Television peaks in electricity demand

This paper discusses the effect that breaks in television programmes have upon the demand for electricity. The results of a study which correlates the pattern of household electricity consumption with the timings of commercial and end-of-programme breaks are summarized. A theory of audience release is developed and various policy implications are explored.     

Small scale impact of gas technologies on electric load management – μCHP & hybrid heat pump

To face winter electricity peaking issues the authors proposes an analysis of the potential of distributed gas technologies for demand side management. This impact has to be analysed at small scale before any large scale extrapolation. Bi-energy technologies (gas and electricity) are a path to transfer loads from one system to another. Indeed, the flexible gas infrastructure adapts to load while electricity demand variations cause risk of black-out. The impacts of two hybrid technologies are studied at transformer level with 1-min experimental load profiles of 40 dwellings equipped with micro Combined Heat and Power (μCHP) boilers over a year in France. An absolute peak load reduction by 17% at small scale is found. Different technology mixes are then simulated to assess the effect on local infrastructure. Finally a methodology for temperature dependence analysis of load is used to assess different potential benefits of gas technologies.     

2013年世界能源行业发展状况

2013年以来,全球经济复苏有所减弱,国际能源供需格局稳中有变,消费东移、生产西移的趋势愈加明显.从能源结构看,全球油气供需格局深刻调整,价格与贸易流向变化显著;煤炭消费总量和增速继续上升,但地区消费的不平衡性加剧,贸易流向有所改变;煤炭、天然气的相对价格变化导致各国电源结构发生显著变化;全球核电消费继续下降,欧美各国在核能的开发和利用上愈加谨慎;水电发展区域性突出;风电行业发展面临不确定性;光伏产业则呈现复苏态势.     

Critical evaluation of financial supporting schemes for wind-based projects: Case study Greece

After a long stagnating period during the second half of the 1990s, the market of wind energy in Greece was described by remarkable but unstable growth rates that resulted in the operation of 1 GW of wind power by the end of 2009. Still though, penetration of wind energy is not the one anticipated. On the other hand, national targets regarding the Renewable Energy Sources’ (RES) contribution and existence of excellent wind potential areas across Greece challenge new wind energy investments. Acknowledging the unsteady development rates of wind power in Greece, efficiency of the State support mechanisms is currently investigated. Based on an analytical evaluation model, the investigation undertaken is extended to provide a detailed cost-benefit analysis of several wind energy case studies, including mainland and island applications as well as comparison with both conventional power stations and photovoltaic plants. For this purpose, the financial support provided by the State is directly compared with benefits accruing from the operation of wind parks, considering also the avoidance of social costs deriving from thermal power stations. Based on the results obtained, the beneficial characteristics of wind energy applications for the Greek society are clearly demonstrated, especially in the case of non-interconnected island grids.     

Causal responsibility and peak load pricing

This article clarifies the basis for peak load pricing when some customers have a steady demand and others have a specific peak period demand. Causal responsibility for peak capacity rests on both types of customers. Peles, in this journal, has proposed that electricity consumption beyond the off-peak period monthly average be priced at a higher rate than other consumption. Customers consuming only on the peak would face higher prices than those who consumed relatively less during the peak. However, such a price structure can discourage economic off-peak consumption and encourage uneconomic peak period consumption. Both steady and nonsteady demanders must face the same price signal during peak periods for the achievement of efficiency, so long as each group imposes the same costs on the system.     

The large-scale integration of wind generation: Impacts on price,reliability and dispatchable conventional suppliers

This work examines the effects of large-scale integration of wind powered electricity generation in a deregulated energy-only market on loads (in terms of electricity prices and supply reliability) and dispatchable conventional power suppliers. Hourly models of wind generation time series, load and resultant residual demand are created. From these a non-chronological residual demand duration curve is developed that is combined with a probabilistic model of dispatchable conventional generator availability, a model of an energy-only market with a price cap, and a model of generator costs and dispatch behavior. A number of simulations are performed to evaluate the effect on electricity prices, overall reliability of supply, the ability of a dominant supplier acting strategically to profitably withhold supplies, and the fixed cost recovery of dispatchable conventional power suppliers at different levels of wind generation penetration. Medium and long term responses of the market and/or regulator in the long term are discussed.     

