Linear programming models for measuring economy-wide energy efficiency performance

Data envelopment analysis (DEA) has recently gained popularity in energy efficiency analysis. A common feature of the previously proposed DEA models for measuring energy efficiency performance is that they treat energy consumption as an input within a production framework without considering undesirable outputs. However, energy use results in the generation of undesirable outputs as by-products of producing desirable outputs. Within a joint production framework of both desirable and undesirable outputs, this paper presents several DEA-type linear programming models for measuring economy-wide energy efficiency performance. In addition to considering undesirable outputs, our models treat different energy sources as different inputs so that changes in energy mix could be accounted for in evaluating energy efficiency. The proposed models are applied to measure the energy efficiency performances of 21 OECD countries and the results obtained are presented.     

Benchmarking the energy performance for cooling purposes in buildings using a novel index-total performance of energy for cooling purposes

Benchmarking the energy performance for cooling purposes in buildings is an important tool for energy management. This paper proposes a novel index and develops a benchmarking process for energy performance for cooling purposes by means of data envelopment analysis and cooling degree hour method. The research begins by using climate data to calculate cooling degree hour and proceeds to build an index of total performance of energy for cooling purposes by linear regression method. Finally, data envelopment analysis is adopted to benchmark the energy performance for cooling purposes in buildings with the index of total performance of energy for cooling that has the effect of ventilation factors (floor area and number of occupants) removed. An application to office buildings in Taiwan is presented to illustrate the development and the use of the evaluating method.     

Challenges to a climate stabilizing energy future

The paper surveys the major challenges to stabilizing the atmospheric CO₂ concentration. Climate change, and policies to deal with it, is viewed as an energy problem. The energy problem stems from the fact that no combination of carbon-free energies is currently capable of displacing fossil fuels as the main sources of the world's base load energy requirements. The paper provides rough estimates of the amount of carbon-free energy required to stabilize climate, the potential contribution of “conventional” carbon-free energies, the contribution of renewable energies, and the size of an “advanced energy technology gap”. The findings indicate that stabilizing CO₂ concentration will require a long-term commitment to research, develop, and eventually deploy new energy sources and technologies including hydrogen. The paper suggests that the role of technology is what makes stabilizing CO₂ concentration economically feasible. In this respect energy technology and economics are complementary, with advances in the former requiring something more than a reliance on market-based instruments, such as carbon taxes and emission permits. The analysis has implications for the credibility of commitments to target climate change-related factors such as CO₂ emissions.     

Does environmental regulation affect energy efficiency in China's thermal power generation? Empirical evidence from a slacks-based DEA model

Data envelopment analysis (DEA) has gained much popularity in performance measurement of power industry. This paper presents a slack-based measure approach to investigating the relationship between fossil fuel consumption and the environmental regulation of China's thermal power generation. We first calculate the total-factor energy efficiency without considering environmental constraints. An environmental performance indicator is proposed through decomposing the total-factor energy efficiency. The proposed approach is then employed to examine whether environmental regulation affects the energy efficiency of China's thermal power generation. We find that the environmental efficiency plays a significant role in affecting energy performance of China's thermal generation sector. Decreasing the discharge of major pollutants can improve both energy performance and environmental efficiency. Besides, we also have three main findings: (1) The energy efficiency and environmental efficiency were relatively low. (2) The energy and environmental efficiency scores show great variations among provinces. (3) Both energy efficiency and environmental efficiency are of obvious geographical characteristics. According to our findings, we suggest some policy implications.     

