The effects of electricity reforms on productivity and efficiency of China's fossil-fired power plants: An empirical analysis

This paper investigates the effects of electricity reforms on productivity and efficiency of China's generation plants, based on the third industrial census data and the first economic census data. Partial factor productivity (PFP) analysis indicates that the productivity improvements in labor and capital inputs associated with the reforms are approximately 26% and 45% respectively. The effect of the reforms on fuel expense is weakly significant, but there is evidence of significant productivity improvement in fuel usage. Further total factor productivity (TFP) analysis shows that the efficiency gain from the reforms is still significant when the substitution effect of labor and capital inputs are considered, though the magnitude is much lower than that of the PFP analysis. The effect of the reforms on technical efficiency becomes weakly significant when fuel expense is further included in TFP analysis, but a significant positive effect is expected if fuel input is measured in physical quantity.     

Greenhouse gas emission intensity factors for marginal electricity generation in Canada

In Canada, each province has its own electric utility system, and each system is responsible for meeting the demand of its customer base. Electricity demand in all provinces is highly variable throughout the day, as well as during the year. In order to achieve a good match between electricity demand and generation, a mix of base, intermediate and peaking load power plants is used, which uses different fuel sources. When a renewable energy technology or an energy efficiency measure that results in electricity savings is implemented on a regional, provincial and national scale, the electricity savings reflect in the peak (marginal) electricity generation. Thus, the greenhouse gas (GHG) emission reduction due to the reduction in electricity generation corresponds to the fuel used to generate the electricity at the margin. In Canada, the fuel used for marginal electricity generation varies from province to province and from hour to hour. To estimate the reduction in GHG emissions due to reducing electricity generation at the margin, it is necessary to have information on the fuel mix used to generate the marginal electricity for each province on a suitable time scale. With such information, it is possible to estimate a marginal GHG emission intensity factor for each province, which would provide the amount of GHG emissions produced as result of producing 1 kWh of electricity on the margin. However, such information is regarded confidential by most electric utilities and is not made public. In this paper, methodologies are presented to estimate the GHG intensity factors (GHGIFs) for marginal electricity generation for each province of Canada based on the information available in the public domain. The GHGIFs developed for each province are also presented, which are expected to be valid within the next 5‐year horizon. Copyright © 2010 John Wiley & Sons, Ltd.     

Cost efficiency and electricity market structure: A case study of OECD countries

The OECD electricity sector has witnessed significant institutional restructuring over the past three decades. As a consequence, many power generation utilities now act as unregulated companies that technically compete to sell power on an open market. This paper analyses the performance in term of cost efficiency for electricity generation in OECD power sector while accounting for the impact of electricity market structures. We employ the short-run cost function in which capital stock is treated as a quasi-fixed factor input. Empirical models are developed for the cost function as a translog form and analysed using panel data of 25 countries during the period 1980 to 2009. We show that it is necessary to model latent country-specific heterogeneity in addition to time-varying inefficiency. The estimated economies of scale are adjusted to take account of the importance of the quasi-fixed capital input in determining cost behaviour, and long run constant returns to scale are verified for the OECD generation sector. The research findings suggest there is a significant impact of electricity market regulatory indicators on cost. In particular, public ownership and vertical integration are found to have significant and sizable increasing impacts on cost, thereby indicating policy lessons on the desirable ways to implement structural electricity generation reforms.     

Electricity regulation and electricity market reforms in China

The electricity industry of China has been in a process of reforms since the 1980s. This paper gives a review on the three main stages of reforms in China so as to trace out key features of various reform measures including those for power investment financing, the separation between government and power enterprises, and the division between power generation firms and power grids. The findings suggest that further regulatory change in China's electricity market reform is necessary when integration of the electricity markets and increased competition are paving the way ahead for a market-oriented structure. Prospective electricity regulation in the form of a strong legal system and effective institutions that protect market competition and promote appropriate incentives for efficiency are suggested in the paper.     