Demand side management: Benefits and challenges

In this paper, the major benefits and challenges of electricity demand side management (DSM) are discussed in the context of the UK electricity system. The relatively low utilisation of generation and networks (of about 50%) means that there is significant scope for DSM to contribute to increasing the efficiency of the system investment. The importance of the diversity of electricity load is discussed and the negative effects of DSM on load diversity illustrated. Ageing assets, the growth in renewable and other low-carbon generation technologies and advances in information and communication technologies are identified as major additional drivers that could lead to wider applications of DSM in the medium term. Potential benefits of DSM are discussed in the context of generation and of transmission and distribution networks. The provision of back-up capacity by generation may not be efficient as it will be needed relatively infrequently, and DSM may be better placed to support security. We also present an analysis of the value of DSM in balancing generation and demand in a future UK electricity system with significant variable renewable generation. We give a number of reasons for the relatively slow uptake of DSM, particularly in the residential, commercial and small business sectors. They include a lack of metering, information and communication infrastructure, lack of understanding of the benefits of DSM, problems with the competitiveness of DSM when compared with traditional approaches, an increase in the complexity of system operation and inappropriate market incentives.     

Has electric utility restructuring led to lower electricity prices for residential consumers in Texas?

This paper analyzes the determination of residential electricity prices in the competitive Electric Reliability Council of Texas (ERCOT) market. This analysis suggests that electricity restructuring in Texas has not yet resulted in lower prices for the majority of residential energy consumers in areas open to competition. Contrary to common expectations, residential electricity costs for consumers at a typical (1000 kWh per month) consumption level have increased at a greater rate in the areas of Texas offering retail choice than in the areas of the State where retail competition has not been introduced.     

Input-output table of electricity demand and its application

It is very important for electric utility to determine dominant sectors which have more impacts on electricity consumption in national economy system. In this paper, an input-output perspective and methodology is proposed to handle this issue. The input-output table of electricity demand (IOTED) is put forward based on the input-output table of national economy (IOTNE). The relevancy of electricity demand in various sectors is revealed by means of electricity consumption chains (ECCs), which are key components in the IOTED. Besides, a new concept, electricity demand multiplier (EDM), is presented to identify dominant sectors imposing great impacts on electricity demand quantitatively. In order to testify the effectiveness of the proposed methodology, a case based on provincial economy system in China is studied. Dominant sectors are identified and discussed.     

The effects of electricity pricing on PHEV competitiveness

Plug-in hybrid electric vehicles (PHEVs) will soon start to be introduced into the transportation sector, thereby raising a host of issues related to their use, adoption and effects on the electricity sector. Their introduction has the potential to significantly reduce carbon emissions from the transportation sector, which has led to government policies aimed at easing their introduction. If their widespread adoption is set as a target it is imperative to consider the effects of existing policies that may increase or decrease their adoption rate. In this study, we present a micro level electricity demand model that can gauge the effects of PHEVs on household electricity consumption and the subsequent economic attractiveness of the vehicles. We show that the electricity pricing policy available to the consumer is a very significant factor in the economic competitiveness of PHEVs. Further analysis shows that the increasing tier electricity pricing system used in California will substantially blunt adoption of PHEVs in the state; and time of use electricity pricing will render PHEVs more economically attractive in any state.     

Cost–benefit analysis of a photovoltaic power plant

This work evaluates the energy generated by photovoltaic generators with different mounting angles to the horizontal plane, and the optimum angle is estimated. Other aspects considered are the costs and legal framework associated with installing a photovoltaic power plant in Santa Fe, Argentina. After having done a cost–benefit analysis under different scenarios, results showing the feasibility of building a photovoltaic power plant were obtained. However, the assessment of costs shows that the rates set by Act 26190 need to be modified in order to increase its feasibility in the location studied.     

