# Energy Efficiency

Online ISSN: 1570-6478
Print ISSN: 1570-646X
Recent publications
The Belt and Road Initiative (BRI) countries are mainly developing countries with severe energy poverty. This study combines the entropy weight and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method to measure energy poverty at the household, enterprise, and national levels in 82 BRI countries. This study aims to investigate and discuss how to encourage BRI countries to develop effective decision-making mechanisms for developing more targeted supply-side solutions to domestic energy poverty. A geographic information system (GIS) is also used to construct spatial distribution maps to assess energy poverty. The findings show that countries in South Asia, Southeast Asia, and North Africa have the highest levels of energy poverty, while countries in West Asia and Europe have the lowest. East Timor, Tonga, and Equatorial Guinea are of the most extremely lowest. The assessment methodology used in this paper focuses not only on the energy poverty faced by households, but also on the overall energy supply and service situation at the enterprise and national levels. These perspectives are likely to influence policy making and help the governments in addressing domestic energy poverty more effectively from the supply side.

Air pollution in the aviation industry is becoming increasingly severe worldwide, along with rapid economic development. Therefore, it is significant to pay close attention to airlines worldwide. Usually, the airlines contain passenger transportation and freight transportation on the operating move. This paper proposes a parallel range adjusted measure (PRAM) to comprehensively measure and evaluate the environmental efficiency of 18 airlines from 2014 to 2019. Different from existing models, the model can handle shared inputs, shared desirable outputs, and shared undesirable outputs simultaneously. We build a shared resource decomposition procedure to perform a comparative analysis of the highest subsystem efficiency, and the sensitivity analysis proves the validity of the results. The main findings are as follows: 1. The optimal efficiency can be achieved by most of the 18 airlines when sharing resources; 2. Operating costs in the freight system should be increased to achieve optimal efficiency; 3. Asian airlines show higher efficiency than the airlines in Europe.

Since the government implemented the supply-side structural reform, the growth of electricity consumption in energy-intensive manufacturing industries has been contained in an all-round way, which poses greater challenges to overcapacity in the power sector. It is still a mystery that how to restrain the electricity consumption of energy-intensive manufacturing industry affects the installed capacity of power generation. Thereupon, this paper empirically studies the relationship between electricity consumption of the six energy-intensive manufacturing subsectors and provincial power generation capacity. The empirical results with line loss rate as instrumental variables indicate that the electricity consumption of the six energy-intensive manufacturing subsectors will increase or decrease the installed capacity of power generation by a one-to-one elastic coefficient. In terms of manufacturing subsectors, the power sector’s own electricity consumption has the highest capacity enhancement effect, followed by non-metallic minerals and chemical raw materials manufacturing subsectors. The resolution of overcapacity for power generation is fundamentally to reduce the electricity consumption intensity of the six high-energy-consuming manufacturing subsectors.

The progress in achieving targets for energy efficiency (EE) and renewable energy sources (RES) is hindered by a set of barriers linked with the end-users (social, educational, cultural, economic, and institutional), but previously, the effect of these barriers was only rarely quantified and no comprehensive methodology to do so is available. This paper, through a step-by-step methodology, examines the development of scenarios for the Bulgarian residential sector until 2030, focusing on the combination of available – for this sector – EE and RES technologies, after incorporating these barriers with the use of the HERON Decision Support Tool (HERON-DST). Two more research tools are used, LEAP (modeling tool) and AMS (multi-criteria evaluation method). Six different scenarios, three of which address barriers, were developed for LEAP. All scenarios are evaluated with the AMS method against a set of criteria/sub-criteria regarding their overall performance under the particular national framework. This results in the identification of the most appropriate (EE/RES) scenario for the country, i.e., addresses behavioral barriers and performs better (one with the highest AMS score) than the others under the particular national framework. This scenario promotes building shell improvement, efficient heating, and cooling in the Bulgarian residential sector. Its policy mixture mainly through financial incentives and more demanding building codes handles social, institutional, and economic barriers linked with end-users behavior. Conclusions concern the methodology, its outcomes, and future use.

