Decomposing energy productivity change: A distance function approach

By using output distance functions, this paper decomposes energy productivity change into several components: effects of the changes in the ratios of non-energy inputs to energy, energy supply composition, and output composition; technical efficiency change; technological change. We apply this method to decompose energy productivity change in 23 OECD countries between 1980 and 1990. Results show that technological change is the most important source; increase in capital–energy ratio and the growing importance within total energy supply of electricity also contribute to it.     

Financial allocation strategy for the regional pollution abatement cost of reducing sulfur dioxide emissions in the thermal power sector in China

This study explores empirical evidence for two hypotheses through a macro productivity analysis using the nonparametric directional distance function approach applied to the thermal power sector. The first hypothesis is that the marginal abatement cost has significantly declined in recent years mainly due to domestic flue gas desulfurization technology in China, which has become available at a reasonable cost. The second is the existence of a certain budget scale, which, with policy intervention, would have significant outcomes. These hypotheses are successfully addressed through the findings that the marginal abatement cost in 2006 had declined by half since 2003 and that the strategic allocation of 10 billion yuan for SO₂ emissions abatement would result in an additional 550,000 tonnes of SO₂ reductions.     

Regional energy efficiency,carbon emission performance and technology gaps in China: A meta-frontier non-radial directional distance function analysis

At present, China is the largest primary energy consumer and carbon emitter in the world. Meantime, China is a large transitional economy with significant regional gaps. Against such backgrounds, the calculated results of energy and carbon performance indicators may be biased, without considering heterogeneity across regions. To this end, after incorporating region-heterogeneity, this paper provides detailed information, regarding energy efficiency, carbon emission performance and the potential of carbon emission reductions from regional perspectives, which may be important and useful for policy makers. Our main findings are as follows. Firstly, there is significant group-heterogeneity across regions in China, in terms of energy efficiency and carbon emission performance. Secondly, there are no considerable differences between total-factor and single-factor performance indices, since there is limited substitutability between energy inputs and other production inputs. Finally, significant carbon emission reductions can be made by “catching up” for regions with low energy efficiency and carbon emission performance. Looking ahead, the Chinese government should adopt measures to promote improvements in terms of energy efficiency and carbon emission performance in the short term.     

Scenario-based energy efficiency and productivity in China: A non-radial directional distance function analysis

Improving energy efficiency and productivity is one of the most cost-effective ways for achieving the sustainable development target in China. This paper employs non-radial directional distance function approach to empirically investigate energy efficiency and energy productivity by including CO₂ emissions as an undesirable output. Three production scenarios, namely energy conservation (EC), energy conservation and emission reduction (ECER), and energy conservation, emission reduction and economic growth (ECEREG), are specified to assess China's energy efficiency and productivity growth during the period of Eleventh Five-Year Plan. Our empirical results show that there exist substantial differences in China's total-factor energy efficiency and productivity under different scenarios. Under the ECEREG scenario, the national average total-factor energy efficiency score was 0.6306 in 2005–2010, while the national average total-factor energy productivity increased by 0.27% annually during the period. The main driving force for energy productivity growth in China was energy technological change rather than energy efficiency change.     

Overcoming the shortcomings of energy intensity index: a directional technology distance function approach

In multilateral comparisons of environmental performance over time, energy intensity measures, especially “real” energy intensity computed either by index decomposition approach or structural decomposition approach, are the most commonly used measures. Recently, researchers also resort to production-theoretical approach, which relies on data envelopment analysis techniques, to decompose energy intensity changes over time into their subcomponents. While their intuitiveness and computational ease make these indices attractive, their time series properties create considerable challenges in performing informative and fair comparisons among the energy efficiency levels of units considered. Furthermore, the resultant measure of energy intensity in these studies is still the inverse of a partial factor productivity (PFP) measure, i.e., energy productivity, that does not take into consideration compositional differences between inputs of the units being compared (which are also subject to change over time) and that ignores the type of substitution among inputs and, hence, makes it a measure that disguises rather than illuminates. The theoretical part of this paper shows how one can overcome the shortcomings of the energy intensity measure by constructing a new energy index using directional technology distance functions. The new index constructed in this study not only overcomes the shortcomings of the energy intensity measures but also satisfies the axiomatic properties of index numbers that are laid down by Fisher. An empirical application on U.S state-level agricultural sectors further complements existing studies.     

China's energy efficiency improvement on account of the development of wind and solar power: Applying a dynamic non-radial directional distance function

China is developing wind energy and solar power as the main channels to deal with climate warming and has put forward the goal of achieving peak carbon emissions by 2030 and carbon neutralization by 2060. Previous studies evaluating the nation energy efficiency rarely consider the impact of wind and solar power. Thus, different from past literature, this research introduces Carbon Emission Reduction Capacity (CERC) by wind and solar power as a new output variable and applies a dynamic non-radial directional distance function to evaluate China's energy efficiency from 2011 to 2019. The empirical results show that northwest provinces with their high proportion of wind and solar power present better energy performance, while some eastern and central provinces with high efficiency as seen in previous study have greater room for improvement of wind and solar power. It is suggested that the China government formulate more flexible policies to support the sustainable development of wind and solar power, so as to reduce the consumption of fossil energy and cope with climate warming.     

