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Focuses on the reliability and power quality at Champion International Corp. paper mill in Deferiet, New York. Numerous process interruptions experienced by Champion; Voltage sags emanating from the Niagara Mohawk Power Corp. transmission system; Causes and location of faults; Mitigation techniques.

Returning monarch butterflies (Danaus plexippus) to sustainable levels of abundance will require an array of contributors to protect and restore habitat over broad areas. Due to the diversity and scale of land managed by electric power companies across the monarch range, plus an additional 32 million hectares needed for new solar arrays by 2050 to meet renewable energy goals, the industry may have potential to contribute to monarch conservation. However, it is challenging to clearly understand an individual company's potential for monarch conservation because of the scale and distribution of their specific land assets (ranging from 4,800 to 240,000 hectares in this study alone), the complexity of monarch science, and the lack of a science-based approach for evaluating large land assets for monarch habitat. With monarchs potentially being protected under the United States Endangered Species Act in the future and thereby limiting land management approaches, there is interest from electric power companies to understand how their lands relate to monarchs. In collaboration with companies, we developed a GIS-based model to identify company landholdings that contain high-quality monarch habitat and applied the model to specific landholdings of eight power companies in the United States. We then facilitated discussions with company teams to balance conservation goals, corporate risk, and social opinion. This paper describes non-confidential results for developing a national GIS-based monarch habitat model and applying it to electric power companies who are considering monarch conservation while simultaneously transitioning to a new clean energy future. The model and applied experience may be useful for other organizations working across large landscapes to manage monarchs. [ABSTRACT FROM AUTHOR]

This paper investigates the impact that economies of scale have had in the success of the wind industry in the United States since 1980 including the trend to larger wind turbines and wind farms and assembly learning curve effects. Analyses utilize average U.S. wind industry historical data to assess past performance and predict the future economic potential for both onshore and offshore wind turbine industries. The intent of this analysis is to serve as a case study to demonstrate the importance of selecting the right product design platform and how the ability to scale a technology can impact the success of products and, in this case, an entire multi-billion dollar industry. From the early stages of development, the wind industry recognized this opportunity and enabled the commercialization of larger and larger wind turbines and subsequently exploited the significant economies of scale possible in producing low-cost electricity via large, horizontal axis turbines and associated wind plants. The cost to produce electricity was reduced more than six-fold over this timeframe and is competitive today with conventional fossil-fuel power generation alternatives. The physics of horizontal axis wind turbines enables them to scale up disproportionately in electric power output and annual energy production with increased size/nameplate rating. [ABSTRACT FROM AUTHOR]

This paper describes GCAM-USA v5.3_water_dispatch, an open-source model that represents key interactions across economic, energy, water, and land systems in a consistent global framework with subnational detail in the United States. GCAM-USA divides the world into 31 geopolitical regions outside the United States (US) and represents the US economy and energy systems in 51 state-level regions (50 states plus the District of Columbia). The model also includes 235 water basins and 384 land use regions, and 23 of each fall at least partially within the United States. GCAM-USA offers a level of process and temporal resolution rare for models of its class and scope, including detailed subnational representation of US water demands and supplies and sub-annual operations (day and night for each month) in the US electric power sector. GCAM-USA can be used to explore how changes in socioeconomic drivers, technological progress, or policy impact demands for (and production of) energy, water, and crops at a subnational level in the United States while maintaining consistency with broader national and international conditions. This paper describes GCAM-USA's structure, inputs, and outputs, with emphasis on new model features. Four illustrative scenarios encompassing varying socioeconomic and energy system futures are used to explore subnational changes in energy, water, and land use outcomes. We conclude with information about how public users can access the model. [ABSTRACT FROM AUTHOR]

Condition monitoring of electric motors avoids severe economical losses resulting from unexpected motor failures and greatly improves the system reliability and maintainability. Efficiency estimation, which shares many common requirements with condition monitoring in terms of data collections, is expected to be implemented in an integrated product. This brings more considerations into the selection of the efficiency-estimation methods. This paper presents the results of an up-to-date literature survey on efficiency-estimation methods of in-service motors, particularly with considerations of the motor-condition-monitoring requirements. More than 20 of the most commonly used methods are briefly described and classified into nine categories according to their physical properties. Six categories of these methods are more related to in-service testing and are compared in a table summarizing the required tests and measurements, intrusion level, and average accuracy. Estimation of the rotor speed and the stator resistance, the two stumbling blocks of various efficiency-estimation methods, is also carefully studied; commonly used methods are summarized. Based on the survey results, four efficiency-estimation methods are suggested as candidates for nonintrusive in-service motor-efficiency estimation and condition-monitoring applications. Another contribution of this paper is that a general approach for developing nonintrusive motor-efficiency-estimation methods is proposed, incorporating rotor speed, stator resistance, and no-load loss estimations. [ABSTRACT FROM AUTHOR]

We discuss the environmental implications of the dramatic drop in the price of natural gas following the US shale gas boom due to the rise of modern hydraulic fracturing. In the first part of the paper, we argue that the ensuing drop in the price of natural gas has an ambiguous effect on global carbon emissions because of three countervailing effects: coal-to-gas switching in the US electric power sector, an increase in the relative cost of US renewable energy sources, and an increase in US coal exports. Our position is that without a meaningful cap, the shale gas boom is likely to increase global emissions and the period during which natural gas is used as a bridge fuel to clean energy should be limited. In the second part of the paper, we review recent environmental policies for the US electric power sector that have contributed to reducing carbon emissions, and discuss the complex economics of the newly introduced Clean Power Plan. Although the availability of cheap natural gas has been factored in US environmental policy and has helped electricity generators to achieve compliance with various rules and regulations, it should not derail policy from its long-run objective, which is the transition to a less fossil-fuel dependent economy. [ABSTRACT FROM AUTHOR]

