which is problematic both due to cost reasons and due to land-use conflicts, in particular with agriculture. Renewable and dispatchable technologies that can be built in sparsely inhabited regions or on land with low competition with agriculture would therefore be especially valuable; this land-use competition greatly limits the potential for hydro and biomass electricity. Deserts, however, are precisely such low-competition land, and are at the same time the most suited places for CSP generation, but this option would necessitate long transmission lines from remote places in the deserts to the demand centers such as big cities. We therefore study the potential for fleets of CSP plants in the large deserts of the world to produce reliable and reasonable-cost renewable electricity for regions with high and/or rapidly increasing electricity demand and with a desert within or close to its borders. The regions in focus here are the European Union, North Africa and the Middle East, China and Australia. We conduct the analysis in three steps. First, we identify the best solar generation areas in the selected deserts using geographic information systems (GIS), and applying restrictions to minimize impact on biodiversity, soils, human heath, and land-use and land-cover change. Second, we identify transmission corridors from the generation areas to the demand centers in the target regions, using a GIS-based transmission algorithm that minimizes economic, social and environmental costs. Third, we use the multi-scale energy system model Calliope to specify the optimal configuration and operation of the CSP fleet to reliably follow the demand every hour of the year in the target regions, and to calculate the levelized cost of doing so, including both generation and transmission costs. The final output will show whether and how much reliable renewable electricity can be supplied from CSP fleets in deserts to demand centers in adjacent regions, at which costs this is possible, as well as a detailed description of the routes of HVDC transmission links. We expect to find that the potential for deserts to supply reliable CSP to the regions in focus is very large in all cases, despite the long distances.

Defining Toll Fee of Wheeling Renewable with Reference to a Gas Pipeline in Indonesia

NASA Astrophysics Data System (ADS)

Hakim, Amrullah

2017-07-01

Indonesia has a huge number of renewable energy sources (RE) however; the utilization of these is currently very low. The main challenge of power production is its alignment with consumption levels; supply should equal demand at all times. There is a strong initiative from corporations with high energy demand, compared to other sectors, to apply a renewable portfolio standard for their energy input, e.g. 15% of their energy consumption requirement must come from a renewable energy source. To support this initiative, the utilization of power wheeling will help large factories on industrial estates to source firm and steady renewables from remote sites. The wheeling renewable via PLN’s transmission line has been regulated under the Ministry Decree in 2015 however; the tariff or toll fee has not yet been defined. The potential project to apply wheeling renewable will obtain power supply from a geothermal power plant, with power demand from the scattered factories under one company. This is the concept driving the application of power wheeling in the effort to push the growth of renewable energy in Indonesia. Given that the capacity of PLN’s transmission line are normally large and less congested compared to distribution line, the wheeling renewable can accommodate the scattered factories locations which then results in the cheaper toll fee of the wheeling renewable. Defining the best toll fee is the main topic of this paper with comparison of the toll fee of the gas pipeline infrastructure in Indonesia, so that it can be applied massively to achieve COP21’s commitment.

Managing Sustainable Demand-side Infrastructure for Power System Ancillary Services

NASA Astrophysics Data System (ADS)

Parkinson, Simon Christopher

Widespread access to renewable electricity is seen as a viable method to mitigate carbon emissions, although problematic are the issues associated with the integration of the generation systems within current power system configurations. Wind power plants are the primary large-scale renewable generation technology applied globally, but display considerable short-term supply variability that is difficult to predict. Power systems are currently not designed to operate under these conditions, and results in the need to increase operating reserve in order to guarantee stability. Often, operating conventional generation as reserve is both technically and economically inefficient, which can overshadow positive benefits associated with renewable energy exploitation. The purpose of this thesis is to introduce and assess an alternative method of enhancing power system operations through the control of electric loads. In particular, this thesis focuses on managing highly-distributed sustainable demand-side infrastructure, in the form of heat pumps, electric vehicles, and electrolyzers, as dispatchable short-term energy balancing resources. The main contribution of the thesis is an optimal control strategy capable of simultaneously balancing grid- and demand-side objectives. The viability of the load control strategy is assessed through model-based simulations that explicitly track end-use functionality of responsive devices within a power systems analysis typically implemented to observe the effects of integrated wind energy systems. Results indicate that there is great potential for the proposed method to displace the need for increased reserve capacity in systems considering a high penetration of wind energy, thereby allowing conventional generation to operate more efficiently and avoid the need for possible capacity expansions.

Olfactory bulb gamma oscillations are enhanced with task demands.

PubMed

Beshel, Jennifer; Kopell, Nancy; Kay, Leslie M

2007-08-01

Fast oscillations in neural assemblies have been proposed as a mechanism to facilitate stimulus representation in a variety of sensory systems across animal species. In the olfactory system, intervention studies suggest that oscillations in the gamma frequency range play a role in fine odor discrimination. However, there is still no direct evidence that such oscillations are intrinsically altered in intact systems to aid in stimulus disambiguation. Here we show that gamma oscillatory power in the rat olfactory bulb during a two-alternative choice task is modulated in the intact system according to task demands with dramatic increases in gamma power during discrimination of molecularly similar odorants in contrast to dissimilar odorants. This elevation in power evolves over the course of criterion performance, is specific to the gamma frequency band (65-85 Hz), and is independent of changes in the theta or beta frequency band range. Furthermore, these high amplitude gamma oscillations are restricted to the olfactory bulb, such that concurrent piriform cortex recordings show no evidence of enhanced gamma power during these high-amplitude events. Our results display no modulation in the power of beta oscillations (15-28 Hz) shown previously to increase with odor learning in a Go/No-go task, and we suggest that the oscillatory profile of the olfactory system may be influenced by both odor discrimination demands and task type. The results reported here indicate that enhancement of local gamma power may reflect a switch in the dynamics of the system to a strategy that optimizes stimulus resolution when input signals are ambiguous.

Mobile Nuclear Power Plants 1960-1970

DTIC Science & Technology

1960-11-01

power for electricity for the Army in the Field cannot be realized until a satisfactory electri- cal power distribution system is developed or low...power plants in the 1960-70 period should be to provide electri- cal power to meet concentrated demands such as those im- posed by Army and Corps...Capital Letter - Order of initiation of field plants whoa« deslg- nationa do not Include thia final letter are prototype or pilot planta

Analysing the lack of Demand Organisation

NASA Astrophysics Data System (ADS)

Boxer, Philip; Cohen, Bernard

1998-07-01

We seek to develop means of intervention in Enterprises that will enable them to react in an effective, sustainable and timely fashion to changes in the ways that markets and demand are organized; that is, to act strategically. We take an enterprise to be some entity that seeks to provide its clients with services that they value while maintaining its ability to do so in the face of changes in the demands of its clients and in the resources at its disposal. The services that clients value form around what the organization of their demands lack. The concept of strategy therefore rests on critically evaluating the ontology and semantics of the Enterprise in relation to these holes in demand organization. We access ontology and semantics by constructing and manipulating hypothetical, first-order, mathematical models of the Enterprise's services and of its value-adding processes. Because an enterprise is an anticipatory system, its semantic domain must include representations of the enterprise's model of itself and of the market and demand organizations within which it competes. First-order (set) theory provides adequate expressive power here, but alternative, higher order, mathematical frameworks, such as Dubois' hyperincursion, provide inadequate power, particularly in relation to the analysis of the properties of emergence. Knowing exactly why and where this mathematical lack manifests in the analysis process enables effective collaboration between systems analysts and psychoanalysts, and suggest directions for mathematical research.

Economic environmental dispatch using BSA algorithm

NASA Astrophysics Data System (ADS)

Jihane, Kartite; Mohamed, Cherkaoui

2018-05-01

Economic environmental dispatch problem (EED) is an important issue especially in the field of fossil fuel power plant system. It allows the network manager to choose among different units the most optimized in terms of fuel costs and emission level. The objective of this paper is to minimize the fuel cost with emissions constrained; the test is conducted for two cases: six generator unit and ten generator unit for the same power demand 1200Mw. The simulation has been computed in MATLAB and the result shows the robustness of the Backtracking Search optimization Algorithm (BSA) and the impact of the load demand on the emission.

The General Evolving Model for Energy Supply-Demand Network with Local-World

NASA Astrophysics Data System (ADS)

Sun, Mei; Han, Dun; Li, Dandan; Fang, Cuicui

2013-10-01

In this paper, two general bipartite network evolving models for energy supply-demand network with local-world are proposed. The node weight distribution, the "shifting coefficient" and the scaling exponent of two different kinds of nodes are presented by the mean-field theory. The numerical results of the node weight distribution and the edge weight distribution are also investigated. The production's shifted power law (SPL) distribution of coal enterprises and the installed capacity's distribution of power plants in the US are obtained from the empirical analysis. Numerical simulations and empirical results are given to verify the theoretical results.

Two New R&D 100 Awards Uphold NREL Winning Streak - Continuum Magazine |

Science.gov Websites

-effective and meet the demand for power. Solution: NREL, in partnership with Solar Junction, a manufacturer escalating power costs, brownouts, and rolling blackouts. Solution: NREL and its partners, AILR Research, Inc

Multi-time scale dynamics in power electronics-dominated power systems

NASA Astrophysics Data System (ADS)

Yuan, Xiaoming; Hu, Jiabing; Cheng, Shijie

2017-09-01

Electric power infrastructure has recently undergone a comprehensive transformation from electromagnetics to semiconductors. Such a development is attributed to the rapid growth of power electronic converter applications in the load side to realize energy conservation and on the supply side for renewable generations and power transmissions using high voltage direct current transmission. This transformation has altered the fundamental mechanism of power system dynamics, which demands the establishment of a new theory for power system control and protection. This paper presents thoughts on a theoretical framework for the coming semiconducting power systems.

Running and Metabolic Demands of Elite Rugby Union Assessed Using Traditional, Metabolic Power, and Heart Rate Monitoring Methods

PubMed Central

Dubois, Romain; Paillard, Thierry; Lyons, Mark; McGrath, David; Maurelli, Olivier; Prioux, Jacques

2017-01-01

The aims of this study were (1) to analyze elite rugby union game demands using 3 different approaches: traditional, metabolic and heart rate-based methods (2) to explore the relationship between these methods and (3) to explore positional differences between the backs and forwards players. Time motion analysis and game demands of fourteen professional players (24.1 ± 3.4 y), over 5 European challenge cup games, were analyzed. Thresholds of 14.4 km·h-1, 20 W.kg-1 and 85% of maximal heart rate (HRmax) were set for high-intensity efforts across the three methods. The mean % of HRmax was 80.6 ± 4.3 % while 42.2 ± 16.5% of game time was spent above 85% of HRmax with no significant differences between the forwards and the backs. Our findings also show that the backs cover greater distances at high-speed than forwards (% difference: +35.2 ± 6.6%; p<0.01) while the forwards cover more distance than the backs (+26.8 ± 5.7%; p<0.05) in moderate-speed zone (10-14.4 km·h-1). However, no significant difference in high-metabolic power distance was found between the backs and forwards. Indeed, the high-metabolic power distances were greater than high-speed running distances of 24.8 ± 17.1% for the backs, and 53.4 ± 16.0% for the forwards with a significant difference (+29.6 ± 6.0% for the forwards; p<0.001) between the two groups. Nevertheless, nearly perfect correlations were found between the total distance assessed using the traditional approach and the metabolic power approach (r = 0.98). Furthermore, there is a strong association (r = 0.93) between the high-speed running distance (assessed using the traditional approach) and the high-metabolic power distance. The HR monitoring methods demonstrate clearly the high physiological demands of professional rugby games. The traditional and the metabolic-power approaches shows a close correlation concerning their relative values, nevertheless the difference in absolute values especially for the high-intensity thresholds demonstrates that the metabolic power approach may represent an interesting alternative to the traditional approaches used in evaluating the high-intensity running efforts required in rugby union games. Key points Elite/professional rugby union players Heart rate monitoring during official games Metabolic power approach PMID:28344455

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 methods are presented. The first method is based on a de-loaded technique while the other method is based on utilizing multiple storage facilities. The de-loaded technique is based on characteristics of the power of a wind turbine and estimation of the generated power according to weather forecasting data. The technique provides a reference power by which the wind power system will operate and generate a smooth power. In contrast, utilizing storage facilities will allow the wind power system to operate at its maximum tracking power points' strategy. Two types of energy storages are considered in this research, battery energy storage system (BESS) and pumped-hydropower storage system (PHSS), to suppress the output fluctuations and to support the wind power system to follow the system load demands. Furthermore, this method provides the ability to store energy when there is a surplus of the generated power and to reuse it when there is a shortage of power generation from wind power systems. Both methods are new in terms of utilizing of the techniques and wind speed data. A microprocessor embedded system using an IntelRTM Atom(TM) processor is presented for controlling the wind power system and for providing the remote communication for enhancing the operation of the individual wind power system in a wind farm. The embedded system helps the wind power system to respond and to follow the commands of the central control of the power system. Moreover, it enhances the performance of the wind power system through self-managing, self-functioning, and self-correcting. Finally, a method of system power management and planning is modeled and studied for a grid containing large-scale wind power systems. The method is based on a new technique through constructing a new load demand curve (NLDC) from merging the estimation of generated power from wind power systems and forecasting of the load. To summarize, the methods and their results presented in this dissertation, enhance the operation of the large-scale wind power systems and reduce their drawbacks on the operation of the power grid.

Insulation Requirements of High-Voltage Power Systems in Future Spacecraft

NASA Technical Reports Server (NTRS)

Qureshi, A. Haq; Dayton, James A., Jr.

1995-01-01

The scope, size, and capability of the nation's space-based activities are limited by the level of electrical power available. Long-term projections show that there will be an increasing demand for electrical power in future spacecraft programs. The level of power that can be generated, conditioned, transmitted, and used will have to be considerably increased to satisfy these needs, and increased power levels will require that transmission voltages also be increased to minimize weight and resistive losses. At these projected voltages, power systems will not operate satisfactorily without the proper electrical insulation. Open or encapsulated power supplies are currently used to keep the volume and weight of space power systems low and to protect them from natural and induced environmental hazards. Circuits with open packaging are free to attain the pressure of the outer environment, whereas encapsulated circuits are imbedded in insulating materials, which are usually solids, but could be liquids or gases. Up to now, solid insulation has usually been chosen for space power systems. If the use of solid insulation is continued, when voltages increase, the amount of insulation for encapsulation also will have to increase. This increased insulation will increase weight and reduce system reliability. Therefore, non-solid insulation media must be examined to satisfy future spacecraft power and voltage demands. In this report, we assess the suitability of liquid, space vacuum, and gas insulation for space power systems.

Multi-Temporal Decomposed Wind and Load Power Models for Electric Energy Systems

NASA Astrophysics Data System (ADS)

Abdel-Karim, Noha

This thesis is motivated by the recognition that sources of uncertainties in electric power systems are multifold and may have potentially far-reaching effects. In the past, only system load forecast was considered to be the main challenge. More recently, however, the uncertain price of electricity and hard-to-predict power produced by renewable resources, such as wind and solar, are making the operating and planning environment much more challenging. The near-real-time power imbalances are compensated by means of frequency regulation and generally require fast-responding costly resources. Because of this, a more accurate forecast and look-ahead scheduling would result in a reduced need for expensive power balancing. Similarly, long-term planning and seasonal maintenance need to take into account long-term demand forecast as well as how the short-term generation scheduling is done. The better the demand forecast, the more efficient planning will be as well. Moreover, computer algorithms for scheduling and planning are essential in helping the system operators decide what to schedule and planners what to build. This is needed given the overall complexity created by different abilities to adjust the power output of generation technologies, demand uncertainties and by the network delivery constraints. Given the growing presence of major uncertainties, it is likely that the main control applications will use more probabilistic approaches. Today's predominantly deterministic methods will be replaced by methods which account for key uncertainties as decisions are made. It is well-understood that although demand and wind power cannot be predicted at very high accuracy, taking into consideration predictions and scheduling in a look-ahead way over several time horizons generally results in more efficient and reliable utilization, than when decisions are made assuming deterministic, often worst-case scenarios. This change is in approach is going to ultimately require new electricity market rules capable of providing the right incentives to manage uncertainties and of differentiating various technologies according to the rate at which they can respond to ever changing conditions. Given the overall need for modeling uncertainties in electric energy systems, we consider in this thesis the problem of multi-temporal modeling of wind and demand power, in particular. Historic data is used to derive prediction models for several future time horizons. Short-term prediction models derived can be used for look-ahead economic dispatch and unit commitment, while the long-term annual predictive models can be used for investment planning. As expected, the accuracy of such predictive models depends on the time horizons over which the predictions are made, as well as on the nature of uncertain signals. It is shown that predictive models obtained using the same general modeling approaches result in different accuracy for wind than for demand power. In what follows, we introduce several models which have qualitatively different patterns, ranging from hourly to annual. We first transform historic time-stamped data into the Fourier Transform (Fr) representation. The frequency domain data representation is used to decompose the wind and load power signals and to derive predictive models relevant for short-term and long-term predictions using extracted spectral techniques. The short-term results are interpreted next as a Linear Prediction Coding Model (LPC) and its accuracy is analyzed. Next, a new Markov-Based Sensitivity Model (MBSM) for short term prediction has been proposed and the dispatched costs of uncertainties for different predictive models with comparisons have been developed. Moreover, the Discrete Markov Process (DMP) representation is applied to help assess probabilities of most likely short-, medium- and long-term states and the related multi-temporal risks. In addition, this thesis discusses operational impacts of wind power integration in different scenario levels by performing more than 9,000 AC Optimal Power Flow runs. The effects of both wind and load variations on system constraints and costs are presented. The limitations of DC Optimal Power Flow (DCOPF) vs. ACOPF are emphasized by means of system convergence problems due to the effect of wind power on changing line flows and net power injections. By studying the effect of having wind power on line flows, we found that the divergence problem applies in areas with high wind and hydro generation capacity share (cheap generations). (Abstract shortened by UMI.).

Market-Based Decision Guidance Framework for Power and Alternative Energy Collaboration

NASA Astrophysics Data System (ADS)

Altaleb, Hesham

With the introduction of power energy markets deregulation, innovations have transformed once a static network into a more flexible grid. Microgrids have also been deployed to serve various purposes (e.g., reliability, sustainability, etc.). With the rapid deployment of smart grid technologies, it has become possible to measure and record both, the quantity and time of the consumption of electrical power. In addition, capabilities for controlling distributed supply and demand have resulted in complex systems where inefficiencies are possible and where improvements can be made. Electric power like other volatile resources cannot be stored efficiently, therefore, managing such resource requires considerable attention. Such complex systems present a need for decisions that can streamline consumption, delay infrastructure investments, and reduce costs. When renewable power resources and the need for limiting harmful emissions are added to the equation, the search space for decisions becomes increasingly complex. As a result, the need for a comprehensive decision guidance system for electrical power resources consumption and productions becomes evident. In this dissertation, I formulate and implement a comprehensive framework that addresses different aspect of the electrical power generation and consumption using optimization models and utilizing collaboration concepts. Our solution presents a two-prong approach: managing interaction in real-time for the short-term immediate consumption of already allocated resources; and managing the operational planning for the long-run consumption. More specifically, in real-time, we present and implement a model of how to organize a secondary market for peak-demand allocation and describe the properties of the market that guarantees efficient execution and a method for the fair distribution of collaboration gains. We also propose and implement a primary market for peak demand bounds determination problem with the assumption that participants of this market have the ability to collaborate in real-time. Moreover, proposed in this dissertation is an extensible framework to facilitate C&I entities forming a consortium to collaborate on their electric power supply and demand. The collaborative framework includes the structure of market setting, bids, and market resolution that produces a schedule of how power components are controlled as well as the resulting payment. The market resolution must satisfy a number of desirable properties (i.e., feasibility, Nash equilibrium, Pareto optimality, and equal collaboration profitability) which are formally defined in the dissertation. Furthermore, to support the extensible framework components' library, power components such as utility contract, back-up power generator, renewable resource, and power consuming service are formally modeled. Finally, the validity of this framework is evaluated by a case study using simulated load scenarios to examine the ability of the framework to efficiently operate at the specified time intervals with minimal overhead cost.

Powered off-road wheelchair for the transportation of tetraplegics along mountain trails.

PubMed

Antonelli, Michele Gabrio; Alleva, Stefano; Beomonte Zobel, Pierluigi; Durante, Francesco; Raparelli, Terenziano

2017-12-08

For off-road mobility, some manual or power assisted devices were conceived to be self-driven by paraplegics while for tetraplegics non power-assisted devices were conceived. These devices require one or more conductors who are subjected to a high physical demand thus potentially creating: precarious safety condition for the user an elevated physical demand of conductors could reduce the care and the attention to give to the user; the time of the outdoor adventure experience of the user could be limited. To address these issues, an innovative user-centered power assisted off-road wheelchair for the transportation of tetraplegics along mountain trails was developed. The device, structured like a trike, is driven by two healthy conductors; the user is placed in the middle of the frame. A movable seat provides for the transfer from the standard to the off-road wheelchair. An electrical motor, powered by a battery pack, provides for the actuation. All the design and prototype aspects, the control system and experimental tests are detailed. The prototype satisfies mechanical, safety and duration requirements. No physical demand while using the device and for the transfer of the user to the device was identified. Fun and engaging tests were carried out and all the participants were involved. Implications for Rehabilitation The device has the potential to enhance the quality of life of tetraplegics in terms of new life experiences. The device revealed the real possibility of a full recreational experience, an enhanced participation and a better social integration of tetraplegics.

Capital investment requirements for greenhouse gas emissions mitigation in power generation on near term to century time scales and global to regional spatial scales

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

Chaturvedi, Vaibhav; Clarke, Leon E.; Edmonds, James A.

Electrification plays a crucial role in cost-effective greenhouse gas emissions mitigation strategies. Such strategies in turn carry implications for financial capital markets. This paper explores the implication of climate mitigation policy for capital investment demands by the electric power sector on decade to century time scales. We go further to explore the implications of technology performance and the stringency of climate policy for capital investment demands by the power sector. Finally, we discuss the regional distribution of investment demands. We find that stabilizing GHG emissions will require additional investment in the electricity generation sector over and above investments that wouldmore » be need in the absence of climate policy, in the range of 16 to 29 Trillion US$ (60-110%) depending on the stringency of climate policy during the period 2015 to 2095 under default technology assumptions. This increase reflects the higher capital intensity of power systems that control emissions. Limits on the penetration of nuclear and carbon capture and storage technology could increase costs substantially. Energy efficiency improvements can reduce the investment requirement by 8 to21 Trillion US$ (default technology assumptions), depending on climate policy scenario with higher savings being obtained under the most stringent climate policy. The heaviest investments in power generation were observed in the China, India, SE Asia and Africa regions with the latter three regions dominating in the second half of the 21st century.« less

A new market risk model for cogeneration project financing---combined heat and power development without a power purchase agreement

NASA Astrophysics Data System (ADS)

Lockwood, Timothy A.

Federal legislative changes in 2006 no longer entitle cogeneration project financings by law to receive the benefit of a power purchase agreement underwritten by an investment-grade investor-owned utility. Consequently, this research explored the need for a new market-risk model for future cogeneration and combined heat and power (CHP) project financing. CHP project investment represents a potentially enormous energy efficiency benefit through its application by reducing fossil fuel use up to 55% when compared to traditional energy generation, and concurrently eliminates constituent air emissions up to 50%, including global warming gases. As a supplemental approach to a comprehensive technical analysis, a quantitative multivariate modeling was also used to test the statistical validity and reliability of host facility energy demand and CHP supply ratios in predicting the economic performance of CHP project financing. The resulting analytical models, although not statistically reliable at this time, suggest a radically simplified CHP design method for future profitable CHP investments using four easily attainable energy ratios. This design method shows that financially successful CHP adoption occurs when the average system heat-to-power-ratio supply is less than or equal to the average host-convertible-energy-ratio, and when the average nominally-rated capacity is less than average host facility-load-factor demands. New CHP investments can play a role in solving the world-wide problem of accommodating growing energy demand while preserving our precious and irreplaceable air quality for future generations.

Task complexity modulates pilot electroencephalographic activity during real flights.

PubMed

Di Stasi, Leandro L; Diaz-Piedra, Carolina; Suárez, Juan; McCamy, Michael B; Martinez-Conde, Susana; Roca-Dorda, Joaquín; Catena, Andrés

2015-07-01

Most research connecting task performance and neural activity to date has been conducted in laboratory conditions. Thus, field studies remain scarce, especially in extreme conditions such as during real flights. Here, we investigated the effects of flight procedures of varied complexity on the in-flight EEG activity of military helicopter pilots. Flight procedural complexity modulated the EEG power spectrum: highly demanding procedures (i.e., takeoff and landing) were associated with higher EEG power in the higher frequency bands, whereas less demanding procedures (i.e., flight exercises) were associated with lower EEG power over the same frequency bands. These results suggest that EEG recordings may help to evaluate an operator's cognitive performance in challenging real-life scenarios, and thus could aid in the prevention of catastrophic events. © 2015 Society for Psychophysiological Research.

The pricing behavior comparison of Canada and Australia exporter in wheat international market using Pricing to Market (PTM) and Residual Demand Elasticity (RDE)

NASA Astrophysics Data System (ADS)

Wibowo, R. P.; Sumono; Iddrisu, Y.; Darus, M.; Sihombing, L. P.; Jufri

2018-02-01

This paper try to identify and examined the degree of market power on wheat international market by 2 major exporting countries comprising Canada and Australia by using the Pricing to Market (PTM) method and Residual Demand Elasticity (RDE) method. The PTM method found that Canada impose noncompetitive strategy by applying price discrimination and apply market power to their importing. Different results come from Australian exporter as they are not using their market power to the importing. Conflicting result arise from estimation using RDE and PTM method suggest that the need to extend the theoretical model of both model by expand its economic and econometric model to have consistent expected result theoretically and empirically.

DEMONSTRATION OF THE ENVIRONMENTAL AND DEMAND-SIDE MANAGEMENT BENEFITS OF GRID-CONNECTED PHOTOVOLTAIC POWER SYSTEMS SITED ON MILITARY BASES

EPA Science Inventory

The report gives results of an investigation into the pollutant emission reduction and demand-side management potential of three photovoltaic (PV) systems installed at Ft. Huachuca, AZ, Ft. Dix, NJ, and Hickam Air Force Base, HI, which began operation between January and July 199...

DEMONSTRATION OF THE ENVIRONMENTAL AND DEMAND-SIDE MANAGEMENT BENEFITS OF GRID-CONNECTED PHOTOVOLTAIC POWER SYSTEMS

EPA Science Inventory

The report gives results of an investigation of the pollutant emission reduction and demand-side management potential of 16 photovoltaic (PV) systems installed across the U.S. in 1993 and 1994. The investigation was sponsored by the U.S. EPA and 11 electric utilities. The report ...

Will the Real Eco-Educator Please Stand Up?

ERIC Educational Resources Information Center

Ross, Janet

This paper examines the long-term impact on public lands of human-powered adventure activities. These activities take individuals into federal- or state-owned wild areas to enjoy backpacking, hiking, camping, and a wide variety of sports. Trends in supply and demand for outdoor opportunities are explored. Factors influencing demand include growing…

Storing Renewable Energy in Chemical Bonds

ScienceCinema

Helm, Monte; Bullock, Morris

2018-01-16

With nearly 7 billion people, the world's population is demanding more electricity every year. Improved technologies are bringing wind and solar power to our electrical grid. However, wind turbines and solar panels only work when the wind blows or the sun shines. PNNL scientists discuss catalysis approaches for storing and releasing energy on demand.

The Responsibilisation of Teachers: A Neoliberal Solution to the Problem of Inclusion

ERIC Educational Resources Information Center

Done, Elizabeth J.; Murphy, Mike

2018-01-01

This paper critically examines competing demands placed on teachers, with reference to recent inclusion policy in England and Australia. The authors draw on Michael Foucault's analysis of power, neoliberalism(s) and biopolitics to explore the ways in which teachers are "responsibilised" into negotiating and fulfilling demands related to…

A Study of the Relationship between Weather Variables and Electric Power Demand inside a Smart Grid/Smart World Framework

PubMed Central

Hernández, Luis; Baladrón, Carlos; Aguiar, Javier M.; Calavia, Lorena; Carro, Belén; Sánchez-Esguevillas, Antonio; Cook, Diane J.; Chinarro, David; Gómez, Jorge

2012-01-01

One of the main challenges of today's society is the need to fulfill at the same time the two sides of the dichotomy between the growing energy demand and the need to look after the environment. Smart Grids are one of the answers: intelligent energy grids which retrieve data about the environment through extensive sensor networks and react accordingly to optimize resource consumption. In order to do this, the Smart Grids need to understand the existing relationship between energy demand and a set of relevant climatic variables. All smart “systems” (buildings, cities, homes, consumers, etc.) have the potential to employ their intelligence for self-adaptation to climate conditions. After introducing the Smart World, a global framework for the collaboration of these smart systems, this paper presents the relationship found at experimental level between a range of relevant weather variables and electric power demand patterns, presenting a case study using an agent-based system, and emphasizing the need to consider this relationship in certain Smart World (and specifically Smart Grid and microgrid) applications.

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

Aabakken, J.

This report, prepared by NREL's Strategic Energy Analysis Center, includes up-to-date information on power technologies, including complete technology profiles. The data book also contains charts on electricity restructuring, power technology forecasts, electricity supply, electricity capability, electricity generation, electricity demand, prices, economic indicators, environmental indicators, and conversion factors.