In the recent times, a severe drop in the environmental quality has been reported due the increase usage of energy for industrial and household purposes. Such environmental degradation is the cause of climate change and global warming. The competition for achieving higher economic growth in emerging economies further promote the use of traditional fossil fuel consumption, where the scholars and policy-makers addressed the importance of energy productivity. This study aims to examine the factors affecting energy productivity in emerging seven economies over the period 2004–2020. Accordingly, this study considers the role financial inclusion, economic growth, globalization, human capital, and composite risk index on energy productivity. Using the second-generation unit root technique, that accommodate the persistent issues of slope heterogeneity and cross-section dependence, that variables are stationary. Also, the long-run cointegration connection exist between these variables. Due to the asymmetrical data distribution, this study uses the unique method of moment quantile regression (MMQR). The results reveal that financial inclusion, economic growth, globalization, human capital, and composite risk are the significant factors of energy productivity in all the quantile (Q0.25, Q0.50, Q0.75, and Q0.90). This study also analyzes the robustness of the model vial Granger causality test. The results verified the robustness by indicating the unidirectional as well as bidirectional causal association between the study variables. This study concludes that policies should consider improved financial inclusion, globalization, and human capital by reducing composite risk.

This study focuses on energy efficiency inequality in the United States. It examines the extent to which class, race, and gender, which have been shown to be key determinants of inequality in other areas, are related to energy efficiency inequality, measured by energy use intensity (EUI). Regression-based analysis of longitudinal data assembled from three waves of the Residential Energy Consumption Survey (2005, 2009, 2015), indeed, shows significant relationships between these variables and EUI in the residential sector. The results show that disadvantage in terms of EUI disparities in the African American community is differentiated by gender and class. Specifically, they show that while female-headed African American households fare worse than White households in terms of electricity EUI, male-headed African American households actually fare better. The relationship between being an African American household and residential EUI is conditioned by income: as incomes rise, EUI for housing units occupied by African American households decreases. This study underscores the importance of considering the joint influence of class, race, and gender when analyzing residential energy inequality, burdens, or insecurity.

Efficient energy use in industry is an important issue capable of reducing the overall energy consumption. Large enterprises in the European Union countries are obliged to conduct regular energy audits or implement energy management systems, while for small and medium enterprises, energy audits are voluntary. However, governments implementing their energy and environmental policy goals support energy audits in small and medium enterprises through national support programs. Another driving factor is compulsory energy audit for companies seeking financial support for their modernization and implementation of renewable energy projects. The article presents an overview of findings from energy audits of 18 small and medium enterprises in Lithuania, starting with energy management and accounting issues and their energy consumption profiles, followed by proposed energy-saving measures, estimated energy savings, and avoided greenhouse gas emissions. Buildings, technological processes, and transport are the main energy consumption sectors in audited companies. The relatively short pay-off time required by industrial small and medium enterprises limits the amount of investment and achievable energy savings. Audit recommendations containing opportunities to introduce renewable energy installations expand the environmental benefits of auditing. The cost of energy savings resulted from recommended energy efficiency measures compared with energy prices and availability of resources is one of the strongest economic arguments for accepting audit recommendations.

We estimate the magnitude of the direct rebound effect (DRE) of households’ electricity consumption in Spain, through an econometric estimation method of panel data. The results indicate a DRE between 26 and 35% in the short run and around 36% in the long run. Moreover, we find a significant influence of other energy sources that appear to be complementary to electricity consumption according to our estimation. Hence, our results suggest that an improvement in the energy efficiency of an energy service may affect its own energy consumption as well as the energy consumption of other energy services. This would entail a new source of DRE.

The COVID-19 pandemic has affected the global economy to varying degrees. Coupled with the widening gap caused by the unbalanced distribution of resources, the sustainability and inclusiveness of economic growth have been challenged. To explore the influencing factors of the level of economic inclusive growth among different countries, we used the spatial Durbin model to analyze the relationship between financial inclusion, renewable energy consumption, and inclusive growth based on panel data of 40 countries from 2010 to 2020. The results indicate a spatial autocorrelation in inclusive growth; financial inclusion and renewable energy consumption both contributed positively to inclusive growth, while industrial structure upgrading played a negative moderating role between domestic renewable energy consumption and inclusive growth. The results of this study provide insights into achieving better inclusive growth and maintaining sustainable and balanced economic development. Based on this, policy recommendations such as expanding the coverage of inclusive finance, optimizing the energy structure, and changing the economic development model are put forward.

Energy Efficiency First (EEF) is an established principle for European Union (EU) energy policy design. It highlights the exploitation of demand-side resources and prioritizes cost-effective options from the demand-side over other options from a societal cost-benefit perspective. However, the involvement of multiple decision-makers makes it difficult to implement. Therefore, we propose a flexible decision-tree framework for applying the EEF principle based on a review of relevant areas and examples. In summary, this paper contributes to applying the EEF principle by defining and distinguishing different types of cases — (1) policy-making, and (2) system planning and investment — identifying the most common elements, and proposing a decision-tree framework that can be flexibly constructed based on the elements for different cases. Finally, we exemplify the application of this framework with two example cases: (1) planning for demand-response in the power sector, and (2) planning for a district heating system.