Abstract In order to assess how seasonality affects disparities in natural gas consumption among sectors, this paper aims to study the pattern of convergence in natural gas consumption in a sample of 11 sectors in the United States between January 1973 and February 2017. In addition to the full sample, the existence of convergence is also examined in five subsets of sectors: residential, commercial, industrial, transport and electric power. By using various types of unit root tests, empirical results provide significant support for the convergence of disaggregated natural gas consumption across sectors in the United States. Another important finding of this paper is that natural gas consumption, despite being convergent, is very persistent. Highlights • This study is to test the hypothesis of the convergence in disaggregated natural gas consumption for the United States. • We use various types of unit root tests. • The energy conservation policies oriented towards the reduction of the seasonal effects of natural gas consumption. [ABSTRACT FROM AUTHOR]

The debate about the threshold effect of sectoral renewable energy consumption on economic growth has attracted extreme attention, but only limited evidence supports this issue. Therefore, the objective of this paper is to study the non-linear relationship between economic growth, capital, labor and sectoral renewable energy consumption for the case of the United States during the period 1981Q1 and 2021Q1. Using the threshold detection method proposed by Hansen (2002), the effect of sectoral renewable energy consumption on economic growth is positive and significant only if the electric power, industrial, residential, commercial, and transport sectors exceed a renewable energy consumption threshold lnREC >7.095; lnREC >6.138; lnREC >4.897; lnREC >3.212; and lnREC >2.849, respectively. Indeed, for the U.S. to achieve positive economic growth from its renewable energy investments, it must exceed a certain threshold of renewable energy consumption for each sector. However, if the United States use renewable energy below a certain threshold, the effect of sectoral renewable energy consumption on economic growth is negative. These results have important implications for both policymakers and investors. [Display omitted] [ABSTRACT FROM AUTHOR]

While the US electric power sector transitioning towards a low-carbon system, the escalated adoption of renewable energy has paradoxically increased water consumption. Consequently, it is imperative to engineer a power generation matrix that mitigates CO 2 emissions and minimizes water utilization. The primary endeavor should be to meticulously identify the variables affecting water consumption changes, especially highlighting and addressing the inherent tension between water conservation and carbon reduction. Employing temporal and spatial Logarithmic Mean Divisia Index methodologies, this study meticulously investigated the factors driving water consumption changes across state-level electricity production sectors in the US from 2010 to 2018. The analysis revealed that the generation mix structure was a predominant factor in escalating water consumption, exerting a more substantial influence than total power generation. Moreover, while the water consumption coefficient initially mitigates the impact of other factors, its effectiveness diminishes over time. Utilizing spatial Logarithmic Mean Divisia Index techniques, this paper further delineated state-level disparities, illuminating the heterogeneous nature of water consumption across regions. Projections up to 2050 suggest that water consumption reductions could be realized even amidst a highly intense scenario. The study's robustness and reliability were further augmented by employing an adaptive Logarithmic Mean Divisia Index. • Temporal-spatial LMDI reveals significant shifts in the US power sector water consumption. • Water consumption coefficient, fuel structure, and generation identified as key drivers. • Scenario analysis forecasts significant water savings potential by 2050. • Findings highlight the necessity for integrated water-energy transition policies. • Study proposes targeted strategies for a sustainable energy-water nexus. [ABSTRACT FROM AUTHOR]

We could get many helpful information and results from satellite remote sensing images and aerial images, including disaster monitoring, grid hidden danger identification, and electricity consumption management. In the recent years, novel computer vision and deep neural network have got a lot of attention in many fields because of mimicking mammalian cognitive mechanism as much as possible. With the in-depth of mammalian cognitive and motor mechanisms research, people trend to adopt these reliable and efficient methods for power grid management and maintenance.For utilizing computing resources and improving analysing efficiency flexibly, we propose an assessing and verification framework based on bio-inspired perception and understanding, which summarizes the most appropriate image scale in the electric facilities place recognition. The proposed framework consists of different scenes aerial images datasets, several electric facilities place recognition methods, and credible evaluating methods mimicking mammals. Firstly, we gather satellite remote images and aerial images of sufficient electric power facilities in the United States via Google Earth and other public datasets. Then, several typical place recognition methods are adopted to testing recognition ability of multi-scale perception results, like SAD, NetVLAD, and GIST descriptor. To get more reliable result, multi-units and multi-scenes experiments are implemented roundly. After all experiments and evaluations, we could get that the most appropriate image scale is 1000 m size and the highest recognition accuracy of electric power facilities location is 500 m. Conclusion in our article shows the recommended perception form and scale closest to human cognition in the power grid management and maintenance. [ABSTRACT FROM AUTHOR]