Exploring Students' Ideas about Risks and Benefits of Nuclear Power Using Risk Perception Theories

ERIC Educational Resources Information Center

Kilinc, Ahmet; Boyes, Edward; Stanisstreet, Martin

2013-01-01

Due to increased energy demand, Turkey is continuing to explore the possibilities of introducing nuclear power. Gaining acceptance from local populations, however, may be problematic because nuclear power has a negative image and risk perceptions are complicated by a range of psychological and cultural factors. In this study, we explore the views…

Managing the Night Off-Peak Power Demand in the Central Region UPS with Newly Commissioned NPP Capacities

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

Aminov, R. Z.; Pron’, D. M.

2014-01-15

The use of hydrogen technologies as a controlled-load consumer based on the newly commissioned base-load nuclear power plants to level out the daily load profile is justified for the Unified Power System (UPS) of the Central Region of Russia, as an example, for the period till 2020.

Skills-demands compatibility as a determinant of flow experience in an inductive reasoning task.

PubMed

Schiefele, Ulrich; Raabe, Andreas

2011-10-01

The skills-demands fit hypothesis of flow theory was examined. Based on the earlier finding that high demands in a game situation do not reduce the experience of flow, a cognitive task paradigm was used. The effect of skills-demands compatibility on the experience of flow but not of other, similar psychological states (i.e., concentration, negative and positive activation) was also investigated. Participants were 89 undergraduate students who worked on a number of inductive reasoning tasks in four successive trials with or without skills-demands compatibility. The results clearly supported the skills-demands fit hypothesis; concentration and activation were affected only by the tasks' difficulty. Inductive reasoning tasks are a useful tool for the experimental analysis of flow, and skills-demands compatibility is a significant and powerful condition of flow, but not of other, similar psychological states.

Analysis of dynamic channel power equalization by using nonlinear amplifying Sagnac interferometer for ASK-WDM optical transmission

NASA Astrophysics Data System (ADS)

Qu, Feng; Liu, Xiaoming; Zhao, Jianhui

2004-05-01

A power equalization using an asymmetric nonlinear amplifying Sagnac interferometer (NASI) for ASK modulation is studied numerically. A nonreciprocal phase bias was proposed to be introduced into the structure. The nonreciprocal phase bias reduces not only the demanding for amplifier power or fiber non-linearity, but also increase the dynamic input power range. The power equalization is demonstrated for RZ modulation by nonlinear phase analysis and eye diagram simulation.

Using coal inside California for electric power

NASA Technical Reports Server (NTRS)

Moore, J. B.

1978-01-01

In a detailed analysis performed at Southern California Edison on a wide variety of technologies, the direct combustion of coal and medium BTU gas from coal were ranked just below nuclear power for future nonpetroleum based electric power generation. As a result, engineering studies were performed for demonstration projects for the direct combustion of coal and medium BTU gas from coal. Graphs are presented for power demand, and power cost. Direct coal combustion and coal gasification processes are presented.

A Novel Methodology for Charging Station Deployment

NASA Astrophysics Data System (ADS)

Sun, Zhonghao; Zhao, Yunwei; He, Yueying; Li, Mingzhe

2018-02-01

Lack of charging stations has been a main obstacle to the promotion of electric vehicles. This paper studies deploying charging stations in traffic networks considering grid constraints to balance the charging demand and grid stability. First, we propose a statistical model for charging demand. Then we combine the charging demand model with power grid constraints and give the formulation of the charging station deployment problem. Finally, we propose a theoretical solution for the problem by transforming it to a Markov Decision Process.

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

Ryu, Jun Hyung; Lee, Soo bin; Hodge, Bri-Mathias

The energy system of process industry are faced with a new unprecedented challenge. Renewable energies should be incorporated but single of them cannot meet its energy demand of high degree and a large quantity. This paper investigates a simulation framework to compute the capacity of multiple energy sources including solar, wind power, diesel and batteries. The framework involves actual renewable energy supply and demand profile generation and supply demand matching. Eight configurations of different supply options are evaluated to illustrate the applicability of the proposed framework with some remarks.

Business Pattern of Distributed Energy in Electric Power System Reformation

NASA Astrophysics Data System (ADS)

Liang, YUE; Zhuochu, LIU; Jun, LI; Siwei, LI

2017-05-01

Under the trend of the electric power system revolution, the operation mode of micro power grid that including distributed power will be more diversified. User’s demand response and different strategies on electricity all have great influence on the operation of distributed power grid. This paper will not only research sensitive factors of micro power grid operation, but also analyze and calculate the cost and benefit of micro power grid operation upon different types. Then it will build a tech-economic calculation model, which applies to different types of micro power grid under the reformation of electric power system.

ESTIMATING RISK TO CALIFORNIA ENERGY INFRASTRUCTURE FROM PROJECTED CLIMATE CHANGE

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

Sathaye, Jayant; Dale, Larry; Larsen, Peter

2011-06-22

This report outlines the results of a study of the impact of climate change on the energy infrastructure of California and the San Francisco Bay region, including impacts on power plant generation; transmission line and substation capacity during heat spells; wildfires near transmission lines; sea level encroachment upon power plants, substations, and natural gas facilities; and peak electrical demand. Some end-of-century impacts were projected:Expected warming will decrease gas-fired generator efficiency. The maximum statewide coincident loss is projected at 10.3 gigawatts (with current power plant infrastructure and population), an increase of 6.2 percent over current temperature-induced losses. By the end ofmore » the century, electricity demand for almost all summer days is expected to exceed the current ninetieth percentile per-capita peak load. As much as 21 percent growth is expected in ninetieth percentile peak demand (per-capita, exclusive of population growth). When generator losses are included in the demand, the ninetieth percentile peaks may increase up to 25 percent. As the climate warms, California's peak supply capacity will need to grow faster than the population.Substation capacity is projected to decrease an average of 2.7 percent. A 5C (9F) air temperature increase (the average increase predicted for hot days in August) will diminish the capacity of a fully-loaded transmission line by an average of 7.5 percent.The potential exposure of transmission lines to wildfire is expected to increase with time. We have identified some lines whose probability of exposure to fire are expected to increase by as much as 40 percent. Up to 25 coastal power plants and 86 substations are at risk of flooding (or partial flooding) due to sea level rise.« less

Optimal Scheduling of Time-Shiftable Electric Loads in Expeditionary Power Grids

DTIC Science & Technology

2015-09-01

NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS OPTIMAL SCHEDULING OF TIME-SHIFTABLE ELECTRIC LOADS IN EXPEDITIONARY POWER GRIDS by John G...to 09-25-2015 4. TITLE AND SUBTITLE OPTIMAL SCHEDULING OF TIME-SHIFTABLE ELECTRIC LOADS IN EXPEDI- TIONARY POWER GRIDS 5. FUNDING NUMBERS 6. AUTHOR(S...eliminate unmanaged peak demand, reduce generator peak-to-average power ratios, and facilitate a persistent shift to higher fuel efficiency. Using

Empirical cost models for estimating power and energy consumption in database servers

NASA Astrophysics Data System (ADS)

Valdivia Garcia, Harold Dwight

The explosive growth in the size of data centers, coupled with the widespread use of virtualization technology has brought power and energy consumption as major concerns for data center administrators. Provisioning decisions must take into consideration not only target application performance but also the power demands and total energy consumption incurred by the hardware and software to be deployed at the data center. Failure to do so will result in damaged equipment, power outages, and inefficient operation. Since database servers comprise one of the most popular and important server applications deployed in such facilities, it becomes necessary to have accurate cost models that can predict the power and energy demands that each database workloads will impose in the system. In this work we present an empirical methodology to estimate the power and energy cost of database operations. Our methodology uses multiple-linear regression to derive accurate cost models that depend only on readily available statistics such as selectivity factors, tuple size, numbers columns and relational cardinality. Moreover, our method does not need measurement of individual hardware components, but rather total power and energy consumption measured at a server. We have implemented our methodology, and ran experiments with several server configurations. Our experiments indicate that we can predict power and energy more accurately than alternative methods found in the literature.

Methods for and estimates of 2003 and projected water use in the Seacoast Region, Southeastern New Hampshire

USGS Publications Warehouse

Horn, Marilee A.; Moore, Richard B.; Hayes, Laura; Flanagan, Sarah M.

2008-01-01

New methods were developed to estimate water use in 2003 and future water demand in 2017 and 2025 in the Seacoast region in southeastern New Hampshire, which has experienced a 37-percent population increase during 1980 to 2000. Water-use activities for which estimates were developed include water withdrawal, delivery, demand, consumptive use, release, return flow, and transfer by registered and aggregated unregistered (less than 20,000 gallons per day (gal/d)) users at the census-block and town scales. Estimates of water use rely on understanding what influences water demand and its associated consumptive use, because changes in demand and consumptive use affect withdrawal and return flow. Domestic water demand was estimated using a per capita water demand model that related metered deliveries to domestic users with census block and block-group data. The model was used to predict annual, summer, and winter per capita water-demand coefficients for each census block. Significant predictors of domestic water demand include population per housing unit, median value of owner-occupied single family homes, median year of housing construction (with 1900 as the base value), population density, housing unit density, and proportion of housing units that are in urban areas. Mean annual domestic per capita water-demand coefficient in the Seacoast region was 75 gal/d; the coefficient increased to 91 gal/d during the summer and decreased to 65 gal/d during the winter. Domestic consumptive use was estimated as the difference between annual and winter domestic water demand. Estimates of commercial and industrial water demand were based on coefficients derived from reported use and metered deliveries. Projections of water demand in 2017 and 2025 were determined by using the housing and employee projections for those years developed through a Transportation Demand Model and applying current domestic and non-domestic coefficients. Water demand in 2003 was estimated as 25.8 million gallons per day (Mgal/d), 35 percent of which was during the summer months of June, July, and August. Domestic water demand was 18.6 Mgal/d (72 percent), commercial water demand was 3.7 Mgal/d (14 percent), industrial water demand was 2.9 Mgal/d (11 percent), irrigation water demand was 0.3 Mgal/d (1 percent), and mining and aquaculture water demand was 0.2 Mgal/d (1 percent). Domestic consumptive use for the Seacoast region was 16 percent of domestic water demand, which translates to a loss of 3 Mgal/d over the entire Seacoast region. In 2003, water withdrawal was 771.2 Mgal/d, of which 742.2 Mgal/d was instream use for hydroelectric power generation and thermoelectric power cooling. The remaining 29.0 Mgal/d was withdrawn by community water systems (22.6 Mgal/d; 72 percent), domestic users (6.4 Mgal/d; 21 percent), commercial users (1.0 Mgal/d; 3 percent), industrial users (1.0 Mgal/d; 3 percent), irrigation (0.2 Mgal/d; 1 percent) and other users (less than 0.1 Mgal/d). Return flow for 2003 was 772.2 Mgal/d, of which 742.0 Mgal/d was returned following use for hydroelectric power generation and thermoelectric plant cooling. The remaining 30.2 Mgal/d was returned by community wastewater systems (20.2 Mgal/d; 68 percent), domestic users (7.8 Mgal/d; 26 percent), commercial users (1.2 Mgal/d; 3 percent), industrial users (0.8 Mgal/d; 3 percent), and other users (0.1 Mgal/d). Domestic water demand is projected to increase by 54 percent to 28.7 Mgal/d from 2003 to 2025 based on projection of future population growth. Non-domestic (commercial, industrial, irrigation, and mining) water demand is projected to increase by 66 percent to 11.8 Mgal/d from 2003 to 2025.

Solar Power. Policy Overview and Good Practices

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

Cox, Sadie; Walters, Terri; Esterly, Sean

2015-05-01

As global electricity demand increases, governments are designing and implementing policies to scale up and catalyze renewable energy, which now meets 22% of global electricity demand (REN21 2014). Solar technologies are a critical component of this expanded deployment, and they have experienced unprecedented growth in recent years. As presented in Figure 1, solar prices have decreased significantly over the last decade (REN21 2014) and in 2013, new capacity installation of solar electricity from photovoltaics (PV) 1 surpassed all other renewable energy technologies worldwide—excluding hydropower—with 39 gigawatts installed that year. Concentrating solar thermal power,2 although it still represents a fairly nascentmore » market, also continues to expand as installed capacity increased by 36% in 2013 compared to 2012. In addition to meeting energy demand in an increasingly cost-effective manner, solar deployment can also support critical economic, social, and environmental development goals (Flavin and Hull Aeck, n.d.).« less

Robust optimization based energy dispatch in smart grids considering demand uncertainty

NASA Astrophysics Data System (ADS)

Nassourou, M.; Puig, V.; Blesa, J.

2017-01-01

In this study we discuss the application of robust optimization to the problem of economic energy dispatch in smart grids. Robust optimization based MPC strategies for tackling uncertain load demands are developed. Unexpected additive disturbances are modelled by defining an affine dependence between the control inputs and the uncertain load demands. The developed strategies were applied to a hybrid power system connected to an electrical power grid. Furthermore, to demonstrate the superiority of the standard Economic MPC over the MPC tracking, a comparison (e.g average daily cost) between the standard MPC tracking, the standard Economic MPC, and the integration of both in one-layer and two-layer approaches was carried out. The goal of this research is to design a controller based on Economic MPC strategies, that tackles uncertainties, in order to minimise economic costs and guarantee service reliability of the system.

Hierarchical control framework for integrated coordination between distributed energy resources and demand response

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

Wu, Di; Lian, Jianming; Sun, Yannan

Demand response is representing a significant but largely untapped resource that can greatly enhance the flexibility and reliability of power systems. In this paper, a hierarchical control framework is proposed to facilitate the integrated coordination between distributed energy resources and demand response. The proposed framework consists of coordination and device layers. In the coordination layer, various resource aggregations are optimally coordinated in a distributed manner to achieve the system-level objectives. In the device layer, individual resources are controlled in real time to follow the optimal power generation or consumption dispatched from the coordination layer. For the purpose of practical applications,more » a method is presented to determine the utility functions of controllable loads by taking into account the real-time load dynamics and the preferences of individual customers. The effectiveness of the proposed framework is validated by detailed simulation studies.« less

Diversity modelling for electrical power system simulation

NASA Astrophysics Data System (ADS)

Sharip, R. M.; Abu Zarim, M. A. U. A.

2013-12-01

This paper considers diversity of generation and demand profiles against the different future energy scenarios and evaluates these on a technical basis. Compared to previous studies, this research applied a forecasting concept based on possible growth rates from publically electrical distribution scenarios concerning the UK. These scenarios were created by different bodies considering aspects such as environment, policy, regulation, economic and technical. In line with these scenarios, forecasting is on a long term timescale (up to every ten years from 2020 until 2050) in order to create a possible output of generation mix and demand profiles to be used as an appropriate boundary condition for the network simulation. The network considered is a segment of rural LV populated with a mixture of different housing types. The profiles for the 'future' energy and demand have been successfully modelled by applying a forecasting method. The network results under these profiles shows for the cases studied that even though the value of the power produced from each Micro-generation is often in line with the demand requirements of an individual dwelling there will be no problems arising from high penetration of Micro-generation and demand side management for each dwellings considered. The results obtained highlight the technical issues/changes for energy delivery and management to rural customers under the future energy scenarios.

Individual muscle contributions to push and recovery subtasks during wheelchair propulsion.

PubMed

Rankin, Jeffery W; Richter, W Mark; Neptune, Richard R

2011-04-29

Manual wheelchair propulsion places considerable physical demand on the upper extremity and is one of the primary activities associated with the high prevalence of upper extremity overuse injuries and pain among wheelchair users. As a result, recent effort has focused on determining how various propulsion techniques influence upper extremity demand during wheelchair propulsion. However, an important prerequisite for identifying the relationships between propulsion techniques and upper extremity demand is to understand how individual muscles contribute to the mechanical energetics of wheelchair propulsion. The purpose of this study was to use a forward dynamics simulation of wheelchair propulsion to quantify how individual muscles deliver, absorb and/or transfer mechanical power during propulsion. The analysis showed that muscles contribute to either push (i.e., deliver mechanical power to the handrim) or recovery (i.e., reposition the arm) subtasks, with the shoulder flexors being the primary contributors to the push and the shoulder extensors being the primary contributors to the recovery. In addition, significant activity from the shoulder muscles was required during the transition between push and recovery, which resulted in increased co-contraction and upper extremity demand. Thus, strengthening the shoulder flexors and promoting propulsion techniques that improve transition mechanics have much potential to reduce upper extremity demand and improve rehabilitation outcomes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Energy Efficiency and Demand Response for Residential Applications

NASA Astrophysics Data System (ADS)

Wellons, Christopher J., II

The purpose of this thesis is to analyze the costs, feasibility and benefits of implementing energy efficient devices and demand response programs to a residential consumer environment. Energy efficiency and demand response are important for many reasons, including grid stabilization. With energy demand increasing, as the years' pass, the drain on the grid is going up. There are two key solutions to this problem, increasing supply by building more power plants and decreasing demand during peak periods, by increasing participation in demand response programs and by upgrading residential and commercial customers to energy efficient devices, to lower demand throughout the day. This thesis focuses on utilizing demand response methods and energy efficient device to reduce demand. Four simulations were created to analyze these methods. These simulations show the importance of energy efficiency and demand response participation to help stabilize the grid, integrate more alternative energy resources, and reduce emissions from fossil fuel generating facilities. The results of these numerical analyses show that demand response and energy efficiency can be beneficial to consumers and utilities. With demand response being the most beneficial to the utility and energy efficiency, specifically LED lighting, providing the most benefits to the consumer.

Research on electricity market operation mechanism and its benefit of demand side participation

NASA Astrophysics Data System (ADS)

Han, Shuai; Yan, Xu; Qin, Li-juan; Lin, Xi-qiao; Zeng, Bo

2017-08-01

Demand response plays an important role in maintaining the economic stability of the system, and has the characteristics of high efficiency, low cost, fast response, good environmental benefits and so on. Demand side resource is an important part of electricity market. The research of demand side resources in our country is still in the initial stage, but the opening of the electricity sales side provides a broad prospect for the development of electricity market. This paper summarizes the main types of demand side resources in our country, analyzes the economic principle of demand response from the micro perspective, puts forward some suggestions on the operation mechanism of China’s demand side resources participating in the electricity market under the condition of electricity sales side opening, analyzes the current situation of pricing in the electricity wholesale market and sets up the pricing strategy of the centralized wholesale market with the demand side power supply participating in quotation, which makes the social and economic benefits reach the maximum.

Power factor regulation for household usage

NASA Astrophysics Data System (ADS)

Daud, Nik Ghazali Nik; Hashim, Fakroul Ridzuan; Tarmizi, Muhammad Haziq Ahmad

2018-02-01

Power factor regulator technology has recently drawn attention to the consumer and to power generation company in order for consumers to use electricity efficiently. Controlling of power factor for efficient usage can reduce the production of power in fulfilment demands hence reducing the greenhouse effect. This paper presents the design method of power factor controller for household usage. There are several methods to improve the power factor. The power factor controller used by this method is by using capacitors. Total harmonic distortion also has become a major problem for the reliability of the electrical appliances and techniques to control it will be discussed.

Movement Demands and Metabolic Power Comparisons Between Elite and Subelite Australian Footballers.

PubMed

Johnston, Richard J; Watsford, Mark L; Austin, Damien J; Pine, Matthew J; Spurrs, Robert W

2015-10-01

This study examined the differences in movement demands and metabolic power output of elite and subelite Australian football (AF) players and quantified the movement profiles of a subelite AF competition. Movement variables were collected from AF players using Global Positioning System devices over 2 AF League (elite) and North East Australian Football League (NEAFL, subelite) seasons. A total of 500 files were collected from 37 elite and subelite nomadic AF players. NEAFL players covered 13,547 m at an average speed of 124.5 m·min(-1). Elite players performed more high-speed running (5.7-6.3%) and high acceleration and deceleration efforts (1.9-14.7%, p ≤ 0.05). The elite players had a higher mean metabolic power output (3.2%) and time spent at the very high power zone (15.9%, p ≤ 0.05). In contrast, elite players recorded a lower total match duration than the subelite players (4%, p ≤ 0.05). The contrasting amount of high-intensity activities performed by the 2 groups demonstrates the need to alter the training programs of subelite players to ensure they are capable of meeting the demands of elite football. The differences in match duration suggest that reducing subelite players' match time through increasing their rotations would assist the replication of movement profiles of elite players.

Power Management in Regenerative Life Support Systems

NASA Technical Reports Server (NTRS)

Crawford, Sekou; Pawlowski, Christopher; Finn, Cory; Mead, Susan C. (Technical Monitor)

1999-01-01

Effective management of power can reduce the cost of launch and operation of regenerative life support systems. Variations in power may be quite severe and may manifest as surges or spikes, While the power plant may have some ability to deal with these variations, with batteries for example, over-capacity is expensive and does nothing to address the fundamental issue of excessive demand. Because the power unit must be sized to accommodate the largest demand, avoiding power spikes has the potential to reduce the required size of the power plant while at the same time increasing the dependability of the system. Scheduling of processors can help to reduce potential power spikes. However, not all power-consuming equipment is easily scheduled. Therefore, active power management is needed to further decrease the risk of surges or spikes. We investigate the use of a hierarchical scheme to actively manage power for a model of a regenerative life support system. Local level controllers individually determine subsystem power usage. A higher level controller monitors overall system power and detects surges or spikes. When a surge condition is detected, the higher level controller conducts an 'auction' and describes subsystem power usage to re-allocate power. The result is an overall reduction in total power during a power surge. The auction involves each subsystem making a 'bid' to buy or sell power based on local needs. However, this re-allocation cannot come at the expense of life support function. To this end, participation in the auction is restricted to those processes meeting certain tolerance constraints. These tolerances represent acceptable limits within which system processes can be operated. We present a simulation model and discuss some of our results.

Power calculation of grading device in desintegrator

NASA Astrophysics Data System (ADS)

Bogdanov, V. S.; Semikopenko, I. A.; Vavilov, D. V.

2018-03-01

This article describes the analytical method of measuring the secondary power consumption, necessitated by the installation of a grading device in the peripheral part of the grinding chamber in the desintegrator. There is a calculation model for defining the power input of the disintegrator increased by the extra power demand, required to rotate the grading device and to grind the material in the area between the external row of hammers and the grading device. The work has determined the inertia moments of a cylindrical section of the grading device with armour plates. The processing capacity of the grading device is adjusted to the conveying capacity of the auger feeder. The grading device enables one to increase the concentration of particles in the peripheral part of the grinding chamber and the amount of interaction between particles and armour plates as well as the number of colliding particles. The perforated sections provide the output of the ground material with the proper size granules, which together with the effects of armour plates, improves the efficiency of grinding. The power demand to rotate the grading device does not exceed the admissible value.

Bifurcation Analysis of a DC-DC Bidirectional Power Converter Operating with Constant Power Loads

NASA Astrophysics Data System (ADS)

Cristiano, Rony; Pagano, Daniel J.; Benadero, Luis; Ponce, Enrique

Direct current (DC) microgrids (MGs) are an emergent option to satisfy new demands for power quality and integration of renewable resources in electrical distribution systems. This work addresses the large-signal stability analysis of a DC-DC bidirectional converter (DBC) connected to a storage device in an islanding MG. This converter is responsible for controlling the balance of power (load demand and generation) under constant power loads (CPLs). In order to control the DC bus voltage through a DBC, we propose a robust sliding mode control (SMC) based on a washout filter. Dynamical systems techniques are exploited to assess the quality of this switching control strategy. In this sense, a bifurcation analysis is performed to study the nonlinear stability of a reduced model of this system. The appearance of different bifurcations when load parameters and control gains are changed is studied in detail. In the specific case of Teixeira Singularity (TS) bifurcation, some experimental results are provided, confirming the mathematical predictions. Both a deeper insight in the dynamic behavior of the controlled system and valuable design criteria are obtained.

Cooperative Strategy for Optimal Management of Smart Grids by Wavelet RNNs and Cloud Computing.

PubMed

Napoli, Christian; Pappalardo, Giuseppe; Tina, Giuseppe Marco; Tramontana, Emiliano

2016-08-01

Advanced smart grids have several power sources that contribute with their own irregular dynamic to the power production, while load nodes have another dynamic. Several factors have to be considered when using the owned power sources for satisfying the demand, i.e., production rate, battery charge and status, variable cost of externally bought energy, and so on. The objective of this paper is to develop appropriate neural network architectures that automatically and continuously govern power production and dispatch, in order to maximize the overall benefit over a long time. Such a control will improve the fundamental work of a smart grid. For this, status data of several components have to be gathered, and then an estimate of future power production and demand is needed. Hence, the neural network-driven forecasts are apt in this paper for renewable nonprogrammable energy sources. Then, the produced energy as well as the stored one can be supplied to consumers inside a smart grid, by means of digital technology. Among the sought benefits, reduced costs and increasing reliability and transparency are paramount.

An Energy-Efficient ASIC for Wireless Body Sensor Networks in Medical Applications.

PubMed

Xiaoyu Zhang; Hanjun Jiang; Lingwei Zhang; Chun Zhang; Zhihua Wang; Xinkai Chen

2010-02-01

An energy-efficient application-specific integrated circuit (ASIC) featured with a work-on-demand protocol is designed for wireless body sensor networks (WBSNs) in medical applications. Dedicated for ultra-low-power wireless sensor nodes, the ASIC consists of a low-power microcontroller unit (MCU), a power-management unit (PMU), reconfigurable sensor interfaces, communication ports controlling a wireless transceiver, and an integrated passive radio-frequency (RF) receiver with energy harvesting ability. The MCU, together with the PMU, provides quite flexible communication and power-control modes for energy-efficient operations. The always-on passive RF receiver with an RF energy harvesting block offers the sensor nodes the capability of work-on-demand with zero standby power. Fabricated in standard 0.18-¿m complementary metal-oxide semiconductor technology, the ASIC occupies a die area of 2 mm × 2.5 mm. A wireless body sensor network sensor-node prototype using this ASIC only consumes < 10-nA current under the passive standby mode, and < 10 ¿A under the active standby mode, when supplied by a 3-V battery.

Providing Reliability Services through Demand Response: A Prelimnary Evaluation of the Demand Response Capabilities of Alcoa Inc.

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

Starke, Michael R; Kirby, Brendan J; Kueck, John D

2009-02-01

Demand response is the largest underutilized reliability resource in North America. Historic demand response programs have focused on reducing overall electricity consumption (increasing efficiency) and shaving peaks but have not typically been used for immediate reliability response. Many of these programs have been successful but demand response remains a limited resource. The Federal Energy Regulatory Commission (FERC) report, 'Assessment of Demand Response and Advanced Metering' (FERC 2006) found that only five percent of customers are on some form of demand response program. Collectively they represent an estimated 37,000 MW of response potential. These programs reduce overall energy consumption, lower greenmore » house gas emissions by allowing fossil fuel generators to operate at increased efficiency and reduce stress on the power system during periods of peak loading. As the country continues to restructure energy markets with sophisticated marginal cost models that attempt to minimize total energy costs, the ability of demand response to create meaningful shifts in the supply and demand equations is critical to creating a sustainable and balanced economic response to energy issues. Restructured energy market prices are set by the cost of the next incremental unit of energy, so that as additional generation is brought into the market, the cost for the entire market increases. The benefit of demand response is that it reduces overall demand and shifts the entire market to a lower pricing level. This can be very effective in mitigating price volatility or scarcity pricing as the power system responds to changing demand schedules, loss of large generators, or loss of transmission. As a global producer of alumina, primary aluminum, and fabricated aluminum products, Alcoa Inc., has the capability to provide demand response services through its manufacturing facilities and uniquely through its aluminum smelting facilities. For a typical aluminum smelter, electric power accounts for 30% to 40% of the factory cost of producing primary aluminum. In the continental United States, Alcoa Inc. currently owns and/or operates ten aluminum smelters and many associated fabricating facilities with a combined average load of over 2,600 MW. This presents Alcoa Inc. with a significant opportunity to respond in areas where economic opportunities exist to help mitigate rising energy costs by supplying demand response services into the energy system. This report is organized into seven chapters. The first chapter is the introduction and discusses the intention of this report. The second chapter contains the background. In this chapter, topics include: the motivation for Alcoa to provide demand response; ancillary service definitions; the basics behind aluminum smelting; and a discussion of suggested ancillary services that would be particularly useful for Alcoa to supply. Chapter 3 is concerned with the independent system operator, the Midwest ISO. Here the discussion examines the evolving Midwest ISO market structure including specific definitions, requirements, and necessary components to provide ancillary services. This section is followed by information concerning the Midwest ISO's classifications of demand response parties. Chapter 4 investigates the available opportunities at Alcoa's Warrick facility. Chapter 5 involves an in-depth discussion of the regulation service that Alcoa's Warrick facility can provide and the current interactions with Midwest ISO. Chapter 6 reviews future plans and expectations for Alcoa providing ancillary services into the market. Last, chapter 7, details the conclusion and recommendations of this paper.« less

Distributed Optimization of Sustainable Power Dispatch and Flexible Consumer Loads for Resilient Power Grid Operations

NASA Astrophysics Data System (ADS)

Srikantha, Pirathayini

Today's electric grid is rapidly evolving to provision for heterogeneous system components (e.g. intermittent generation, electric vehicles, storage devices, etc.) while catering to diverse consumer power demand patterns. In order to accommodate this changing landscape, the widespread integration of cyber communication with physical components can be witnessed in all tenets of the modern power grid. This ubiquitous connectivity provides an elevated level of awareness and decision-making ability to system operators. Moreover, devices that were typically passive in the traditional grid are now `smarter' as these can respond to remote signals, learn about local conditions and even make their own actuation decisions if necessary. These advantages can be leveraged to reap unprecedented long-term benefits that include sustainable, efficient and economical power grid operations. Furthermore, challenges introduced by emerging trends in the grid such as high penetration of distributed energy sources, rising power demands, deregulations and cyber-security concerns due to vulnerabilities in standard communication protocols can be overcome by tapping onto the active nature of modern power grid components. In this thesis, distributed constructs in optimization and game theory are utilized to design the seamless real-time integration of a large number of heterogeneous power components such as distributed energy sources with highly fluctuating generation capacities and flexible power consumers with varying demand patterns to achieve optimal operations across multiple levels of hierarchy in the power grid. Specifically, advanced data acquisition, cloud analytics (such as prediction), control and storage systems are leveraged to promote sustainable and economical grid operations while ensuring that physical network, generation and consumer comfort requirements are met. Moreover, privacy and security considerations are incorporated into the core of the proposed designs and these serve to improve the resiliency of the future smart grid. It is demonstrated both theoretically and practically that the techniques proposed in this thesis are highly scalable and robust with superior convergence characteristics. These distributed and decentralized algorithms allow individual actuating nodes to execute self-healing and adaptive actions when exposed to changes in the grid so that the optimal operating state in the grid is maintained consistently.