Regulatory road maps for the integration of intermittent electricity generation: Methodology development and the case of The Netherlands

The envisaged increase in the share of electricity generation from intermittent renewable energy sources (RES-E) like wind and photovoltaics will pose challenges to the existing electricity system. A successful integration of these sources requires a cost-efficient use of system flexibility. The literature on the options to improve system flexibility, and thus the costs of successfully integrating intermittent electricity generating units, is still growing but what is lacking is an overarching systematic view on when to adopt which option in particular energy systems. This paper aims to bridge this gap in literature. We use existing insights on market and network integration of intermittent electricity sources within a regulatory road map framework. The framework allows policy makers and other electricity system stakeholders to arrive at a consistent strategy in dealing with integration issues over a longer period of time. In this contribution we present and explain the framework and apply it for the case of The Netherlands.     

Cost and sensitivity analysis for photovoltaic station in Kuwait

A full analysis is shown in this paper for the cost of kWh generated from photovoltaic station located in Kuwait. By using a 21 years weather data for Kuwait, the yearly generated energy was found by proposing the PV station capacity with known panels tilt angle. The cost of kWh generated from PV station was compared with the kWh generated from conventional units in the country. A sensitivity analysis was done to some factors; capital cost per installed PV peak watt, discount rate, and operating peak hours, which affect the cost of kWh production from both PV and conventional units. If the PV station is proposed to be installed in Kuwait, the capital cost per PV installed peak watt must be less than today's prices.     

Subsidies for electricity-generating technologies: A review

This paper presents estimates of the extent of subsidisation globally, via selected mechanisms, for a number of different electricity-generating technologies. The technologies covered are coal-fired, nuclear, wind, solar PV, concentrating solar, geothermal, biomass and hydroelectric power. To the knowledge of the authors, this study provides the most complete and comprehensive collation of energy subsidies so far at a global level. Our series of information allows a comparison of subsidies for electricity-generating technologies, based on the respective states of development and deployment during different time periods. To date, on average, hydropower receives the least subsidies per unit of electricity it generates and geothermal and nuclear power receive an equally low level of subsidies per kWh generated. Amongst renewables, wind power has registered a spectacular success story in reducing the need for subsidisation. The same cannot be said for the two solar technologies, and for biomass. Coal-fired power has the highest subsidisation level, despite its high level of global deployment, which is mainly because of external costs due to climate change impacts. Our study demonstrates that accounting for subsidies under an agreed framework can be important for informing future policy decisions on subsidisation.     

Trends in prices to commercial energy consumers in the competitive Texas electricity market

To date, the price of electricity to commercial or business energy consumers has generally increased at greater rates in the areas of Texas where retail competition has been introduced than in areas that do not enjoy competition. Trends in commercial competitive prices have largely mirrored trends in residential prices. Market restructuring has tended to increase the sensitivity of retail electricity prices to changes in the price of natural gas, the marginal fuel used for generation in Texas. Consequently, the rapid increases in the commodity price of natural gas following restructuring led to increases in competitive electric rates which exceeded the increases in areas not exposed to restructuring, where the fuel component of electric rates tend to reflect a weighted average of the utilities’ fuel costs. There is some evidence that pricing behavior by competitive retailers changed when the retailers affiliated with the incumbent utilities were permitted some pricing flexibility, resulting in a reduction in prices.     

The impact on electricity demand and emissions due to the introduction of electric cars in the São Paulo Power System

Over the past years, the pursuit of using less polluting energy sources throughout society has been on the increase. In general, the transportation sector is responsible for most of the emissions of greenhouse gases. Therefore, in this article a methodological approach is applied in such a way that it is possible to quantify the impact of the penetration of electric vehicles vis-à-vis others that use different types of fuel (flexible fuel, for example). The study is conducted for a road modal in São Paulo, the main state in Brazil in terms of economy, energy and environment, taking into account only automobiles. A comparative analysis of forecasting scenarios until 2035 for various inputs of electric cars in the whole state fleet is presented, aiming to verify the susceptibility of the model suggested, upon the introduction of electric vehicles, taking into account also the electrical and environmental impacts related to it. The analysis was possible due to the use of a simulation tool, Long range Energy Alternatives Planning System (LEAP), which is an energy environmental model based on scenarios, allowing an integrated and reliable support to develop studies on integrated energy planning.     