Investing in renewable energy is of utmost importance, especially in the context of addressing climate change. However, while numerous studies have explored the role of renewable energy in achieving carbon neutrality, there is a noticeable gap in the literature regarding how uncertainties affect the impact of renewable energy on electric power CO2. To bridge this gap, the present study employs recently developed nonparametric techniques, namely multivariate quantile-on-quantile regression (MQQR) and time-varying quantile causality (TVQC), to investigate the relationship between renewable energy and electric power CO2 in the presence of uncertainties. The study utilizes monthly data spanning from January 1988 to May 2023. The bivariate results reveal that renewable energy and low uncertainties contribute to improving ecological quality by reducing electric power CO2. Furthermore, the multivariate quantile-on-quantile regression results highlight the substantial influence of low uncertainties on the impact of renewable energy in lowering electric power CO2. Additionally, the TVQC analysis demonstrates that both renewable energy and uncertainties possess predictive power regarding electric power sector CO2. The study discoveries showcase that the influence of renewable energy on electric power CO2 is subject to external moderation. The suggested policy framework in this study is structured to assist the United States in accomplishing the goals outlined in SDG 7. [ABSTRACT FROM AUTHOR]

The widespread use of incentive regulation in telecom, electricity, and other industries in the U.S. and elsewhere has raised questions about its possible adverse effect on the quality of service. This paper examines U.S. electricity distribution utilities in the years 1993-1999, several of which were subject to incentive regulation. Controlling for other possible influences, including possible endogeneity of the regulatory regime, the data and model indicate that incentive regulation is indeed associated with significantly longer duration of service outages, although not necessarily more frequent outages. Importantly, this quality reduction is offset in cases where regulation incorporates service quality standards. We also examine the causal chain connecting incentive regulation, cost expenditures, and service quality. We conclude that careful design of quality standards can allow incentive regulation to achieve cost savings without quality degradation. [ABSTRACT FROM AUTHOR]

In 2005, wind-induced structural damage from Hurricane Katrina resulted in extensive energy supply disruptions across the Gulf of Mexico. In this paper, we examine the resilience of these systems with a particular emphasis on the electric power delivery systems. We investigate the correlations of the power outage data with weather parameters such as wind speed, rainfall, and storm surge. We examine the resilience and recovery of the electric delivery system spatially and temporally and compare the results with other natural disasters. We conclude that the behavior of the delivery systems under hurricane loadings is affected by rainfall and storm surge as well as wind speed. Widespread failures may occur at wind speeds less than predicted peak values. [ABSTRACT FROM AUTHOR]

This paper evaluates ERCOT's existing annual Black Start service selection analysis and subsequently presents novel selection procedures. ERCOT procures Black Start resources annually through a competitive process. It selects and awards contracts to qualifying resources after completing a Black Start unit selection analysis, which selects a group of Black Start resources that meet a set of system selection criteria consisting of system reliability and minimum cost parameters. A current analysis methodology exists, but due to its inherent limitations, it is very labor intensive. Further analysis methodology development is performed to streamline the selection process, enable additional functions, reduce the manual intervention of personnel, and overall to improve the selection analysis. This paper analyzes the current Black Start automatic program analysis, and proposes new methodologies, programming improvements, and enhanced user ability. [ABSTRACT FROM AUTHOR]

This paper focuses on the implications of multi-agency review of electricity mergers. It highlights fundamental differences between regulatory and antitrust merger enforcement procedures–ranging from standards of review to data collection, economic analysis, and remedies. Such disparities potentially introduce costly and potentially conflicting redundancy into the merger review process. Illustrative examples are drawn from a number of cases, including apparent inconsistencies across applicant-filed analyses in FERC merger cases. Absent the delegation of competition analysis to the antitrust agencies, the paper makes the case for harmonizing review across regulators and antitrust enforcers. [ABSTRACT FROM AUTHOR]

Restructuring efforts in the U.S. electric power sector have tried to encourage transmission investment by independent (non-utility) transmission companies, and have promoted various levels of market-based transmission investment. Underlying this shift to "merchant" transmission investment is an assumption that new transmission infrastructure can be classified as providing a congestion-relief benefit or a reliability benefit. In this paper, we demonstrate that this assumption is largely incorrect for meshed interconnections such as electric power networks. We focus on a particular network topology known as the Wheatstone network to show how congestion and reliability can represent tradeoffs. Lines that cause congestion may be justified on reliability grounds. We decompose the congestion and reliability effects of a given network alteration, and demonstrate their dependence through simulations on a 118- bus test network. The true relationship between congestion and reliability depends critically on identifying the relevant range of demand for evaluating any network externalities. [ABSTRACT FROM AUTHOR]

On August 14, 2003, the U.S. faced the largest blackout in history, which left over 50 million people without electricity in eight U.S. states and part of Canada. This paper investigates the effects of the blackout on the security values of the U.S. electric utilities and manufacturing firms in the electric power equipment industry, using an event study method. The results of this empirical study show that the electric utilities were negatively affected, but the electrical equipment manufacturing firms were significantly, positively affected. [ABSTRACT FROM AUTHOR]

The market uncertainties in the generation business in the U.S. electric power industry have increased the significance of two factors in generation planning: financial risks and managerial flexibilities. At the same time, numerous utilities have multiple generation planning: projects that are interrelated with respect to their market values. For such utilities, in order to quantitatively address these two factors, in this paper, we develop and analyze a real options model for general n interrelated projects. Specifically, first, we derive a unique lattice process that approximates interrelated continuous processes for the evolution of values of projects and options (e.g., selling a constructed project). The steps of the approximation for n projects are presented progressively starting from two projects. Next, based on the lattice process, we investigate the impact of interrelation on the values of options. Then, we provide a backward dynamic programming model for optimal sequential decision making where the decisions are made over the options. Finally, managerial insights and economic implications are illustrated via numerical examples. [ABSTRACT FROM AUTHOR]