Worldwide electricity used in data centers

NASA Astrophysics Data System (ADS)

Koomey, Jonathan G.

2008-07-01

The direct electricity used by data centers has become an important issue in recent years as demands for new Internet services (such as search, music downloads, video-on-demand, social networking, and telephony) have become more widespread. This study estimates historical electricity used by data centers worldwide and regionally on the basis of more detailed data than were available for previous assessments, including electricity used by servers, data center communications, and storage equipment. Aggregate electricity use for data centers doubled worldwide from 2000 to 2005. Three quarters of this growth was the result of growth in the number of the least expensive (volume) servers. Data center communications and storage equipment each contributed about 10% of the growth. Total electricity use grew at an average annual rate of 16.7% per year, with the Asia Pacific region (without Japan) being the only major world region with growth significantly exceeding that average. Direct electricity used by information technology equipment in data centers represented about 0.5% of total world electricity consumption in 2005. When electricity for cooling and power distribution is included, that figure is about 1%. Worldwide data center power demand in 2005 was equivalent (in capacity terms) to about seventeen 1000 MW power plants.

Economic Rebalancing and Electricity Demand in China

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

He, Gang; Lin, Jiang; Yuan, Alexandria

Understanding the relationship between economic growth and electricity use is essential for power systems planning. This need is particularly acute now in China, as the Chinese economy is going through a transition to a more consumption and service oriented economy. This study uses 20 years of provincial data on gross domestic product (GDP) and electricity consumption to examine the relationship between these two factors. We observe a plateauing effect of electricity consumption in the richest provinces, as the electricity demand saturates and the economy develops and moves to a more service-based economy. There is a wide range of forecasts formore » electricity use in 2030, ranging from 5,308 to 8,292 kWh per capita, using different estimating functions, as well as in existing studies. It is therefore critical to examine more carefully the relationship between electricity use and economic development, as China transitions to a new growth phase that is likely to be less energy and resource intensive. The results of this study suggest that policymakers and power system planners in China should seriously re-evaluate power demand projections and the need for new generation capacity to avoid over-investment that could lead to stranded generation assets.« less

Trends in laser micromachining

NASA Astrophysics Data System (ADS)

Gaebler, Frank; van Nunen, Joris; Held, Andrew

2016-03-01

Laser Micromachining is well established in industry. Depending on the application lasers with pulse length from μseconds to femtoseconds and wavelengths from 1064nm and its harmonics up to 5μm or 10.6μm are used. Ultrafast laser machining using pulses with pico or femtosecond duration pulses is gaining traction, as it offers very precise processing of materials with low thermal impact. Large-scale industrial ultrafast laser applications show that the market can be divided into various sub segments. One set of applications demand low power around 10W, compact footprint and are extremely sensitive to the laser price whilst still demanding 10ps or shorter laser pulses. A second set of applications are very power hungry and only become economically feasible for large scale deployments at power levels in the 100+W class. There is also a growing demand for applications requiring fs-laser pulses. In our presentation we would like to describe these sub segments by using selected applications from the automotive and electronics industry e.g. drilling of gas/diesel injection nozzles, dicing of LED substrates. We close the presentation with an outlook to micromachining applications e.g. glass cutting and foil processing with unique new CO lasers emitting 5μm laser wavelength.

Integrated underground gas storage of CO2 and CH4 for renewable energy storage for a test case in China

NASA Astrophysics Data System (ADS)

Kühn, Michael; Li, Qi; Nakaten, Natalie, Christine; Kempka, Thomas

2017-04-01

Integration and further development of the energy supply system in China is a major challenge for the years to come. Part of the strategy is the implementation of a low carbon energy system based on carbon dioxide capture and storage (CCS). The innovative idea presented here is based on an extension of the power-to-gas-to-power (PGP) technology by establishing a closed carbon dioxide cycle [1]. Thereto, hydrogen generated from excess renewable energy is transformed into methane for combustion in a combined cycle gas power plant. To comply with the fluctuating energy demand, carbon dioxide produced during methane combustion and required for the methanation process as well as excess methane are temporarily stored in two underground reservoirs located close to each other [2]. Consequently, renewable energy generation units can be operated even if energy demand is below consumption, while stored energy can be fed into the grid as energy demand exceeds production [3]. We studied a show case for Xinjiang in China [4] to determine the energy demand of the entire process chain based on numerical computer simulations for the operation of the CO2 and CH4 storage reservoirs, and to ascertain the pressure regimes present in the storage formations during the injection and production phases of the annual cycle. [1] Streibel M., Nakaten N., Kempka T., Kühn M. (2013) Analysis of an integrated carbon cycle for storage of renewables. Energy Procedia 40, 202-211. doi: 10.1016/j.egypro.2013.08.024. [2] Kühn M., Streibel M., Nakaten N.C., Kempka T. (2014) Integrated Underground Gas Storage of CO2 and CH4 to Decarbonise the "Power-to-gas-to-gas-to-power" Technology. Energy Procedia 59, 9-15. doi: 10.1016/j.egypro.2014.10.342 [3] Kühn M., Nakaten N.C., Streibel M., Kempka T. (2014) CO2 Geological Storage and Utilization for a Carbon Neutral "Power-to-gas-to-power" Cycle to Even Out Fluctuations of Renewable Energy Provision. Energy Procedia 63, 8044-8049. doi: 10.1016/j.egypro.2014.11.841 [4] Li Q., Chen Z.A., Zhang J.T., Liu L.C., Li X.C., Jia L. (2016) Positioning and Revision of CCUS Technology Development in China. International Journal of Greenhouse Gas Control 46, 282-293. doi: 10.1016/j.ijggc.2015.02.024

Running and Metabolic Demands of Elite Rugby Union Assessed Using Traditional, Metabolic Power, and Heart Rate Monitoring Methods.

PubMed

Dubois, Romain; Paillard, Thierry; Lyons, Mark; McGrath, David; Maurelli, Olivier; Prioux, Jacques

2017-03-01

The aims of this study were (1) to analyze elite rugby union game demands using 3 different approaches: traditional, metabolic and heart rate-based methods (2) to explore the relationship between these methods and (3) to explore positional differences between the backs and forwards players. Time motion analysis and game demands of fourteen professional players (24.1 ± 3.4 y), over 5 European challenge cup games, were analyzed. Thresholds of 14.4 km·h -1 , 20 W.kg -1 and 85% of maximal heart rate (HR max ) were set for high-intensity efforts across the three methods. The mean % of HR max was 80.6 ± 4.3 % while 42.2 ± 16.5% of game time was spent above 85% of HR max with no significant differences between the forwards and the backs. Our findings also show that the backs cover greater distances at high-speed than forwards (% difference: +35.2 ± 6.6%; p<0.01) while the forwards cover more distance than the backs (+26.8 ± 5.7%; p<0.05) in moderate-speed zone (10-14.4 km·h -1 ). However, no significant difference in high-metabolic power distance was found between the backs and forwards. Indeed, the high-metabolic power distances were greater than high-speed running distances of 24.8 ± 17.1% for the backs, and 53.4 ± 16.0% for the forwards with a significant difference (+29.6 ± 6.0% for the forwards; p<0.001) between the two groups. Nevertheless, nearly perfect correlations were found between the total distance assessed using the traditional approach and the metabolic power approach (r = 0.98). Furthermore, there is a strong association (r = 0.93) between the high-speed running distance (assessed using the traditional approach) and the high-metabolic power distance. The HR monitoring methods demonstrate clearly the high physiological demands of professional rugby games. The traditional and the metabolic-power approaches shows a close correlation concerning their relative values, nevertheless the difference in absolute values especially for the high-intensity thresholds demonstrates that the metabolic power approach may represent an interesting alternative to the traditional approaches used in evaluating the high-intensity running efforts required in rugby union games.

Energy production estimation for Kosh-Agach grid-tie photovoltaic power plant for different photovoltaic module types

NASA Astrophysics Data System (ADS)

Gabderakhmanova, T. S.; Kiseleva, S. V.; Frid, S. E.; Tarasenko, A. B.

2016-11-01

This paper is devoted to calculation of yearly energy production, demanded area and capital costs for first Russian 5 MW grid-tie photovoltaic (PV) plant in Altay Republic that is named Kosh-Agach. Simple linear calculation model, involving average solar radiation and temperature data, grid-tie inverter power-efficiency dependence and PV modules parameters is proposed. Monthly and yearly energy production, equipment costs and demanded area for PV plant are estimated for mono-, polycrystalline and amorphous modules. Calculation includes three types of initial radiation and temperature data—average day for every month from NASA SSE, average radiation and temperature for each day of the year from NASA POWER and typical meteorology year generated from average data for every month. The peculiarities for each type of initial data and their influence on results are discussed.

Integrating market processes into utility resource planning

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

Kahn, E.P.

1992-11-01

Integrated resource planning has resulted in an abundance of alternatives for meeting existing and new demand for electricity services: (1) utility demand-side management (DSM) programs, (2) DSM bidding, (3) competitive bidding for private power supplies, (4) utility re-powering, and (5) new utility construction. Each alternative relies on a different degree of planning for implementation and, therefore, each alternative relies on markets to a greater or lesser degree. This paper shows how the interaction of planning processes and market forces results in resource allocations among the alternatives. The discussion focuses on three phenomena that are driving forces behind the unanticipated consequences'more » of contemporary integrated resource planning efforts. These forces are: (1) large-scale DSM efforts, (2) customer bypass, and (3) large-scale independent power projects. 22 refs., 3 figs., 2 tabs.« less

Consumption Behavior Analytics-Aided Energy Forecasting and Dispatch

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

Zhang, Yingchen; Yang, Rui; Jiang, Huaiguang

For decades, electricity customers have been treated as mere recipients of electricity in vertically integrated power systems. However, as customers have widely adopted distributed energy resources and other forms of customer participation in active dispatch (such as demand response) have taken shape, the value of mining knowledge from customer behavior patterns and using it for power system operation is increasing. Further, the variability of renewable energy resources has been considered a liability to the grid. However, electricity consumption has shown the same level of variability and uncertainty, and this is sometimes overlooked. This article investigates data analytics and forecasting methodsmore » to identify correlations between electricity consumption behavior and distributed photovoltaic (PV) output. The forecasting results feed into a predictive energy management system that optimizes energy consumption in the near future to balance customer demand and power system needs.« less

Storage Free Smart Energy Management for Frequency Control in a Diesel-PV-Fuel Cell-Based Hybrid AC Microgrid.

PubMed

Sekhar, P C; Mishra, S

2016-08-01

This paper proposes a novel, smart energy management scheme for a microgrid, consisting of a diesel generator and power electronic converter interfaced renewable energy-based generators, such as photovoltaic (PV) and fuel cell, for frequency regulation without any storage. In the proposed strategy, output of the PV is controlled in coordination with other generators using neurofuzzy controller, either only for transient frequency regulation or for both transient and steady-state frequency regulation, depending on the load demand, thereby eliminating the huge storage requirements. The option of demand response control is also explored along with the generation control. For accurate and quick tracking of maximum power point and its associated reserve power from the PV generator, this paper also proposes a novel adaptive-predictor-corrector-based tracking mechanism.

Investigation of Tidal Power, Cobscook Bay, Maine. Environmental Appendix.

DTIC Science & Technology

1980-08-01

Peromyscus leucopus Clethrionomys gapperi Microtus pennsylvanicus Ondatra zibethica Synaptomys cooperi Rattus norvegicua Mus musculus Zapus...hanks of si i oanis so I. ii.il it w i I I ant hi« necessary f<> reset , piles from time to t i r.w ilut" to bank...power. Since tidal power varies with the tides, tidal power is often completely out of phase with normal demand patterns. The surface area of the Bay

Water Use in the US Electric Power Sector: Energy Systems Level Perspectives

EPA Science Inventory

This presentation reviews the water demands of long-range electricity scenarios. It addresses questions such as: What are the aggregate water requirements of the U.S. electric power sector? How could water requirements evolve under different long-range regional generation mixes? ...

Demand response, behind-the-meter generation and air quality.

PubMed

Zhang, Xiyue; Zhang, K Max

2015-02-03

We investigated the implications of behind-the-meter (BTM) generation participating in demand response (DR) programs. Specifically, we evaluated the impacts of NOx emissions from BTM generators enrolled in the New York Independent System Operator (NYISO)'s reliability-based DR programs. Through analyzing the DR program enrollment data, DR event records, ozone air quality monitoring data, and emission characteristics of the generators, we found that the emissions from BTM generators very likely contribute to exceedingly high ozone concentrations in the Northeast Corridor region, and very likely account for a substantial fraction of total NOx emissions from electricity generation. In addition, a companion study showed that the emissions from BTM generators could also form near-source particulate matter (PM) hotspots. The important policy implications are that the absence of up-to-date regulations on BTM generators may offset the current efforts to reduce the emissions from peaking power plants, and that there is a need to quantify the environmental impacts of DR programs in designing sound policies related to demand-side resources. Furthermore, we proposed the concept of "Green" DR resources, referring to those that not only provide power systems reliability services, but also have verifiable environmental benefits or minimal negative environmental impacts. We argue that Green DR resources that are able to maintain resource adequacy and reduce emissions at the same time are key to achieving the cobenefits of power system reliability and protecting public health during periods with peak electricity demand.

Fuel and power coproduction: The Liquid Phase Methanol (LPMEOH{trademark}) process demonstration at Kingsport

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

Drown, D.P.; Brown, W.R.; Heydorn, E.C.

1997-12-31

The Liquid Phase Methanol (LPMEOH{trademark}) process uses a slurry bubble column reactor to convert syngas (primarily a mixture of carbon monoxide and hydrogen) to methanol. Because of its superior heat management, the process is able to be designed to directly handle the carbon monoxide (CO)-rich syngas characteristic of the gasification of coal, petroleum coke, residual oil, wastes, or of other hydrocarbon feedstocks. When added to an integrated gasification combined cycle (IGCC) power plant, the LPMEOH{trademark} process converts a portion of the CO-rich syngas produced by the gasifier to methanol, and the remainder of the unconverted gas is used to fuelmore » the gas turbine combined-cycle power plant. The LPMEOH{trademark} process has the flexibility to operate in a daily electricity demand load-following manner. Coproduction of power and methanol via IGCC and the LPMEOH{trademark} process provides opportunities for energy storage for electrical demand peak shaving, clean fuel for export, and/or chemical methanol sales.« less

Research on Operation Strategy for Bundled Wind-thermal Generation Power Systems Based on Two-Stage Optimization Model

NASA Astrophysics Data System (ADS)

Sun, Congcong; Wang, Zhijie; Liu, Sanming; Jiang, Xiuchen; Sheng, Gehao; Liu, Tianyu

2017-05-01

Wind power has the advantages of being clean and non-polluting and the development of bundled wind-thermal generation power systems (BWTGSs) is one of the important means to improve wind power accommodation rate and implement “clean alternative” on generation side. A two-stage optimization strategy for BWTGSs considering wind speed forecasting results and load characteristics is proposed. By taking short-term wind speed forecasting results of generation side and load characteristics of demand side into account, a two-stage optimization model for BWTGSs is formulated. By using the environmental benefit index of BWTGSs as the objective function, supply-demand balance and generator operation as the constraints, the first-stage optimization model is developed with the chance-constrained programming theory. By using the operation cost for BWTGSs as the objective function, the second-stage optimization model is developed with the greedy algorithm. The improved PSO algorithm is employed to solve the model and numerical test verifies the effectiveness of the proposed strategy.

Advanced microgrid design and analysis for forward operating bases

NASA Astrophysics Data System (ADS)

Reasoner, Jonathan

This thesis takes a holistic approach in creating an improved electric power generation system for a forward operating base (FOB) in the future through the design of an isolated microgrid. After an extensive literature search, this thesis found a need for drastic improvement of the FOB power system. A thorough design process analyzed FOB demand, researched demand side management improvements, evaluated various generation sources and energy storage options, and performed a HOMERRTM discrete optimization to determine the best microgrid design. Further sensitivity analysis was performed to see how changing parameters would affect the outcome. Lastly, this research also looks at some of the challenges which are associated with incorporating a design which relies heavily on inverter-based generation sources, and gives possible solutions to help make a renewable energy powered microgrid a reality. While this thesis uses a FOB as the case study, the process and discussion can be adapted to aide in the design of an off-grid small-scale power grid which utilizes high-penetration levels of renewable energy.

Failure Mechanisms of Ni-H2 and Li-Ion Batteries Under Hypervelocity Impacts

NASA Technical Reports Server (NTRS)

Miller, J. E.; Lyons, F.; Christiansen, E. L.; Lear, D. M.

2017-01-01

Lithium-Ion (Li-Ion) batteries have yielded significant performance advantages for many industries, including the aerospace industry, and have been selected to replace nickel hydrogen (Ni-H2) batteries for the International Space Station (ISS) program to meet the energy storage demands. As the ISS uses its vast solar arrays to generate its power, the solar arrays meet their sunlit power demands and supply excess power to battery packs for power delivery on the sun obscured phase of the approximate 90 minute low Earth orbit. These large battery packs are located on the exterior of the ISS, and as such, the battery packs are exposed to external environment threats like naturally occurring meteoroids and artificial orbital debris (MMOD). While the risks from these solid particle environments has been known and addressed to an acceptable risk of failure through shield design, it is not possible to completely eliminate the risk of loss of these assets on orbit due to MMOD, and as such, failure consequences to the ISS have been considered.

EEG alpha power and creative ideation☆

PubMed Central

Fink, Andreas; Benedek, Mathias

2014-01-01

Neuroscientific studies revealed first insights into neural mechanisms underlying creativity, but existing findings are highly variegated and often inconsistent. Despite the disappointing picture on the neuroscience of creativity drawn in recent reviews, there appears to be robust evidence that EEG alpha power is particularly sensitive to various creativity-related demands involved in creative ideation. Alpha power varies as a function of creativity-related task demands and the originality of ideas, is positively related to an individuals’ creativity level, and has been observed to increase as a result of creativity interventions. Alpha increases during creative ideation could reflect more internally oriented attention that is characterized by the absence of external bottom-up stimulation and, thus, a form of top-down activity. Moreover, they could indicate the involvement of specific memory processes such as the efficient (re-)combination of unrelated semantic information. We conclude that increased alpha power during creative ideation is among the most consistent findings in neuroscientific research on creativity and discuss possible future directions to better understand the manifold brain mechanisms involved in creativity. PMID:23246442

Stochastic and Statistical Analysis of Utility Revenues and Weather Data Analysis for Consumer Demand Estimation in Smart Grids

PubMed Central

Ali, S. M.; Mehmood, C. A; Khan, B.; Jawad, M.; Farid, U; Jadoon, J. K.; Ali, M.; Tareen, N. K.; Usman, S.; Majid, M.; Anwar, S. M.

2016-01-01

In smart grid paradigm, the consumer demands are random and time-dependent, owning towards stochastic probabilities. The stochastically varying consumer demands have put the policy makers and supplying agencies in a demanding position for optimal generation management. The utility revenue functions are highly dependent on the consumer deterministic stochastic demand models. The sudden drifts in weather parameters effects the living standards of the consumers that in turn influence the power demands. Considering above, we analyzed stochastically and statistically the effect of random consumer demands on the fixed and variable revenues of the electrical utilities. Our work presented the Multi-Variate Gaussian Distribution Function (MVGDF) probabilistic model of the utility revenues with time-dependent consumer random demands. Moreover, the Gaussian probabilities outcome of the utility revenues is based on the varying consumer n demands data-pattern. Furthermore, Standard Monte Carlo (SMC) simulations are performed that validated the factor of accuracy in the aforesaid probabilistic demand-revenue model. We critically analyzed the effect of weather data parameters on consumer demands using correlation and multi-linear regression schemes. The statistical analysis of consumer demands provided a relationship between dependent (demand) and independent variables (weather data) for utility load management, generation control, and network expansion. PMID:27314229

Stochastic and Statistical Analysis of Utility Revenues and Weather Data Analysis for Consumer Demand Estimation in Smart Grids.

PubMed

Ali, S M; Mehmood, C A; Khan, B; Jawad, M; Farid, U; Jadoon, J K; Ali, M; Tareen, N K; Usman, S; Majid, M; Anwar, S M

2016-01-01

In smart grid paradigm, the consumer demands are random and time-dependent, owning towards stochastic probabilities. The stochastically varying consumer demands have put the policy makers and supplying agencies in a demanding position for optimal generation management. The utility revenue functions are highly dependent on the consumer deterministic stochastic demand models. The sudden drifts in weather parameters effects the living standards of the consumers that in turn influence the power demands. Considering above, we analyzed stochastically and statistically the effect of random consumer demands on the fixed and variable revenues of the electrical utilities. Our work presented the Multi-Variate Gaussian Distribution Function (MVGDF) probabilistic model of the utility revenues with time-dependent consumer random demands. Moreover, the Gaussian probabilities outcome of the utility revenues is based on the varying consumer n demands data-pattern. Furthermore, Standard Monte Carlo (SMC) simulations are performed that validated the factor of accuracy in the aforesaid probabilistic demand-revenue model. We critically analyzed the effect of weather data parameters on consumer demands using correlation and multi-linear regression schemes. The statistical analysis of consumer demands provided a relationship between dependent (demand) and independent variables (weather data) for utility load management, generation control, and network expansion.

Greenhouse gas and air pollutant emission reduction potentials of renewable energy--case studies on photovoltaic and wind power introduction considering interactions among technologies in Taiwan.

PubMed

Kuo, Yu-Ming; Fukushima, Yasuhiro

2009-03-01

To achieve higher energy security and lower emission of greenhouse gases (GHGs) and pollutants, the development of renewable energy has attracted much attention in Taiwan. In addition to its contribution to the enhancement of reliable indigenous resources, the introduction of renewable energy such as photovoltaic (PV) and wind power systems reduces the emission of GHGs and air pollutants by substituting a part of the carbon- and pollutant-intensive power with power generated by methods that are cleaner and less carbon-intensive. To evaluate the reduction potentials, consequential changes in the operation of different types of existing power plants have to be taken into account. In this study, a linear mathematical programming model is constructed to simulate a power mix for a given power demand in a power market sharing a cost-minimization objective. By applying the model, the emission reduction potentials of capacity extension case studies, including the enhancement of PV and wind power introduction at different scales, were assessed. In particular, the consequences of power mix changes in carbon dioxide, nitrogen oxides, sulfur oxides, and particulates were discussed. Seasonally varying power demand levels, solar irradiation, and wind strength were taken into account. In this study, we have found that the synergetic reduction of carbon dioxide emission induced by PV and wind power introduction occurs under a certain level of additional installed capacity. Investigation of a greater variety of case studies on scenario development with emerging power sources becomes possible by applying the model developed in this study.

Influence of Forecast Accuracy of Photovoltaic Power Output on Capacity Optimization of Microgrid Composition under 30 min Power Balancing Control

NASA Astrophysics Data System (ADS)

Sone, Akihito; Kato, Takeyoshi; Shimakage, Toyonari; Suzuoki, Yasuo

A microgrid (MG) is one of the measures for enhancing the high penetration of renewable energy (RE)-based distributed generators (DGs). If a number of MGs are controlled to maintain the predetermined electricity demand including RE-based DGs as negative demand, they would contribute to supply-demand balancing of whole electric power system. For constructing a MG economically, the capacity optimization of controllable DGs against RE-based DGs is essential. By using a numerical simulation model developed based on a demonstrative study on a MG using PAFC and NaS battery as controllable DGs and photovoltaic power generation system (PVS) as a RE-based DG, this study discusses the influence of forecast accuracy of PVS output on the capacity optimization. Three forecast cases with different accuracy are compared. The main results are as follows. Even with no forecast error during every 30 min. as the ideal forecast method, the required capacity of NaS battery reaches about 40% of PVS capacity for mitigating the instantaneous forecast error within 30 min. The required capacity to compensate for the forecast error is doubled with the actual forecast method. The influence of forecast error can be reduced by adjusting the scheduled power output of controllable DGs according to the weather forecast. Besides, the required capacity can be reduced significantly if the error of balancing control in a MG is acceptable for a few percentages of periods, because the total periods of large forecast error is not so often.

Performance Assessment of Flashed Steam Geothermal Power Plant

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

Alt, Theodore E.

1980-12-01

Five years of operating experience at the Comision Federal de Electricidad (CFE) Cerro Prieto flashed steam geothermal power plant are evaluated from the perspective of U. S. utility operations. We focus on the design and maintenance of the power plant that led to the achievement of high plant capacity factors for Units No. 1 and 2 since commercial operation began in 1973. For this study, plant capacity factor is the ratio of the average load on the machines or equipment for the period of time considered to the capacity rating of the machines or equipment. The plant capacity factor ismore » the annual gross output in GWh compared to 657 GWh (2 x 37.5 MW x 8760 h). The CFE operates Cerro Prieto at base load consistent with the system connected electrical demand of the Baja California Division. The plant output was curtailed during the winter months of 1973-1975 when the system electric demand was less than the combined output capability of Cerro Prieto and the fossil fuel plant near Tijuana. Each year the system electric demand has increased and the Cerro Prieto units now operate at full load all the time. The CFE added Units 3 and 4 to Cerro Prieto in 1979 which increased the plant name plate capacity to 150 MW. Part of this additional capacity will supply power to San Diego Gas and Electric Company through an interconnection across the border. The achievement of a high capacity factor over an extensive operating period was influenced by operation, design, and maintenance of the geothermal flash steam power plant.« less

Short-term load and wind power forecasting using neural network-based prediction intervals.

PubMed

Quan, Hao; Srinivasan, Dipti; Khosravi, Abbas

2014-02-01

Electrical power systems are evolving from today's centralized bulk systems to more decentralized systems. Penetrations of renewable energies, such as wind and solar power, significantly increase the level of uncertainty in power systems. Accurate load forecasting becomes more complex, yet more important for management of power systems. Traditional methods for generating point forecasts of load demands cannot properly handle uncertainties in system operations. To quantify potential uncertainties associated with forecasts, this paper implements a neural network (NN)-based method for the construction of prediction intervals (PIs). A newly introduced method, called lower upper bound estimation (LUBE), is applied and extended to develop PIs using NN models. A new problem formulation is proposed, which translates the primary multiobjective problem into a constrained single-objective problem. Compared with the cost function, this new formulation is closer to the primary problem and has fewer parameters. Particle swarm optimization (PSO) integrated with the mutation operator is used to solve the problem. Electrical demands from Singapore and New South Wales (Australia), as well as wind power generation from Capital Wind Farm, are used to validate the PSO-based LUBE method. Comparative results show that the proposed method can construct higher quality PIs for load and wind power generation forecasts in a short time.

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

Dalimunthe, Amty Ma’rufah Ardhiyah; Mindara, Jajat Yuda; Panatarani, Camellia

Smart grid and distributed generation should be the solution of the global climate change and the crisis energy of the main source of electrical power generation which is fossil fuel. In order to meet the rising electrical power demand and increasing service quality demands, as well as reduce pollution, the existing power grid infrastructure should be developed into a smart grid and distributed power generation which provide a great opportunity to address issues related to energy efficiency, energy security, power quality and aging infrastructure systems. The conventional of the existing distributed generation system is an AC grid while for amore » renewable resources requires a DC grid system. This paper explores the model of smart DC grid by introducing a model of smart DC grid with the stable power generation give a minimal and compressed circuitry that can be implemented very cost-effectively with simple components. The PC based application software for controlling was developed to show the condition of the grid and to control the grid become ‘smart’. The model is then subjected to a severe system perturbation, such as incremental change in loads to test the performance of the system again stability. It is concluded that the system able to detect and controlled the voltage stability which indicating the ability of power system to maintain steady voltage within permissible rangers in normal condition.« less

Power system requirements and definition for lunar and Mars outposts

NASA Technical Reports Server (NTRS)

Petri, D. A.; Cataldo, R. L.; Bozek, J. M.

1990-01-01

Candidate power systems being considered for outpost facilities (stationary power systems) and vehicles (mobile systems) are discussed, including solar, chemical, isotopic, and reactor. The current power strategy was an initial outpost power system composed of photovoltaic arrays for daytime energy needs and regenerative fuel cells for power during the long lunar night. As day and night power demands grow, the outpost transitions to nuclear-based power generation, using thermoelectric conversion initially and evolving to a dynamic conversion system. With this concept as a guideline, a set of requirements has been established, and a reference definition of candidate power systems meeting these requirements has been identified.

The Design of the Trading Mechanism to Adapt the Development of Mixed Cooling Heating and Power

NASA Astrophysics Data System (ADS)

Liu, D. N.; Li, Z. H.; Zhou, H. M.; Zhao, Q.; Xu, X. F.