The Energy Efficiency First (EE1st) principle has recently been placed onto the political agenda in the European Union (EU). While the general rationale for EE1st is described in EU legislation and supporting literature, a common understanding of the principle’s implications for energy-related planning, investment, and policymaking is still missing. Based on an exploratory review of the literature, the objective of this article is to improve the theoretical understanding of EE1st. First, it develops a conceptual framework, describing EE1st as a decision-making principle that prioritises demand-side resources over supply-side alternatives whenever these provide greater value to society in meeting decision objectives. Second, it highlights the unique aspects of EE1st by systematically comparing the principle with associated concepts, such as Integrated Resource Planning. Third, it provides theoretical justification for EE1st by describing the economic rationale behind the principle. Fourth, it outlines policy considerations for its practical implementation. In sum, the EE1st principle is shown to have a compelling theoretical background that can help inform the design of effective policy interventions in order to move from principle to practice.

as well as the significant effect of perceived behavior control, moral responsibility, and intention on house-hold's energy-saving behavior. This study also evi-dences the significant mediating and moderating role of households' intention to save energy and moral responsibility. This study's model explains 70.5% of variations in households' intention to save energy and 63.1% of variations in households' energy-saving behavior. In particular, the extended model explains 11.6% more of the variation in households' intention to save energy compared to the TPB model. This research has several theoretical and practical implications for scholars, environmental protection agencies, and policy-makers. Keywords Theory of planned behavior · Energy-saving behavior · Energy consumption · Households

Energy is one of the primary inputs in textile and garment processing industries and its cost share is reported between 5 and 10% of the total production cost in developed countries but is far higher in developing countries. The textile and garment sector is one of the fast growing economic sectors in developing nations like Ethiopia which have very limited scientific data particularly in the industries where there is no clear and concise information about the energy consumption pattern as well as the energy conservation practices. Thus, the main purpose of this study was to understand the energy usage pattern and conservation practices and to recommend evidence-based conservation measures and policy directions. The aim of this comprehensive study was therefore to conduct a detailed energy audit in the MAA garment and textile industry, in the town of Mekelle, at the northern part of Ethiopia, to analyze the major energy-consuming areas and implementation of evidence-based energy conservation solutions. This was achieved through primary and secondary data collected from the company. Accordingly, a total of 15 energy conservation recommendation was identified and proposed for possible implementation that have the potential to save a total cost of around $214,600 per year but requires nearly$98,300 investment leading to a payback period of 7 months. These recommendations include in the utilities of boiler, thermic fluid heater, air compressors, and lightings. In addition, key policy directions are recommended to support the sectors to reduce their energy consumption.

Buildings and construction are responsible for about 40% of the energy and process-related CO 2 emissions worldwide. At present, the renewal rate of building stock is relatively low, for example in Finland, which is the case under study in this work, it is 1.5% per year. With respect to the target of a carbon neutral world by 2050, the effect on emissions of existing building stock must be considered. In this paper, we present the results of analysis of energy efficiency improvement investment in 12 city-owned buildings in two Finnish cities. Using measured heat and electrical energy consumption data, a model was developed for analyzing the impact of active and passive energy efficiency improvement investment options per building. The examined active technologies were heat pumps, solar photovoltaic panels, and heat recovery in ventilation system, and the passive improvement compared was structural improvements in the building envelope. The results show that investments in energy efficiency improvements can reduce the yearly energy-related operating costs of the buildings by 35% on average. The study further finds that usually investment in active energy efficiency improvements provides a bigger return on investment than passive improvements. The profitability of examined measures makes Public–Private Partnership a feasible way to provide funding for renovation of public buildings. Graphical abstract

Urban areas’ energy consumption accounts for almost three fourths the global energy use with 70% of the related emissions. Therefore, cities play a meaningful role in decoupling economic growth from greenhouse gases (GHGs) emissions. This study presents a system dynamic approach to model the energy efficiency impact on the Togolese capital city’s residential electricity consumption and carbon dioxide emissions reduction. The time spans from 2000 to 2050. An assessment of household appliances, such as lighting, refrigeration, cooling, and ventilation, was conducted along with monitoring electricity consumption of used and newly bought televisions, refrigerators, and freezers. Then, using Stella software, Lomé’s residential electricity consumption model was built based on the following variables: (1) population, (2) the number of existing households with access to electricity, (3) new homes having access to electricity, and (4) per capita electricity consumption. The model was calibrated and validated using data for the years 2000 to 2016. Afterward, this previous knowledge was used to evaluate three efficient energy policies: 1) business-as-usual scenario, 2) new policies scenario, and 3) sensitivity scenario. Lomé’s households present a predominantly low efficient appliances percentage. Therefore, the study found that substituting inefficient electric appliances with new and efficient models can lead Togo to substantial energy savings and reduce CO2 emissions of about 680 GWh and 350 kt in the horizon of 2050, respectively. Additionally, the findings of this study could stimulate policymakers to audit other sectors to implement related energy efficiency policies and/or set up corresponding energy management strategies in neighboring emerging countries.