环境约束下河北省全要素能源效率实证研究

运用DEA模型,以环境生产技术和方向性距离函数为基础,测算了河北省1980～2009年环境约束下的全要素能源效率;在此基础上,考察了结构因素对环境约束下全要素能源效率的影响。结果表明,改革开放30年来河北省全要素能源效率呈波动性上升趋势,但上升缓慢,近年达到了相对有效状态;长期来看,增加第三产业比重、降低重工业比重和煤炭在能源消费中的比重、加速城市化进程将有助于河北省能源效率的提高。因此,调整产业结构和工业内部结构、优化能源消费结构等应成为河北省节能减排的现实选择。     

A model for distribution of oxygen in multicrystalline silicon ingot grown by directional solidification

A model, including segregation from silicon melt to silicon crystal as well as evaporation from silicon melt to Ar atmosphere, was established for simulating the oxygen distribution in multicrystalline silicon (mc-si) ingot, which shows good agreement with the experimental results. According to this model, the oxygen distribution in the bottom of ingot is mainly determined by the evaporation of oxygen, whereas that in the top of ingot is dominated by the segregation of oxygen. Furthermore, it could be found that the O_i profiles in growth direction of ingots become more and more steeper with the increase of the exponent X.     

Efficiency analysis of Turkish natural gas distribution companies by using data envelopment analysis method

This paper analyzes the performance of 38 Turkish natural gas distribution companies by using a non-parametric method, Data Envelopment Analysis (DEA). The results are used to determine the most proper model specification, to detect the important criteria affecting the efficiency levels, and to find the common characteristics of the most inefficient firms. We find that public firms compared to private firms, non-tender firms compared to tender firms, large firms compared to small firms and firms operating in more developed areas compared to firms operating in underdeveloped areas that utilize resources and manage costs more efficiently. However, we cannot reach a certain conclusion about the comparison of old firms versus the new firms. Lastly, we try to detect the common characteristics of the most inefficient firms and find that most of these firms are immature and low scale companies. Therefore, we think these firms can increase efficiency level either by increasing their delivery amounts through higher penetration rates or by merging or doing both together.     

Efficiency assessment of Turkish power plants using data envelopment analysis

The performance of electricity generation plants in Turkey are analyzed and compared. The data set contains inputs from 65 thermal, hydro and wind power plants, owned by private and public sectors. Data envelopment analysis (DEA) is used as the primary mathematical tool. Two efficiency indexes, reflecting operational and investment performance, are defined and pursued. Constant returns to scale, variable returns to scale and assurance region type DEA models are used in the analysis. Scale efficiency is also considered. Performance comparisons include public versus private sector plants, and natural gas versus coal versus oil fired plants. Also, relationships between efficiency scores and various input/output factors are investigated and some interesting trends are identified.     

Distribution network tariffs: A closed question?

Electricity regulators are facing new challenges to keep the pace of the liberalization process and the revision of regulatory schemes that is taking place all over the world. The pressure is also felt by regulated activities such as distribution. One of the main objectives of this process is to improve efficiency. Electricity rates and more specifically distribution network tariffs should also be adapted to these new requirements. This paper describes the main rate design approaches that are used to recover distribution costs. Drawbacks of the current methods are highlighted, and a new tariff design methodology based on cost causality is presented. Efficiency achievement as well as compliance with legal and regulatory criteria, such as cost recovery and non-discrimination, is analyzed.     

Thermal rating and design of woodstoves: A new approach

The paper is divided into two parts. In the first part, the results of tests on 13 stoves currently being marketed in India, compared with two traditional stoves, are presented. The bulk of the tests (about 140) pertain to variation of efficiency against fuel burning rate. Also, a few tests on the variation of chimney heights (18 tests) and damper position (20 tests) were conducted. The levels of efficiency were quite low on account of improper dimensioning of the stoves. Except for two stoves, all recorded consistently low efficiency figures. In the second part of the paper, the results of tests on combustion chambers of different sizes, ranging from a diameter of 180 mm to 500 mm, are presented in the form of design equations. The optimum length to diameter ratio is about 0.35, and optimum height of the ash chamber is 0.2 times the height of combustion chamber. A new approach to the sizing of combustion chambers is presented.     

Innovation and international technology transfer: The case of the Chinese photovoltaic industry

China is the largest solar photovoltaic cell producer in the world, with more than one third of worldwide production in 2008, exporting more than 95 percent of what it produces. The purpose of this paper is to understand the drivers of this success and its limits, with a particular emphasis on the role of technology transfers and innovation. Our analysis combines a review of international patent data at a detailed technology level with field interviews of ten Chinese PV companies. We show that Chinese producers have acquired the technologies and skills necessary to produce PV products through two main channels: the purchasing of manufacturing equipment in a competitive international market and the recruitment of skilled executives from the Chinese diaspora who built pioneer PV firms. The success of these firms in their market is, however, not reflected in their performance in terms of innovation. Rather, patent data highlight a policy-driven effort to catch up in critical technological areas.     