2017-08-01

The enterprise who has combined cooling heating and power system has both the customer group and the power generation resources. Therefore, it can be used as a power user, and can also be used as a power generation enterprise to participate in the direct purchase of electricity. This paper combines characteristics of mixed cooling heating and power, designs application business model of mixed cooling heating and power, and puts forward to the scene of cooling heating and power trading scheme, helping the enterprise according to the power supply and demand situation in the region adjust their positions and participate in the electricity market.

Solar powered multipurpose remotely powered aircraft

NASA Technical Reports Server (NTRS)

Alexandrou, A. N.; Durgin, W. W.; Cohn, R. F.; Olinger, D. J.; Cody, Charlotte K.; Chan, Agnes; Cheung, Kwok-Hung; Conley, Kristin; Crivelli, Paul M.; Javorski, Christian T.

1992-01-01

Increase in energy demands coupled with rapid depletion of natural energy resources have deemed solar energy as an attractive alternative source of power. The focus was to design and construct a solar powered, remotely piloted vehicle to demonstrate the feasibility of solar energy as an effective, alternate source of power. The final design included minimizing the power requirements and maximizing the strength-to-weight and lift-to-drag ratios. Given the design constraints, Surya (the code-name given to the aircraft), is a lightweight aircraft primarily built using composite materials and capable of achieving level flight powered entirely by solar energy.

Radioisotope Reduction Using Solar Power for Outer Planetary Missions

NASA Technical Reports Server (NTRS)

Fincannon, James

2008-01-01

Radioisotope power systems have historically been (and still are) the power system of choice from a mass and size perspective for outer planetary missions. High demand for and limited availability of radioisotope fuel has made it necessary to investigate alternatives to this option. Low mass, high efficiency solar power systems have the potential for use at low outer planetary temperatures and illumination levels. This paper documents the impacts of using solar power systems instead of radioisotope power for all or part of the power needs of outer planetary spacecraft and illustrates the potential fuel savings of such an approach.

Policy impacts on agricultural irrigation electricity demand in the Columbia Basin

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

Martin, M.; Cox, L.; Nakamoto, S.

Accurately estimating the price elasticity of demand for irrigation electricity is important to major electricity suppliers such as the Bonneville Power Administration (BPA) of the Pacific Northwest. The BPA has a revenue maximization objective, and the elasticity of demand is central to its rate setting process. Several studies have attempted to estimate demand for irrigation electricity, but none has explicitly included federal agricultural policy and program variables. Tins paper discusses how agricultural programs may influence farmers' irrigation decisions and thus their demand for irrigation electricity. It suggests that existing programs serve to make farmers more responsive to electricity rate increasesmore » than would otherwise be the case. Thus, studies that fail to include them may underestimate the responsiveness of farmers to electricity rate increases.« less

Dynamics Behaviors of Scale-Free Networks with Elastic Demand

NASA Astrophysics Data System (ADS)

Li, Yan-Lai; Sun, Hui-Jun; Wu, Jian-Jun

Many real-world networks, such as transportation networks and Internet, have the scale-free properties. It is important to study the bearing capacity of such networks. Considering the elastic demand condition, we analyze load distributions and bearing capacities with different parameters through artificially created scale-free networks. The simulation results show that the load distribution follows a power-law form, which means some ordered pairs, playing the dominant role in the transportation network, have higher demand than other pairs. We found that, with the decrease of perceptual error, the total and average ordered pair demand will decrease and then stay in a steady state. However, with the increase of the network size, the average demand of each ordered pair will decrease, which is particularly interesting for the network design problem.

Apples to Apples: Equivalent-Reliability Power Systems Across Diverse Resource Mix Scenarios

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

Stephen, Gordon W; Frew, Bethany A; Sigler, Devon

Electricity market research is highly price sensitive, and prices are strongly influenced by balance of supply and demand. This work looks at how to combine capacity expansion models and reliability assessment tools to assess equivalent-reliability power systems across diverse resource mix scenarios.

Pressure retarded osmosis as a controlling system for traditional renewables

NASA Astrophysics Data System (ADS)

Carravetta, Armando; Fecarotta, Oreste; La Rocca, Michele; Martino, Riccardo

2015-04-01

Pressure retarded osmosis (PRO) is a viable but still not diffused form of renewable energy (see Maisonneuve et al., 2015 for a recent literature review). In PRO, water from a low salinity feed solution permeates through a membrane into a pressurized, high salinity draw solution, giving rise to a positive pressure drop; then energy is obtained by depressurizing the permeate through a hydro-turbine and brackish water is discharged. Many technological, environmental and economical aspects are obstacles in the diffusion of PRO, like the vulnerability of the membranes to fouling, the impact of the brackish water on the local marine environment, the high cost of membranes, etc. We are interested in the use of PRO as a combined form of energy with other renewable energy source like solar, wind or mini hydro in water supply networks (WSN). For the wide diffusion of renewables one of the major concerns of commercial power companies is to obtain very stable form of energy to comply with prescriptions of electricity grid operators and with the instant energy demand curve. Renewables are generally very variable form of energy, for the influence of climatic conditions on available power, and of the fluctuation in water demand in WSN. PRO is a very flexible technology where with appropriate turbines and control system power can be varied continuously to compensate for variation of other source of energy. Therefore, PRO is suitable to be used as a balancing system for commercial power system. We will present a simulation of the performance of a PRO used in combination with three different renewables. In the first two scenarios PRO compensate the difference between energy demand and energy production of a solar power plant and hydro power plant in a WSN. In the third scenario PRO is used to compensate daily variation of energy production in a wind power plant. Standard curves of energy production and energy demand for southern Italy are used. In order to control PRO production an appropriate hydro turbine system is necessary. Therefore, pumps as turbine (PAT) are used in alternative to a classical hydraulic turbine (Carravetta et al., 2013). PAT can be easily regulated by hydraulic system, of by an inverter, granting the necessary flexibility of energy production with a sensible reduction of machinery cost. Maisonneuve J, Pillay P, Laflamme C.B. Pressure-retarded osmotic power system model considering non-ideal effects. Renewable Energy. 2015; 75(3): 416-424. Carravetta A, Del Giudice G, Fecarotta O, Ramos HM. Pump as Turbine (PAT) Design in Water Distribution Network by System Effectiveness. Water. 2013; 5(3):1211-1225.

Study of the possibilities of more rational use of energy in the sector of trade and commerce, part 2

NASA Astrophysics Data System (ADS)

Ebersbach, K. F.; Fischer, A.; Layer, G.; Steinberger, W.; Wegner, M.; Wiesner, B.

1982-07-01

The energy demand in the sector of trade and commerce was registered and analyzed. Measures to improve the energy demand structure are presented. In several typical firms like hotels, office buildings, locksmith's shops, motor vehicle repair shops, butcher's shops, laundries and bakeries, detailed surveys of energy consumption were done and included in a statistic evaluation. Subjects analyzed were: development of the energy supply; technology of energy application; final energy demand broken down into demand for light, power, space heating and process heat as well as the demand for cooling; daily and annual load curves of energy consumption and their dependence on various parameters; and measures to improve the structure of energy demand. Detailed measurement points out negligences in the surveyed firms and shows possibilities for likely energy savings. In addition, standard values for specific energy consumption are obtained.

Study of the possibilities of more rational use of energy in the sector of trade and commerce, part 1

NASA Astrophysics Data System (ADS)

Ebersbach, K. F.; Fischer, A.; Layer, G.; Steinberger, W.; Wegner, M.; Wiesner, B.

1982-06-01

The energy demand in trade and commerce was analyzed. Measures to improve the energy demand structure are presented. In several typical firms, like hotels, office buildings, locksmith's shops, motor vehicle repair shops, butcher's shops, laundries and bakeries, energy consumption was surveyed and statistically evaluated. Subjects analyzed are: the development of the energy supply; the technology of energy application; the final energy demand broken down into demand for light, power, space heating and process heat as well as the demand for cooling; the daily and annual load curve of energy consumption and its dependence on various parameters; and measures to improve the structure of energy demand. The detailed measurement points out negligences in the surveyed firms and shows some possibilities for likely energy savings. In addition, standard values for specific energy consumption are obtained.

Assessment of utility side financial benefits of demand side management considering environmental impacts

NASA Astrophysics Data System (ADS)

Abeygunawardane, Saranga Kumudu

2018-02-01

Any electrical utility prefers to implement demand side management and change the shape of the demand curve in a beneficial manner. This paper aims to assess the financial gains (or losses) to the generating sector through the implementation of demand side management programs. An optimization algorithm is developed to find the optimal generation mix that minimizes the daily total generating cost. This daily total generating cost includes the daily generating cost as well as the environmental damage cost. The proposed optimization algorithm is used to find the daily total generating cost for the base case and for several demand side management programs using the data obtained from the Sri Lankan power system. Results obtained for DSM programs are compared with the results obtained for the base case to assess the financial benefits of demand side management to the generating sector.

Sectoral contributions to surface water stress in the coterminous United States

NASA Astrophysics Data System (ADS)

Averyt, K.; Meldrum, J.; Caldwell, P.; Sun, G.; McNulty, S.; Huber-Lee, A.; Madden, N.

2013-09-01

Here, we assess current stress in the freshwater system based on the best available data in order to understand possible risks and vulnerabilities to regional water resources and the sectors dependent on freshwater. We present watershed-scale measures of surface water supply stress for the coterminous United States (US) using the water supply stress index (WaSSI) model which considers regional trends in both water supply and demand. A snapshot of contemporary annual water demand is compared against different water supply regimes, including current average supplies, current extreme-year supplies, and projected future average surface water flows under a changing climate. In addition, we investigate the contributions of different water demand sectors to current water stress. On average, water supplies are stressed, meaning that demands for water outstrip natural supplies in over 9% of the 2103 watersheds examined. These watersheds rely on reservoir storage, conveyance systems, and groundwater to meet current water demands. Overall, agriculture is the major demand-side driver of water stress in the US, whereas municipal stress is isolated to southern California. Water stress introduced by cooling water demands for power plants is punctuated across the US, indicating that a single power plant has the potential to stress water supplies at the watershed scale. On the supply side, watersheds in the western US are particularly sensitive to low flow events and projected long-term shifts in flow driven by climate change. The WaSSI results imply that not only are water resources in the southwest in particular at risk, but that there are also potential vulnerabilities to specific sectors, even in the ‘water-rich’ southeast.

Green Power Marketing Abroad: Recent Experience and Trends

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

Bird, L.; Wustenhagen, R.; Aabakken, J.

Green power marketing--the act of differentially selling electricity generated wholly or in part from renewable sources--has emerged in more than a dozen countries around the world. This report reviews green power marketing activity abroad to gain additional perspective on consumer demand and to discern key factors or policies that affect the development of green power markets. The objective is to draw lessons from experience in other countries that could be applicable to the U.S. market.

Space Power for Communication Satellites Beyond 1995

NASA Technical Reports Server (NTRS)

Pierce, P. R.

1984-01-01

The space power trends for communication satellites beginning in the mid-70's are reviewed. Predictions of technology advancements and requirements were compared with actual growth patterns. The conclusions derived suggest that the spacecraft power system technology base and present rate of advancement will not be able to meet the power demands of the early to mid-90's. It is recommended that an emphasis on accelerating the technology development be made to minimize the technology gap.

China’s Largesse: Why China Is Generous With Foreign Aid

DTIC Science & Technology

2017-12-01

leftist factions failed to establish a foothold for communism, and Kenyatta maintained the power of his right-wing regime. Shortly after independence...avenues of diplomatic pressure. Even if this model holds explanatory power , it is unlikely by itself to explain a state’s decisions when accepting...Global Power .............70  3.  China’s Intent and the Supply and Demand of Foreign Aid

Reach a New Threshold of Freedom and Control with Dell's Flexible Computing Solution: On-Demand Desktop Streaming

ERIC Educational Resources Information Center

Technology & Learning, 2008

2008-01-01

When it comes to IT, there has always been an important link between data center control and client flexibility. As computing power increases, so do the potentially crippling threats to security, productivity and financial stability. This article talks about Dell's On-Demand Desktop Streaming solution which is designed to centralize complete…

How to Shift Power to Learners: Encouraging FE Dynamism, Replacing Centralised Procurement

ERIC Educational Resources Information Center

Wolf, Alison

2010-01-01

This monograph discusses how to make England's further education (FE) system genuinely responsive to learner demand, as well as stable, affordable, and of high quality. It looks at how a demand-driven system can be organised and funded, at what is required of governments, and what can be left to learners themselves and to the education and…

Demand Response at the Naval Postgraduate School

DTIC Science & Technology

2008-12-01

service, cost avoidance of starting extra power plants during emergencies, and reduction of negative environmental impact . The illustration below...on. Refraining from starting a peak performance plant means less pollution and lower environmental impact . Operations at the Naval Postgraduate...affect the environment. F. STEP 5: MONETIZE ALL IMPACTS The environmental impact that a Demand Response program has is an intangible one. Over

Differentiating between Confrontive and Coercive Kinds of Parental Power-Assertive Disciplinary Practices

ERIC Educational Resources Information Center

Baumrind, Diana

2012-01-01

In this essay, I differentiate between coercive and confrontive kinds of power assertion to elucidate the significantly different effects on children's well-being of authoritarian and authoritative styles of parental authority. Although both parenting styles (in contrast to the permissive style) are equally demanding, forceful, and…

Atoms to Electricity.

ERIC Educational Resources Information Center

Department of Energy, Washington, DC.

This booklet explains the basic technology of nuclear fission power reactors, the nuclear fuel cycle, and the role of nuclear energy as one of the domestic energy resources being developed to meet the national energy demand. Major topic areas discussed include: the role of nuclear power; the role of electricity; generating electricity with the…

ULTRA-LOW POWER CO2 SENSOR FOR INTELLIGENT BUILDING CONTROL - PHASE I

EPA Science Inventory

The proposed EPA SBIR Phase I program will create a novel ultra-low power and low-cost microfabricated CO₂ sensor. The initial developments of sensor technology will serve the very large Demand Controlled Ventilation market that has been identified by KWJ and its...

Developing a multi-modal freight movement plan for the sustainable growth of wind energy related industries.

DOT National Transportation Integrated Search

2012-06-01

As the demand for wind power increases so too has the popularity of larger and larger turbines. Larger turbines are able to : produce more power for the input they receive but they are also much more difficult to transport. This project examines thes...

25 CFR 175.30 - Billing.

Code of Federal Regulations, 2010 CFR

2010-04-01

... AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN ELECTRIC POWER UTILITIES Billing, Payments, and... determined from the register on the utility's meter at the customer's point of delivery. A reasonable estimate of the amount of energy and/or power demand may be made by the utility in the event a meter is...

OpenADR Specification to Ease Saving Power in Buildings

ScienceCinema

None

2017-12-09

A new data model developed by researchers at the Department of Energys Lawrence Berkeley National Laboratory and their colleagues at other universities and in the private sector will help facilities and buildings save power through automated demand response technology, and advance the development of the Smart Grid.

Solar-Powered Supply Is Light and Reliable

NASA Technical Reports Server (NTRS)

Willis, A. E.; Garrett, H.; Matheney, J.

1982-01-01

DC supply originally intended for use in solar-powered spacecraft propulsion is lightweight and very reliable. Operates from 100-200 volt output of solar panels to produce 11 different dc voltages, with total demand of 3,138 watts. With exception of specially wound inductors and transformers, system uses readily available components.

A review of water use in the U.S. electric power sector: insights from systems-level perspectives

EPA Science Inventory

Thermoelectric power production comprised 41% of total freshwater withdrawals in the U.S., surpassing even agriculture. This review highlights scenarios of the electric sector’s future demands for water, including scenarios that limit both CO2 and water availability. A number o...

The Hazards Posed by the Global Development of Nuclear Power

ERIC Educational Resources Information Center

O'Reilly, S. A.

1976-01-01

Outlines the growth in the demand for energy on a world-wide basis. Reviews the development of nuclear power and points out the many hazards in the nuclear fuel cycle. Describes the nature of nuclear wastes and explains the quantities involved and the current techniques for waste disposal. (GS)

Atoms to Electricity.

ERIC Educational Resources Information Center

Department of Energy, Washington, DC. Nuclear Energy Office.

This booklet explains the basic technology of nuclear fission power reactors, the nuclear fuel cycle, and role of nuclear energy as one of the domestic energy resources being developed to meet the national energy demand. Major topic areas discussed include: (1) "The Role of Nuclear Power"; (2) "The Role of Electricity"; (3)…

OUT Success Stories: Solar Trough Power Plants

DOE R&D Accomplishments Database

Jones, J.

2000-08-01

The Solar Electric Generating System (SEGS) plants use parabolic-trough solar collectors to capture the sun's energy and convert it to heat. The SEGS plants range in capacity from 13.8 to 80 MW, and they were constructed to meet Southern California Edison Company's periods of peak power demand.

Using Seasonal Forecasts for medium-term Electricity Demand Forecasting on Italy

NASA Astrophysics Data System (ADS)

De Felice, M.; Alessandri, A.; Ruti, P.

2012-12-01

Electricity demand forecast is an essential tool for energy management and operation scheduling for electric utilities. In power engineering, medium-term forecasting is defined as the prediction up to 12 months ahead, and commonly is performed considering weather climatology and not actual forecasts. This work aims to analyze the predictability of electricity demand on seasonal time scale, considering seasonal samples, i.e. average on three months. Electricity demand data has been provided by Italian Transmission System Operator for eight different geographical areas, in Fig. 1 for each area is shown the average yearly demand anomaly for each season. This work uses data for each summer during 1990-2010 and all the datasets have been pre-processed to remove trends and reduce the influence of calendar and economic effects. The choice of focusing this research on the summer period is due to the critical peaks of demand that power grid is subject during hot days. Weather data have been included considering observations provided by ECMWF ERA-INTERIM reanalyses. Primitive variables (2-metres temperature, pressure, etc) and derived variables (cooling and heating degree days) have been averaged for summer months. A particular attention has been given to the influence of persistence of positive temperature anomaly and a derived variable which count the number of consecutive days of extreme-days has been used. Electricity demand forecast has been performed using linear and nonlinear regression methods and stepwise model selection procedures have been used to perform a variable selection with respect to performance measures. Significance tests on multiple linear regression showed the importance of cooling degree days during summer in the North-East and South of Italy with an increase of statistical significance after 2003, a result consistent with the diffusion of air condition and ventilation equipment in the last decade. Finally, using seasonal climate forecasts we evaluate the performances of electricity demand forecast performed with predicted variables on Italian regions with encouraging results on the South of Italy. This work gives an initial assessment on the predictability of electricity demand on seasonal time scale, evaluating the relevance of climate information provided by seasonal forecasts for electricity management during high-demand periods.;

Stability analysis of offshore wind farm and marine current farm

NASA Astrophysics Data System (ADS)

Shawon, Mohammad Hasanuzzaman

Renewable energy has been playing an important role to meet power demand and 'Green Energy' market is getting bigger platform all over the world in the last few years. Due to massive increase in the prices of fossil fuels along with global warming issues, energy harvesting from renewable energy sources has received considerable interest, nowadays, where extensive researches are going on to ensure optimum use of renewable sources. In order to meet the increasing demand of electricity and power, integration of renewable energy is getting highest priorities around the world. Wind is one of the most top growing renewable energy resources and wind power market penetration is expected to reach 3.35 percent by 2013 from its present market of about 240 GW. A wind energy system is the most environmental friendly, cost effective and safe among all renewable energy resources available. Another promising form of renewable energy is ocean energy which covers 70 % of the earth. Ocean energy can be tapped from waves, tides and thermal elements. Offshore Wind farm (OWF) has already become very popular for large scale wind power integration with the onshore grid. Recently, marine current farm (MCF) is also showing good potential to become mainstream energy sources and already successfully commissioned in United Kingdom. However, squirrel cage induction generator (SCIG) has the stability problem similar to synchronous generator especially during fault location to restore the electromagnetic torque. Series dynamic braking resistor (SDBR) has been known as a useful mean to stabilize fixed speed wind generator system. On the other hand, doubly fed induction generator (DFIG) has the capability of coupling the control of active and reactive power and to provide necessary reactive power demand during grid fault conditions. Series dynamic braking resistor (SDBR) can also be employed with DFIG to limit the rotor over current. An integration of wind and tidal energy represents a new-trend for large electric energy production using offshore wind generators and marine current generators, respectively. Thus DFIG based offshore wind farm can be an economic solution to stabilize squirrel cage induction generator based marine current farm without installing any addition FACTS devices. This thesis first focuses on the stabilization of fixed speed IG based marine current farm using SDBR. Also stabilization of DFIG based variable speed wind farm utilizing SDBR is studied in this work. Finally a co-operative control strategy is proposed where DFIG is controlled in such a way that it can even provide necessary reactive power demand of induction generator, so that additional cost of FACTS devices can be avoided. In that way, the DFIGs of the offshore wind farm (OWF) will actively compensate the reactive power demand of adjacent IGs of the marine current farm (MCF) during grid fault. Detailed modeling and control scheme for the proposed system are demonstrated considering some realistic scenarios. The power system small signal stability analysis is also carried out by eigenvalue analysis for marine current generator topology, wind turbine generator topology and integrated topology. The relation between the modes and state variables are discussed in light of modal and sensitivity analyses. The results of theoretical analyses are verified by MATLAB/SIMULINK and laboratory standard power system simulator PSCAD/EMTDC.

MEMS-Based Communications Systems for Space-Based Applications

NASA Technical Reports Server (NTRS)

DeLosSantos, Hector J.; Brunner, Robert A.; Lam, Juan F.; Hackett, Le Roy H.; Lohr, Ross F., Jr.; Larson, Lawrence E.; Loo, Robert Y.; Matloubian, Mehran; Tangonan, Gregory L.

1995-01-01

As user demand for higher capacity and flexibility in communications satellites increases, new ways to cope with the inherent limitations posed by the prohibitive mass and power consumption, needed to satisfy those requirements, are under investigation. Recent studies suggest that while new satellite architectures are necessary to enable multi-user, multi-data rate, multi-location satellite links, these new architectures will inevitably increase power consumption, and in turn, spacecraft mass, to such an extent that their successful implementation will demand novel lightweight/low power hardware approaches. In this paper, following a brief introduction to the fundamentals of communications satellites, we address the impact of micro-electro-mechanical systems (MEMS) technology, in particular micro-electro-mechanical (MEM) switches to mitigate the above mentioned problems and show that low-loss/wide bandwidth MEM switches will go a long way towards enabling higher capacity and flexibility space-based communications systems.

The IBM PC at NASA Ames

NASA Technical Reports Server (NTRS)

Peredo, James P.

1988-01-01

Like many large companies, Ames relies very much on its computing power to get work done. And, like many other large companies, finding the IBM PC a reliable tool, Ames uses it for many of the same types of functions as other companies. Presentation and clarification needs demand much of graphics packages. Programming and text editing needs require simpler, more-powerful packages. The storage space needed by NASA's scientists and users for the monumental amounts of data that Ames needs to keep demand the best database packages that are large and easy to use. Availability to the Micom Switching Network combines the powers of the IBM PC with the capabilities of other computers and mainframes and allows users to communicate electronically. These four primary capabilities of the PC are vital to the needs of NASA's users and help to continue and support the vast amounts of work done by the NASA employees.

Study on new energy development planning and absorptive capability of Xinjiang in China considering resource characteristics and demand prediction

NASA Astrophysics Data System (ADS)

Shao, Hai; Miao, Xujuan; Liu, Jinpeng; Wu, Meng; Zhao, Xuehua

2018-02-01

Xinjiang, as the area where wind energy and solar energy resources are extremely rich, with good resource development characteristics, can provide a support for regional power development and supply protection. This paper systematically analyzes the new energy resource and development characteristics of Xinjiang and carries out the demand prediction and excavation of load characteristics of Xinjiang power market. Combing the development plan of new energy of Xinjiang and considering the construction of transmission channel, it analyzes the absorptive capability of new energy. It provides certain reference for the comprehensive planning of new energy development in Xinjiang and the improvement of absorptive capacity of new energy.

The Geography of Green Power

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

OShaughnessy, Eric J; Heeter, Jenny S; Volpi, Christina M

Green power refers to the voluntary purchase of renewable electricity by retail electricity customers. Green power is unlike compliance-based renewable energy procurement imposed by law or regulation. In 2016, over six million customers procured about 95 million megawatt-hours (MWh) of green power in the United States, which represents about 28% of all U.S. renewable energy sales, excluding large hydropower. In this fact sheet, we use available data to illustrate the geography of green power demand (in terms of number of customers) and supply (in terms of MWh of generation) by state.

Quantifying the Sensitivity of the Production of Environmental Externalities to Market-Based Interventions in the Power Sector

NASA Astrophysics Data System (ADS)

Peer, R.; Sanders, K.

2017-12-01

The optimization function that governs the dispatching of power generators to meet electricity demand minimizes the marginal cost of electricity generation without regard to the environmental or public health damages caused by power production. Although technologies exist for reducing the externalities resulting from electricity generation at power plants, current solutions typically raise the cost of power production or introduce operational challenges for the grid. This research quantifies the trade-offs and couplings between the cooling water, greenhouse gas emissions, and air quality impacts of different power generating technologies under business as usual market conditions, as well as a series of market-based interventions aimed to reduce the production of those externalities. Using publicly available data from the US Environmental Protection Agency (EPA) and the US Energy Information Administration (EIA) for power plant water use and emissions, a unit commitment and dispatch power market simulation model is modified to evaluate the production of environmental externalities from power production. Scenarios are developed to apply a set of fees for cooling water, carbon dioxide, nitrous oxide and sulfur oxide emissions, respectively. Trade-offs between environmental performance, overall generation costs, and shifts in the power plants dispatched to meet demand are quantified for each power market simulation. The results from this study will provide insight into the development of a novel market-based framework that modifies the optimization algorithms governing the dispatching of electricity onto the grid in efforts to achieve cost-effective improvements in its environmental performance without the need for new infrastructure investments.

Skill acquisition while operating in-vehicle information systems: interface design determines the level of safety-relevant distractions.

PubMed

Jahn, Georg; Krems, Josef F; Gelau, Christhard

2009-04-01

This study tested whether the ease of learning to use human-machine interfaces of in-vehicle information systems (IVIS) can be assessed at standstill. Assessing the attentional demand of IVIS should include an evaluation of ease of learning, because the use of IVIS at low skill levels may create safety-relevant distractions. Skill acquisition in operating IVIS was quantified by fitting the power law of practice to training data sets collected in a driving study and at standstill. Participants practiced manual destination entry with two route guidance systems differing in cognitive demand. In Experiment 1, a sample of middle-aged participants was trained while steering routes of varying driving demands. In Experiment 2, another sample of middle-aged participants was trained at standstill. In Experiment 1, display glance times were less affected by driving demands than by total task times and decreased at slightly higher speed-up rates (0.02 higher on average) than task times collected at standstill in Experiment 2. The system interface that minimized cognitive demand was operated more quickly and was easier to learn. Its system delays increased static task times, which still predicted 58% of variance in display glance times compared with even 76% for the second system. The ease of learning to use an IVIS interface and the decrease in attentional demand with training can be assessed at standstill. Fitting the power law of practice to static task times yields parameters that predict display glance times while driving, which makes it possible to compare interfaces with regard to ease of learning.

Hydro, wind and solar power as a base for a 100% renewable energy supply for South and Central America.

PubMed

Barbosa, Larissa de Souza Noel Simas; Bogdanov, Dmitrii; Vainikka, Pasi; Breyer, Christian

2017-01-01

Power systems for South and Central America based on 100% renewable energy (RE) in the year 2030 were calculated for the first time using an hourly resolved energy model. The region was subdivided into 15 sub-regions. Four different scenarios were considered: three according to different high voltage direct current (HVDC) transmission grid development levels (region, country, area-wide) and one integrated scenario that considers water desalination and industrial gas demand supplied by synthetic natural gas via power-to-gas (PtG). RE is not only able to cover 1813 TWh of estimated electricity demand of the area in 2030 but also able to generate the electricity needed to fulfil 3.9 billion m3 of water desalination and 640 TWhLHV of synthetic natural gas demand. Existing hydro dams can be used as virtual batteries for solar and wind electricity storage, diminishing the role of storage technologies. The results for total levelized cost of electricity (LCOE) are decreased from 62 €/MWh for a highly decentralized to 56 €/MWh for a highly centralized grid scenario (currency value of the year 2015). For the integrated scenario, the levelized cost of gas (LCOG) and the levelized cost of water (LCOW) are 95 €/MWhLHV and 0.91 €/m3, respectively. A reduction of 8% in total cost and 5% in electricity generation was achieved when integrating desalination and power-to-gas into the system.

Hydro, wind and solar power as a base for a 100% renewable energy supply for South and Central America

PubMed Central

Barbosa, Larissa de Souza Noel Simas; Bogdanov, Dmitrii; Vainikka, Pasi; Breyer, Christian

2017-01-01

Power systems for South and Central America based on 100% renewable energy (RE) in the year 2030 were calculated for the first time using an hourly resolved energy model. The region was subdivided into 15 sub-regions. Four different scenarios were considered: three according to different high voltage direct current (HVDC) transmission grid development levels (region, country, area-wide) and one integrated scenario that considers water desalination and industrial gas demand supplied by synthetic natural gas via power-to-gas (PtG). RE is not only able to cover 1813 TWh of estimated electricity demand of the area in 2030 but also able to generate the electricity needed to fulfil 3.9 billion m3 of water desalination and 640 TWhLHV of synthetic natural gas demand. Existing hydro dams can be used as virtual batteries for solar and wind electricity storage, diminishing the role of storage technologies. The results for total levelized cost of electricity (LCOE) are decreased from 62 €/MWh for a highly decentralized to 56 €/MWh for a highly centralized grid scenario (currency value of the year 2015). For the integrated scenario, the levelized cost of gas (LCOG) and the levelized cost of water (LCOW) are 95 €/MWhLHV and 0.91 €/m3, respectively. A reduction of 8% in total cost and 5% in electricity generation was achieved when integrating desalination and power-to-gas into the system. PMID:28329023

Evaluation of Contribution for Voltage Control Ancillary Services Based on Social Surplus

NASA Astrophysics Data System (ADS)

Ueki, Yuji; Hara, Ryoichi; Kita, Hiroyuki; Hasegawa, Jun

Reactive power supply plays an important role in active power supply with adequate system voltages. Various pricing mechanism for reactive power supply have been developed and some of them are adopted in some power systems, however they are in a trial stage. The authors also focus on development of a pricing method for reactive power ancillary services. This problem involves two technical issues: rational estimation of the cost associated with reactive power supply and fair and transparent allocation of the estimated cost among the market participants. This paper proposes methods for evaluating the contribution of generators and demands.