Research into transmission pricing and congestion management in interconnected power systems, such as those found in USA and Europe, requires an appropriate benchmark system to test different methodologies. Creation of a realistic benchmark system is difficult as utilities are often unwilling to disclose details of their own systems because of commercial sensitivity and security reasons. This paper presents development of an approximate model of a European interconnected system which could be used to study the effects of cross-border trades. In creating the load-flow model, only publicly available information was used. Comparison of simulation results conducted on the test system with the published cross-border flows and power transfer distribution factors showed a very good correlation, exceeding 90%. [ABSTRACT FROM AUTHOR]

Following in the steps of the gas industry, the traditional paradigm of the vertically integrated electric utility structure has begun to change. In the United States, the Federal Energy Regulatory Commission has issued several rules and Notices of Proposed Rulemaking to set the road map for the deregulated utility industry. The crisis in California has drawn great attention and sparked intense discussion within the utility industry. One general conclusion is to rejuvenate the idea of integrated resource planning and promote the distributed generation via traditional or renewable generation facilities for the deregulated utility systems. Wind generation is one of the most mature and cost-effective resources among different renewable energy technologies. Recently, several large-scale wind generation projects have been implemented in the U.S. and other parts of the world. Similar to other new generation facilities, the impacts of a large-scale wind generation on the system operation, voltage profile, and system security have to be investigated and studied. Remedies for possible operation issues have to be evaluated and implemented. This paper discusses the impact study of connecting a 120-MW wind farm into the transmission system of a utility company within the Southwest Power Pool. [ABSTRACT FROM AUTHOR]

The electricity industry is undergoing a substantial process of restructuring, with an emphasis on the introduction of competition in the generation sector. Traditional planning methods are not necessarily appropriate for this new environment. This paper extends a previously developed linear programming model to the problem of optimal expansion planning in the face of uncertainty. The model explicitly accounts for equipment availability and load duration curves in selecting optimal investment. The use of the model is illustrated with a simple 2-region problem calibrated with data from Hydro-Québec and the northeastern United States that suggests how the LP model can help decision makers. [ABSTRACT FROM AUTHOR]

This paper aims to assess the Darrieus vertical axis wind turbine (VAWT) configurations, including the drawbacks of each variation that hindered the development into large scale rotor. A comprehensive timeline is given as a lineage chart. The variations are assessed on the performance, components and operational reliability. In addition, current development and future prospects of Darrieus VAWT are presented. The Darrieus VAWT patented in France in 1925 and in the US in 1931 had two configurations: (i) curved blades and (ii) straight blades configurations. Curved blades configuration (egg-beater or phi-rotor) has evolved from the conventional guy-wires support into fixed-on-tower and cantilevered versions. Straight blades configuration used to have variable-geometry (Musgrove-rotor), variable-pitch (Giromill), Diamond, Delta and V/Y rotor variations. They were stopped due to low economical value, i.e. high specific cost of energy (COE). Musgrove-rotor has evolved into fixed-pitch straight-bladed H-rotor (referred as H-rotor in this paper for simplicity). H-rotor, in turn, has evolved into several variations: Articulating, Tilted and Helical H-rotors. [ABSTRACT FROM AUTHOR]

Space weather, a natural hazard, can adversely impact human technological assets. High‐voltage electric power transmission grids constitute one of the most critical technological systems vulnerable to space weather driven geomagnetically induced currents (GICs). One of the major challenges pertaining to the study of GICs over the continental United States has been the availability of GIC measurements, which are critical for validation of geoelectric field and power flow models, for example. In this study, we analyze GIC measurements collected at 17 Electrical Power Research Institute (EPRI) SUNBURST transformer locations across the United States for which a GIC value of 10 A or greater was recorded. This data set includes 52 individual geomagnetic storms with Kp index 6 and above during the period from 2010 to 2021. The analysis confirms that there is a good correlation between the number of geomagnetic storms per year and the number of recorded GIC events. Our results also show that about 76% of the top 17 GIC events are associated with the storm main phase, while only 24% are attributed to storm sudden commencements. In addition, it is shown, for the first time, that mid‐latitude positive bays can cause large GICs over the continental United States. Finally, this study shows that the largest measured GIC event in the data set was associated with a localized intense dB/dt structure, which could be attributed to substorm activity. Plain Language Summary: Space weather, a natural hazard, can adversely impact human technological assets. High‐voltage electric power transmission grids constitute one of the most critical technological systems vulnerable to induced currents produced by enhanced space weather conditions. One of the major challenges pertaining to the study of these induced currents over the continental United States has been the lack of measurements. In this study, we analyze induced current measurements collected at 17 high‐voltage power transformer locations across the United States for which a value of 10 A or greater was recorded during the period from 2010 to 2021. The analysis confirms a good correlation between the number of geomagnetic storms per year and the number of recorded induced current events. The results also show that about 76% of the top 17 induced current events are associated with the storm main phase, while only 24% are attributed to storm sudden commencements. In addition, it is shown for the first time that mid‐latitude positive bays can cause large induced currents over the continental United States. Finally, this study also shows that the largest measured GIC event in the data set was associated with a localized intense dB/dt structure, which could be attributed to substorm activity. Key Points: We analyze geomagnetically induced current (GIC) measurements collected under the EPRI SUNBURST project from across the United States and CanadaAbout 76% of the top 17 GIC events occur during main phase (MP) of geomagnetic storms, while 24% during sudden storm commencementFor the first time it is directly shown that mid‐latitude positive bays can cause large GICs at US locations [ABSTRACT FROM AUTHOR]