Decomposition for emission baseline setting in China's electricity sector

Decomposition analysis is used to generate carbon dioxide emission baselines in China's electricity sector to the year 2020. This is undertaken from the vantage point of the final consumer of electricity, and therefore considers factors influencing electricity demand, efficiency of generation, sources of energy used for generation purposes, and the effectiveness of transmission and distribution. It is found that since 1980, gains in efficiency of generation have been the most important factor affecting change in the emission intensity of electricity generated. Based upon known energy and economic policy, efficiency gains will continue to contribute to reductions in the emission intensity of electricity generated, however, fuel shifts to natural gas and increases in nuclear generation will further these trends into the future. The analysis confirms other sources in the literature that decomposition is an appropriate technique available for baseline construction, thereby suitable for the emerging carbon market and its related mechanisms.     

固体氧化物燃料电池与燃气轮机联合发电系统模拟研究

固体氧化物燃料电池(SOFC)是一种高效低污染的新型能源。建立了以天然气为燃料的固体氧化物燃料电池和燃气轮机(GT)联合发电系统的计算模型,并对具体系统进行计算。结果表明：SOFC与GT组戍的联合发电系统,发电效率可达68％(LHV);加上利用的余热,整个系统的能量利用率可以超过80％。文中还分析了SOFC的工作压力、电流密度等参数对系统性能的影响,提高工作压力,可以增加电池发电量,提高系统的发电效率;而电流密度的增大将使SOFC及整个系统的发电量降低。     

An experimental investigation of a PEM fuel cell to supply both heat and power in a solar-hydrogen RAPS system

The potential for both heat and power extraction from a PEM fuel cell is investigated experimentally and using computer simulation to improve the economics of a solar-hydrogen system supplying energy to a remote household. The overall average energy efficiency of the fuel cell was measured to be about 70% by utilizing the heat generated for domestic water heating, compared to only 35-50% for electricity generation alone. The corresponding round-trip energy efficiency of the hydrogen storage sub-system (electrolyzer, storage tank, and fuel cell) was raised from about 34% in a power-only application to about 50% in combined heat and power (CHP) mode. The economic benefit of using the fuel cell heat for boosting an LPG hot water system over a 30-year assessment period is estimated to be equivalent to about 15% of the total capital cost of the solar-hydrogen system. The stoichiometry of the input air, and the fuel cell operating temperature, were found to influence significantly the overall performance of the solar-hydrogen CHP system.     

The impact of the North Atlantic Oscillation on electricity markets: A case study on Ireland

The North Atlantic Oscillation (NAO) is a large-scale atmospheric circulation pattern driving climate variability in north-western Europe. As the deployment of wind-powered generation expands on electricity networks across Europe, the impacts of the NAO on the electricity system will be amplified. This study assesses the impact of the NAO, via wind-power generation, on the electricity market considering thermal generation costs, wholesale electricity prices and wind generation subsidies. A Monte Carlo approach is used to model NAO phases and generate hourly wind speed time-series data, electricity demand and fuel input data. A least-cost unit commitment and economic dispatch model is used to simulate an island electricity system, modelled on the all-island Irish electricity system. The impact of the NAO obviously depends on the level of wind capacity within an electricity system. Our results indicate that on average a switch from negative to positive NAO phase can reduce thermal generation costs by up to 8%, reduce wholesale electricity prices by as much as €1.5/MWh, and increase wind power generators' revenue by 12%.     

Generation expansion planning (GEP) - A long-term approach using system dynamics and genetic algorithms (GAs)

This paper presents a model to solve the Generation Expansion Planning (GEP), problem in competitive electricity markets. The developed approach recognizes the presence of several generation agents aiming at maximizing their profits and that the planning environment is influenced by uncertainties affecting the demand, fuel prices, investment and maintenance costs and the electricity price. Several of these variables have interrelations between them turning it important to develop an approach that adequately captures the long-run behavior of electricity markets. In the developed approach we used System Dynamics to capture this behavior and to characterize the evolution of electricity prices and of the demand. Using this information, generation agents can then prepare their individual expansion plans. The resulting individual optimization problems have a mixed integer nature, justifying the use of Genetic Algorithms (GAs). Once individual plans are obtained, they are input once again on the System Dynamics model to update the evolution of the price, of the demand and of the capacity factors. This defines a feedback mechanism between the individual expansion planning problems and the long-term System Dynamics model. This approach can be used by a generation agent to build a robust expansion plan in the sense it can simulate different reactions of the other competitors and also by regulatory or state agencies to investigate the impact of regulatory decisions on the evolution of the generation system. Finally, the paper includes a Case Study to illustrate the use and the results of this approach.     