An international comparison of four polycentric approaches to climate and energy governance

Drawing from work on governance, this article explores four programs and policies that respond in some way to the challenges induced by climate change and modern energy use. Relying primarily on original data collected from research interviews and field research in seven countries along with four case studies, the article notes that polycentric approaches – those that mix scales (such as local/national or national/global), mechanisms (such as subsidies, tax credits, and mandates), and actors (such as government regulators, business stakeholders, and members of civil society) – can foster equity, inclusivity, information, accountability, organizational multiplicity, and adaptability that result in the resolution of climate and energy related problems. After explaining its case selection and research methods, defining climate and energy governance, and conceptualizing polycentrism, the study explores cases related to electricity supply in Denmark, ethanol production in Brazil, small-scale renewable energy in Bangladesh, and off-grid energy use in China. It concludes by highlighting how polycentrism may enhance effective climate and energy governance, but that further research is needed to fully substantiate that claim.     

Study on energy efficiency in corn production of Iran

The aims of this study are determining the energy use, qualitative analyzing of energy flow and also investigating energy efficiency by Data Envelopment Analysis (DEA) in corn production of Iran during a seven years period. Results indicated that the average of total energy input increased from 40.98 GJ ha⁻¹ in 2001 to 63.64 GJ ha⁻¹ in the year of 2007. Similarly, the average of total output energy rose from 89.03 to 107.54 GJ ha⁻¹ in the same years, respectively. Also the results showed that average energy use efficiency, energy productivity, specific energy and net energy gain in the studied period was 2.59, 0.17 kg MJ⁻¹, 7.24 MJ kg⁻¹ and 51.34 GJ ha⁻¹, respectively. DEA considered the yield (kg ha⁻¹) as output and three major energy inputs; fertilizers, diesel fuel and machinery as input of 10 provinces in each year. Findings revealed that average energy efficiency score was 90.26%. There is impermanent trend in growth of energy efficiency in corn production of Iran, which needed to further analysis in future studies to realize relevant fluctuations in corn farming.     

Interactions between energy security and climate change: A focus on developing countries

We briefly consider the tensions between climate change and energy security policy imperatives, and highlight some concepts that may bring additional clarity to decision-making at the nexus of the two areas. We focus on developing countries and use the case of the Medupi supercritical coal plant in South Africa. The justification for the plant's construction stemmed from an Integrated Resource Planning process informed by South Africa's national utility. Often, as in the case of South Africa, there are tensions not easily captured in quantitative algorithms between, inter alia, a lack of access to electricity by millions of people (and associated welfare losses) and greenhouse gas emissions from electricity generation. It is difficult to identify any formal processes that have prioritised climate change considerations over those of energy access. Thus, it becomes imperative to have a clear understanding of the consequences of this reality when considering power system expansion. We find that the processes often employed do not provide an entirely satisfactory precedent for future planning analyses, and the justifications do not adequately reflect the complexity of the decision space. Finally, we highlight some options by which these tools might be enhanced in areas including explicit and formal consideration of risk.     

Improving energy use efficiency of canola production using data envelopment analysis (DEA) approach

In this study energy use pattern for canola production in Golestan province of Iran was studied and the degrees of technical and scale efficiency of producers were analyzed using a non-parametric data envelopment analysis technique. The study also helped to identify the wasteful uses of energy by inefficient farmers and to suggest reasonable savings in energy uses from different inputs. Further, the effect of optimization of energy on energy ratio and energy productivity was investigated. Data used in this study were obtained from 130 randomly selected canola farms from Golestan, the most important center of canola production in Iran. The inputs were human labor, diesel, machinery, fertilizers, chemicals, water for irrigation, seeds and electrical energies; while the yield value of canola was considered as output. The results revealed that, the total energy of 17,786 MJ ha⁻¹ was consumed for canola production; about 15% of farmers were found to be technically efficient and the mean efficiency of farmers was found to be 0.74 and 0.88 under constant and variable returns to scale assumptions, respectively. The results also suggested that, on average, a potential 9.5% (1696 MJ ha⁻¹) reduction in total energy input could be achieved provided that all farmers operated efficiently.     