Energy efficiency, coupled with distributed renewable generation, is not only relevant to decrease the energy consumption and environmental emissions, but is also a large opportunity in terms of job creation and development of new business areas that stimulate investment (foreign and national). Moreover, energy efficiency and off-grid systems are a cost-effective strategy for a fast increase the number of people with energy access, as well as a way to fulfil the United Nations Sustainable Development Goals no. 7 by 2030. In Mozambique, in 2020, despite the significant efforts made by national authorities, only 32% of the inhabitants have access to electricity services. This paper presents an overview on the Mozambique electricity sector (grid-connected and off-grid) and how electric mobility, digitalization and energy efficiency may help the country to increase its electricity access rate. A characterization of Mozambique renewable energy potential per energy source, as well as the energy-efficient technology options in each sector, is carried out. Additionally, several key actions to improve energy access and to promote energy efficiency in Mozambique are also addressed. A variety of projects and key actions, addressing both the supply side and the demand side, is presented within this paper, supported by tailored policies and programs.

China has gradually strengthened its carbon-reduction policies and measures in recent years. However, the impact of China’s carbon policy on regional industrial competitiveness has received little attention. This paper proposed a method for calculating the intensity of carbon-reduction policies, and empirically analyzed the impact of China’s carbon-reduction policy on provincial industrial competitiveness by using a panel regression model, and compared differences carbon policy impacting on competitiveness in three regions (East, Central, and West China) as well as four types of industry. Overall, the findings revealed that China’s carbon-reduction policy harmed provincial industrial competitiveness (PIC). The carbon emission trading policy had a generally positive impact on PIC. The negative effect of carbon-reduction policies on industrial competitiveness in the eastern regions was relatively significant, while relatively minor in the central regions. The positive impact of the carbon emission trading policy on the industrial competitiveness of eastern regions was rather substantial, while it was relatively small in the western areas. The carbon-reduction policy harmed the provincial competitiveness of extractive industries, low-energy-consuming industries, and high-tech manufacturing industries. However, there was no discernible impact on high-energy-consuming industries. Finally, the carbon trading policy improved the provincial competitiveness of high energy-consuming industries. This research can aid in the optimization of China’s carbon-reduction policy, as well as the coordination of provincial industrial development and the balance of different industrial development strategies.

On the path of seeking sustainable development, ecological decoupling is usually selected to measure the achievements of climate governance. Based on the theoretical assumption arising from solution to endogenous growth model and using the panel data of 50 countries during the period of 2004–2016, this paper establishes a threshold model to quantify effects of industrial structure, income, urbanization, and other production factors on decoupling of economic growth from energy consumption (decoupling) under the constraint of technological level. The results show that there is strong decoupling in developed countries, while weak and even coupling in developing countries. The impact of industrial structure and income on decoupling has changed in direction and is characterized by inverted U-shaped curve under a single technology threshold. In the low-tech regime, income and industry structure deepen decoupling, while it weaken in the high-tech regime. The substitution effect from renewable energy rather than production factors is conducive to decoupling, not restricted by the technological level. The robust driving force of urbanization on decoupling strengthens with technological progress. Deepening decoupling should be devoted to exploring the potential of driving factors and refraining from the dragging effects of resisting force.

