On the stability of electric utility fossil fuel demand

The view that the regional demand for fossil fuels by electric utilities in the United States is characterized by stable relationship is subjected to an objective statistical test. The test utilizes a statistic which equals the ratio of the sum of squared residuals of one period prediction from the k + 1 period to the rth period to the sum of squared residuals of one period prediction from the k + 1 to the Tth period, where k is the number of estimated coefficients in the model and T is the sample size. The results suggest, for the period 1973 – 1978, that the fossil fuel demand functions in Region II and Region VIII and the coal demand function in Region X became unstable around 1977. For the other regions, the results indicate no apprenciable (statistically significant) change in the relative importance of the underlying determinants of the demand for fossil fuels.     

电能替代下考虑需求响应的综合园区风光储配置方法

推进园区电能替代是改善环境问题的重要措施,针对综合园区能源系统进行电能替代受配电网络改造限制的情况,提出采用风光储系统作为供电系统的方案。首先构建综合园区能源系统中电替热、电替冷和电替油负荷模型。然后提出考虑配电网运行状态和需求响应的风光储最优容量双层配置模型,该模型包括配电网层和风光储系统层。最后采用Cplex进行求解,得到综合园区电能替代下考虑配电网运行状态和需求响应的风光储系统最优配置方案。通过IEEE 33节点系统以及某实际园区的电能替代负荷数据进行仿真计算,结果表明采用风光储系统供电并计及负荷的需求响应能解决园区电能替代负荷增长的需求并兼顾其最优经济配置。     

Group search optimization for economic fuel scheduling

The economical use of fuel available for the generation of power has become a major concern of electric utilities. This paper presents an approach for economic fuel scheduling problem by using group search optimization. This is a minimization technique that includes the standard load constraints as well as the fuel constraints. The generation schedule is compared to that which would result if fuel constraints were ignored. The comparison shows that fuel consumed can be adequately controlled by adjusting the power output of various generating units so that the power system operates within its fuel limitations and within contractual constraints. It has been found that small additional amount of fuel may be required to serve the same power demand but the additional cost of this fuel may well compensate for the penalty that might otherwise be imposed for not maintaining the fuel contract. Numerical results for two test systems have been presented and the test results obtained from group search optimization are compared with those obtained from particle swarm optimization and evolutionary programming.     

Load‐following control for dispersed generators using a PI controller

Recently, there has been growing interest in utilizing dispersed generation systems, which are grouped into micro turbine systems, co‐generation systems, and so on, as a substitute for fuel oil energy and a technology to prevent global warming. Since start‐up time of dispersed generation systems is short, it is possible to operate systems to supply load power corresponding to a demand. Moreover, PPSs (Power Producers and Suppliers) can participate in a power retail sales company, since deregulation of electric utilities was instituted in March 2000. However, PPSs have to keep instantaneous generating power commissioning rule, to maintain supply‐and‐demand balance between customer and supplier. Therefore, in this paper, we examine instantaneous generating power commissioning for dispersed generators where start‐up time is short and it is possible to operate systems to supply a power load corresponding to a demand. We adopt a PI controller as a controller. The system is composed of double control loop in inner loop and in outer loop. In inner loop electric power is controlled and in outer loop electric energy is controlled. The controller parameters are designed using the pole‐placement technique. The effectiveness of the proposed control system is confirmed by simulations. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(2): 58–66, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10200     

Planning for future uncertainties in electric power generation: ananalysis of transitional strategies for reduction of carbon and sulfuremissions

The authors discuss strategies for the US electric utility industry for reduction of both acid rain producing and global warming gases. The EPRI electric generation expansion analysis system (EGEAS) utility optimization/simulation modeling structure and the EPRI developed regional utilities were used. The focus is on the northeast and east central regions of the US. Strategies identified are fuel switching (predominantly between coal and natural gas), mandated emission limits, and a carbon tax. The overall conclusions are that conservation will always benefit carbon emissions but may not reduce acid rain emissions by the offsetting forces of improved performance of new plant as opposed to reduced overall consumption of final product. Results of the study are highly utility and regional demand specific     

Analysis of Energy Saving and Environmental Characteristics of Electric Vehicles in Regionally Disaggregated World Energy Model