Designing building energy efficiency programs for greenhouse gas reductions

Costs and benefits of building energy efficiency are estimated as a means of reducing greenhouse gas emissions in Pittsburgh, PA and Austin, TX. The analysis includes electricity and natural gas consumption, covering 75% of building energy consumption in Pittsburgh and 85% in Austin. Two policy objectives were evaluated: maximize GHG reductions given initial budget constraints or maximize social savings given target GHG reductions. This approach evaluates the trade-offs between three primary and often conflicting program design parameters: initial capital constraints, social savings, and GHG reductions. Results suggest uncertainty in local stocks, demands, and efficiency significantly impacts anticipated outcomes. Annual GHG reductions of 1 ton CO₂ eq/capita/yr in Pittsburgh could cost near nothing or over $20 per capita annually. Capital-constrained policies generate slightly less social savings (a present value of a few hundred dollars per capita) than policies that maximize social savings. However, sectors and end uses targeted for intervention vary depending on policy objectives and constraints. Optimal efficiency investment strategies for some end uses vary significantly (in excess of 100%) between Pittsburgh and Austin, suggesting that resources and guidance conducted at the national scale may mislead state and local decision-makers. Results are used to provide recommendations for efficiency program administrators.     

Using principal component and cluster analysis in the heating evaluation of the school building sector

In the field of energy savings in buildings, the interest towards the school sector is deeply motivated: schools have standard energy demands and high levels of environmental comforts should be guaranteed. The University of Athens in collaboration with the School Authority of Greece undertook a complete program on energy classification and environmental quality of school buildings. Data on energy consumptions were gathered and analysed with the participation of 1100 schools from all the prefectures of Greece. The data have been provided by the school authority of the country (OSK), in collaboration with the management of each school building. With regards to the size of the building and the external climate variability (HDD-method) energy normalization techniques have been applied in order to homogenize the data set. An energy classification tool has been created through clustering techniques, using the collected data regarding the heating energy consumption and as a result five energy classes have been defined. To evaluate the potential energy conservation for each class, the typical characteristics of school buildings belonging to an energy class have to be identified. A new methodology based on the use of the principal components analysis (PCA) has been developed. The method allows to define in an accurate way the typical building of each energy class and thus to perform analysis on the potential energy savings for the specific group of school buildings. By reducing the dimensionality of the problem, a bi-dimensional graphic in the first two PCs coordinate system promotes the understanding of the correlation between the examined variables, as well as the determination of sub-groups of school buildings with similar characteristics. The typical school of seven variables sample is defined as the closest to the medians in the principal components’ coordinate system.     

Project portfolio management applied to building energy projects management system

This paper is based on the project portfolio management technology to introduce a new energy projects management system. For the increasingly complex of current Chinese energy project management, and traditional project management system not being very good for energy projects in regulated status, this thesis put forward an energy portfolio management system using energy portfolio management technology combined with the unique characteristics of energy projects, which includes from proposition of energy projects, energy projects selection and evaluation, and then to portfolio assessment and implementation of energy projects and the assessment and control of energy portfolio implementation process. Therefore, portfolio management techniques are used in energy project management and control to solve the current complex problems of energy project management, and ensure that more energy projects meet the national and enterprise strategy.     

Optimization of energy consumption for soybean production using Data Envelopment Analysis (DEA) approach

In this study a non-parametric method of Data Envelopment Analysis (DEA) is used to estimate the energy efficiencies of soybean producers based on eight energy inputs including human labor, diesel fuel, machinery, fertilizers, chemicals, water for irrigation, electricity and seed energy and single output of grain yield. The study also helps to rank efficient and inefficient farmers and to identify optimal energy requirement and wasteful uses of energy. Data were collected using face-to-face surveys from 94 farms in Golestan province which is the most important center of soybean production in Iran. Based on the results, average yield and energy consumption for soybean production were 3233.15 kg ha⁻¹ and 35372.23 MJ ha⁻¹, respectively. Also, the results of DEA application showed that, the technical, pure technical and scale efficiencies of farmers were 0.853, 0.919 and 0.926, respectively. Moreover, energy saving target ratio for soybean production was calculated as 20.12%, indicating that by following the recommendations resulted from this study, about 7116.84 MJ ha⁻¹ of total input energy could be saved while holding the constant level of soybean yield. Also, electrical energy had the highest share (78.08%) from total saving energy, followed by fertilizers (10.46%) and diesel fuel (6.18%) energy inputs.     