Recent severe ice storms across the United States severely damaged trees resulting in extensive electrical power outages. Furthermore, trees and branches can fall on nearby roads, blocking traffic flow and reducing the safety of drivers. In this study, trees subjected to ice loads were analyzed using the finite element method and Monte Carlo simulation to develop analytical fragility curves. Two-dimensional, fractal trees were constructed with randomly generated geometric and mechanical parameters for four deciduous tree species: Acer saccharum, Tilia americana, Fagus grandifolia, and Quercus alba. Two load case scenarios were considered – with and without the effects of leaves – which were then subjected to varying ice accumulation thicknesses. The resulting fragility curves suggest that leaves have a substantial impact on tree branch damage under ice loads, which is significant because of the increase in unseasonably early ice storms due to climate change. [ABSTRACT FROM AUTHOR]

The National Aeronautics and Space Administration Glenn Research Center (GRC) has a rich heritage of developing electrochemical technologies and energy storage systems for aerospace. Primary and rechargeable batteries, fuel cells, flywheels, and regenerative fuel cells are among the GRC's portfolio of energy storage devices and primary power systems. These technologies have been developed for missions and applications such as low Earth orbit and geosynchronous Earth orbit satellites, space shuttle, astronaut spacesuit, International Space Station, landers and rovers, and lunar and planetary habitats. The desire for lower mass, lower volume, higher efficiency, and more reliable power systems has most often been the driving force behind the development of these technologies. Often, as with fuel cells for the early Gemini and Apollo missions, development of the technology has been mission enabling. Although many of these technologies were initially developed for applications in space, the existence of such capabilities or development successes at GRC has led to their adoption for terrestrial uses or further research and development for terrestrial applications, including electric vehicles, unmanned aerial and underwater vehicles, and all-electric aircraft. This paper discusses the history of and the current research and development at the GRC in electrochemical and energy storage technologies. The future outlook for each of these technologies is also addressed. [ABSTRACT FROM AUTHOR]

Energy consumption is critical to economic growth and quality of life. America's energy system, however, is malfunctioning. The status quo is characterized by a tilted playing field, where energy choices are based on the visible costs that appear on utility bills and at gas pumps. This system masks the "external" costs arising from those energy choices, including shorter lives, higher health care expenses, a changing climate, and weakened national security. As a result, we pay unnecessarily high costs for energy. New "rules of the road" could level the energy playing field. Drawing from our work for The Hamilton Project, this paper offers four principles for reforming U.S. energy policies in order to increase Americans' well-being. [ABSTRACT FROM AUTHOR]

This paper proposes methodologies to estimate the electric energy and power consumption by light-duty plug-in electric vehicles (PEVs). Using the travel patterns of light-duty vehicles in the U.S. obtained from the 2009 National Household Travel Survey, the PEVs' energy and power consumption are estimated for two uncontrolled charging scenarios. [ABSTRACT FROM PUBLISHER]

Abstract In this paper we conduct an empirical analysis of the environmental and economic performance of coal-fired power plants in the United States. Using nonparametric methods for efficiency analysis we propose a theoretical framework that builds upon the restrictions of mass balances for production possibilities and explicitly takes into account heterogeneous fuel quality and prices of the fuel input. This heterogeneity influences both the cost of the production and the emission of environmentally harmful pollutants. Moreover, we analyze how the incorporation of transportation costs influences the cost efficiency of the electricity generating units and quantify the trade-off between environmentally efficient and cost-minimizing production of electricity. Highlights • A nonparametric model to estimate cost and environmental efficiency is proposed. • The model accounts for heterogeneous input quality and transportation costs. • Cost and environmental efficiency of U.S. power plants is evaluated. • Transportation costs significantly influence the results. • A trade-off between environmental and cost efficiency exists. [ABSTRACT FROM AUTHOR]

This paper generalizes Benders decomposition to maximize a nonconcave objective function and uses that decomposition to solve an "electric power grid interdiction problem." Under one empirically verified assumption, the solution to this bilevel optimization problem identifies a set of components, limited by cardinality or "interdiction resource," whose destruction maximizes economic losses to customers (and can thereby guide defensive measures). The decomposition subproblem typically incorporates a set of dc optimal power-flow models that cover various states of repair after an attack, along with a load-duration curve. Test problems describe a regional power grid in the United States with approximately 5000 buses, 6000 lines, and 500 generators. Solution time on a 2-GHz personal computer is approximately one hour. [ABSTRACT FROM AUTHOR]