Recent Efforts and Experiments in the Construction of Aviation Engines

NASA Technical Reports Server (NTRS)

SCHWAGER

1920-01-01

It became evident during World War I that ever-increasing demands were being placed on the mean power of aircraft engines as a result of the increased on board equipment and the demands of aerial combat. The need was for increased climbing efficiency and climbing speed. The response to these demands has been in terms of lightweight construction and the adaptation of the aircraft engine to the requirements of its use. Discussed here are specific efforts to increase flying efficiency, such as reduction of the number of revolutions of the propeller from 1400 to about 900 r.p.m. through the use of a reduction gear, increasing piston velocity, locating two crankshafts in one gear box, and using the two-cycle stroke. Also discussed are improvements in the transformation of fuel energy into engine power, the raising of compression ratios, the use of super-compression with carburetors constructed for high altitudes, the use of turbo-compressors, rotary engines, and the use of variable pitch propellers.

Avoiding 100 new power plants by increasing efficiency of room air conditioners in India: opportunities and challenges

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

Phadke, Amol; Abhyankar, Nikit; Shah, Nihar

Electricity demand for room ACs is growing very rapidly in emerging economies such as India. We estimate the electricity demand from room ACs in 2030 in India considering factors such as weather and income growth using market data on penetration of ACs in different income classes and climatic regions. We discuss the status of the current standards, labels, and incentive programs to improve the efficiency of room ACs in these markets and assess the potential for further large improvements in efficiency and find that efficiency can be improved by over 40% cost effectively. The total potential energy savings from Roommore » AC efficiency improvement in India using the best available technology will reach over 118 TWh in 2030; potential peak demand saving is found to be 60 GW by 2030. This is equivalent to avoiding 120 new coal fired power plants of 500 MW each. We discuss policy options to complement, expand and improve the ongoing programs to capture this large potential.« less

Enhanced Component Performance Study: Air-Operated Valves 1998-2014

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

Schroeder, John Alton

2015-11-01

This report presents a performance evaluation of air-operated valves (AOVs) at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience failure reports from fiscal year 1998 through 2014 for the component reliability as reported in the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The AOV failure modes considered are failure-to-open/close, failure to operate or control, and spurious operation. The component reliability estimates and the reliability data are trended for the most recent 10-year period, while yearly estimates for reliability are provided for the entire active period. One statistically significantmore » trend was observed in the AOV data: The frequency of demands per reactor year for valves recording the fail-to-open or fail-to-close failure modes, for high-demand valves (those with greater than twenty demands per year), was found to be decreasing. The decrease was about three percent over the ten year period trended.« less

Assessment of Renewable Energy Sources & Municipal Solid Waste for Sustainable Power Generation in Nigeria

NASA Astrophysics Data System (ADS)

Aderoju, Olaide M.; Dias, Guerner A.; Echakraoui, Zhour

2017-12-01

The demand for Energy in most Sub-Saharan African countries has become unimaginable despite its high potential of natural and renewable resources. The deficit has impeded the regions’ economic growth and sustainability. Nigeria as a nation is blessed with fossil fuels, abundant sunlight, hydro, wind and many among others, but the energy output to its population (185 million) still remains less than 4000MW. Currently, the clamour for an alternative but renewable energy source is the demand of the globe but it is quite expensive to achieve the yield that meets the Nigeria demand. Hence, this study aims at identifying and mapping out various regions with renewable energy potentials. The study also considers municipal solid waste as a consistent and available resource for power generation. Furthermore, this study examines the drawbacks inhibiting the inability to harness these renewable, energy generating potentials in full capacity. The study will enable the authorities and other stakeholders to invest and plan on providing a sustainable energy for the people.

System Study: Emergency Power System 1998–2013

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

Schroeder, John Alton

2015-02-01

This report presents an unreliability evaluation of the emergency power system (EPS) at 104 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2013 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant trends were identified in the EPS results.

Improving the Investment Potential of the Evenkiiskaya HPP When Working Jointly with HPPS of the Volga – Kama Cascade

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

Aleksandrovskii, A. Yu., E-mail: ayaleksand@mail.ru; Soldatkin, A. Yu.; Volkov, D. M.

The capability is studied of improving the investment potential of the Evenkiiskaya HPP by using the power it generates in the United Power System of the European part of Russia by transitioning to a compensated electrical regime of water reservoir resource usage. A quantitative assessment of Evenkiiskaya HPP usage is presented using daily load demand. Increasing the guaranteed HPP power is proposed as an alternative to new nuclear power stations.

Improving flexibility characteristics of 200 MW unit

NASA Astrophysics Data System (ADS)

Taler, Jan; Trojan, Marcin; Taler, Dawid; Dzierwa, Piotr; Kaczmarski, Karol

2017-03-01

Calculations were performed of the thermal system of a power plant with installed water pressure tanks. The maximum rise in the block electric power resulting from the shut-off of low-pressure regenerative heaters is determined. At that time, the boiler is fed with hot water from water pressure tanks acting as heat accumulators. Accumulation of hot water in water tanks is also proposed in the periods of the power unit small load. In order to lower the plant electric power in the off-peak night hours, water heated in low-pressure regenerative heaters and feed water tank to the nominal temperature is directed to water pressure tanks. The water accumulated during the night is used to feed the boiler during the period of peak demand for electricity. Drops in the power block electric power were determined for different capacities of the tanks and periods when they are charged. A financial and economic profitability analysis (of costs and benefits) is made of the use of tanks for a 200 MW power unit. Operating in the automatic system of frequency and power control, the tanks may also be used to ensure a sudden increase in the electric power of the unit. The results of the performed calculations and analyses indicate that installation of water pressure tanks is well justified. The investment is profitable. Water pressure tanks may not only be used to reduce the power unit power during the off-peak night hours and raise it in the periods of peak demand, but also to increase the power capacity fast at any time. They may also be used to fill the boiler evaporator with hot water during the power unit start-up from the cold state.

Greenhouse gas and air pollutant emission reduction potentials of renewable energy - case studies on photovoltaic and wind power introduction considering interactions among technologies in Taiwan

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

Yu-Ming Kuo; Yasuhiro Fukushima

2009-03-15

To achieve higher energy security and lower emission of greenhouse gases (GHGs) and pollutants, the development of renewable energy has attracted much attention in Taiwan. In addition to its contribution to the enhancement of reliable indigenous resources, the introduction of renewable energy such as photovoltaic (PV) and wind power systems reduces the emission of GHGs and air pollutants by substituting a part of the carbon- and pollutant-intensive power with power generated by methods that are cleaner and less carbon-intensive. To evaluate the reduction potentials, consequential changes in the operation of different types of existing power plants have to be takenmore » into account. In this study, a linear mathematical programming model is constructed to simulate a power mix for a given power demand in a power market sharing a cost-minimization objective. By applying the model, the emission reduction potentials of capacity extension case studies, including the enhancement of PV and wind power introduction at different scales, were assessed. In particular, the consequences of power mix changes in carbon dioxide, nitrogen oxides, sulfur oxides, and particulates were discussed. Seasonally varying power demand levels, solar irradiation, and wind strength were taken into account. In this study, we have found that the synergetic reduction of carbon dioxide emission induced by PV and wind power introduction occurs under a certain level of additional installed capacity. Investigation of a greater variety of case studies on scenario development with emerging power sources becomes possible by applying the model developed in this study. 15 refs., 8 figs., 11 tabs.« less

Children and adults minimise activated muscle volume by selecting gait parameters that balance gross mechanical power and work demands.

PubMed

Hubel, Tatjana Y; Usherwood, James R

2015-09-01

Terrestrial locomotion on legs is energetically expensive. Compared with cycling, or with locomotion in swimming or flying animals, walking and running are highly uneconomical. Legged gaits that minimise mechanical work have previously been identified and broadly match walking and running at appropriate speeds. Furthermore, the 'cost of muscle force' approaches are effective in relating locomotion kinetics to metabolic cost. However, few accounts have been made for why animals deviate from either work-minimising or muscle-force-minimising strategies. Also, there is no current mechanistic account for the scaling of locomotion kinetics with animal size and speed. Here, we report measurements of ground reaction forces in walking children and adult humans, and their stance durations during running. We find that many aspects of gait kinetics and kinematics scale with speed and size in a manner that is consistent with minimising muscle activation required for the more demanding between mechanical work and power: spreading the duration of muscle action reduces activation requirements for power, at the cost of greater work demands. Mechanical work is relatively more demanding for larger bipeds--adult humans--accounting for their symmetrical M-shaped vertical force traces in walking, and relatively brief stance durations in running compared with smaller bipeds--children. The gaits of small children, and the greater deviation of their mechanics from work-minimising strategies, may be understood as appropriate for their scale, not merely as immature, incompletely developed and energetically sub-optimal versions of adult gaits. © 2015. Published by The Company of Biologists Ltd.

Promise, pitfalls of rate reform shown in Vermont experiment

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

Not Available

1977-03-01

Both utilities and customers are unhappy with the way existing rate structures are handling rapidly rising fixed plant expenses and operating costs. Results of an experiment by Green Mountain Power in Vermont are discussed. The residential sector one-year study tested six rates: an off-peak rate, an interruptible rate, a peak-kilowatt demand rate, a three-part demand rate, an inverted demand rate, and a contract demand rate. The most successful of the kilowatt-related rates was the peak demand rate, and the most effective rate was probably the interruptible rate. The off-peak rate provided some savings for all who tried it, although theremore » are some who would have lost money in comparison to the conventional rate. The other three rate experiments proved unsuccessful because customers could not adapt to them. (MCW)« less

Crossing the Barriers: An Analysis of Market Barriers to Geothermal Development and Potential Improvement Scenarios

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

Young, Katherine R; Levine, Aaron L; Cook, Jeffrey J

Developers have identified many non-technical barriers to geothermal power development, including market barriers. Understanding the challenges to market deployment of geothermal power is important since obtaining power purchase agreements is often cited as one of the largest barriers to geothermal development. This paper discusses the impacts to deployment caused by market challenges, including market demand, price of electricity, policies and incentives.

High-average-power CTH:YAG for the medical environment

NASA Astrophysics Data System (ADS)

Wright, Sidney P.; Adamkiewicz, Edward J.; Moulton, Peter F.

1992-06-01

Medical procedures such as arthroscopy have placed increasing demands on the output performance of the CTH:YAG laser at 2.1 micrometers . Intensive research has been conducted to improve the average power, pulse energies, and rep rates while reducing any failure mechanisms. The results of this work is reported along with a discussion of the important engineering parameters concerning the design of a high power medical CTH:YAG laser.

The Army’s Operational Energy Challenge

DTIC Science & Technology

2011-05-01

battery chargers . Solar Hybrid—a system capable of providing up to 10 kilowatts of power continuously while reducing gen- erator running time by 20...granted. Army vehicles consume unprecedented amounts of fuel for mobility and onboard power. Average fuel demand per soldier has increased from about 1... electric power. This depen- dence translates to a vulnerability as fuel and water com- pose the vast majority of resupply volume, which, in turn

Improving Legacy Aircraft Systems Through Condition-Based Maintenance: An H-60 Case Study

DTIC Science & Technology

2014-09-01

level functions. These decompositions are equivalent to a detailed design effort in systems engineering. NAMPSOPs have a common architectural structure...Assembly Power Available Spindle Cables No.1 Engine Load Demand Spindle Control Cables Engine Pneumatic Starters Auxiliary Power Unit IRCM FLIR Mission...Analysis Fuel System Main Rotor Head Main Module Main Gear Box Radiator Engine Output Shaft Auxiliary Power Unit Flight Control Cables Tail Landing

Econophysics of adaptive power markets: When a market does not dampen fluctuations but amplifies them

NASA Astrophysics Data System (ADS)

Krause, Sebastian M.; Börries, Stefan; Bornholdt, Stefan

2015-07-01

The average economic agent is often used to model the dynamics of simple markets, based on the assumption that the dynamics of a system of many agents can be averaged over in time and space. A popular idea that is based on this seemingly intuitive notion is to dampen electric power fluctuations from fluctuating sources (as, e.g., wind or solar) via a market mechanism, namely by variable power prices that adapt demand to supply. The standard model of an average economic agent predicts that fluctuations are reduced by such an adaptive pricing mechanism. However, the underlying assumption that the actions of all agents average out on the time axis is not always true in a market of many agents. We numerically study an econophysics agent model of an adaptive power market that does not assume averaging a priori. We find that when agents are exposed to source noise via correlated price fluctuations (as adaptive pricing schemes suggest), the market may amplify those fluctuations. In particular, small price changes may translate to large load fluctuations through catastrophic consumer synchronization. As a result, an adaptive power market may cause the opposite effect than intended: Power demand fluctuations are not dampened but amplified instead.

The mechanics and energetics of human walking and running: a joint level perspective.

PubMed

Farris, Dominic James; Sawicki, Gregory S

2012-01-07

Humans walk and run at a range of speeds. While steady locomotion at a given speed requires no net mechanical work, moving faster does demand both more positive and negative mechanical work per stride. Is this increased demand met by increasing power output at all lower limb joints or just some of them? Does running rely on different joints for power output than walking? How does this contribute to the metabolic cost of locomotion? This study examined the effects of walking and running speed on lower limb joint mechanics and metabolic cost of transport in humans. Kinematic and kinetic data for 10 participants were collected for a range of walking (0.75, 1.25, 1.75, 2.0 m s(-1)) and running (2.0, 2.25, 2.75, 3.25 m s(-1)) speeds. Net metabolic power was measured by indirect calorimetry. Within each gait, there was no difference in the proportion of power contributed by each joint (hip, knee, ankle) to total power across speeds. Changing from walking to running resulted in a significant (p = 0.02) shift in power production from the hip to the ankle which may explain the higher efficiency of running at speeds above 2.0 m s(-1) and shed light on a potential mechanism behind the walk-run transition.

The Radical Flank Effect and Cross-occupational Collaboration for Technology Development during a Power Shift

PubMed Central

Truelove, Emily; Kellogg, Katherine C.

2016-01-01

This 12-month ethnographic study of an early entrant into the U.S. car-sharing industry demonstrates that when an organization shifts its focus from developing radical new technology to incrementally improving this technology, the shift may spark an internal power struggle between the dominant engineering group and a challenger occupational group such as the marketing group. Analyzing 42 projects in two time periods that required collaboration between engineering and marketing during such a shift, we show how cross-occupational collaboration under these conditions can be facilitated by a radical flank threat, through which the bargaining power of moderates is strengthened by the presence of a more-radical group. In the face of a strong threat by radical members of a challenger occupational group, moderate members of the dominant engineering group may change their perceptions of their power to resist challengers’ demands and begin to distinguish between the goals of radical versus more-moderate challengers. To maintain as much power as possible and prevent the more-dramatic change in engineering occupational goals demanded by radical challengers, moderate engineers may build a coalition with moderate challengers and collaborate for incremental technology development. PMID:28424533

The Radical Flank Effect and Cross-occupational Collaboration for Technology Development during a Power Shift.

PubMed

Truelove, Emily; Kellogg, Katherine C

2016-12-01

This 12-month ethnographic study of an early entrant into the U.S. car-sharing industry demonstrates that when an organization shifts its focus from developing radical new technology to incrementally improving this technology, the shift may spark an internal power struggle between the dominant engineering group and a challenger occupational group such as the marketing group. Analyzing 42 projects in two time periods that required collaboration between engineering and marketing during such a shift, we show how cross-occupational collaboration under these conditions can be facilitated by a radical flank threat, through which the bargaining power of moderates is strengthened by the presence of a more-radical group. In the face of a strong threat by radical members of a challenger occupational group, moderate members of the dominant engineering group may change their perceptions of their power to resist challengers' demands and begin to distinguish between the goals of radical versus more-moderate challengers. To maintain as much power as possible and prevent the more-dramatic change in engineering occupational goals demanded by radical challengers, moderate engineers may build a coalition with moderate challengers and collaborate for incremental technology development.

Design of An Energy Efficient Hydraulic Regenerative circuit

NASA Astrophysics Data System (ADS)

Ramesh, S.; Ashok, S. Denis; Nagaraj, Shanmukha; Adithyakumar, C. R.; Reddy, M. Lohith Kumar; Naulakha, Niranjan Kumar

2018-02-01

Increasing cost and power demand, leads to evaluation of new method to increase through productivity and help to solve the power demands. Many researchers have break through to increase the efficiency of a hydraulic power pack, one of the promising methods is the concept of regenerative. The objective of this research work is to increase the efficiency of a hydraulic circuit by introducing a concept of regenerative circuit. A Regenerative circuit is a system that is used to speed up the extension stroke of the double acting single rod hydraulic cylinder. The output is connected to the input in the directional control value. By this concept, increase in velocity of the piston and decrease the cycle time. For the research, a basic hydraulic circuit and a regenerative circuit are designated and compared both with their results. The analysis was based on their time taken for extension and retraction of the piston. From the detailed analysis of both the hydraulic circuits, it is found that the efficiency by introducing hydraulic regenerative circuit increased by is 5.3%. The obtained results conclude that, implementing hydraulic regenerative circuit in a hydraulic power pack decreases power consumption, reduces cycle time and increases productivity in a longer run.

Nuclear power grows in China`s energy mix

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

Chen, Xavier

1996-07-01

China`s rapid economic growth in the past two decades has caused the nations`s demand for electricity to exceed its capacity. AS of 1992, with power shortages as high as 25 percent, {open_quotes}power plant operators were often forced to resort to rolling brownouts to avoid complete system breakdowns,{close_quotes} says Xavier Chen, an assistant professor with the Asian Institute of Technology`s Energy Program in Bangkok, Thailand. To keep pace with China`s economic development, Chen estimates that {open_quotes}China must increase its electricity capacity 6 to 8 percent a year each year into the foreseeable future.{close_quotes} For now, coal is transported to power plantsmore » in the rapidly developing eastern coastal provinces at great expense. Chen also notes that the environmental disadvantages of coal make it a less desirable source of energy than nuclear. Development of nuclear energy is likely to go forward for another reason: In China, there is much less opposition to nuclear power plants than in other developing nations. {open_quotes}Nuclear energy likely will plan an important role in China`s future energy mix and help close the gap between electricity production and demand,{close_quotes} Chen says.« less

Power Management Based Current Control Technique for Photovoltaic-Battery Assisted Wind-Hydro Hybrid System

NASA Astrophysics Data System (ADS)

Ram Prabhakar, J.; Ragavan, K.

2013-07-01

This article proposes new power management based current control strategy for integrated wind-solar-hydro system equipped with battery storage mechanism. In this control technique, an indirect estimation of load current is done, through energy balance model, DC-link voltage control and droop control. This system features simpler energy management strategy and necessitates few power electronic converters, thereby minimizing the cost of the system. The generation-demand (G-D) management diagram is formulated based on the stochastic weather conditions and demand, which would likely moderate the gap between both. The features of management strategy deploying energy balance model include (1) regulating DC-link voltage within specified tolerances, (2) isolated operation without relying on external electric power transmission network, (3) indirect current control of hydro turbine driven induction generator and (4) seamless transition between grid-connected and off-grid operation modes. Furthermore, structuring of the hybrid system with appropriate selection of control variables enables power sharing among each energy conversion systems and battery storage mechanism. By addressing these intricacies, it is viable to regulate the frequency and voltage of the remote network at load end. The performance of the proposed composite scheme is demonstrated through time-domain simulation in MATLAB/Simulink environment.

Multi-Fluid Geo-Energy Systems for Bulk and Thermal Energy Storage and Dispatchable Renewable and Low-Carbon Electricity

NASA Astrophysics Data System (ADS)

Buscheck, T. A.; Randolph, J.; Saar, M. O.; Hao, Y.; Sun, Y.; Bielicki, J. M.

2014-12-01

Integrating renewable energy sources into electricity grids requires advances in bulk and thermal energy storage technologies, which are currently expensive and have limited capacity. We present an approach that uses the huge fluid and thermal storage capacity of the subsurface to harvest, store, and dispatch energy from subsurface (geothermal) and surface (solar, nuclear, fossil) thermal resources. CO2 captured from fossil-energy systems and N2 separated from air are injected into permeable formations to store pressure, generate artesian flow of brine, and provide additional working fluids. These enable efficient fluid recirculation, heat extraction, and power conversion, while adding operational flexibility. Our approach can also store and dispatch thermal energy, which can be used to levelize concentrating solar power and mitigate variability of wind and solar power. This may allow low-carbon, base-load power to operate at full capacity, with the stored excess energy being available to addresss diurnal and seasonal mismatches between supply and demand. Concentric rings of horizontal injection and production wells are used to create a hydraulic divide to store pressure, CO2, N2, and thermal energy. Such storage can take excess power from the grid and excess thermal energy, and dispatch that energy when it is demanded. The system is pressurized and/or heated when power supply exceeds demand and depressurized when demand exceeds supply. Supercritical CO2 and N2 function as cushion gases to provide enormous pressure-storage capacity. Injecting CO2 and N2 displaces large quantities of brine, reducing the use of fresh water. Geologic CO2 storage is a crucial option for reducing CO2 emissions, but valuable uses for CO2 are needed to justify capture costs. The initial "charging" of our system requires permanently isolating large volumes of CO2 from the atmosphere and thus creates a market for its disposal. Our approach is designed for locations where a permeable geologic formation is overlain by an impermeable formation that constrains migration of buoyant CO2 and/or N2, and heated brine. Such geologic conditions exist over nearly half of the contiguous United States. This work was performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Electricity by intermittent sources: An analysis based on the German situation 2012

NASA Astrophysics Data System (ADS)

Wagner, Friedrich

2014-02-01

The 2012 data of the German load, the on- and offshore and the photo-voltaic energy production are used and scaled to the limit of supplying the annual demand (100% case). The reference mix of the renewable energy (RE) forms is selected such that the remaining back-up energy is minimised. For the 100% case, the RE power installation has to be about 3 times the present peak load. The back-up system can be reduced by 12% in this case. The surplus energy corresponds to 26% of the demand. The back-up system and more so the grid must be able to cope with large power excursions. All components of the electricity supply system operate at low capacity factors. Large-scale storage can hardly be motivated by the effort to further reduce CO2 emission. Demand-side management will intensify the present periods of high economic activities. Its rigorous implementation will expand the economic activities into the weekends. On the basis of a simple criterion, the increase of periods with negative electricity prices in Germany is assessed. It will be difficult with RE to meet the low CO2 emission factors which characterise those European Countries which produce electricity mostly by nuclear and hydro power.

Medium-term electric power demand forecasting based on economic-electricity transmission model

NASA Astrophysics Data System (ADS)

Li, Wenfeng; Bao, Fangmin; Bai, Hongkun; Liu, Wei; Liu, Yongmin; Mao, Yubin; Wang, Jiangbo; Liu, Junhui

2018-06-01

Electric demand forecasting is a basic work to ensure the safe operation of power system. Based on the theories of experimental economics and econometrics, this paper introduces Prognoz Platform 7.2 intelligent adaptive modeling platform, and constructs the economic electricity transmission model that considers the economic development scenarios and the dynamic adjustment of industrial structure to predict the region's annual electricity demand, and the accurate prediction of the whole society's electricity consumption is realized. Firstly, based on the theories of experimental economics and econometrics, this dissertation attempts to find the economic indicator variables that drive the most economical growth of electricity consumption and availability, and build an annual regional macroeconomic forecast model that takes into account the dynamic adjustment of industrial structure. Secondly, it innovatively put forward the economic electricity directed conduction theory and constructed the economic power transfer function to realize the group forecast of the primary industry + rural residents living electricity consumption, urban residents living electricity, the second industry electricity consumption, the tertiary industry electricity consumption; By comparing with the actual value of economy and electricity in Henan province in 2016, the validity of EETM model is proved, and the electricity consumption of the whole province from 2017 to 2018 is predicted finally.

75 FR 61459 - Idaho Power Company and Milner Dam, Inc.; Notice of Application for Amendment of License and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-05

... irrigation demands, is between 10,000 and 12,500 cfs. Powerhouse operation will resume when inflow in excess of irrigation demand is greater than 12,500 cfs and utilize for generation any flows in excess of 12,500 cfs. The licensees are required by article 417 to provide a communication network used to predict...

Optimization and Performance Study of Select Heating Ventilation and Air Conditioning Technologies for Commercial Buildings

NASA Astrophysics Data System (ADS)

Kamal, Rajeev

Buildings contribute a significant part to the electricity demand profile and peak demand for the electrical utilities. The addition of renewable energy generation adds additional variability and uncertainty to the power system. Demand side management in the buildings can help improve the demand profile for the utilities by shifting some of the demand from peak to off-peak times. Heating, ventilation and air-conditioning contribute around 45% to the overall demand of a building. This research studies two strategies for reducing the peak as well as shifting some demand from peak to off-peak periods in commercial buildings: 1. Use of gas heat pumps in place of electric heat pumps, and 2. Shifting demand for air conditioning from peak to off-peak by thermal energy storage in chilled water and ice. The first part of this study evaluates the field performance of gas engine-driven heat pumps (GEHP) tested in a commercial building in Florida. Four GEHP units of 8 Tons of Refrigeration (TR) capacity each providing air-conditioning to seven thermal zones in a commercial building, were instrumented for measuring their performance. The operation of these GEHPs was recorded for ten months, analyzed and compared with prior results reported in the literature. The instantaneous COPunit of these systems varied from 0.1 to 1.4 during typical summer week operation. The COP was low because the gas engines for the heat pumps were being used for loads that were much lower than design capacity which resulted in much lower efficiencies than expected. The performance of equivalent electric heat pump was simulated from a building energy model developed to mimic the measured building loads. An economic comparison of GEHPs and conventional electrical heat pumps was done based on the measured and simulated results. The average performance of the GEHP units was estimated to lie between those of EER-9.2 and EER-11.8 systems. The performance of GEHP systems suffers due to lower efficiency at part load operation. The study highlighted the need for optimum system sizing for GEHP/HVAC systems to meet the building load to obtain better performance in buildings. The second part of this study focusses on using chilled water or ice as thermal energy storage for shifting the air conditioning load from peak to off-peak in a commercial building. Thermal energy storage can play a very important role in providing demand-side management for diversifying the utility demand from buildings. Model of a large commercial office building is developed with thermal storage for cooling for peak power shifting. Three variations of the model were developed and analyzed for their performance with 1) ice storage, 2) chilled water storage with mixed storage tank and 3) chilled water storage with stratified tank, using EnergyPlus 8.5 software developed by the US Department of Energy. Operation strategy with tactical control to incorporate peak power schedule was developed using energy management system (EMS). The modeled HVAC system was optimized for minimum cost with the optimal storage capacity and chiller size using JEPlus. Based on the simulation, an optimal storage capacity of 40-45 GJ was estimated for the large office building model along with 40% smaller chiller capacity resulting in higher chiller part-load performance. Additionally, the auxiliary system like pump and condenser were also optimized to smaller capacities and thus resulting in less power demand during operation. The overall annual saving potential was found in the range of 7-10% for cooling electricity use resulting in 10-17% reduction in costs to the consumer. A possible annual peak shifting of 25-78% was found from the simulation results after comparing with the reference models. Adopting TES in commercial buildings and achieving 25% peak shifting could result in a reduction in peak summer demand of 1398 MW in Tampa.

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

NASA Astrophysics Data System (ADS)

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

2018-05-01

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

Necromass as a source of energy to microorganisms in marine sediments.

NASA Astrophysics Data System (ADS)

Bradley, J.; Amend, J.; LaRowe, D.

2017-12-01

Marine sediments constitute one of the largest, most energy-limited biospheres on Earth. Despite increasing exploration and interest characterizing microbial communities in marine sediments, the production and role of microbial dead-matter (necromass) has largely been overlooked. Necromass is produced on a global scale, yet its significance as a power source to heterotrophic microorganisms remains unknown. We developed a physical, bio-energetic and geochemical model to quantify the total power supply from necromass oxidation and the total power demand of living microorganisms in marine sediments. This model is first applied to sediments from the oligotrophic South Pacific Gyre (SPG), where organic carbon and biomass concentrations are extremely low, yet microorganisms persist for millions of years in some of the lowest energy states on Earth. We show that necromass does not supply sufficient power to support the total demands of the living community (<39%) at SPG. Application of our model on a global scale, however, shows that necromass produced and subsequently oxidized can provide sufficient power to satisfy the maintenance demands of microorganisms in marine sediments for up to 60,000 years following burial. Our model assumes that all counted cells are viable. Yet, if only a fraction of counted cells are alive, the role of necromass as an electron donor in fueling microbial metabolisms is even greater. This new insight requires a reassessment of carbon fluxes in the deep biosphere. By extension, we also demonstrate a mechanism for microbial communities to persist by oxidizing necromass over geological timescales, and thereby endure unfavorable, low-energy settings that might be analogous to conditions on early Earth and on other planetary bodies.