This paper investigates the impact of an extensive introduction of electric vehicles (EV) and plug‐in hybrid vehicles (PHEV) into the global energy system by 2050. The significant growth of automobile ownership in emerging countries is likely to increase world oil demand and the associated carbon dioxide emissions. In order to address these energy, security, and environmental concerns, the deployment of clean energy vehicles, such as EV and PHEV, is expected to play a crucial role due to their high fuel efficiency. Consequently, we develop both a global energy system model and a world vehicle penetration model, which can explicitly analyze the impact of EV introduction into the seasonal daily electric load curve, with consideration of the specific electricity charging profile through 2050. The simulation results confirm that EV deployment contributes to energy conservation, because oil demand reduction outstrips the growth in electricity demand and the associated fuel input into the power generation mix. Concerning carbon dioxide abatement, the magnitude of the impact relies on the carbon intensity of the power generation mix. If the intensity is low enough to guarantee a carbon mitigation effect due to EV fuel saving, emissions reduction is well assured. It should be noted, however, that in regions with high carbon intensity in the power generation mix, carbon emissions per mileage of EVs is almost equivalent to that of efficient gasoline vehicles such as hybrid vehicles, and the figure for PHEV is slightly higher than for hybrid vehicles. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(4): 20–36, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22373     

Demand forecasting in power distribution systems usingnonparametric probability density estimation

Customer demand data are required by power flow programs to accurately simulate the behavior of electric distribution systems. At present, economic constraints limit widespread customer monitoring, resulting in a need to forecast these demands for distribution system analysis. This paper presents the application of nonparametric probability density estimation to the problem of customer demand forecasting using information readily available at most utilities. The method utilizes demand survey information, including weather conditions, to build a probabilistic demand model that expresses both the random nature of demand and its temperature dependence. The paper describes a procedure for developing such a model and its application for demand forecasting based on customer energy usage and outside temperature     

An integrated resource planning model for utilities with quantified outage costs

Integrated resource planning (IRP) for electric utilities involves management planning of supply as well as demand at the same time. In this paper, we develop a mixed integer linear programming model for IRP. The two key distinctions of this model are the incorporation of the forced outage cost and the inclusion of power deficit/surplus. The forced outage cost will more accurately reflect the true cost to a utility, and the power deficit/surplus features will more accurately represent the existence of power deficit/surplus in utilities nowadays. A comprehensive numerical example is provided for illustrative purposes.     

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

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.     

A linear programming model for minimizing U.S. oil consumption

This paper describes applications of a new model which can be used to help minimize oil consumption by electric utilities in the U.S. The model can be employed to determine the theoretical upper bound on oil savings against which performance can be measured. It can also be used to identify oil conservation options on an hourly basis. In conjunction with other models it can be used to determine system additions and contractual changes necessary for exercising these options. Further, the results can be verified by inspection. Test results using actual hourly data for the Eastern Interconnected System indicate that significant oil savings, over and above those already achieved by electricity transfers, may be realizable.     

Economic evaluation of independent power producers viewed from total generating costs of electric power systems

In Japan, electric power utilities purchase electricity from independent power producers (IPPs) through competitive bidding; the IPP evaluation is based on the avoided costs of corresponding generators of utilities. In this evaluation, however, nonpricing factors such as power flow constraints in the electric power system cannot be considered. In this paper, we propose a new approach to evaluate economic impacts of IPPs, the IPP electricity being priced on the basis of total generating costs of the electric power utilities. Such a price to purchase the electricity of IPPs is referred to as the “break‐even cost.” The main results are summarized as follows: 1) Break‐even cost depends on not only the power flow constraints in the system, but also various IPP factors such as generating pattern, location, and capacity, 2) Break‐even cost for the base‐type IPP is higher than the avoided cost of corresponding utility generators, because IPPs located on demand sides can reduce the transmission power loss in the electric power system, 3) Break‐even cost is affected by available capacity of utility generators, especially for the peak‐type IPP generating only during peak demand periods. © 2000 Scripta Technica, Electr Eng Jpn, 133(2): 20–30, 2000     

An examination of factors influencing aggregate electric utility equity return shortfalls

From 1976 to the present, electric utilities have earned returns that were either appreciably less or greater than their allowed equity return. The evidence suggests that equity earnings shortfalls can be explained in large part by inflation levels and changes in demand for electric power, as well as distortions in the regulatory process.     

Customer Thermal Energy Storage a Marketing Opportunity for Cooling off Electric Peak Demand

Traditionally, electric utilities have forecast the demand for their product and planned a supply system to satisfy the market. Rather than treating the forecast demand as a given, Florida Power & Light Company (FPL), has established a marketing planning function to alter future demand through direct involvement in the marketplace. The crucial element in management's evaluation of opportunities to build, maintain, shift, or reduce customer load is a better understanding of our customers, including their preferences and behavior in purchasing energy. A market analysis utilizing a comprehensive marketing planning model, the Load Management Strategy Testing Model (LMSTM), indicates that the commercial sector, in general, and customer thermal energy storage, in particular, is a demand-side option the Company will actively promote. That identification is made by a detailed market feasibility study FPL is currently managing.     