Impact of electric vehicles on a future renewable energy‐based power system in Europe with a focus on Germany

Electric mobility is expected to play a key role in the decarbonisation of the energy system. Continued development of battery electric vehicles is fundamental to achieving major reductions in the consumption of fossil fuels and of CO₂ emissions in the transport sector. Hydrogen can become an important complementary synthetic fuel providing electric vehicles with longer ranges. However, the environmental benefit of electric vehicles is significant only if their additional electricity consumption is covered by power production from renewable energy sources. Analysing the implications of different scenarios of electric vehicles and renewable power generation considering their spatial and temporal characteristics, we investigate possible effects of electric mobility on the future power system in Germany and Europe. The time horizon of the scenario study is 2050. The approach is based on power system modelling that includes interchange of electricity between European regions, which allows assessing long‐term structural effects in energy systems with over 80% of renewable power generation. The study exhibits strong potential of controlled charging and flexible hydrogen production infrastructure to avoid peak demand increases and to reduce the curtailment of renewable power resulting in reduced system operation, generation, and network expansion costs. A charging strategy that is optimised from a systems perspective avoids in our scenarios 3.5 to 4.5 GW of the residual peak load in Germany and leads to efficiency gains of 10% of the electricity demand of plug‐in electric vehicles compared with uncontrolled loading.     

Modeling the life cycle energy and environmental performance of amorphous silicon BIPV roofing in the US

Building integrated photovoltaics (BIPV) perform traditional architectural functions of walls and roofs while also generating electricity. The displacement of utility generated electricity and conventional building materials can conserve fossil fuels and have environmental benefits. A life cycle inventory model is presented that characterizes the energy and environmental performance of BIPV systems relative to the conventional grid and displaced building materials. The model is applied to an amorphous silicon PV roofing shingle in different regions across the US. The electricity production efficiency (electricity output/total primary energy input excluding insolation) for a reference BIPV system (2kW_p PV shingle system with a 6% conversion efficiency and 20 year life) ranged from 3.6 in Portland OR to 5.9 in Phoenix, AZ indicating a significant return on energy investment. The reference system had the greatest air pollution prevention benefits in cities with conventional electricity generation mixes dominated by coal and natural gas, not necessarily in cities where the insolation and displaced conventional electricity were greatest.     

Estimating the potential for electricity savings in households

Improving efficiency in the use of energy is an important goal for many nations since end-use energy efficiency can help to reduce CO₂ emissions. Furthermore, since the residential sector in industrialised countries requires around one third of the end-use electricity, it is important for policy makers to estimate the scope for electricity saving in households to reduce electricity consumption by using appropriate steering mechanisms. We estimate the level of technical efficiency in the use of electricity using data from a Swiss household survey. We find an average inefficiency in electricity use by Swiss households of around 20 to 25%. Bottom-up economic-engineering models estimate the potential in Switzerland to be around 15%. In this paper we use a sub-vector input distance frontier function based on economic foundations. Our estimates lie at the upper end of the electricity saving potential estimated by the afore-mentioned economic-engineering approach.     