The Navy's Next Generation Integrated Power System (NGIPS) master plan calls for the evolution of the IPS system from its current medium voltage, 60 Hz state to a high-frequency, medium-voltage AC (HFAC) system in the next 10 years. Beyond that, and pending development of key protection components, a medium-voltage DC system will be considered for implementation. The master plan calls for power generation modules at three power levels across these systems: ▪ A low power level (2–5 MW) driven by a fuel-efficient diesel prime mover, ▪ A medium power level (10–15 MW) driven by a gas turbine, and ▪ A main propulsion power level (20–40 MW) driven by a gas turbine. EMD is currently developing a high-speed, high-frequency, liquid-cooled generator under contract with NAVSEA that will effectively demonstrate the mid-level generator for the HFAC system. It will be coupled directly to the output of a GE LM1600 Gas Turbine to provide a TG set with power density four times more favorable than conventional ATG sets. The generator development is proceeding favorably, with testing at the Navy's land-based test site (LBTS) expected to begin in July 2008. The technology embodied in the high-speed generator can be easily extrapolated to main turbine generator power levels. Given the availability of prime movers at appropriate speeds, the power generation modules for the HFAC system, at all three power levels, could be provided in a much shorter time frame than noted in the NGIPS master plan. This paper will explore the combinations of prime movers and advanced generators that would suit the three power generation modules of the HFAC system. A description of the prime mover and the generator used for each module will be provided to demonstrate the modest level of development needed. The performance parameters for each generation module will be provided, along with key characteristics and dimensions for the set. In the end, the paper will make the case that demonstration of a HFAC power generation system can be made in the short term, allowing the shipbuilding community to take advantage of the benefits of state-of-the-art power dense electrical generation. [ABSTRACT FROM AUTHOR]

This paper presents the development of a single-phase utility-interactive inverter for residential power generation to meet the specifications laid down for the 2005 Future Energy Challenge Competition sponsored by U.S. DOE and IEEE. The proposed inverter system is capable of working in both stand-alone and grid-connected mode. A control scheme for implementing both modes of operation is presented, which has simple structure with smaller number of sensors. The proposed control algorithm including the whole system control is implemented on a low cost, fixed-point DSP TM5320F2812. The experimental results from a I kW prototype show that the proposed inverter system exhibits not only low THD grid current during the grid-connected mode and well regulated inverter voltage during the stand-alone mode, but also smooth and automatic transfer between the two modes of operation. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a DSP based algorithm to control inverters used in interfacing alternate energy systems with the electric utility. Since a constant and ripple free dc bus voltage is not ensured at the output of alternate energy sources, the main aim of the proposed algorithm is to make the output of the inverter immune to the fluctuations in the dc input voltage. In this paper a modified space vector pulse width modulation (SVPWM) technique is proposed which will maintain the quality of the ac output of the inverter, regardless of the ripple present at the inverter input. The principle is explained qualitatively and extensive experiments have been carried out to verify and validate the proposed algorithm. A 16-bit fixed-point C2000 family DSP from Texas Instruments was used as the controller to implement the proposed control algorithm. [Copyright &y& Elsevier]

This paper develops statistical models for estimating the impacts of tree trimming on electric power system outages under normal (nonstorm) operating conditions. The models are based on an extensive data set from Duke Power, a company in the southeastern U.S., and the models used are a negative binomial generalized linear model and a Poisson generalized linear mixed model (GLMM). The results show that: 1) increasing tree trimming frequency does lead to a decrease in the number of outages on the electric power distribution system; 2) the effects of tree trimming on different circuits can be differentiated and measured; and 3) the Poisson GLMM provides a good fit to the data in this situation. In particular, the results of the model show that for the Duke Power system, one would have expected, on average, 0.9 fewer outages per circuit over the 43-month data recording period if the time between tree trimming cycles was decreased by 1 yr across the whole system. These models could be applied to other power systems, and the results should be useful for power managers in setting tree trimming frequencies and in focusing on the most frequent trimming efforts on those circuits for which trimming will have the greatest benefit. [ABSTRACT FROM AUTHOR]

Ongoing changes in the US electricity market include restructuring and increased competition. With this unfettering of the market, the fuel choice in generation is expected to become more flexible and responsive. To investigate this hypothesis, studies of US electricity fuel choices over the last three decades are summarized and the most recent analysis is provided on a market very different from the one on which earlier studies were done. Modern data handling techniques allow the consideration of the most comprehensive database including 185 utilities on monthly data for 1993. This paper finds fuel choice to show a considerable amount of price responsiveness, the amount of responsiveness is sensitive to the fuel substitution possibilities within the utility, and the amount of responsiveness seems to have increased recently for oil and natural gas. [ABSTRACT FROM AUTHOR]

This paper estimates short- and long-run marginal production costs and returns to scale in electric power generation in the United States. We find substantial short-run diseconomies of scale at high output levels. A relatively large number of small and mid-sized firms have optimal capital stocks below actual levels. In contrast, several large firms have optimal capital stock targets substantially above current levels. These disparities in actual and optimal capital suggest a possible consolidation in the industry. [ABSTRACT FROM AUTHOR]

State-level renewable portfolio standards (RPSs) aim to encourage renewable energy and discourage greenhouse gas (GHG) emissions from the electric power sector in the United States. Do they work? Some prominent government agencies and advocacy groups assert that U.S. renewables growth has been largely due to RPSs. That seems unlikely, given that in most regions, renewables exceed RPS requirements. But it is not an easy question to answer, thanks to interstate trading and the possibility that states with abundant renewable resources might set the most ambitious RPS goals. We combine the best features of four recent academic studies, using ordinary least-squares and instrumental variables approaches. In some specifications, RPSs do appear to reduce the use of natural gas to generate electricity and decrease GHG emissions, while boosting the use of wind and solar power. But the effects are small--consistent with the academic findings and in contrast to the public claims and policy goals. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to examine the structure of power pools and to explain the variance in tightness that exists across pools. To do this, the benefits of pooling are delineated in the next section, while costs are taken up in section III. Although benefits have been documented elsewhere, the cost side has been largely ignored. Since tightness is determined by the benefit/cost trade off, costs are an essential part of attempting to explain the status of power pooling. In section IV, key provisions in the pooling agreements of 17 formal power pools are examined, and the results support our conclusion that U.S. pools tend toward looseness. Section V provides conclusions. [ABSTRACT FROM AUTHOR]