Electric Utility Flicker Limitations

In providing electric service to a utilization device which creates a variation in electrical demand, one of the considerations facing the utility is the prevention of unacceptable voltage fluctuation on the supplying system. The criteria as applied by various utilities in the United States are discussed presenting general background and development of the existing guidelines. Attention is given to how a utility can more realistically evaluate potential flicker if provided with certain information by the party requesting electric service.     

Cost Allocation Considerations and Methods for Electric Rate Analysis and Design for Rural Distribution Systems

The continuing increase in the cost of wholesale and retail electric rates has caused both consumer and regulatory attention to focus on the reasonableness of the rates being charged by utilities. Rate increases generally precipitate concern over discriminatory pricing questions. Because the resolution of rate discrimination issues in part involves a cost allocation study, it is important for the rural electric system to be aware of the general considerations involved in the development of a cost of service study. A complete allocation of electric service costs is not an exact procedure, and any cost allocation effort must also involve an analysis of the assumptions that are a part of the cost of service study, particularly if comprehensive customer demand data are not available. The general considerations involved in developing a cost of service study are outlined to define a technique to evaluate the impact of the assumptions that are a part of the allocation of demand related costs.     

Decarbonization of electricity requires market-based demand flexibility

To effectively decarbonize the electric sector, utilities will need to address the growing load shape challenges driven by the variability of many renewable resources. Behind-the-meter solutions, such as energy efficiency, demand response, electrification and storage, will play an important role in grid stability, but only if they can deliver changes in demand that meet the time and locational needs of the grid. This article will discuss how smart meter interval data, combined with open source methods and software, provide transparent measurement of savings load shapes (resource curves) that enable the integration of demand flexibility into energy, capacity and carbon markets, and as a transmission and distribution resource. This allows utilities to procure demand flexibility in the same way they procure other resources by leveraging a price signal and pay-for-performance to drive innovation and attract private investment.     

Supplementing demand management programs with distributed generation options

Ever increasing electrical energy demand is forcing power serving entities around the world to use various demand management programs to help in stressful times of the electric power grid. Demand management programs aim to control electrical energy demand among customers and create load relief for electric utilities. Recently demand management contracts have been designed in which incentives are offered to customers who willingly sign up for load interruption. In recent years much technological advancement has been made in distributed generation, and the cost of using this option can bring about extra flexibility into existing demand management schemes. This paper explores the use of distributed generation technology within the existing demand management ideas. More specifically, it compares economic aspects of using demand management contracts with the use of distributed generation. A key observation of this paper is that there may be cases where it is more beneficial to use distributed generation rather than demand management contracts.     

华东地区电动汽车发展趋势及用电需求预测

对2020-2040年华东地区电动汽车用电需求进行预测。首先对华东地区电动汽车保有量进行预估,然后利用平均用电量法和油耗计算法分别预测电动汽车的用电耗能情况。最后分情景对电动汽车引起的用电负荷进行预测。结果显示,华东地区电动汽车保有量2020-2030年快速增长,年均增长率为79.11%,2040年达到3720万辆。电动汽车引起的用电需求2020年、2030年和2040年分别为7 TWh、132 TWh和198 TWh,年均增长率从24.60%降至4.11%,2020-2040年整体年均增长率超过18%。2040年电动汽车年均用电负荷增长率为2.27%,最低负荷为41859 MW,最高负荷为93021 MW。     

电动公交车换电站—电池充电站优化规划

充电设施的规划与建设是解决电动汽车发展瓶颈的重要问题。电动汽车在公共交通领域发展迅速,并广泛采用换电模式。文中充分考虑了电动公交汽车换电电量需求和充换电行为,提出了一种换电站—电池充电站建设模式,并给出了相应的优化规划方法。该方法首先使用近邻传播聚类算法对换电需求点进行空间聚类,以确定电池充电站的站址和规模,并利用化石燃料与电能的热值关系,将当前柴油公交车日消耗能量折算成电能以确定换电电量需求。然后,利用排队论方法对电池充电站内的工作情形进行建模,提出以拒绝服务率为主要约束,以综合建设成本最小为目标的优化模型。最后,以某城市实际统计数据为例给出了该市公交汽车换电站、电池充电站以及其充电设备、换电设备、电池的规划方案,为电动公交车充、换电站的实际规划提供参考。     

Production costing strategy for optimal SO2 compliance using Monte Carlo simulation

One of the main goals of electric utilities is to meet the required load demand in the most cost effective manner. With the continuing emphasis on environmental factors and the addition of the Clean Air Act Amendments of November 1990, cost effective solutions must now be subject to environmental considerations. This paper describes a simple framework which uses the Monte Carlo method to develop an economic and emissions based objective function for use in a production cost model. A computer program has been developed to implement this method on a DEC 3100 workstation. System studies are performed to illustrate the technique.