High gas dependence for power generation in Thailand: The vulnerability analysis

Thailand uses 74% of its natural gas supply for power generation and 70% of its power comes from gas-based technology. High dependence on natural gas in power generation raises concerns about security of electricity supply that could affect competitiveness of Thai manufacturing and other industries at the global level. The effect of fuel dependence on security of electricity supply has received less emphasis in the literature. Given this gap, this research examines the economic impact of high dependence on natural gas for power generation in Thailand by analyzing the effect of changes in fuel prices (including fuel oil and natural gas) on electricity tariff in Thailand. At the same time, the research quantifies the vulnerability of the Thai economy due to high gas dependence in power generation. Our research shows that for every 10% change in natural gas price, electricity tariff in Thailand would change by 3.5%. In addition, we found that the gas bill for power generation consumed between 1.94% and 3.05% of gross domestic product (GDP) between 2000 and 2004 and in terms of GDP share per unit of energy, gas dependence in power generation is almost similar to that of crude oil import dependence. We also found that the basic metal industry, being an electricity intensive industry, is the most affected industry. Additionally, we find that volatility of gas price is the main factor behind the vulnerability concern. The research accordingly simulates two mitigation options of the problem, namely reducing gas dependence and increasing efficiency of gas-fired power plants, where the results show that these methods can reduce the vulnerability of the country from high gas dependence in power generation.     

Thermodynamic development and design of a concentrating solar thermochemical water-splitting process for co-production of hydrogen and electricity

A concentrating solar plant is proposed for a thermochemical water-splitting process with excess heat used for electricity generation in an organic Rankine cycle. The quasi-steady state thermodynamic model consisting of 23 components and 45 states uses adjustable design parameters to optimize hydrogen production and system efficiency. The plant design and associated thermodynamic model demonstrate that cerium oxide is suitable for thermochemical water-splitting cycles involving the co-production of hydrogen and electricity. Design point analyses at 900 W/m² DNI indicate that a single tower with solar radiation input of 27.74 MW and an aperture area of 9.424 m² yields 10.96 MW total output comprised of 5.55 MW hydrogen (Gibbs free energy) and 5.41 MW net electricity after subtracting off 22.0% of total power generation for auxiliary loads. Pure hydrogen output amounts to 522 tonne/year at 20.73 GWh/year (HHV) or 17.20 GWh/year (Gibbs free energy) with net electricity generation at 14.52 GWh/year using TMY3 data from Daggett, California, USA. Annual average system efficiency is 38.2% with the constituent hydrogen fraction and electrical fraction being 54.2% and 45.8%, respectively. Sensitivity analyses illustrate that increases in particle loop recuperator effectiveness create an increase in hydrogen production and a decrease in electricity generation. Further, recuperator effectiveness has a measurable effect on hydrogen production, but has limited impact on total system efficiency given that 81.1% of excess heat is recuperated within the system for electricity generation.     

Thermoelectric Module Integrated Fuel Cell in a Liquid Desiccant-Assisted Air-Conditioning System

Abstract

This study aims to estimate the energy performance of a liquid desiccant and evaporative cooling-assisted 100% outdoor air system (LD-IDECOAS) combined with a thermoelectric module integrated proton exchange membrane fuel cell (TEM-PEMFC). During the cooling season, recovered heat from the PEMFC was reclaimed to heat a weak desiccant solution and the generated electricity was used to operate the LD-IDECOAS. The TEM was operated as an auxiliary heater for heating the weak desiccant solution. In the off-cooling season, the PEMFC was operated to generate electricity and the recovered heat was also used to generate electricity using TEMs. In this study, a detailed energy simulation model was developed to estimate the energy savings potentials of the proposed system compared with the conventional LD-IDECOAS that uses a gas boiler and grid power without TEM-PEMFC. The result shows that TEMs can operate with a mean coefficient of performance of 2.0 when utilized for auxiliary heater in the cooling season. In addition, TEMs generate additional electricity with a mean power generation efficiency of 0.9%. Finally, the proposed system can save the 10.6% of annual primary energy compared with the conventional LD-IDECOAS. Therefore, the advantages of using TEM-PEMFC as heating and energy harvesting components were verified.     

Employment trends in the U.S. Electricity Sector, 2008–2012

Between 2008–2012, electricity generated (GWh) from coal, the longtime dominant fuel for electric power in the US, declined 24%, while electricity generated from natural gas, wind and solar grew by 39%, 154%, and 400%, respectively. These shifts had major effects on domestic employment in those sectors of the coal, natural gas, wind and solar industries involved in operations and maintenance (O&M) activities for electricity generation. Using an economic input–output model, we estimate that the coal industry lost more than 49,000 jobs (12%) nationally over the five-year period, while in the natural gas, solar, and wind industries, employment increased by nearly 175,000 jobs (21%). We also combine published ratios for jobs per unit of fuel production and per megawatt of power plant capacity with site-specific data on fuel production and power plant retirements, additions and capacity changes to estimate and map direct job changes at the county level. The maps show that job increases in the natural gas, solar and wind industries generally did not occur where there were significant job losses in the coal industry, particularly in West Virginia and Kentucky.     