This paper reviews data dealing with energy use in residential and commercial buildings and their determinants. Three types of data are discussed: data prepared by and for the federal government on overall trends in buildings energy use, data prepared by and for the federal government related to the details of energy use, and data collected at the state and utility level. The major conclusion from this review is that existing national data sources are inadequate for answering the kinds of questions being raised on buildings energy use and conservation. These questions concern overall trends, recent changes, determinants of changes, roles of the private sector and government intervention in implementing conservation measures, and the effectiveness of different kinds of government programs. Relevant data are being collected by many state energy offices and by gas and electric utilities. However, the existence of these potentially-useful subnational data sources is not widely known. [ABSTRACT FROM AUTHOR]

This paper uses an estimation procedure consistent with accepted industry practice and firing unit level data to provide empirical evidence of the potential efficiencies of power pool arrangements. The procedure permits a comparison of the costs of generating electricity by a group of electric utilities operating both independently and as a fully integrated power pool. This research shows that firms substitute fuels by substituting the firing units (i.e. the disaggregated production units) under their control. Since the power pool brings a larger number of units under one control, the pool has greater potential than a single firm to respond to fluctuations in fuel prices and demand. By using the lowest marginal cost procedures, the power pool has the potential to produce aggregate output at a lower cost than the firms operating independently. The data for the study come from the Pennsylvania--New Jersey--Maryland Interconnection (PJM Pool) for the year 1981. This paper shows that the pool may reduce cost significantly, if firms are willing to cede control to the power pool and operate as a single, multiunit firm. [ABSTRACT FROM AUTHOR]

Non-energy benefits of energy efficiency programs have been studied as early as 1993, and there have been hundreds of papers and reports published since then, many of them finding that NEB are significant. Yet many U.S. states do not include NEB in their cost-benefit analyses. This article tries to provide some insight into this mismatch between the findings of NEB research and policy by analyzing the empirical basis of such research. [ABSTRACT FROM AUTHOR]

Comments on several articles about energy resources and research in the U.S. Correlation between oil prices and electric security and supply; Discussion of the economic significance of the inversion of electric rate schedule; Benefits from energy research and development.

Comments on articles about the demand for energy in the U.S. Relationship between consumption of electricity, population and real income per capita; Estimation of electricity demand; Effect of alternative fuels on electricity demand; Price elasticity of demand functions.

Wind power is one of the fastest growing renewable sources of generation in the U.S. and many other countries. As wind-generated electricity continues to grow, electric utilities increasingly grapple with the challenges of connecting that power to the grid although maintaining system security. It is difficult to predict and control the output of wind generation because of wind intermittency and a reserve capacity is required to deal with inherent uncertainty. This study presents an approach for security-constrained unit commitment (SCUC) with integration of an energy storage system (ESS) and wind generation. Compressed air energy storage (CAES) is considered as an alternative solution to store energy. For economical operation and control purposes, utilities with CAES are interested in the availability and the dispatch of CAES on an hourly basis, given the specific characteristics of CAES. The main contribution of this study is the development of enhanced SCUC formulation and solution techniques with wind power, CAES and multiple constraints including fuel and emission limit. Proposed approach allows simultaneous optimisation of the energy and the ancillary services (AS). Case studies with eight-bus and 118-bus systems are presented to validate the proposed model. This study also contributes by conducting comprehensive studies to analyse the impact of CAES system on locational pricing, economics, peak-load shaving, transmission congestion management, wind curtailment and environmental perspective. [ABSTRACT FROM AUTHOR]

Abstract: As the NASA Vision for Space Exploration takes shape, one of the key issues that will affect the lunar exploration is the ability to provide electric power to various surface locations. This power should be available through daylight times as well as night times. While nuclear reactors and radioisotope power sources are a choice for continuous power, it is the purpose of this paper to explore the advantages of an electric propulsion spacecraft plus laser power beaming to provide power to any location on the lunar surface. The starting point for the electric propulsion mission is a 500km altitude. Thrusting only occurs when the satellite is in sunlight. Radiation damage that occurs during transit of the Earth''s radiation belts is taken into account. The satellite is placed in a 30,000 by 500km orbit around the moon where it beams power to locations within 45° north or south of the equator. Laser power beaming only occurs when the satellite views the sun and the surface location is in the dark. Power delivered to the surface over a two year mission is presented along with the results of adding a second satellite. With two satellites, the maximum time when the site won’t receive power at night is about three days. This significantly reduces the need for a lunar storage system. [Copyright &y& Elsevier]

Previous applications of different benchmarking techniques, both in academia and regulation practice, have shown substantial differences among the models' results. To analyse the sensitivity of efficiency estimates of a sample of US electricity distribution utilities, we compare the results of the generalized least squares frontier model proposed by Schmidt and Sickles (1984) and the maximum likelihood estimation frontier model of Pitt and Lee (1981) with the true random effects frontier model introduced by Greene (2004, 2005). We find substantially higher efficiency scores for the Greene model, indicating that the other formulations underestimate firms' efficiency due to an insufficient consideration of firm specific heterogeneity. In contrast to other studies, the efficiency estimates in this article do not differ considerably. [ABSTRACT FROM AUTHOR]