Design of stationary PEFC system configurations to meet heat and power demands

NASA Astrophysics Data System (ADS)

Wallmark, Cecilia; Alvfors, Per

This paper presents heat and power efficiencies of a modeled PEFC system and the methods used to create the system configuration. The paper also includes an example of a simulated fuel cell system supplying a building in Sweden with heat and power. The main method used to create an applicable fuel cell system configuration is pinch technology. This technology is used to evaluate and design a heat exchanger network for a PEFC system working under stationary conditions, in order to find a solution with high heat utilization. The heat exchanger network in the system connecting the reformer, the burner, gas cleaning, hot-water storage and the PEFC stack will affect the heat transferred to the hot-water storage and thereby the heating of the building. The fuel, natural gas, is reformed to a hydrogen-rich gas within a slightly pressurized system. The fuel processor investigated is steam reforming, followed by high- and low-temperature shift reactors and preferential oxidation. The system is connected to the electrical grid for backup and peak demands and to a hot-water storage to meet the varying heat demand for the building. The procedure for designing the fuel cell system installation as co-generation system is described, and the system is simulated for a specific building in Sweden during 1 year. The results show that the fuel cell system in combination with a burner and hot-water storage could supply the building with the required heat without exceeding any of the given limitations. The designed co-generation system will provide the building with most of its power requirements and would further generate income by sale of electricity to the power grid.

Laser power beaming: an emerging technology for power transmission and propulsion in space

NASA Astrophysics Data System (ADS)

Bennett, Harold E.

1997-05-01

A ground based laser beam transmitted to space can be used as an electric utility for satellites. It can significantly increase the electric power available to operate a satellite or to transport it from low earth orbit (LEO) to mid earth or geosynchronous orbits. The increase in electrical power compared to that obtainable from the sun is as much as 1000% for the same size solar panels. An increase in satellite electric power is needed to meet the increasing demands for power caused by the advent of 'direct to home TV,' for increased telecommunications, or for other demands made by the burgeoning 'space highway.' Monetary savings as compared to putting up multiple satellites in the same 'slot' can be over half a billion dollars. To obtain propulsion, the laser power can be beamed through the atmosphere to an 'orbit transfer vehicle' (OTV) satellite which travels back and forth between LEO and higher earth orbits. The OTV will transport the satellite into orbit as does a rocket but does not require the heavy fuel load needed if rocket propulsion is used. Monetary savings of 300% or more in launch costs are predicted. Key elements in the proposed concept are a 100 to 200 kW free- electron laser operating at 0.84 m in the photographic infrared region of the spectrum and a novel adaptive optic telescope.

Dynamic EROI Assessment of the IPCC 21st Century Electricity Production Scenario

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

Neumeyer, Charles; Goldston, Robert

Abstract: The Energy Return on Investment (EROI) is an important measure of the energy gain of an electrical power generating facility that is typically evaluated based on the life cycle energy balance of a single facility. The EROI concept can be extended to cover a collection of facilities that comprise a complete power system and used to assess the expansion and evolution of a power system as it transitions from one portfolio mix of technologies to another over time. In this study we develop a dynamic EROI model that simulates the evolution of a power system and we perform anmore » EROI simulation of one of the electricity production scenarios developed under the auspices of the Intergovernmental Panel on Climate Change (IPCC) covering the global supply of electricity in the 21st century. Our analytic tool provides the means for evaluation of dynamic EROI based on arbitrary time-dependent demand scenarios by modeling the required expansion of power generation, including the plowback needed for new construction and to replace facilities as they are retired. The results provide insight into the level of installed and delivered power, above and beyond basic consumer demand, that is required to support construction during expansion, as well as the supplementary power that may be required if plowback constraints are imposed. In addition, sensitivity to EROI parameters, and the impact of energy storage efficiency are addressed.« less

Dynamic EROI Assessment of the IPCC 21st Century Electricity Production Scenario

DOE PAGES

Neumeyer, Charles; Goldston, Robert

2016-04-28

Abstract: The Energy Return on Investment (EROI) is an important measure of the energy gain of an electrical power generating facility that is typically evaluated based on the life cycle energy balance of a single facility. The EROI concept can be extended to cover a collection of facilities that comprise a complete power system and used to assess the expansion and evolution of a power system as it transitions from one portfolio mix of technologies to another over time. In this study we develop a dynamic EROI model that simulates the evolution of a power system and we perform anmore » EROI simulation of one of the electricity production scenarios developed under the auspices of the Intergovernmental Panel on Climate Change (IPCC) covering the global supply of electricity in the 21st century. Our analytic tool provides the means for evaluation of dynamic EROI based on arbitrary time-dependent demand scenarios by modeling the required expansion of power generation, including the plowback needed for new construction and to replace facilities as they are retired. The results provide insight into the level of installed and delivered power, above and beyond basic consumer demand, that is required to support construction during expansion, as well as the supplementary power that may be required if plowback constraints are imposed. In addition, sensitivity to EROI parameters, and the impact of energy storage efficiency are addressed.« less

A multiscale forecasting method for power plant fleet management

NASA Astrophysics Data System (ADS)

Chen, Hongmei

In recent years the electric power industry has been challenged by a high level of uncertainty and volatility brought on by deregulation and globalization. A power producer must minimize the life cycle cost while meeting stringent safety and regulatory requirements and fulfilling customer demand for high reliability. Therefore, to achieve true system excellence, a more sophisticated system-level decision-making process with a more accurate forecasting support system to manage diverse and often widely dispersed generation units as a single, easily scaled and deployed fleet system in order to fully utilize the critical assets of a power producer has been created as a response. The process takes into account the time horizon for each of the major decision actions taken in a power plant and develops methods for information sharing between them. These decisions are highly interrelated and no optimal operation can be achieved without sharing information in the overall process. The process includes a forecasting system to provide information for planning for uncertainty. A new forecasting method is proposed, which utilizes a synergy of several modeling techniques properly combined at different time-scales of the forecasting objects. It can not only take advantages of the abundant historical data but also take into account the impact of pertinent driving forces from the external business environment to achieve more accurate forecasting results. Then block bootstrap is utilized to measure the bias in the estimate of the expected life cycle cost which will actually be needed to drive the business for a power plant in the long run. Finally, scenario analysis is used to provide a composite picture of future developments for decision making or strategic planning. The decision-making process is applied to a typical power producer chosen to represent challenging customer demand during high-demand periods. The process enhances system excellence by providing more accurate market information, evaluating the impact of external business environment, and considering cross-scale interactions between decision actions. Along with this process, system operation strategies, maintenance schedules, and capacity expansion plans that guide the operation of the power plant are optimally identified, and the total life cycle costs are estimated.

Bipolar Ag-Zn battery

NASA Astrophysics Data System (ADS)

Giltner, L. John

1994-02-01

The silver-zinc (AgZn) battery system has been unique in its ability to safely satisfy high power demand applications with low mass and volume. However, a new generation of defense, aerospace, and commercial applications will impose even higher power demands. These new power demands can be satisfied by the development of a bipolar battery design. In this configuration the power consuming, interelectrode current conductors are eliminated while the current is then conducted via the large cross-section electrode substrate. Negative and positive active materials are applied to opposite sides of a solid silver foil substrate. In addition to reducing the weight and volume required for a specified power level, the output voltage performance is also improved as follows. Reduced weight through: elimination of the plastic cell container; elimination of plate leads and intercell connector; and elimination of internal plate current collector. Increased voltage through: elimination of resistance of current collector; elimination of resistance of plate lead; and elimination of resistance of intercell connector. EPI worked previously on development of a secondary bipolar silver zinc battery. This development demonstrated the electrical capability of the system and manufacturing techniques. One difficulty with this development was mechanical problems with the seals. However, recent improvements in plastics and adhesives should eliminate the major problem of maintaining a seal around the periphery of the bipolar module. The seal problem is not as significant for a primary battery application or for a requirement for only a few discharge cycles. A second difficulty encountered was with activation (introducing electrolyte into the cell) and with venting gas from the cell without loss of electrolyte. During previous work, the following projections for energy density were made from test data for a high power system which demonstrated in excess of 50 discharge/charge cycles. Projected system power = 100 kilowatts; discharge time = 30 seconds; discharge current density = 1.75 amps/sq in.; system weight = 86 lbs (9.7 WH/lb); and system volume = 1071 cu. in. (.78 WH/cu. in.). EPI is currently working on a development program to produce a bipolar silver-zinc battery design for NASA. The potential application would be to power electromechanical actuators for space launch vehicles.

Bipolar Ag-Zn battery

NASA Technical Reports Server (NTRS)

Giltner, L. John

1994-01-01

The silver-zinc (AgZn) battery system has been unique in its ability to safely satisfy high power demand applications with low mass and volume. However, a new generation of defense, aerospace, and commercial applications will impose even higher power demands. These new power demands can be satisfied by the development of a bipolar battery design. In this configuration the power consuming, interelectrode current conductors are eliminated while the current is then conducted via the large cross-section electrode substrate. Negative and positive active materials are applied to opposite sides of a solid silver foil substrate. In addition to reducing the weight and volume required for a specified power level, the output voltage performance is also improved as follows. Reduced weight through: elimination of the plastic cell container; elimination of plate leads and intercell connector; and elimination of internal plate current collector. Increased voltage through: elimination of resistance of current collector; elimination of resistance of plate lead; and elimination of resistance of intercell connector. EPI worked previously on development of a secondary bipolar silver zinc battery. This development demonstrated the electrical capability of the system and manufacturing techniques. One difficulty with this development was mechanical problems with the seals. However, recent improvements in plastics and adhesives should eliminate the major problem of maintaining a seal around the periphery of the bipolar module. The seal problem is not as significant for a primary battery application or for a requirement for only a few discharge cycles. A second difficulty encountered was with activation (introducing electrolyte into the cell) and with venting gas from the cell without loss of electrolyte. During previous work, the following projections for energy density were made from test data for a high power system which demonstrated in excess of 50 discharge/charge cycles. Projected system power = 100 kilowatts; discharge time = 30 seconds; discharge current density = 1.75 amps/sq in.; system weight = 86 lbs (9.7 WH/lb); and system volume = 1071 cu. in. (.78 WH/cu. in.). EPI is currently working on a development program to produce a bipolar silver-zinc battery design for NASA. The potential application would be to power electromechanical actuators for space launch vehicles.

Integrated Energy-Water Planning in the Western and Texas Interconnections (Invited)

NASA Astrophysics Data System (ADS)

Tidwell, V. C.

2013-12-01

While thermoelectric power generation accounts for less than one percent of total water consumption in the western U.S, steady growth in demand is projected for this sector. Complexities and heterogeneity in water supply, water demand, and institutional controls make water development a challenging proposition throughout the West. A consortium of National Laboratories, the University of Texas and the Electric Power Research Institute are working with the Western Governors' Association and Western States Water Council to assist the Western Electricity Coordinating Council and the Electric Reliability Council of Texas to integrate water related issues into long-term transmission planning. Specifically, water withdrawal and consumption have been estimated for each western power plant and their susceptibility to climate impacts assessed. To assist with transmission planning, water availability and cost data have been mapped at the 8-digit Hydrologic Unit Code level for the conterminous western U.S. (1208 watersheds). Five water sources were individually considered, including unappropriated surface water, unappropriated groundwater, appropriated water, municipal wastewater and brackish groundwater. Also mapped is projected growth in consumptive water demand to 2030. The relative costs (capital and O&M) to secure, convey, and treat the water as necessary have also been estimated for each source of water. These data configured into watershed level supply curves were subsequently used to constrain West-wide transmission planning. Results across a range of alternative energy futures indicate the impact of water availability and cost on the makeup and siting of future power generation. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. Water budgets at a 8-digit HUC level constructed by aggregating available water (all five sources) and subtracting projected change in demand for 2010-2030.

Measuring market performance in restructured electricity markets: An empirical analysis of the PJM energy market

NASA Astrophysics Data System (ADS)

Tucker, Russell Jay

2002-09-01

Today the electric industry in the U.S. is transitioning to competitive markets for wholesale electricity. Independent system operators (ISOs) now manage broad regional markets for electrical energy in several areas of the U.S. A recent rulemaking by the Federal Energy Regulatory Commission (FERC) encourages the development of regional transmission organizations (RTOs) and restructured competitive wholesale electricity markets nationwide. To date, the transition to competitive wholesale markets has not been easy. The increased reliance on market forces coupled with unusually high electricity demand for some periods have created conditions amenable to market power abuse in many regions throughout the U.S. In the summer of 1999, hot and humid summer conditions in Pennsylvania, New Jersey, Maryland, Delaware, and the District of Columbia pushed peak demand in the PJM Interconnection to record levels. These demand conditions coincided with the introduction of market-based pricing in the wholesale electricity market. Prices for electricity increased on average by 55 percent, and reached the $1,000/MWh range. This study examines the extent to which generator market power raised prices above competitive levels in the PJM Interconnection during the summer of 1999. It simulates hourly market-clearing prices assuming competitive market behavior and compares these prices with observed market prices in computing price markups over the April 1-August 31, 1999 period. The results of the simulation analysis are supported with an examination of actual generator bid data of incumbent generators. Price markups averaged 14.7 percent above expected marginal cost over the 5-month period for all non-transmission-constrained hours. The evidence presented suggests that the June and July monthly markups were strongly influenced by generator market power as price inelastic peak demand approached the electricity generation capacity constraint of the market. While this analysis of the performance of the PJM market finds evidence of market power, the measured markups are markedly less than estimates from prior analysis of the PJM market.

Neuro-Fuzzy Computational Technique to Control Load Frequency in Hydro-Thermal Interconnected Power System

NASA Astrophysics Data System (ADS)

Prakash, S.; Sinha, S. K.

2015-09-01

In this research work, two areas hydro-thermal power system connected through tie-lines is considered. The perturbation of frequencies at the areas and resulting tie line power flows arise due to unpredictable load variations that cause mismatch between the generated and demanded powers. Due to rising and falling power demand, the real and reactive power balance is harmed; hence frequency and voltage get deviated from nominal value. This necessitates designing of an accurate and fast controller to maintain the system parameters at nominal value. The main purpose of system generation control is to balance the system generation against the load and losses so that the desired frequency and power interchange between neighboring systems are maintained. The intelligent controllers like fuzzy logic, artificial neural network (ANN) and hybrid fuzzy neural network approaches are used for automatic generation control for the two area interconnected power systems. Area 1 consists of thermal reheat power plant whereas area 2 consists of hydro power plant with electric governor. Performance evaluation is carried out by using intelligent (ANFIS, ANN and fuzzy) control and conventional PI and PID control approaches. To enhance the performance of controller sliding surface i.e. variable structure control is included. The model of interconnected power system has been developed with all five types of said controllers and simulated using MATLAB/SIMULINK package. The performance of the intelligent controllers has been compared with the conventional PI and PID controllers for the interconnected power system. A comparison of ANFIS, ANN, Fuzzy and PI, PID based approaches shows the superiority of proposed ANFIS over ANN, fuzzy and PI, PID. Thus the hybrid fuzzy neural network controller has better dynamic response i.e., quick in operation, reduced error magnitude and minimized frequency transients.

Variable-Displacement Hydraulic Drive Unit

NASA Technical Reports Server (NTRS)

Lang, D. J.; Linton, D. J.; Markunas, A.

1986-01-01

Hydraulic power controlled through multiple feedback loops. In hydraulic drive unit, power closely matched to demand, thereby saving energy. Hydraulic flow to and from motor adjusted by motor-control valve connected to wobbler. Wobbler angle determines motor-control-valve position, which in turn determines motor displacement. Concept applicable to machine tools, aircraft controls, and marine controls.

18 CFR 35.28 - Non-discriminatory open access transmission tariff.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Non-discriminatory open access transmission tariff. 35.28 Section 35.28 Conservation of Power and Water Resources FEDERAL ENERGY.... (4) Demand response means a reduction in the consumption of electric energy by customers from their...

18 CFR 35.28 - Non-discriminatory open access transmission tariff.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Non-discriminatory open access transmission tariff. 35.28 Section 35.28 Conservation of Power and Water Resources FEDERAL ENERGY.... (4) Demand response means a reduction in the consumption of electric energy by customers from their...

Student Leadership Demand and Problem of the Educational System

ERIC Educational Resources Information Center

Adeyanju, 'Lade Joel

2006-01-01

Leadership is a subjective concept that can be applied in diverse ways, depending on the circumstances either negative or positive (Ubong and Wokocha, 2001) Subjective as the concept of leadership is, it is definable in relationship with power. Galbraith (1984) used Max Weber's definition of power to make leadership more understandable. In the…

Reversible solid oxide fuel cell for natural gas/renewable hybrid power generation systems

NASA Astrophysics Data System (ADS)

Luo, Yu; Shi, Yixiang; Zheng, Yi; Cai, Ningsheng

2017-02-01

Renewable energy (RE) is expected to be the major part of the future energy. Presently, the intermittence and fluctuation of RE lead to the limitation of its penetration. Reversible solid oxide fuel cell (RSOFC) as the energy storage device can effectively store the renewable energy and build a bidirectional connection with natural gas (NG). In this paper, the energy storage strategy was designed to improve the RE penetration and dynamic operation stability in a distributed system coupling wind generators, internal combustion engine, RSOFC and lithium-ion batteries. By compromising the relative deviation of power supply and demand, RE penetration, system efficiency and capacity requirement, the strategy that no more than 36% of the maximum wind power output is directly supplied to users and the other is stored by the combination of battery and reversible solid oxide fuel cell is optimal for the distributed system. In the case, the RE penetration reached 56.9% and the system efficiency reached 55.2%. The maximum relative deviation of power supply and demand is also lower than 4%, which is significantly superior to that in the wind curtailment case.

Feasibility study for the swaziland/mozambique interconector. Executive summary of the final report. Export trade information

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

NONE

1997-11-01

This study, conducted by Black & Veatch, was funded by the U.S. Trade and Development Agency. The report, produced for the Ministry of National Resources, Energy and Environment (MNRE) of Swaziland, determines the least cost capacity expansion option to meet the future power demand and system reliability criteria of Swaziland, with particular emphasis on the propsoed Interconnector between Swaziland and Mozambique. Volume 1 contains the Executive Summary and is divided into the following sections: (1.0) Study Objectives; (2.0) Swaziland and its Economy; (3.0) The Power Sector Structure in Swaziland; (4.0) Electric Power Resources; (5.0) Past Demand Growth; (6.0) Load andmore » Energy Forecasts; (7.0) Need for Power; (8.0) Generation and Transmission Capacity Addition Option; (9.0) SEB Expansion Plan Scenario Development; (10.0) EDM Expansion Plan Development; (11.0) Cost Sharing of the Interconnector; (12.0) Interconnector Options and Environmental Evaluation; (13.0) Generation/Transmission Trade Offs; (14.0) EPC RFP and Draft Interconnection Agreement; (15.0) Transmission System Study; (16.0) Conclusions and Recommendations.« less

Failure Mechanisms of Ni-H2 and Li-Ion Batteries Under Hypervelocity Impacts

NASA Technical Reports Server (NTRS)

Miller, J. E.; Lyons, F.; Christiansen, E. L.; Lear, D. M.

2017-01-01

Lithium-Ion (Li-Ion) batteries have yielded significant performance advantages for many industries, including the aerospace industry, and have been selected to replace nickel hydrogen (Ni-H2) batteries for the International Space Station (ISS) program to meet the energy storage demands. As the ISS uses its vast solar arrays to generate its power, the solar ar-rays meet their sunlit power demands and supply excess power to battery packs for power de-livery on the sun obscured phase of the approximate 90 minute low Earth orbit. These large battery packs are located on the exterior of the ISS, and as such, the battery packs are ex-posed to external environment threats like naturally occurring meteoroids and artificial orbital debris (MMOD). While the risks from these solid particle environments has been known and addressed to an acceptable risk of failure through shield design, it is not possible to completely eliminate the risk of loss of these assets on orbit due to MMOD, and as such, failure consequences to the ISS have been considered.

Design analysis of levitation facility for space processing applications. [Skylab program, space shuttles

NASA Technical Reports Server (NTRS)

Frost, R. T.; Kornrumpf, W. P.; Napaluch, L. J.; Harden, J. D., Jr.; Walden, J. P.; Stockhoff, E. H.; Wouch, G.; Walker, L. H.

1974-01-01

Containerless processing facilities for the space laboratory and space shuttle are defined. Materials process examples representative of the most severe requirements for the facility in terms of electrical power, radio frequency equipment, and the use of an auxiliary electron beam heater were used to discuss matters having the greatest effect upon the space shuttle pallet payload interfaces and envelopes. Improved weight, volume, and efficiency estimates for the RF generating equipment were derived. Results are particularly significant because of the reduced requirements for heat rejection from electrical equipment, one of the principal envelope problems for shuttle pallet payloads. It is shown that although experiments on containerless melting of high temperature refractory materials make it desirable to consider the highest peak powers which can be made available on the pallet, total energy requirements are kept relatively low by the very fast processing times typical of containerless experiments and allows consideration of heat rejection capabilities lower than peak power demand if energy storage in system heat capacitances is considered. Batteries are considered to avoid a requirement for fuel cells capable of furnishing this brief peak power demand.

The Potential of Combined Heat and Power Generation, Wind Power Generation and Load Management Techniques for Cost Reduction in Small Electricity Supply Systems.

NASA Astrophysics Data System (ADS)

Bass, Jeremy Hugh

Available from UMI in association with The British Library. Requires signed TDF. An evaluation is made of the potential fuel and financial savings possible when a small, autonomous diesel system sized to meet the demands of an individual, domestic consumer is adapted to include: (1) combined heat and power (CHP) generation, (2) wind turbine generation, (3) direct load control. The potential of these three areas is investigated by means of time-step simulation modelling on a microcomputer. Models are used to evaluate performance and a Net Present Value analysis used to assess costs. A cost/benefit analysis then enables those areas, or combination of areas, that facilitate and greatest savings to be identified. The modelling work is supported by experience gained from the following: (1) field study of the Lundy Island wind/diesel system, (2) laboratory testing of a small diesel generator set, (3) study of a diesel based CHP unit, (4) study of a diesel based direct load control system, (5) statistical analysis of data obtained from the long-term monitoring of a large number of individual household's electricity consumption. Rather than consider the consumer's electrical demand in isolation, a more flexible approach is adopted, with consumer demand being regarded as the sum of primarily two components: a small, electricity demand for essential services and a large, reschedulable demand for heating/cooling. The results of the study indicate that: (1) operating a diesel set in a CHP mode is the best strategy for both financial and fuel savings. A simple retrofit enables overall conversion efficiencies to be increased from 25% to 60%, or greater, at little cost. (2) wind turbine generation in association with direct load control is a most effective combination. (3) a combination of both the above areas enables greatest overall financial savings, in favourable winds resulting in unit energy costs around 20% of those of diesel only operation.

Robust Unit Commitment Considering Uncertain Demand Response

DOE PAGES

Liu, Guodong; Tomsovic, Kevin

2014-09-28

Although price responsive demand response has been widely accepted as playing an important role in the reliable and economic operation of power system, the real response from demand side can be highly uncertain due to limited understanding of consumers' response to pricing signals. To model the behavior of consumers, the price elasticity of demand has been explored and utilized in both research and real practice. However, the price elasticity of demand is not precisely known and may vary greatly with operating conditions and types of customers. To accommodate the uncertainty of demand response, alternative unit commitment methods robust to themore » uncertainty of the demand response require investigation. In this paper, a robust unit commitment model to minimize the generalized social cost is proposed for the optimal unit commitment decision taking into account uncertainty of the price elasticity of demand. By optimizing the worst case under proper robust level, the unit commitment solution of the proposed model is robust against all possible realizations of the modeled uncertain demand response. Numerical simulations on the IEEE Reliability Test System show the e ectiveness of the method. Finally, compared to unit commitment with deterministic price elasticity of demand, the proposed robust model can reduce the average Locational Marginal Prices (LMPs) as well as the price volatility.« less

Using Information Processing Techniques to Forecast, Schedule, and Deliver Sustainable Energy to Electric Vehicles

NASA Astrophysics Data System (ADS)

Pulusani, Praneeth R.

As the number of electric vehicles on the road increases, current power grid infrastructure will not be able to handle the additional load. Some approaches in the area of Smart Grid research attempt to mitigate this, but those approaches alone will not be sufficient. Those approaches and traditional solution of increased power production can result in an insufficient and imbalanced power grid. It can lead to transformer blowouts, blackouts and blown fuses, etc. The proposed solution will supplement the ``Smart Grid'' to create a more sustainable power grid. To solve or mitigate the magnitude of the problem, measures can be taken that depend on weather forecast models. For instance, wind and solar forecasts can be used to create first order Markov chain models that will help predict the availability of additional power at certain times. These models will be used in conjunction with the information processing layer and bidirectional signal processing components of electric vehicle charging systems, to schedule the amount of energy transferred per time interval at various times. The research was divided into three distinct components: (1) Renewable Energy Supply Forecast Model, (2) Energy Demand Forecast from PEVs, and (3) Renewable Energy Resource Estimation. For the first component, power data from a local wind turbine, and weather forecast data from NOAA were used to develop a wind energy forecast model, using a first order Markov chain model as the foundation. In the second component, additional macro energy demand from PEVs in the Greater Rochester Area was forecasted by simulating concurrent driving routes. In the third component, historical data from renewable energy sources was analyzed to estimate the renewable resources needed to offset the energy demand from PEVs. The results from these models and components can be used in the smart grid applications for scheduling and delivering energy. Several solutions are discussed to mitigate the problem of overloading transformers, lack of energy supply, and higher utility costs.

Case-study of a user-driven prosthetic arm design: bionic hand versus customized body-powered technology in a highly demanding work environment.

PubMed

Schweitzer, Wolf; Thali, Michael J; Egger, David

2018-01-03

Prosthetic arm research predominantly focuses on "bionic" but not body-powered arms. However, any research orientation along user needs requires sufficiently precise workplace specifications and sufficiently hard testing. Forensic medicine is a demanding environment, also physically, also for non-disabled people, on several dimensions (e.g., distances, weights, size, temperature, time). As unilateral below elbow amputee user, the first author is in a unique position to provide direct comparison of a "bionic" myoelectric iLimb Revolution (Touch Bionics) and a customized body-powered arm which contains a number of new developments initiated or developed by the user: (1) quick lock steel wrist unit; (2) cable mount modification; (3) cast shape modeled shoulder anchor; (4) suspension with a soft double layer liner (Ohio Willowwood) and tube gauze (Molnlycke) combination. The iLimb is mounted on an epoxy socket; a lanyard fixed liner (Ohio Willowwood) contains magnetic electrodes (Liberating Technologies). An on the job usage of five years was supplemented with dedicated and focused intensive two-week use tests at work for both systems. The side-by-side comparison showed that the customized body-powered arm provides reliable, comfortable, effective, powerful as well as subtle service with minimal maintenance; most notably, grip reliability, grip force regulation, grip performance, center of balance, component wear down, sweat/temperature independence and skin state are good whereas the iLimb system exhibited a number of relevant serious constraints. Research and development of functional prostheses may want to focus on body-powered technology as it already performs on manually demanding and heavy jobs whereas eliminating myoelectric technology's constraints seems out of reach. Relevant testing could be developed to help expediting this. This is relevant as Swiss disability insurance specifically supports prostheses that enable actual work integration. Myoelectric and cosmetic arm improvement may benefit from a less forgiving focus on perfecting anthropomorphic appearance.

Ultra Low Power Datalogger

NASA Astrophysics Data System (ADS)

Holik, Michael

2010-01-01

The article describes a design and the test of the datalogger unit. Main demands on the datalogger were to achieve the power consumption as low as possible and the ability to capture short-time events. The datalogger is based on a programmable logic device FPGA. VHDL language is used to design the architecture fitted into the FPGA. The results of the test confirmed low power consumption feature of the device as well as proper functionality of the unit.

Unintended Consequences of the Goldwater-Nichols Act (Joint Force Quarterly, Spring 1998)

DTIC Science & Technology

1998-01-01

Armed Forces to achieve mili- tary success, the unified direction of DOD neces- sary for budgetary efficiency, and the separation of powers demanded by...its actions. The Constitution has stood for two centuries precisely because it flexibly applies simple concepts such as the separation of powers and...replaced, it has created a national military command structure that ignores the separation of powers . The amended National Security Act has consolidated

Prediction-based manufacturing center self-adaptive demand side energy optimization in cyber physical systems

NASA Astrophysics Data System (ADS)

Sun, Xinyao; Wang, Xue; Wu, Jiangwei; Liu, Youda

2014-05-01

Cyber physical systems(CPS) recently emerge as a new technology which can provide promising approaches to demand side management(DSM), an important capability in industrial power systems. Meanwhile, the manufacturing center is a typical industrial power subsystem with dozens of high energy consumption devices which have complex physical dynamics. DSM, integrated with CPS, is an effective methodology for solving energy optimization problems in manufacturing center. This paper presents a prediction-based manufacturing center self-adaptive energy optimization method for demand side management in cyber physical systems. To gain prior knowledge of DSM operating results, a sparse Bayesian learning based componential forecasting method is introduced to predict 24-hour electric load levels for specific industrial areas in China. From this data, a pricing strategy is designed based on short-term load forecasting results. To minimize total energy costs while guaranteeing manufacturing center service quality, an adaptive demand side energy optimization algorithm is presented. The proposed scheme is tested in a machining center energy optimization experiment. An AMI sensing system is then used to measure the demand side energy consumption of the manufacturing center. Based on the data collected from the sensing system, the load prediction-based energy optimization scheme is implemented. By employing both the PSO and the CPSO method, the problem of DSM in the manufacturing center is solved. The results of the experiment show the self-adaptive CPSO energy optimization method enhances optimization by 5% compared with the traditional PSO optimization method.