Nuclear power,climate change and energy security: Exploring British public attitudes

Public attitudes towards nuclear power in the UK have historically been deeply divided, but as concern about climate change and energy security has exerted an increasing influence on British energy policy, nuclear power has been reframed as a low-carbon technology. Previous research has suggested that a significant proportion of people may ‘reluctantly accept’ nuclear power as a means of addressing the greater threat of climate change. Drawing on the results of a national British survey (n=1822), the current study found that attitudes towards nuclear remain divided, with only a minority expressing unconditional acceptance. In general, people who expressed greater concern about climate change and energy security and possessed higher environmental values were less likely to favour nuclear power. However, when nuclear power was given an explicit ‘reluctant acceptance’ framing – allowing people to express their dislike for nuclear power alongside their conditional support – concerns about climate change and energy security became positive predictors of support for nuclear power. These findings suggest that concern about climate change and energy security will only increase acceptance of nuclear power under limited circumstances—specifically once other (preferred) options have been exhausted.     

The performance of industrial sector voluntary climate programs: Climate Wise and 1605(b)

Corporate voluntary climate programs have had limited evaluation. The self-selection of participants—an essential element of such initiatives—poses challenges to researchers because the decision to participate may not be random and may be correlated with outcomes. This study aims to gage the environmental effectiveness of the industrial sector elements of two early voluntary climate change programs with established track records, the U.S. Environmental Protection Agency's Climate Wise and the U.S. Department of Energy's Voluntary Reporting of Greenhouse Gases Program (1605(b)). Particular attention is paid to the participation decision and how various assumptions affect estimates of program outcomes using propensity score matching methods applied to plant-level Census data. Overall, the effects are modest: reductions in fuel and electricity expenditures are no more than 10 percent and probably less than 5 percent. Virtually no evidence suggests either program has a statistically significant effect on fuel costs. Some evidence indicates that participation in Climate Wise led to a 3–5 percent increase in electricity costs that vanished after two years. Stronger evidence suggests that participation in 1605(b) led to a 4–8 percent decrease in electricity costs that persisted for at least three years. These results suggest that while voluntary programs can play some role in addressing climate change, they are unlikely to bring about the kinds of steep reductions called for in the current debate.     

The role of nuclear energy in Lithuania under various post-Kyoto climate change mitigation regimes

The article aims to evaluate the potential role of nuclear energy in Lithuania under various post-Kyoto climate change mitigation regimes. Seeking to achieve this target the analysis of possible energy sector development scenarios in Lithuania was performed and CO₂ emission projections for these scenarios were developed. The analysis of post-Kyoto climate change mitigation architectures was performed and the requirements of these possible climate change mitigation regimes for greenhouse gas (GHG) emission reduction in Lithuania were assessed. Based on these assessments the potential role of new nuclear power in Lithuania was identified under various future climate change mitigation regimes.     