• Renewable hydrogen can compete with lithium-ion batteries for seasonal storage. • Hydrogen's competitiveness depends on heat rate of plant it is replacing. • Net present value of hydrogen-fired gas turbine varies based on operation of plant. • Lack of infrastructure will impede demand growth for hydrogen in the United States. Non-emitting variable renewable energy (VRE) resources are needed on the power grid if the United States is to "deeply decarbonize" the power sector. The intermittent nature of these resources makes them difficult to integrate into the power system. Existing energy storage technologies, such as lithium-ion (LI) batteries, could be used to aid the integration of these resources, but these technologies are sized to produce power for hours at a time before needing to be charged again. While these energy storage technologies could address daily imbalances between supply and demand for electric power, they cannot address the seasonal nature of power production of VREs. This paper details a methodology to estimate the levelized cost of energy (LCOE) of meeting this seasonal imbalance with either a hydrogen-fired gas turbine (HFGT) or lithium-ion battery system (LI) as a measure of economic efficiency of the technologies. Applying our model, we find the average LCOE associated with meeting this seasonal imbalance is $2400/MWh using a HFGT fueled with green hydrogen and $3000/MWh using a LI. If we allow the model to operate the HFGT with blue hydrogen the average LCOE decreases to $1560/MWh. However, we find the power prices required to justify investment in an HFGT to replace a natural gas-fired gas turbine are considerably higher than those seen in the market today. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents new statistical models that predict the number of hurricane- and ice storm-related electric power outages likely to occur in each 3km×3km grid cell in a region. The models are based on a large database of recent outages experienced by three major East Coast power companies in six hurricanes and eight ice storms. A spatial generalized linear mixed modeling (GLMM) approach was used in which spatial correlation is incorporated through random effects. Models were fitted using a composite likelihood approach and the covariance matrix was estimated empirically. A simulation study was conducted to test the model estimation procedure, and model training, validation, and testing were done to select the best models and assess their predictive power. The final hurricane model includes number of protective devices, maximum gust wind speed, hurricane indicator, and company indicator covariates. The final ice storm model includes number of protective devices, ice thickness, and ice storm indicator covariates. The models should be useful for power companies as they plan for future storms. The statistical modeling approach offers a new way to assess the reliability of electric power and other infrastructure systems in extreme events. [Copyright &y& Elsevier]

Energy management in the industrial context is an important factor to attain energy savings as well as environmental efficiency. Often, linear regression models quite well represent the consumption of energy carriers and statistical process control (SPC) techniques, such as the cumulative sum (CUSUM) plot and Shewhart-like control charts, are currently applied to identify when a system changes the way energy is consumed. Despite the fact that SPC is widely applied in many fields, there is a lack of published material in energy management. The purpose of this paper is to widen the SPC techniques to be applied to energy management. Particular emphasis is given to small- and medium-sized enterprises since energy data are limited and generally known at system level. The CUSUM of the recursive residuals is proposed as the main tool for the analysis of energy consumption data, both for the historical and the monitoring phases. in addition, tabular CUSUM and EWMA control charts are also included. [ABSTRACT FROM AUTHOR]

This paper summarizes the energy resource, the energy conversion technology, and the economic and social benefits of using wave energy technology. The Electric Power Research Institute (EPRI) estimates that the U.S. wave resource potential that could credibly be harnessed is about 6.5% of the 2004 U.S. national electricity energy demand (the total 2004 demand was about 4,000 TWh). Wave energy conversion (WEC) is an emerging technology; ten WEC devices have been tested to date in natural waters worldwide over the past 10 years. The economic opportunities are significant. A relatively minor investment by government in the public good today could stimulate a worldwide industry generating billions of dollars of economic output and employing thousands of people, while using an abundant and clean natural resource to meet our energy needs. Wave energy is potentially more easily assimilated into the grid (compared to wind and solar) because it may be more accurately predictable two to three days ahead and sold as firm power. Given proper care in siting, deployment, operations, maintenance and decommissioning, wave power promises to be one of the most environmentally benign electrical generation technologies. The primary barrier to the development and use of these technologies in the U.S. is the cumbersome regulatory process. We recommend and encourage the development of an effective regulatory system that fosters the application of this environmentally friendly electricity generation technology for our society. [ABSTRACT FROM AUTHOR]

U.S. offshore wind energy resources are abundant, indigenous, and broadly dispersed among the most expensive and highly constrained electricity load centers. Economic capacity expansion models developed at the National Renewable Energy Laboratory show that offshore wind energy can compete in future U.S. electric energy markets without major changes in the market variables or revolutionary technological breakthroughs. However, significant research, development, and deployment will be needed to bring the current technology through a course of cost reductions. To maximize the resource potential, these reductions need to be made along parallel technology paths that will expand the available resource by allowing wind turbines to be installed in deep water. Analysis shows that incremental technology improvements leading to moderate cost reductions, and reasonable increases in the cost of conventional energy will help offshore wind achieve cost competitiveness by 2030 and become a major contributor to the energy supply of the United States. This paper describes a wide range of technical research and development that can reduce costs and improve technology for deep water deployment. [ABSTRACT FROM AUTHOR]