Economies of scale in the Korean district heating system: A variable cost function approach

This paper aims to investigate the cost efficiency of South Korea’s district heating (DH) system by using a variable cost function and cost-share equation. We employ a seemingly unrelated regression model, with quarterly time-series data from the Korea District Heating Corporation (KDHC)—a public utility that covers about 59% of the DH system market in South Korea—over the 1987–2011 period. The explanatory variables are price of labor, price of material, capital cost, and production level. The results indicate that economies of scale are present and statistically significant. Thus, expansion of its DH business would allow KDHC to obtain substantial economies of scale. According to our forecasts vis-à-vis scale economies, the KDHC will enjoy cost efficiency for some time yet. To ensure a socially efficient supply of DH, it is recommended that the KDHC expand its business proactively. With regard to informing policy or regulations, our empirical results could play a significant role in decision-making processes.     

Alkaline fuel cell: A test plant,measurements and analysis of the results

An experimental study of an alkaline fuel cell test plant with a 0.5 kW fuel cell module is presented in this paper. The characteristics of the fuel cell module are measured in different steady state load conditions and with different electrolyte temperatures. The results are analysed by calculating the different efficiencies of the module.     

A review of the biogas industry in China

This article presents an overview of the development and future perspectives of the Chinese biogas industry. The development of the industry has the potential to improve the rural environment and produce significant amounts of sustainable energy for China. Barriers to the development are the relatively weak environmental policies, imperfect financial policies and lack of long-term follow-up services. The rapid economic development of China has also seen a development in the scales of biogas plants constructed. Although the technology has been improved, this review has identified problems in the construction and operation of Chinese biogas plants, particularly in the efficiency of household systems. All levels of China's government acknowledge this and recent biogas projects have more focus on quality and less on the quantity. The intention is to gradually introduce stricter environmental policies, to provide better service systems, improve the financial policies that support the construction and follow-up service of biogas projects, promote the use of standardized engineering equipment and materials and standards for plant construction and production. This will promote the development of biogas projects at various scales further, and reduce the dependency on fossil fuels and emissions of greenhouse gases.     

Performance of wind power industry development in China: A DiamondModel study

A reliable supply of energy is essential to maintain and to improve human being's living conditions. Compared to the conventional coal-fired approach, renewable energy (RE) helps to mitigate the impacts of greenhouse gas emissions to a large extent. As a newly developed sector with large resource potential and good commercial prospects, China's wind power industry is exceeding expectations. By 2008, installed capacity of wind power in China totaled over 12 GW, making China the fourth largest wind market in the world. However, China has to admit the gap with foreign leading countries, mainly in technical R&D for large-scale wind turbine generation units. This paper attempts to formulate an analytical model for studying and assessing factors that have significant impacts on the local industry. An improved dynamic Diamond Model is developed to help the international community to understand the status quo of the Chinese wind power industry. In order to build a stronger wind power industry, the elements identified in the model need to be strengthened.     

Interactions between renewable energy policy and renewable energy industrial policy: A critical analysis of China's policy approach to renewable energies

This paper analyzes China's policy approach to renewable energies and assesses how effectively China has met the ideal of appropriate interactions between renewable energy policy and renewable energy industrial policy. First we briefly discuss the interactions between these two policies. Then we outline China's key renewable energy and renewable industrial policies and find that China's government has well recognized the need for this policy interaction. After that, we study the achievements and problems in China's wind and solar PV sector during 2005–2012 and argue that China's policy approach to renewable energies has placed priority first on developing a renewable energy manufacturing industry and only second on renewable energy itself, and it has not effectively met the ideal of appropriate interactions between renewable energy policy and renewable energy industrial policy. Lastly, we make an in-depth analysis of the three ideas underlying this policy approach, that is, the green development idea, the low-carbon leadership idea and indigenous innovation idea. We conclude that Chinas' policy approach to renewable energies needs to enhance the interactions between renewable energy policy and renewable energy industrial policy. The paper contributes to a deeper understanding of China's policy strategy toward renewable energies.     

Exergetic analysis of distillation processes—A case study

The concept of exergy has been introduced to establish a universal standard for quality and efficient use of energy. In this work, applications of this concept to compression, heat exchange, and separation processes, in addition to the computation of their irreversibility rate and thermodynamic efficiency, are considered. An industrial case study on the purification of 1,2-ethylenedichloride (EDC) in a high-purity distillation column is presented. Due to its large throughput, this distillation column consumes a large amount of thermal energy (steam to the reboiler) and in order to reduce the energy requirements without large process modifications, a new configuration using a vapour compression heat pump is proposed which yields considerable improvement in the use of energy. Both configurations were implemented using the commercial simulator Aspen Plus™; the results of the original configuration were validated with data extracted from the plant. The objective of this work was to compare the original configuration and the new proposed one, from a thermodynamic approach. Furthermore, two forms of process thermodynamic analysis based on the concept of exergy were applied to the new proposed configuration.