An integrated assessment of climate change,air pollution,and energy security policy

This article presents an integrated assessment of climate change, air pollution, and energy security policy. Basis of our analysis is the MERGE model, designed to study the interaction between the global economy, energy use, and the impacts of climate change. For our purposes we expanded MERGE with expressions that quantify damages incurred to regional economies as a result of air pollution and lack of energy security. One of the main findings of our cost–benefit analysis is that energy security policy alone does not decrease the use of oil: global oil consumption is only delayed by several decades and oil reserves are still practically depleted before the end of the 21st century. If, on the other hand, energy security policy is integrated with optimal climate change and air pollution policy, the world’s oil reserves will not be depleted, at least not before our modeling horizon well into the 22nd century: total cumulative demand for oil decreases by about 24%. More generally, we demonstrate that there are multiple other benefits of combining climate change, air pollution, and energy security policies and exploiting the possible synergies between them. These benefits can be large: for Europe the achievable CO₂ emission abatement and oil consumption reduction levels are significantly deeper for integrated policy than when a strategy is adopted in which one of the three policies is omitted. Integrated optimal energy policy can reduce the number of premature deaths from air pollution by about 14,000 annually in Europe and over 3 million per year globally, by lowering the chronic exposure to ambient particulate matter. Only the optimal strategy combining the three types of energy policy can constrain the global average atmospheric temperature increase to a limit of 3 °C with respect to the pre-industrial level.     

An analysis of future building energy use in subtropical Hong Kong

Principal component analysis of prevailing weather conditions in subtropical Hong Kong was conducted, and a new climatic index Z (as a function of the dry-bulb temperature, wet-bulb temperature and global solar radiation) determined for past (1979–2008, measurements made at local meteorological station) and future (2009–2100, predictions from general circulation models) years. Multi-year (1979–2008) building energy simulations were carried out for a generic office building. It was found that Z exhibited monthly and seasonal variations similar to the simulated cooling/heating loads and building energy use. Regression models were developed to correlate the simulated monthly building cooling loads and total energy use with the corresponding Z. Error analysis indicated that annual building energy use from the regression models were very close to the simulated values; the difference was about 1%. Difference in individual monthly cooling load and energy use, however, could be up to 4%. It was also found that both the DOE-simulated results during 1979–2008 and the regression-predicted data during 2009–2100 indicated an increasing trend in annual cooling load and energy use and a gradual reduction in the already insignificant heating requirement in cooling-dominated office buildings in subtropical climates.     

Energy performance of building envelopes in different climate zones in China

Energy performance of office building envelope designs in the five major climate zones – severe cold, cold, hot summer and cold winter, mild, and hot summer and warm winter – in China was investigated. A major city within each climate zone was selected. These were Harbin, Beijing, Shanghai, Kunming and Hong Kong. Generic building envelopes were developed based on data gathered from building surveys, local energy codes and the ASHRAE Standard. The overall thermal transfer value (OTTV) method and the heating degree-days technique were adopted in the analysis. Cooling and heating requirements due to heat gain/loss through the building envelopes were determined based on the respective OTTV parameters and building load coefficients. Different shape coefficients were also considered. For a typical floor, chiller load due to heat gain through the building envelope varied from 1.0 kW h/m² in Kunming to 23.5 kW h/m² in Beijing, and the heating load ranged from 2.7 kW h/m² in Hong Kong to 124.3 kW h/m² in Harbin.     

Effects of climate and energy policy related measures and targets on the future structure of the European energy system in 2020 and beyond

Stabilising the concentration of CO₂ in the atmosphere at a level of 450 ppm in order to keep global temperature increase below 2 °C requires an ambitious climate policy. This study analyses the role of different technologies in the EU-27 with regard to efficiency improvements, fuel switching and energy saving measures under such a climate policy target. The analysis is carried out using the regionalised Pan-European TIMES energy system model, a technology oriented, linear optimisation model. Thereby limited resources and import potentials of various energy carriers, competition among different sectors and the country-specific differences in energy demand are taken into account. As a result, it turns out that the structure of energy use inside the EU-27 is much stronger, influenced by political targets and positions regarding climate protection, energy security and the use of nuclear energy than by available technologies. In the case of climate protection polices and limited use of nuclear energy, the most important measures for the reduction of greenhouse gases are an increased use of renewables, carbon capture and storage, fuel switching and the intensified application of electricity in the end use sectors. Efficiency improvements play an additional role when security of supply is taken into account.