Indications for a changing electricity demand pattern: The temperature dependence of electricity demand in the Netherlands

This study assesses the electricity demand pattern in the relatively temperate climate of the Netherlands (latitude 52°30′N). Daily electricity demand and average temperature during the period from 1970 until 2007 are investigated for possible trends in the temperature dependence of electricity demand. We hypothesize that the increased use of cooling applications has shifted the temperature dependence of electricity demand upwards in summer months. Our results show significant increases in temperature dependence of electricity demand in May, June, September, October and during the summer holidays. During the period studied, temperature dependence in these months has shifted from negative to positive, meaning that a higher temperature now leads to an increased electricity demand in these months, rather than a decreased demand as observed historically. Although electricity demand in countries with moderate summer temperatures such as the Netherlands generally peaks in winter months and shows a minimum in summer months, this trend may signal the development of an additional peak in summer, especially given the expected climatic change. As power generating capacity may be negatively influenced by higher temperatures due to decreasing process cooling possibilities, an increasing electricity demand at higher temperatures may have important consequences for power generation capacity planning and maintenance scheduling.     

The prospective of coal power in China: Will it reach a plateau in the coming decade?

Coal power holds the king position in China's generation mix and has resulted in ever-increasing ecological and environmental issues; hence, the development of the electric power sector is confronted with a series of new challenges. China has recently adopted a new economic principle of the “new economic normal,” which has a large effect on the projection electricity demand and power generation planning through 2020. This paper measures electricity demand based upon China's social and economic structure. The 2020 roadmap presents China's developing targets for allocating energy resources to meet new demands, and the 2030 roadmap is compiled based upon an ambitious expansion of clean energy sources. Results show that electricity demand is expected to reach 7500 TWh in 2020 and 9730 TWh in 2030. Coal power is expected to reach its peak in 2020 at around 970 GW, and will then enter a plateau, even with a pathway of active electricity substitution in place.     

Electricity market participation of wind farms: the success story of the Spanish pragmatism

In the last 10 years, more than 15 GW of wind power (Asociación Empresarial Eólica (Spanish Wind Energy Association), Nota de prensa (Press release) 17 de enero de 2008. http://www.aeeolica.org/doc/NP_080117_Espana_supera_los_15000_MW_eolicos.pdf) have been installed in Spain, of which more than 3.5 GW in 2007. Furthermore, plans are to reach 20 GW by 2010 and there are expectations of an installed capacity exceeding 40 GW by 2020. This article will present the innovative solutions for technical and economical integration that allow to reach such high level wind penetration objectives (the system peaks at around 44 GW and is almost isolated). It will be described how the regulation has evolved from a pure Feed-in-Tariff to a market+premium option, where technical and economic integration has been a priority. Today, approximately 97% of installed wind capacity accesses the Spanish wholesale electricity market. Market integration has been crucial, sending the correct signals to participants to look for the optimum technical solutions. Technical improvements have come from both wind power producers (fault-ride-through capabilities, visibility and controllability of wind power, power production forecasting, reactive power control) and the system operator (specific control centre dedicated to Renewable Energy Sources (RES), new security analysis tools, gaining technical confidence of wind capabilities).     

Did the expiration of retail price caps affect prices in the restructured Texas electricity market?

On January 1, 2007, the Electric Reliability Council of Texas (ERCOT) market became the first restructured market in the US to completely remove caps on the prices which could be charged to residential energy consumers by the retailers associated with the traditional or incumbent utility service providers. Our analysis suggests that the expiration of the price-to-beat (PTB) price caps may have led to a reduction in the average prices charged by competitive retail electric providers (REPs).