Comparing supply and demand models for future photovoltaic power generation in the USA

DOE PAGES

Basore, Paul A.; Cole, Wesley J.

2018-02-22

We explore the plausible range of future deployment of photovoltaic generation capacity in the USA using a supply-focused model based on supply-chain growth constraints and a demand-focused model based on minimizing the overall cost of the electricity system. Both approaches require assumptions based on previous experience and anticipated trends. For each of the models, we assign plausible ranges for the key assumptions and then compare the resulting PV deployment over time. Each model was applied to 2 different future scenarios: one in which PV market penetration is ultimately constrained by the uncontrolled variability of solar power and one in whichmore » low-cost energy storage or some equivalent measure largely alleviates this constraint. The supply-focused and demand-focused models are in substantial agreement, not just in the long term, where deployment is largely determined by the assumed market penetration constraints, but also in the interim years. For the future scenario without low-cost energy storage or equivalent measures, the 2 models give an average plausible range of PV generation capacity in the USA of 150 to 530 GWdc in 2030 and 260 to 810 GWdc in 2040. With low-cost energy storage or equivalent measures, the corresponding ranges are 160 to 630 GWdc in 2030 and 280 to 1200 GWdc in 2040. The latter range is enough to supply 10% to 40% of US electricity demand in 2040, based on current demand growth.« less

Comparing supply and demand models for future photovoltaic power generation in the USA

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

Basore, Paul A.; Cole, Wesley J.

We explore the plausible range of future deployment of photovoltaic generation capacity in the USA using a supply-focused model based on supply-chain growth constraints and a demand-focused model based on minimizing the overall cost of the electricity system. Both approaches require assumptions based on previous experience and anticipated trends. For each of the models, we assign plausible ranges for the key assumptions and then compare the resulting PV deployment over time. Each model was applied to 2 different future scenarios: one in which PV market penetration is ultimately constrained by the uncontrolled variability of solar power and one in whichmore » low-cost energy storage or some equivalent measure largely alleviates this constraint. The supply-focused and demand-focused models are in substantial agreement, not just in the long term, where deployment is largely determined by the assumed market penetration constraints, but also in the interim years. For the future scenario without low-cost energy storage or equivalent measures, the 2 models give an average plausible range of PV generation capacity in the USA of 150 to 530 GWdc in 2030 and 260 to 810 GWdc in 2040. With low-cost energy storage or equivalent measures, the corresponding ranges are 160 to 630 GWdc in 2030 and 280 to 1200 GWdc in 2040. The latter range is enough to supply 10% to 40% of US electricity demand in 2040, based on current demand growth.« less

Manipulation of M demand of chemistry problems and its effect on student performance: A neo-piagetian study

NASA Astrophysics Data System (ADS)

Niaz, Mansoor

It has been shown that student performance in chemistry problems decreases as the M demand of the problem increases, thus emphasizing the role of information processing in problem solving. It was hypothesized that manipulation (increase or decrease) of the M demand of a problem can affect student performance. Increasing the M demand of a problem would affect more the performance of subjects with a limited functional M capacity. The objective of this study is to investigate the effect of manipulation (increase) of the M demand of chemistry problems, having the same logical structure, on performance of students having different functional M capacity, cognitive style, and formal operational reasoning patterns. As predicted the performance of one group of students was lower after the manipulation (increase) in the M demand of the problem. This shows how even small changes in the amount of information required for processing can lead to working memory overload, as a consequence of a poor capacity for mobilization of M power.

Western Energy Corridor -- Energy Resource Report

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

Leslie Roberts; Michael Hagood

2011-06-01

The world is facing significant growth in energy demand over the next several decades. Strategic in meeting this demand are the world-class energy resources concentrated along the Rocky Mountains and northern plains in Canada and the U.S., informally referred to as the Western Energy Corridor (WEC). The fossil energy resources in this region are rivaled only in a very few places in the world, and the proven uranium reserves are among the world's largest. Also concentrated in this region are renewable resources contributing to wind power, hydro power, bioenergy, geothermal energy, and solar energy. Substantial existing and planned energy infrastructure,more » including refineries, pipelines, electrical transmission lines, and rail lines provide access to these resources.« less

Real-time pricing strategy of micro-grid energy centre considering price-based demand response

NASA Astrophysics Data System (ADS)

Xu, Zhiheng; Zhang, Yongjun; Wang, Gan

2017-07-01

With the development of energy conversion technology such as power to gas (P2G), fuel cell and so on, the coupling between energy sources becomes more and more closely. Centralized dispatch among electricity, natural gas and heat will become a trend. With the goal of maximizing the system revenue, this paper establishes the model of micro-grid energy centre based on energy hub. According to the proposed model, the real-time pricing strategy taking into account price-based demand response of load is developed. And the influence of real-time pricing strategy on the peak load shifting is discussed. In addition, the impact of wind power predicted inaccuracy on real-time pricing strategy is analysed.

Space power for space

NASA Technical Reports Server (NTRS)

Mullin, J. P.

1978-01-01

The total energy demanded by space missions of the future is expected to exceed past needs by orders of magnitude. The unit costs of this energy must be reduced from present levels if these missions are to be carried out at projected budget levels. The broad employment of electric propulsion and the capability to utilize novel high power sensors hinge on the availability of systems lighter by factors of ten or more than have flown to date. The NASA program aimed at providing the technological basis to meet these demands is described in this paper. Research and technology efforts in areas of energy conversion, storage and management are covered. In addition, work aimed at evolving the understanding necessary to cope with space environment interactions and at advanced concepts is described.

High power, gel polymer lithium-ion cells with improved low temperature performance for NASA and DoD applications

NASA Technical Reports Server (NTRS)

Smart, M. C.; Ratnakumar, B. V.; Whitcanack, L. D.; Chin, K. B.; Surampudi, S.; Narayanan, S. R.; Alamgir, Mohamed; Yu, Ji-Sang; Plichta, Edward P.

2004-01-01

Both NASA and the U.S. Army have interest in developing secondary energy storage devices that are capable of meeting the demanding performance requirements of aerospace and man-portable applications. In order to meet these demanding requirements, gel-polymer electrolyte-based lithium-ion cells are being actively considered, due to their promise of providing high specific energy and enhanced safety aspects.

The cost of meeting increased cooling-water demands for CO2 capture and storage utilizing non-traditional waters from geologic saline formations

NASA Astrophysics Data System (ADS)

Klise, Geoffrey T.; Roach, Jesse D.; Kobos, Peter H.; Heath, Jason E.; Gutierrez, Karen A.

2013-05-01

Deep (> ˜800 m) saline water-bearing formations in the United States have substantial pore volume that is targeted for storage of carbon dioxide (CO2) and the associated saline water can be extracted to increase CO2 storage efficiency, manage pressure build up, and create a new water source that, once treated, can be used for power-plant cooling or other purposes. Extraction, treatment and disposal costs of saline formation water to meet added water demands from CO2 capture and storage (CCS) are discussed. This underutilized water source may be important in meeting new water demand associated with CCS. For a representative natural gas combined-cycle (NGCC) power plant, simultaneous extraction of brine from the storage formation could provide enough water to meet all CCS-related cooling demands for 177 out of the 185 (96 %) saline formations analyzed in this study. Calculated total cost of water extraction, treatment and disposal is less than 4.00 US Dollars (USD) m-3 for 93 % of the 185 formations considered. In 90 % of 185 formations, treated water costs are less than 10.00 USD tonne-1 of CO2 injected. On average, this represents approximately 6 % of the total CO2 capture and injection costs for the NGCC scenario.

Reduction of peak energy demand based on smart appliances energy consumption adjustment

NASA Astrophysics Data System (ADS)

Powroźnik, P.; Szulim, R.

2017-08-01

In the paper the concept of elastic model of energy management for smart grid and micro smart grid is presented. For the proposed model a method for reducing peak demand in micro smart grid has been defined. The idea of peak demand reduction in elastic model of energy management is to introduce a balance between demand and supply of current power for the given Micro Smart Grid in the given moment. The results of the simulations studies were presented. They were carried out on real household data available on UCI Machine Learning Repository. The results may have practical application in the smart grid networks, where there is a need for smart appliances energy consumption adjustment. The article presents a proposal to implement the elastic model of energy management as the cloud computing solution. This approach of peak demand reduction might have application particularly in a large smart grid.

How to Integrate Variable Power Source into a Power Grid

NASA Astrophysics Data System (ADS)

Asano, Hiroshi

This paper discusses how to integrate variable power source such as wind power and photovoltaic generation into a power grid. The intermittent renewable generation is expected to penetrate for less carbon intensive power supply system, but it causes voltage control problem in the distribution system, and supply-demand imbalance problem in a whole power system. Cooperative control of customers' energy storage equipment such as water heater with storage tank for reducing inverse power flow from the roof-top PV system, the operation technique using a battery system and the solar radiation forecast for stabilizing output of variable generation, smart charging of plug-in hybrid electric vehicles for load frequency control (LFC), and other methods to integrate variable power source with improving social benefits are surveyed.

Metabolic power and energetic costs of professional Australian Football match-play.

PubMed

Coutts, Aaron J; Kempton, Thomas; Sullivan, Courtney; Bilsborough, Johann; Cordy, Justin; Rampinini, Ermanno

2015-03-01

To compare the metabolic power demands between positional groups, and examine temporal changes in these parameters during Australian Football match-play. Longitudinal observational study. Global positioning system data were collected from 39 Australian Football players from the same club during 19 Australian Football League competition games over two seasons. A total of 342 complete match samples were obtained for analysis. Players were categorised into one of six positional groups: tall backs, mobile backs, midfielders, tall forwards, mobile forwards and rucks. Instantaneous raw velocity data obtained from the global positioning system units was exported to a customised spreadsheet which provided estimations of both speed-based (e.g. total and high-speed running distance) and derived metabolic power and energy expenditure variables (e.g. average metabolic power, high-power distance, total energy expenditure). There were significant differences between positional groups for both speed-based and metabolic power indices, with midfielders covering more total and high-speed distance, as well as greater average and overall energy expenditure compared to other positions (all p<0.001). There were reductions in total, high-speed, and high-power distance, as well as average metabolic power throughout the match (all p<0.001). Positional differences exist for both metabolic power and traditional running based variables. Generally, midfielders, followed by mobile forwards and mobile backs had greater activity profiles compared to other position groups. We observed that the reductions in most metabolic power variables during the course of the match are comparable to traditional running based metrics. This study demonstrates that metabolic power data may contribute to our understanding of the physical demands of Australian Football. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Climate change impacts on thermoelectric-power generation in the United States

NASA Astrophysics Data System (ADS)

Liu, L.

2015-12-01

Thermoelectric-power generation accounts for more than 70% of the total electricity generation in the United States, which requires large amounts of water for cooling purposes. Water withdrawals for thermoelectric-power generation accounted for 45% of total water use in the United States in 2010. Across the country, water demand from power plants is increasing due to pressures from growing populations and other needs, and is straining existing water resources. Moreover, temperature exceedance in receiving waters has increasingly caused power plants shut downs across parts of the country. Thermoelectric power is vulnerable to climate change owing to the combined effects of lower summer river flows and higher receiving water temperatures. In addition, the efficiency of production is reduced as air temperature rises, which propagates to more unfulfilled power demand during peak seasons. Therefore, a holistic modeling framework of water-energy-climate for the contiguous U.S. is presented here to quantify thermal output from power plants and estimate water use and energy production fluctuations due to ambient climate as well as environmental regulations. The model is calibrated on a plant-by-plant basis for year 2010 and 2011 using the available power plant inventory from the Energy Information Administration (EIA). Simulations were carried out for years 2012 and 2013, and results show moderate improvements in capturing thermal output variabilities after calibration. Future power plant operations under scenarios featuring different climate and regulatory settings were investigated. Results demonstrate the interplay among water, energy and climate, and that future changes in climate and socioeconomics significantly affect power plant operations, which may provide insights to climate change mitigation considerations and energy decisions.

NASA advanced design program: Analysis, design, and construction of a solar powered aircraft. B.S. Thesis

NASA Technical Reports Server (NTRS)

Chan, Agnes; Conley, Kristin; Javorski, Christian T.; Cheung, Kwok-Hung; Crivelli, Paul M.; Torrey, Nancy P.; Traver, Michael L.

1992-01-01

Increase in energy demands coupled with rapid depletion of natural energy resources have deemed solar energy as the most logical alternative source of power. The major objective of this project was to build a solar powered remotely controlled aircraft to demonstrate the feasibility of solar energy as an effective, alternate source of power. The final design was optimized for minimum weight and maximum strength of the structure. These design constraints necessitated a carbon fiber composite structure. Surya is a lightweight, durable aircraft capable of achieving level flight powered entirely by solar cells.

Fuzzy Logic Based Controller for a Grid-Connected Solid Oxide Fuel Cell Power Plant.

PubMed

Chatterjee, Kalyan; Shankar, Ravi; Kumar, Amit

2014-10-01

This paper describes a mathematical model of a solid oxide fuel cell (SOFC) power plant integrated in a multimachine power system. The utilization factor of a fuel stack maintains steady state by tuning the fuel valve in the fuel processor at a rate proportional to a current drawn from the fuel stack. A suitable fuzzy logic control is used for the overall system, its objective being controlling the current drawn by the power conditioning unit and meet a desirable output power demand. The proposed control scheme is verified through computer simulations.

Applied sport science of rugby league.

PubMed

Johnston, Rich D; Gabbett, Tim J; Jenkins, David G

2014-08-01

Rugby league is a team sport in which players engage in repeated high-intensity exercise involving frequent collisions. Recent research, much of which has involved global positioning system (GPS) technology, has provided coaches and sport scientists with a deeper understanding of match demands, particularly at the elite level. This has allowed for the development of training programmes that prepare players for the most intense contact and running demands likely to be experienced in competition. At the elite level, rugby league players have well-developed aerobic and anaerobic endurance, muscular strength and power, reactive agility, and speed. Upper- and lower-body strength and aerobic power are associated with a broad range of technical and sport-specific skills, in addition to a lower risk of injury. Significant muscle damage (as estimated from creatine kinase concentrations) and fatigue occurs as a result of match-play; while muscle function and perceptual fatigue generally return to baseline 48 h following competition, increases in plasma concentrations of creatine kinase can last for up to 5 days post-match. Well-developed physical qualities may minimise post-match fatigue and facilitate recovery. Ultimately, the literature highlights that players require a broad range of physical and technical skills developed through specific training. This review evaluates the demands of the modern game, drawing on research that has used GPS technology. These findings highlight that preparing players based on the average demands of competition is likely to leave them underprepared for the most demanding passages of play. As such, coaches should incorporate drills that replicate the most intense repeated high-intensity demands of competition in order to prepare players for the worst-case scenarios expected during match-play.

Dissociation between dorsal and ventral hippocampal theta oscillations during decision-making.

PubMed

Schmidt, Brandy; Hinman, James R; Jacobson, Tara K; Szkudlarek, Emily; Argraves, Melissa; Escabí, Monty A; Markus, Etan J

2013-04-03

Hippocampal theta oscillations are postulated to support mnemonic processes in humans and rodents. Theta oscillations facilitate encoding and spatial navigation, but to date, it has been difficult to dissociate the effects of volitional movement from the cognitive demands of a task. Therefore, we examined whether volitional movement or cognitive demands exerted a greater modulating factor over theta oscillations during decision-making. Given the anatomical, electrophysiological, and functional dissociations along the dorsal-ventral axis, theta oscillations were simultaneously recorded in the dorsal and ventral hippocampus in rats trained to switch between place and motor-response strategies. Stark differences in theta characteristics were found between the dorsal and ventral hippocampus in frequency, power, and coherence. Theta power increased in the dorsal, but decreased in the ventral hippocampus, during the decision-making epoch. Interestingly, the relationship between running speed and theta power was uncoupled during the decision-making epoch, a phenomenon limited to the dorsal hippocampus. Theta frequency increased in both the dorsal and ventral hippocampus during the decision epoch, although this effect was greater in the dorsal hippocampus. Despite these differences, ventral hippocampal theta was responsive to the navigation task; theta frequency, power, and coherence were all affected by cognitive demands. Theta coherence increased within the dorsal hippocampus during the decision-making epoch on all three tasks. However, coherence selectively increased throughout the hippocampus (dorsal to ventral) on the task with new hippocampal learning. Interestingly, most results were consistent across tasks, regardless of hippocampal-dependent learning. These data indicate increased integration and cooperation throughout the hippocampus during information processing.

European questions related to satelite power systems

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

Kassing, D.

1983-01-01

A number of problems which have been identified in recent European studies related to satellite power systems are addressed. Based on energy demand and supply projections for Europe, developed by the International Institute for Applied Systems Analysis, the potential of power satellites in a future energy mix is discussed. A few major constraints are presented which may restrict power transmission to European receiving sites, e.g., orbital limitations, siting problems of the ground station, and economic and institutional issues. Conceptual designs for the structure of ground receiving stations located offshore near the European coastlines are described.

Thermal energy storage for organic Rankine cycle solar dynamic space power systems

NASA Astrophysics Data System (ADS)

Heidenreich, G. R.; Parekh, M. B.

An organic Rankine cycle-solar dynamic power system (ORC-SDPS) comprises a concentrator, a radiator, a power conversion unit, and a receiver with a thermal energy storage (TES) subsystem which charges and discharges energy to meet power demands during orbital insolation and eclipse periods. Attention is presently given to the criteria used in designing and evaluating an ORC-SDPS TES, as well as the automated test facility employed. It is found that a substantial data base exists for the design of an ORC-SDPS TES subsystem.

User's manual for the Shuttle Electric Power System analysis computer program (SEPS), volume 2 of program documentation

NASA Technical Reports Server (NTRS)

Bains, R. W.; Herwig, H. A.; Luedeman, J. K.; Torina, E. M.

1974-01-01

The Shuttle Electric Power System Analysis SEPS computer program which performs detailed load analysis including predicting energy demands and consumables requirements of the shuttle electric power system along with parameteric and special case studies on the shuttle electric power system is described. The functional flow diagram of the SEPS program is presented along with data base requirements and formats, procedure and activity definitions, and mission timeline input formats. Distribution circuit input and fixed data requirements are included. Run procedures and deck setups are described.

A Proof of Concept: Grizzly, the LWRS Program Materials Aging and Degradation Pathway Main Simulation Tool

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

Ben Spencer; Jeremey Busby; Richard Martineau

2012-10-01

Nuclear power currently provides a significant fraction of the United States’ non-carbon emitting power generation. In future years, nuclear power must continue to generate a significant portion of the nation’s electricity to meet the growing electricity demand, clean energy goals, and ensure energy independence. New reactors will be an essential part of the expansion of nuclear power. However, given limits on new builds imposed by economics and industrial capacity, the extended service of the existing fleet will also be required.

Returning vacationers face heavy reading loads. [Reports, surveys and projections on the national energy supply

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

Berg, T.F.

1991-10-01

This article reviews the various reports, surveys and projections on the national energy supply of the summer of 1991. Discussed are the natural gas supplies, competitive electric power production, reliability of independent power, public attitudes toward natural gas, the market share of natural gas, and projection of US energy supply and demand.

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…

Targeted On-Demand Team Performance App Development

DTIC Science & Technology

2016-10-01

from three sites; 6) Preliminary analysis indicates larger than estimate effect size and study is sufficiently powered for generalizable outcomes...statistical analyses, and examine any resulting qualitative data for trends or connections to statistical outcomes. On Schedule 21 Predictive...Preliminary analysis indicates larger than estimate effect size and study is sufficiently powered for generalizable outcomes.  What opportunities for

OpenADR Specification to Ease Saving Power in Buildings

ScienceCinema

Piette, Mary Ann

2017-12-09

A new data model developed by researchers at the Department of Energys Lawrence Berkeley National Laboratory and their colleagues at other universities and in the private sector will help facilities and buildings save power through automated demand response technology, and advance the development of the Smart Grid. http://newscenter.lbl.gov/press-releases/2009/04/27/openadr-specification/

Implications of China’s Growing Demand for Oil: A Case Study in Venezuela

DTIC Science & Technology

2007-12-01

Mearsheimer is a leading exponent of the perspective that a rising China poses a danger. He contends that a rising power is always interested in...Soft power. 57 Mike Hurst , “A Giant Awakens - $48 bn to kick-start a new era --- Beijing 2008,” The Daily Telegraph (Australia), Extended Metro

The Energy Imperative: Report Update

DTIC Science & Technology

2008-11-01

projections for 2030.2 • Renewable power generation from solar , wind, biomass, and geothermal resources is growing rapidly, but these sources still...consistent policy approach to address cost, regulatory, and transmission infrastructure challenges. For solar photovoltaic (PV) technology, basic...research is particularly important to make the needed improvements in cost and performance. • Solar power can help meet peak load electricity demand

The Columbus Myth: Power and Ideology in Picturebooks about Christopher Columbus

ERIC Educational Resources Information Center

Desai, Christina M.

2013-01-01

In 1992, the 500th anniversary of Columbus's landing in the Bahamas was simultaneously celebrated and denounced in the US. Damaging facts about Columbus and the impact of his voyages were aired along with demands for truth and change. This study analyzes the power relationships and political ideology of picturebooks about Columbus published…

Hidden in Plain Sight: Signs of Great Power War

DTIC Science & Technology

2016-06-01

China can change the strategic balance of power in the region without ever fighting—the acme of skill according to Sun Tzu . In fact, the balance of...68 BIBLIOGRAPHY ...put anyone into the shade, but we demand a place for ourselves in the sun .”20 This speech became the ideological foundation for Germany’s

Energy production for environmental issues in Turkey

NASA Astrophysics Data System (ADS)

Yuksel, Ibrahim; Arman, Hasan; Halil Demirel, Ibrahim

2017-11-01

Due to the diversification efforts of energy sources, use of natural gas that was newly introduced into Turkish economy, has been growing rapidly. Turkey has large reserves of coal, particularly of lignite. The proven lignite reserves are 8.0 billion tons. The estimated total possible reserves are 30 billion tons. Turkey, with its young population and growing energy demand per person, its fast growing urbanization, and its economic development, has been one of the fast growing power markets of the world for the last two decades. It is expected that the demand for electric energy in Turkey will be 580 billion kWh by the year 2020. Turkey's electric energy demand is growing about 6-8% yearly due to fast economic growing. This paper deals with energy demand and consumption for environmental issues in Turkey.

Design and simulation of front end power converter for a microgrid with fuel cells and solar power sources

NASA Astrophysics Data System (ADS)

Jeevargi, Chetankumar; Lodhi, Anuj; Sateeshkumar, Allu; Elangovan, D.; Arunkumar, G.

2017-11-01

The need for Renewable Energy Sources (RES) is increasing due to increased demand for the supply of power and it is also environment friendly.In the recent few years, the cost of generation of the power from the RES has been decreased. This paper aims to design the front end power converter which is required for integrating the fuel cells and solar power sources to the micro grid. The simulation of the designed front end converter is carried out in the PSIM 9.1.1 software. The results show that the designed front end power converter is sufficient for integrating the micro grid with fuel cells and solar power sources.

Tides and turbines

NASA Astrophysics Data System (ADS)

Charlier, R. H.

1980-12-01

Tidal power plants are examined with attention to potential sites worldwide and to existing projects in France, the Soviet Union, and China. It is noted that maximum power cannot always be made available during peak demand periods because of the continuous variation of the daily tidal cycle throughout the year. However, this can be alleviated if a two-pool design or pumping are used. The economic impact of tidal power has been favorable, with the use of cellular units reducing construction costs substantially.

Near East/South Asia Report

DTIC Science & Technology

1985-06-13

vegetables, we find that there is the pressure of purchasing power on the part of the Egyptian citizen and this pressure has extended to all goods in a...happened- is that the supply is available and has been increasing year after year. But the purchase power has also been growing more rapidly. For...example, if production grows by 5 percent a year, we find that the purchasing power and the demand are growing by 10 percent a year. This is the

Small Business Voucher CRADA Report: Natural Gas Powered HVAC System for Commercial and Residential Buildings

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

Betts, Daniel; Ally, Moonis Raza; Mudiraj, Shyam

Be Power Tech is commercializing BeCool, the first integrated electricity-producing heating, ventilation, and air conditioning (HVAC) system using a non-vapor compression cycle (VCC), packaged rooftop HVAC unit that also produces base-load electricity, heating, ventilation, and air conditioning. BeCool is a distributed energy resource with energy storage that eliminates the tremendous peak electricity demand associated with commonly used electricity-powered vapor compression air conditioning systems.

Department of Defense Operational Energy Strategy: A Content Analysis of Energy Literature from 1973-2014

DTIC Science & Technology

2014-03-27

Globalization has resulted in increased demand for energy, specifically, crude oil as the primary means to power economic development. As countries continue...represent technologies that produce energy from wind, solar, biomass, hydropower, nuclear power , natural gas, and clean coal (The White House, 2011). On...dollars whereby the largest partition of that money ($11B) was appropriated for development of an electric “smart grid” to digitize power distribution and

A general method to analyze the thermal performance of multi-cavity concentrating solar power receivers

DOE PAGES

Fleming, Austin; Folsom, Charles; Ban, Heng; ...

2015-11-13

Concentrating solar power (CSP) with thermal energy storage has potential to provide grid-scale, on-demand, dispatachable renewable energy. As higher solar receiver output temperatures are necessary for higher thermal cycle efficiency, current CSP research is focused on high outlet temperature and high efficiency receivers. Here, the objective of this study is to provide a simplified model to analyze the thermal efficiency of multi-cavity concentrating solar power receivers.

Perform qualify reliability-power tests by shooting common mistakes: practical problems and standard answers per Telcordia/Bellcore requests

NASA Astrophysics Data System (ADS)

Yu, Zheng

2002-08-01

Facing the new demands of the optical fiber communications market, almost all the performance and reliability of optical network system are dependent on the qualification of the fiber optics components. So, how to comply with the system requirements, the Telcordia / Bellcore reliability and high-power testing has become the key issue for the fiber optics components manufacturers. The qualification of Telcordia / Bellcore reliability or high-power testing is a crucial issue for the manufacturers. It is relating to who is the outstanding one in the intense competition market. These testing also need maintenances and optimizations. Now, work on the reliability and high-power testing have become the new demands in the market. The way is needed to get the 'Triple-Win' goal expected by the component-makers, the reliability-testers and the system-users. To those who are meeting practical problems for the testing, there are following seven topics that deal with how to shoot the common mistakes to perform qualify reliability and high-power testing: ¸ Qualification maintenance requirements for the reliability testing ¸ Lots control for preparing the reliability testing ¸ Sampling select per the reliability testing ¸ Interim measurements during the reliability testing ¸ Basic referencing factors relating to the high-power testing ¸ Necessity of re-qualification testing for the changing of producing ¸ Understanding the similarity for product family by the definitions

Water Stress on U.S. Power Production at Decadal Time Horizons

NASA Astrophysics Data System (ADS)

Ganguli, P.; Kumar, D.; Yun, J.; Short, G.; Klausner, J.; Ganguly, A. R.

2014-12-01

Thermoelectric power production at risk, owing to current and projected water scarcity and rising stream temperatures, is assessed for the continental United States (US) at decadal scales. Regional water scarcity is driven by climate variability and change, as well as by multi-sector water demand. While a planning horizon of zero to about thirty years is occasionally prescribed by stakeholders, the challenges to risk assessment at these scales include the difficulty in delineating decadal climate trends from intrinsic natural or multiple model variability. Current generation global climate or earth system models are not credible at the spatial resolutions of power plants, especially for surface water quantity and stream temperatures, which further exacerbates the assessment challenge. Population changes, which are anyway difficult to project, cannot serve as adequate proxies for changes in the water demand across sectors. The hypothesis that robust assessments of power production at risks are possible, despite the uncertainties, has been examined as a proof of concept. An approach is presented for delineating water scarcity and temperature from climate models, observations and population storylines, as well as for assessing power production at risk by examining geospatial correlations of power plant locations within regions where the usable water supply for energy production happens to be scarcer and warmer. Acknowledgment: Funding provided by US DOE's ARPA-E through Award DE-AR0000374.

A multifunctional energy-storage system with high-power lead-acid batteries

NASA Astrophysics Data System (ADS)

Wagner, R.; Schroeder, M.; Stephanblome, T.; Handschin, E.

A multifunctional energy storage system is presented which is used to improve the utilization of renewable energy supplies. This system includes three different functions: (i) uninterruptible power supply (UPS); (ii) improvement of power quality; (iii) peak-load shaving. The UPS application has a long tradition and is used whenever a reliable power supply is needed. Additionally, nowadays, there is a growing demand for high quality power arising from an increase of system perturbation of electric grids. Peak-load shaving means in this case the use of renewable energy stored in a battery for high peak-load periods. For such a multifunctional application large lead-acid batteries with high power and good charge acceptance, as well as good cycle life are needed. OCSM batteries as with positive tubular plates and negative copper grids have been used successfully for a multitude of utility applications. This paper gives two examples where multifunctional energy storage systems have started operation recently in Germany. One system was installed in combination with a 1 MW solar plant in Herne and another one was installed in combination with a 2 MW wind farm in Bocholt. At each place, a 1.2 MW h (1 h-rate) lead-acid battery has been installed. The batteries consist of OCSM cells with the standard design but modified according to the special demand of a multifunctional application.