Regulatory reforms and productivity: An empirical analysis of the Japanese electricity industry

The Japanese electricity industry has experienced regulatory reforms since the mid-1990s. This article measures productivity in Japan's steam power-generation sector and examines the effect of reforms on the productivity of this industry over the period 1978–2003. We estimate the Luenberger productivity indicator, which is a generalization of the commonly used Malmquist productivity index, using a data envelopment analysis approach. Factors associated with productivity change are investigated through dynamic generalized method of moments (GMM) estimation of panel data. Our empirical analysis shows that the regulatory reforms have contributed to productivity growth in the steam power-generation sector in Japan.     

Profitability and productivity changes in the Korean electricity industry

The Korean electricity industry saw significant changes following the reform in April 2001. Until the last decade, the industry was monopolized by the Korea Electric Power Corporation (KEPCO), a state-owned, vertically integrated company. The 2001 reform divided KEPCO's power generation division into six power generation companies (GENCOs), with the aim of improving efficiency and introducing competition in the electricity industry. In this study, we used capital total factor productivity (KTFP) to analyze profit changes from fixed input capital, and an index number profit decomposition (INPD) to examine the sources of the profit changes. We investigate the industry thoroughly from three points of view: the overall industry over time; the power generation sector by company; and the transmission and distribution sectors of the Korea Electric Power Corporation (KEPCO). Next, we measured how the profits from productivity growth were distributed to consumers, fuel suppliers, employees, and company owners. The results suggest that a more reasonable price system for both wholesale and consumer prices needs to be implemented prior to the privatization and deregulation of the Korean electricity industry.     

Efficiency and deregulation of the electricity market in Singapore

This study examines production efficiency of electricity generation in the New Electricity Market of Singapore (NEMS), where deregulation is currently proceeding. Singapore is reliant on foreign direct investments and exports so competition from countries with lower costs such as China and India is exerting pressure on the government to reduce the costs of doing business here. Electricity cost is one of these. Deregulation is believed to be able to bring about lower electricity costs due to the various efficiency gains possible. This study concerns itself mainly with production efficiency and attempts to calculate possible production efficiency gains by using linear programming model. Production-efficiency gains are quantified by the base case scenario of continued regulation versus four counterfactual deregulation scenarios. The results indicate that cost gains could be about eight per cent of current production cost, and this is possibly a lower-bound estimate. However, whether the purported efficiency gains are realized is to be seen as the deregulation proceeds.     

Energy from sugarcane bagasse under electricity rationing in Brazil: a computable general equilibrium model

In the midst of the institutional reforms of the Brazilian electric sectors initiated in the 1990s, a serious electricity shortage crisis developed in 2001. As an alternative to blackout, the government instituted an emergency plan aimed at reducing electricity consumption. From June 2001 to February 2002, Brazilians were compelled to curtail electricity use by 20%. Since the late 1990s, but especially after the electricity crisis, energy policy in Brazil has been directed towards increasing thermoelectricity supply and promoting further gains in energy conservation. Two main issues are addressed here. Firstly, we estimate the economic impacts of constraining the supply of electric energy in Brazil. Secondly, we investigate the possible penetration of electricity generated from sugarcane bagasse. A computable general equilibrium (CGE) model is used. The traditional sector of electricity and the remainder of the economy are characterized by a stylized top-down representation as nested CES (constant elasticity of substitution) production functions. The electricity production from sugarcane bagasse is described through a bottom-up activity analysis, with a detailed representation of the required inputs based on engineering studies. The model constructed is used to study the effects of the electricity shortage in the preexisting sector through prices, production and income changes. It is shown that installing capacity to generate electricity surpluses by the sugarcane agroindustrial system could ease the economic impacts of an electric energy shortage crisis on the gross domestic product (GDP).