A Nuclear Renaissance: The Role of Nuclear Power in Mitigating Climate Change

NASA Astrophysics Data System (ADS)

Winslow, Anne

2011-06-01

The U. N. Framework Convention on Climate Change calls for the stabilization of greenhouse gas (GHG) emissions at double the preindustrial atmospheric carbon dioxide concentration to avoid dangerous anthropogenic interference with the climate system. To achieve this goal, carbon emissions in 2050 must not exceed their current level, despite predictions of a dramatic increase in global electricity demand. The need to reduce GHG emissions and simultaneously provide for additional electricity demand has led to a renewed interest in the expansion of alternatives to fossil fuels—particularly renewable energy and nuclear power. As renewable energy sources are often constrained by the intermittency of natural energy forms, scale-ability concerns, cost and environmental barriers, many governments and even prominent environmentalist turn to nuclear energy as a source of clean, reliable base-load electricity. Described by some as a "nuclear renaissance", this trend of embracing nuclear power as a tool to mitigate climate change will dramatically influence the feasibility of emerging nuclear programs around the world.

A Nuclear Renaissance: The Role of Nuclear Power in Mitigating Climate Change

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

Winslow, Anne

2011-06-28

The U. N. Framework Convention on Climate Change calls for the stabilization of greenhouse gas (GHG) emissions at double the preindustrial atmospheric carbon dioxide concentration to avoid dangerous anthropogenic interference with the climate system. To achieve this goal, carbon emissions in 2050 must not exceed their current level, despite predictions of a dramatic increase in global electricity demand. The need to reduce GHG emissions and simultaneously provide for additional electricity demand has led to a renewed interest in the expansion of alternatives to fossil fuels--particularly renewable energy and nuclear power. As renewable energy sources are often constrained by the intermittencymore » of natural energy forms, scale-ability concerns, cost and environmental barriers, many governments and even prominent environmentalist turn to nuclear energy as a source of clean, reliable base-load electricity. Described by some as a ''nuclear renaissance'', this trend of embracing nuclear power as a tool to mitigate climate change will dramatically influence the feasibility of emerging nuclear programs around the world.« less

Production of electricity from proteins using a microbial fuel cell.

PubMed

Heilmann, Jenna; Logan, Bruce E

2006-05-01

Electricity generation was examined from proteins and a protein-rich wastewater using a single chamber microbial fuel cell (MFC). The maximum power densities achieved were 354 +/- 10 mW/m2 using bovine serum albumin (BSA) and 269 +/- 14 mW/m2 using peptone (1100 mg/L BSA and 300 mg/L peptone). The recovery of organic matter as electricity, defined as the Coulombic efficiency (CE), was comparable to that obtained with other substrates with CE = 20.6% for BSA and CE = 6.0% for peptone. A meat packing wastewater (MPW), diluted to 1420 mg/L chemical oxygen demand, produced 80 +/- 1 mW/m2, and power was increased by 33% by adding salt (300 mg/L sodium chloride) to increase solution conductivity. A wastewater inoculum generated 33% less power than the MPW inoculum. The MFC was an effective method of wastewater treatment, demonstrated by >86% of biochemical oxygen demand and total organic carbon removal from wastewater.

Increasing nuclear power at liberalised energy markets- case Finland

NASA Astrophysics Data System (ADS)

Syri, S.; Kurki-Suonio, T.; Satka, V.

2012-10-01

Several Finnish projections for future electricity demand and the need for peak load capacity indicate a demand growth of about 2 GW from the present to the year 2030. The retirement of existing fossil fuel plants and old nuclear power plants will cause increased net import needs during 2020's, even when assuming additional energy efficiency measures and the commissioning of two new nuclear power plants recently approved by the Finnish Parliament. By the year 2030, the need for additional new capacity will be about 6 GW. The increased dependence on import is in contradiction with the official Government targets. This situation is not unique to Finland, but rather is likely to be the case in many other European countries as well. Both the energy company Fortum and energy-intensive industry in Finland see nuclear energy as a viable future generation technology. We describe the « Mankala » concept which is successfully used to build new nuclear capacity at liberalised electricity market in Finland.

Quantum cascade lasers for defense and security

NASA Astrophysics Data System (ADS)

Day, Timothy; Pushkarsky, Michael; Caffey, Dave; Cecchetti, Kristen; Arp, Ron; Whitmore, Alex; Henson, Michael; Takeuchi, Eric B.

2013-10-01

Quantum cascade laser (QCL) systems are mature and at the vanguard of a new generation of products that support military applications such as Infrared Countermeasures (IRCM) and targeting. The demanding product requirements for aircraft platforms that include reduced size, weight, power consumption and cost (SWaP-C) extends to portable, battery powered handheld products. QCL technology operates throughout the mid-wave (MWIR) and long-wave (LWIR) infrared to provide new capabilities that leverage existing thermal imaging cameras. In addition to their suitability for aircraft platforms, QCL products are a natural fit to meet operator demands for small, lightweight pointer and beacon capabilities. Field-testing of high power, lightweight, battery operated devices has demonstrated their utility across a range of air and ground applications. This talk will present an overview of QCL technology and the Defense and Security products and capabilities that are enabled by it. This talk will also provide an overview of the extensive environmental and performance testing associated with products based on QCL technology.

Solar power potential of North-east India - A case study for Silchar

NASA Astrophysics Data System (ADS)

Maisanam, Anil; Biswas, Agnimitra; Sharma, Kaushal Kumar

2018-04-01

High energy demand has necessitated search for all possible sources of energy. Conventional energy source is having negative impact on our environment, therefore our attention is focused on renewable energy sources, such as solar, wind, hydro, which are considered to be clean and sustainable energy sources. India has set an ambitious target of producing 175 GW of energy using solar energy. Therefore, it is necessary to estimate the solar potential to observe the feasibility of such project. North-east India is an underdeveloped region of India and due to its geographical location and difficult terrain, many regions are still not electrified. Such regions can be electrified by installing renewable energy based power plants, which can also generate number of jobs hence improving the quality of life and economic condition of the region. The objective of this paper is to estimate the solar power potential of Silchar (Assam, India) and perform a feasibility study for installation of solar-based power plant in the region. In this paper, solar radiation on tilted surface is estimated by using an anisotropic sky model. This radiation data has been used to estimate the PV power output. Finally, feasibility of the PV plant has been verified by mapping with a practical load demand.

Stochastic control of smart home energy management with plug-in electric vehicle battery energy storage and photovoltaic array

NASA Astrophysics Data System (ADS)

Wu, Xiaohua; Hu, Xiaosong; Moura, Scott; Yin, Xiaofeng; Pickert, Volker

2016-11-01

Energy management strategies are instrumental in the performance and economy of smart homes integrating renewable energy and energy storage. This article focuses on stochastic energy management of a smart home with PEV (plug-in electric vehicle) energy storage and photovoltaic (PV) array. It is motivated by the challenges associated with sustainable energy supplies and the local energy storage opportunity provided by vehicle electrification. This paper seeks to minimize a consumer's energy charges under a time-of-use tariff, while satisfying home power demand and PEV charging requirements, and accommodating the variability of solar power. First, the random-variable models are developed, including Markov Chain model of PEV mobility, as well as predictive models of home power demand and PV power supply. Second, a stochastic optimal control problem is mathematically formulated for managing the power flow among energy sources in the smart home. Finally, based on time-varying electricity price, we systematically examine the performance of the proposed control strategy. As a result, the electric cost is 493.6% less for a Tesla Model S with optimal stochastic dynamic programming (SDP) control relative to the no optimal control case, and it is by 175.89% for a Nissan Leaf.

A review on energy harvesting approaches for renewable energies from ambient vibrations and acoustic waves using piezoelectricity

NASA Astrophysics Data System (ADS)

Ahmed, Riaz; Mir, Fariha; Banerjee, Sourav

2017-08-01

The principal objective of this article is to categorically review and compare the state of the art vibration based energy harvesting approaches. To evaluate the contemporary methodologies with respect to their physics, average power output and operational frequencies, systematically divided and easy readable tables are presented followed by the description of the energy harvesting methods. Energy harvesting is the process of obtaining electrical energy from the surrounding vibratory mechanical systems through an energy conversion method using smart structures, like, piezoelectric, electrostatic materials. Recent advancements in low power electronic gadgets, micro electro mechanical systems, and wireless sensors have significantly increased local power demand. In order to circumvent the energy demand; to allow limitless power supply, and to avoid chemical waste from conventional batteries, low power local energy harvesters are proposed for harvesting energy from different ambient energy sources. Piezoelectric materials have received tremendous interest in energy harvesting technology due to its unique ability to capitalize the ambient vibrations to generate electric potential. Their crystalline configuration allows the material to convert mechanical strain energy into electrical potential, and vice versa. This article discusses the various approaches in vibration based energy scavenging where piezoelectric materials are employed as the energy conversion medium.

Supply and Demand Control of Distributed Generators in a Microgrid for New Energy

NASA Astrophysics Data System (ADS)

Shimakage, Toyonari; Sumita, Jiro; Uchiyama, Noriyuki; Kato, Takeyoshi; Suzuoki, Yasuo

We report the operational results of distributed generators (DGs) in a microgrid and present the effects after incorporating photovoltaic power generation (PV) systems into the microgrid for electric power system. The microgrid was constructed at the EXPO 2005 Aichi site as part of a demonstration promoted by NEDO. A solution is needed to problems where instability in the DGs that utilize natural energy such as solar light and wind force negatively influence existing electric power systems. So, we developed energy control system and controlled DGs output to reduce the fluctuation at the grid connected point caused by PV system's instability output. Our microgrid consists of DGs such as PV systems, fuel cells, and NaS batteries, and these DGs are controlled by an energy control system. We verified practical effectiveness of the installing the microgrid as follows. (1) 99.5% of the power imbalance in the supply and demand over 30 minutes was within a range of ±3% under normal operating conditions, (2) the microgrid contributes to the load leveling, (3) energy control system smoothes the power flow fluctuation of PV system output at the grid connected point, (4) in the future, installing a microgrid will help reduce the additional LFC (Load Frequency Control) capacity.

A New Approach to Design of an optimized Grid Tied Smart Solar Photovoltaic (PV) System

NASA Astrophysics Data System (ADS)

Farhad, M. Mehedi; Ali, M. Mohammad; Iqbal, M. Asif; Islam, N. Nahar; Ashraf, N.

2012-11-01

Energy is the key element for the economical development of a country. With the increasing concern about the global demand for Renewable Energy (RE) energy, it is very much important to reduce the cost of the whole solar photovoltaic (PV) system. Still now most of the solar photovoltaic (PV) system is highly expensive. In this paper we have shown that grid tied solar system can be developed by omitting the energy storage device like large capacity battery bank. It will not only reduce the internallosses for charging and discharging of battery bank but also at the same time a large amount of cost of the battery will be reduced. So, the system maintenance cost will be reduced also. We have proposed a new approach to design a photovoltaic (PV) solar power system which can be operated by feeding the solar power to the national grid along with the residential load. Again if there is an extra power demand for residential load along with the solar power then this system can also provide an opportunity to consume the power from the national grid. The total system is controlled with the help of some the sensors and a microcontroller. As a whole a significant reduction in the system costs and efficient system performance can be realized.

Data and code for the exploratory data analysis of the electrical energy demand in the time domain in Greece.

PubMed

Tyralis, Hristos; Karakatsanis, Georgios; Tzouka, Katerina; Mamassis, Nikos

2017-08-01

We present data and code for visualizing the electrical energy data and weather-, climate-related and socioeconomic variables in the time domain in Greece. The electrical energy data include hourly demand, weekly-ahead forecasted values of the demand provided by the Greek Independent Power Transmission Operator and pricing values in Greece. We also present the daily temperature in Athens and the Gross Domestic Product of Greece. The code combines the data to a single report, which includes all visualizations with combinations of all variables in multiple time scales. The data and code were used in Tyralis et al. (2017) [1].

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.

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.

CO{sub 2} mitigation potential of efficient demand-side technologies: The case of Thailand

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

Shrestha, R.M.; Biswas, W.K.; Timilsina, G.R.

This study assesses the techno-economic potential of selected demand-side efficient appliances to mitigate CO{sub 2} emission from the power sector in Thailand under national, consumer, and utility perspectives. A key finding of this study is that about 5.5--7% of the total annual CO{sub 2} emission from the electricity sector of the country can be reduced during 1996--2011 from the national perspective.

Air & Space Power Journal. Volume 28, Number 3, May-June 2014

DTIC Science & Technology

2014-06-01

critical role that AETC organizations—such as the Air Force Security Assistance Training Squadron; HQ AETC/A3Q; the AAA; and, potentially , the IAAFA... Potential de- fects in the design are more likely than computer hacking and are most effectively abated through comprehensive testing demanded by the best...fascinating picture of the potential employment methodologies and skill sets demanded of crews that operate assets like FQ-X. From a cyber-defense

Avoiding 100 New Power Plants by Increasing Efficiency of Room Air Conditioners in India: Opportunities and Challenges

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

Phadke, Amol; Abhyankar, Nikit; Shah, Nihar

Electricity demand for room ACs is growing very rapidly in emerging economies such as India. We estimate the electricity demand from room ACs in 2030 in India considering factors such as weather and income growth using market data on penetration of ACs in different income classes and climatic regions. We discuss the status of the current standards, labels, and incentive programs to improve the efficiency of room ACs in these markets and assess the potential for further large improvements in efficiency and find that efficiency can be improved by over 40percent cost effectively. The total potential energy savings from Roommore » AC efficiency improvement in India using the best available technology will reach over 118 TWh in 2030; potential peak demand saving is found to be 60 GW by 2030. This is equivalent to avoiding 120 new coal fired power plants of 500 MW each. We discuss policy options to complement, expand and improve the ongoing programs to capture this large potential.« less

Material challenges for transducer designers in the 21st century

NASA Astrophysics Data System (ADS)

Lindberg, Jan F.

2002-07-01

The modern U.S. Navy is rapidly evolving to meet the challenges of operating in the littorals. This focus changes the rules, especially to the designers of sonar systems that now need to aggressively engage quiet diesel electric submarine threats and neutralize sophisticated underwater mines. These new responsibilities dictate that new concepts be developed. To meet these new demands on the sonar system, transducer designers are being tasked to design transducers and to utilize new materials to address performance requirements that were never even imagined a decade ago. Sensor needs are no longer limited to pressure types but now have to sense velocity or acceleration. Sources are challenged to both frequency extent and power levels. The need to physically move sources off of submarines and surface combatants and onto vehicles with limited energy capabilities prompt the challenge of efficient bandwidth and high coupling. These are the needs of the 'next Navy'; the needs of the 'Navy after next' will present an even more demanding scenario. The future will demand revolutionary technology at the micro level with devices utilizing new power sources and new materials.

Essays on Infrastructure Design and Planning for Clean Energy Systems

NASA Astrophysics Data System (ADS)

Kocaman, Ayse Selin

The International Energy Agency estimates that the number of people who do not have access to electricity is nearly 1.3 billion and a billion more have only unreliable and intermittent supply. Moreover, current supply for electricity generation mostly relies on fossil fuels, which are finite and one of the greatest threats to the environment. Rising population growth rates, depleting fuel sources, environmental issues and economic developments have increased the need for mathematical optimization to provide a formal framework that enables systematic and clear decision-making in energy operations. This thesis through its methodologies and algorithms enable tools for energy generation, transmission and distribution system design and help policy makers make cost assessments in energy infrastructure planning rapidly and accurately. In Chapter 2, we focus on local-level power distribution systems planning for rural electrification using techniques from combinatorial optimization. We describe a heuristic algorithm that provides a quick solution for the partial electrification problem where the distribution network can only connect a pre-specified number of households with low voltage lines. The algorithm demonstrates the effect of household settlement patterns on the electrification cost. We also describe the first heuristic algorithm that selects the locations and service areas of transformers without requiring candidate solutions and simultaneously builds a two-level grid network in a green-field setting. The algorithms are applied to real world rural settings in Africa, where household locations digitized from satellite imagery are prescribed. In Chapter 3 and 4, we focus on power generation and transmission using clean energy sources. Here, we imagine a country in the future where hydro and solar are the dominant sources and fossil fuels are only available in minimal form. We discuss the problem of modeling hydro and solar energy production and allocation, including long-term investments and storage, capturing the stochastic nature of hourly supply and demand data. We mathematically model two hybrid energy generation and allocation systems where time variability of energy sources and demand is balanced using the water stored in the reservoirs. In Chapter 3, we use conventional hydro power stations (incoming stream flows are stored in large dams and water release is deferred until it is needed) and in Chapter 4, we use pumped hydro stations (water is pumped from lower reservoir to upper reservoir during periods of low demand to be released for generation when demand is high). Aim of the models is to determine optimal sizing of infrastructure needed to match demand and supply in a most reliable and cost effective way. An innovative contribution of this work is the establishment of a new perspective to energy modeling by including fine-grained sources of uncertainty such as stream flow and solar radiations in hourly level as well as spatial location of supply and demand and transmission network in national level. In addition, we compare the conventional and the pumped hydro power systems in terms of reliability and cost efficiency and quantitatively show the improvement provided by including pumped hydro storage. The model will be presented with a case study of India and helps to answer whether solar energy in addition to hydro power potential in Himalaya Mountains would be enough to meet growing electricity demand if fossil fuels could be almost completely phased out from electricity generation.

Thermal power systems small power systems applications project. Volume 2: Detailed report

NASA Technical Reports Server (NTRS)

Marriott, A. T.

1979-01-01

Small power system technology as applied to power plants up to 10 MW in size was considered. Markets for small power systems were characterized and cost goals were established for the project. Candidate power plant system design concepts were selected for evaluation and preliminary performance and cost assessments were made. Breakeven capital costs were determined for leading contenders among the candidate systems. The potential use of small power systems in providing part of the demand for pumping power by the extensive aqueduct system of California, was studied. Criteria and methodologies were developed for the ranking of candidate power plant system design concepts. Experimental power plant concepts of 1 MW rating were studied to define a power plant configuration for subsequent detail design construction, testing and evaluation. Site selection criteria and ground rules were developed.

Muscle coordination limits efficiency and power output of human limb movement under a wide range of mechanical demands

PubMed Central

Wakeling, James M.

2015-01-01

This study investigated the influence of cycle frequency and workload on muscle coordination and the ensuing relationship with mechanical efficiency and power output of human limb movement. Eleven trained cyclists completed an array of cycle frequency (cadence)-power output conditions while excitation from 10 leg muscles and power output were recorded. Mechanical efficiency was maximized at increasing cadences for increasing power outputs and corresponded to muscle coordination and muscle fiber type recruitment that minimized both the total muscle excitation across all muscles and the ineffective pedal forces. Also, maximum efficiency was characterized by muscle coordination at the top and bottom of the pedal cycle and progressive excitation through the uniarticulate knee, hip, and ankle muscles. Inefficiencies were characterized by excessive excitation of biarticulate muscles and larger duty cycles. Power output and efficiency were limited by the duration of muscle excitation beyond a critical cadence (120–140 rpm), with larger duty cycles and disproportionate increases in muscle excitation suggesting deteriorating muscle coordination and limitations of the activation-deactivation capabilities. Most muscles displayed systematic phase shifts of the muscle excitation relative to the pedal cycle that were dependent on cadence and, to a lesser extent, power output. Phase shifts were different for each muscle, thereby altering their mechanical contribution to the pedaling action. This study shows that muscle coordination is a key determinant of mechanical efficiency and power output of limb movement across a wide range of mechanical demands and that the excitation and coordination of the muscles is limited at very high cycle frequencies. PMID:26445873

SU-E-J-102: Separation of Metabolic Supply and Demand: From Power Grid Economics to Cancer Metabolism

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

Epstein, T; Xu, L; Gillies, R

2014-06-01

Purpose: To study a new model of glucose metabolism which is primarily governed by the timescale of the energetic demand and not by the oxygen level, and its implication on cancer metabolism (Warburg effect) Methods: 1) Metabolic profiling of membrane transporters activity in several cell lines, which represent the spectrum from normal breast epithelium to aggressive, metastatic cancer, using Seahorse XF reader.2) Spatial localization of oxidative and non-oxidative metabolic components using immunocytochemical imaging of the glycolytic ATP-producing enzyme, pyruvate kinase and mitochondria. 3) Finite element simulations of coupled partial differential equations using COMSOL and MATLAB. Results: Inhibition or activation ofmore » pumps on the cell membrane led to reduction or increase in aerobic glycolysis, respectively, while oxidative phosphorylation remained unchanged. These results were consistent with computational simulations of changes in short-timescale demand for energy by cell membrane processes. A specific model prediction was that the spatial distribution of ATP-producing enzymes in the glycolytic pathway must be primarily localized adjacent to the cell membrane, while mitochondria should be predominantly peri-nuclear. These predictions were confirmed experimentally. Conclusion: The results in this work support a new model for glucose metabolism in which glycolysis and oxidative phosphorylation supply different types of energy demand. Similar to power grid economics, optimal metabolic control requires the two pathways, even in normoxic conditions, to match two different types of energy demands. Cells use aerobic metabolism to meet baseline, steady energy demand and glycolytic metabolism to meet short-timescale energy demands, mainly from membrane transport activities, even in the presence of oxygen. This model provides a mechanism for the origin of the Warburg effect in cancer cells. Here, the Warburg effect emerges during carcinogenesis is a physiological response to an increase in energy demands from membrane transporters, required for cell division, growth, and migration. This work is supported by the NIH Physical Sciences in Oncology Center grant 1U54CA143970-03 and NIH R01 CA077575-10.« less

Emerging Trends in Technology Education Computer Applications.

ERIC Educational Resources Information Center

Hazari, Sunil I.

1993-01-01

Graphical User Interface (GUI)--and its variant, pen computing--is rapidly replacing older types of operating environments. Despite its heavier demand for processing power, GUI has many advantages. (SK)

12 CFR 206.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... credit and liquidity risks, including operational risks, related to intraday and interday transactions... substantial extent in the regular course of business; and (5) Has the power to accept demand deposits. (f...

12 CFR 206.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... credit and liquidity risks, including operational risks, related to intraday and interday transactions... substantial extent in the regular course of business; and (5) Has the power to accept demand deposits. (f...

Analysis of an integrated carbon cylce for storage of renewables

NASA Astrophysics Data System (ADS)

Streibel, Martin; Nakaten, Natalie; Kempka, Thomas; Kühn, Michael

2013-04-01

In order to mitigate the consequences of climate change the energy concept of the Government of Germany foresees the reduction of CO2 emissions by 80 % in 2050 compared to the status in 1990. Different routes are followed to achieve this goal. Most advanced is the construction of renewable energy sources in order to replace fossil fuel driven parts of the electricity generation. The increasing share of renewable energy sources in power production introduces the problem of high fluctuation of energy generated by windmills and photovoltaic. On top the production is not driven by demand but by availability of wind and sun. In this context, the "Power to Gas" concept has been developed. Main idea is the storage of excess renewable energy in form of hydrogen produced by electrolysis. If in a second step H2 reacts with CO2 to form CH4 the current natural gas infrastructure can be used. In times of energy production by renewables below the actual electricity demand CH4 is combusted to produce electricity. The emissions can be further reduced if CO2 is captured in the power plant and buffered in a dynamic geological storage (CCS). Subsequently the CO2 is back produced when excess energy is available to synthesise CH4. Storing CH4 locally also reduces energy for transport. Hence an integrated almost closed carbon cycle is implemented. In the present study this extended "Power to Gas" concept is elaborated on a regional-scale for the State of Brandenburg and the control area of 50 hertz. Focus of the analysis is the energetic balance of the concept for the integration of a geological CH4 and CO2 storage. Therefore, the energy conversion efficiency for the "Power to Gas" concept has been calculated using available data from literature. According to our calculations approximately 33 % of the wind energy used can be regained by combusting the synthesised CH4 in a combined cycle plant. In order to fuel a peaking power plant with a power of 120 MW for 2,500 hours a year approximately 450 onshore wind turbines in full load or 16 % of the produced electricity of solar and wind assets in the State of Brandenburg in 2010 are needed. In order to quantify the energy demand of the extended "Power to Gas" concept the following was done: The demand of electricity and the production of electricity by solar and wind assets have been analysed for the year 2010 in order to determine when and how much CH4 or CO2 need to be stored or produced from the storage. Reservoir simulations were applied to determine the pressure elevation during cushion gas injection as well as the dynamic pressure behaviour in the reservoir during cyclic storage of CO2 and CH4. Based on that data the well head pressures and the needed compression and injection power to store the gases were calculated. According to these simplified calculations the overall efficiency of a combined "Power to Gas" - CCS concept is about 27%.

Technological hurdles to the application of intercalated graphite fibers

NASA Technical Reports Server (NTRS)

Gaier, James R.

1988-01-01

Before intercalated graphite fibers can be developed as an effective power material, there are several technological hurdles which must be overcome. These include the environmental stability, homogeneity and bulk properties, connection procedures, and costs. Strides were made within the last several years in stability and homogeneity of intercalated graphite fibers. Bulk properties and connection procedures are areas of active research now. Costs are still prohibitive for all but the most demanding applications. None of these problems, however, appear to be unsolvable, and their solution may result in wide spread GOC application. The development of a relatively simple technology application, such as EMI shielding, would stimulate the solution of scale-up problems. Once this technology is developed, then more demanding applications, such as power bus bars, may be possible.

CSTI high capacity power. [Civil Space Technology Initiative

NASA Technical Reports Server (NTRS)

Winter, Jerry M.

1989-01-01

In FY-88, the Advanced Technology Program was incorporated into NASA's Civil Space Technology Initiative (CSTI). The CSTI Program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA SP-100 Advanced Technology project, and provides a bridge to NASA Project Pathfinder. The elements of CSTI High Capacity Power development include Converrsion Systems, Thermal Management, Power Management, System Diagnostics, and Environmental Interactions. Technology advancement in all areas, including materials, is required to assure the high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems.

Multi-criteria assessment of energy conversion systems by means of thermodynamic, economic and environmental parameters

NASA Astrophysics Data System (ADS)

Becerra Lopez, Humberto Ruben

2007-12-01

High expansion of power demand is expected in the Upper Rio Grande region (El Paso, Hudspeth, Culberson, Jeff Davis, Presidio and Brewster counties) as a result of both electrical demand growth and decommissioning of installed capacity. On the supply side a notable deployment of renewable power technologies can be projected owing to the recent introduction of a new energy policy in Texas, which attempts to reach 10,000 installed-MWe of renewable capacity for 2025. Power generation fueled by natural-gas might consistently expand due to the encouraged use of this fuel. In this context the array of participating technologies can be optimized, which, within a sustainability framework, translates into a multidimensional problem. The solution to the problem is presented through this dissertation in two main parts. The first part solves the thermodynamic-environmental problem through developing a dynamic model to project maximum allowable expansion of technologies. Predetermined alternatives include diverse renewable energy technologies (wind turbine, photovoltaic conversion, hybrid solar thermal parabolic trough, and solid oxide fuel cells), a conventional fossil-fuel technology (natural gas combined-cycle), and a breakthrough fossil-fuel technology (solid oxide fuel cells). The analysis is based on the concept of cumulative exergy consumption, expanded to include abatement of emissions. A Gompertz sigmoid growth is assumed and constrained by both exergetic self-sustenance and regional energy resource availability. This part of the analysis assumes that power demand expansion is met by full deployment of alternative technologies backed up by conventional technology. Results show that through a proper allowance for exergy reinvestment the power demand expansion may be met largely by alternative technologies minimizing the primary resource depletion. The second part of the study makes use of the dynamic model to support a multi-objective optimization routine, where the exergetic and economic costs are established as primary competing factors. An optimization algorithm is implemented using the constraint method. The solution is given as Pareto optimality with arrays for minimum cost and possible arrays for the tradeoff front. These arrays are further analyzed in terms of sustainability, cumulative exergy loss (i.e. irreversibilities and waste exergy) and incremental economic cost, and the results are compared with the goals of current legislated energy policy.

Analysis on the accommodation of renewable energy in northeast China

NASA Astrophysics Data System (ADS)

Liu, Jun; Zhang, Jinfang; Tian, Feng; Mi, Zhe

2017-01-01

The accommodation and curtailment of renewable energy in northeast China have attracted much attention with the rapid growth of wind and solar power generation. Large amount of wind power has been curtailed or abandoned in northeast China due to several reasons, such as, the redundancy of power supplies, inadequate power demands, imperfect power structure with less flexibility and limited cross-regional transmission capacity. In this paper, we use multi-area production simulation to analyse the accommodation of renewable energy in northeast China by 2020. Furthermore, we suggest the measures that could be adopted in generation, grid and load side to reduce curtailment of renewables.

New Active Remote-sensing Capabilities: Laser Ablation Spectrometer and Lidar Atmospheric Species Profile Measurements

NASA Technical Reports Server (NTRS)

DeYoung, R. J.; Bergstralh, J. T.

2005-01-01

Introduction: With the anticipated development of high-capacity fission power and electric propulsion for deep-space missions, it will become possible to propose experiments that demand higher power than current technologies (e.g. radioisotope power sources) provide. Jupiter Icy Moons Orbiter (JIMO), the first mission in the Project Prometheus program, will explore the icy moons of Jupiter with a suite of high-capability experiments that take advantage of the high power levels (and indirectly, the high data rates) that fission power affords. This abstract describes two high-capability active-remote-sensing experiments that will be logical candidates for subsequent Prometheus-class missions.

The mass of massive rover software

NASA Technical Reports Server (NTRS)

Miller, David P.

1993-01-01

A planetary rover, like a spacecraft, must be fully self contained. Once launched, a rover can only receive information from its designers, and if solar powered, power from the Sun. As the distance from Earth increases, and the demands for power on the rover increase, there is a serious tradeoff between communication and computation. Both of these subsystems are very power hungry, and both can be the major driver of the rover's power subsystem, and therefore the minimum mass and size of the rover. This situation and software techniques that can be used to reduce the requirements on both communication and computation, allowing the overall robot mass to be greatly reduced, are discussed.