Home energy retrofit has recurred in public policy throughout recent decades. However, the savings in energy usage attributable to home retrofit have remained difficult to accurately predict. Occupants cause prediction inaccuracies by varying different factors, especially heating setpoints temperatures and heating patterns. Acting together, such occupant factors result in distributions - not single values - of heat-energy usage, even among similar homes. Datasets of heat-energy distributions can be found by building performance simulation using modern grey-box models. This study presents a methodology to simulate grey-box models of home heating through ranges of heating setpoints and patterns. An entire process to calibrate, validate and simulate at a large scale is described, and then demonstrated using case studies. Grey-box models, written in Modelica language, can conveniently simulate through large ranges of occupant factors. The case studies exploited this advantage of grey-box models to simulate empirical data on occupant factors. (For instance, empirical data found that home heating setpoints shifted before and after home energy retrofit.) In doing so, the datasets of simulation results enabled the exploration of home heat-energy usage with the normal and Weibull statistical distributions. Additionally, the heat-energy distributions of case-study homes were statistically tested, first for retrofit savings, second for equality to each other and third for equality to an official heat-energy estimate. Results demonstrate that home heat-energy usage, at a large scale, is best expressed as a Weibull distribution not normality. After home energy retrofit, heat-energy usage displays less variation (in general), less skewness, and thus becomes closer to normality. Occupant factors were found to vary home heat-energy usage into distinct distributions, even within similar homes. Therefore, in most case-study homes, heat-energy usage did not equal an official estimate. Finally, shallow retrofit of a modern home in Ireland fails to save heat-energy usage by most occupants. Supplementary information: The online version contains supplementary material available at 10.1007/s12053-022-10038-9.

In order to support European-wide transition of heating systems, it is useful to categorise the types of transitions that are necessary. Coherent actions are needed at (supra-)national level to support transition aligned with the energy efficiency first principle and long-term development of a smart energy system. Owing to the decentralised nature of heating, transition must also reflect particular local circumstances. This article uses commonalities between countries to create a representative typology, which can suggest appropriate policies for transition. Following the energy efficiency first principle, transition should include supply-side and demand-side efficiency to ensure coherency and efficient use of resources. Their comparative analysis supports implementing the energy efficiency first principle locally, and a more coherent European strategy for the heating sector. Methodologically, 14 national heating strategies are considered which include current and future energy system developments, demand- and supply side energy efficiency, hectare-level thermal mapping and energy system analysis. Four heat sector types are proposed and discussed. These are (1) extant heat planning traditions, aiming for more efficiency and integration; (2) extant heating infrastructure, aiming to refurbish and upgrade both building stock and existing heating infrastructure; (3) existing gas infrastructure, requiring radical transition; (4) and those without strong historic heat planning traditions.

Abstract Past research has focused on either environmental or energy efficiency analyses but has not looked at combining energy and environmental policies. By combining energy economy governance and government environmental policies, this study developed a modified EBM (Epsilon-Based Measure) two-stage network DEA model to analyze the economic, environmental, and governance efficiencies in various provinces in China. The first stage produces the undesirable output, and links to the second stage remove the undesirable output. It was found that the production stage was more efficient than the treatment stage in most provinces, the provinces in China are with an obvious efficiency gap in the governance treatment stage, especially the provinces of inner China. Even though the efficiency of the governance treatment stage still performed poorly with much room for improvement. However, through the efforts of local governments in air pollution control and treatment expenditure investment, the air pollution situation such as SO2 and NO2 emissions has been continuously and effectively removed and improved. The government environmental policy was improving CO2 reduction governance efficiencies varied across the provinces, and the governance efficiencies in most provinces were low but improving.

The building sector uses a large amount of energy among all end-use sectors. This sector consumes approximately 34% of Iran’s total energy. Environmental, technical, economic, social, and legal obstacles are the main energy efficiency barriers in buildings. Economic aspects have a more significant impact than others do. This paper identifies the main financial barriers to residential buildings’ energy efficiency in Iran through interviews, questionnaires, and factor analysis. Semi-structured interviews were conducted with energy efficiency professionals. Buildings’ service engineers, project managers, architects, and facility managers completed questionnaires. The results indicate that misplaced incentives, unpriced costs and benefits, fear of hidden costs, controversial evaluation methods, distortionary fiscal and regulatory policies, focus on initial costs, and mistaken beliefs in energy efficiency are the main perspectives on financial barriers to residential buildings’ energy efficiency in Iran. Regulation, loan financing and project financing, grants and subsidies, fiscal incentives, creating real fossil fuel prices, and training and information programs are recommendations to overcome these barriers. Adapting these perspectives with corresponding strategies indicates that the human decision-making for investment in energy efficiency measures is the most critical issue for policymakers. The findings provide a helpful reference for Iranian policymakers to understand current barriers to energy-efficient buildings and develop new policies to overcome these barriers. The results also provide a valuable reference for other countries.

To track the driving forces of rebound effects, the household electricity consumption of air conditioner (AC) was decomposed into the number, power size, and operating hours of AC. A set of regression models was built to find the influence pathways of increasing electricity consumption. Then, a two-stage decision-making process of AC purchase was studied to find the target customers of energy-efficient AC, using the joint estimation of logistic and zero-truncated negative binomial regression models. Data of 371 households in Hsinchu County in Taiwan were used based on the questionnaire survey of the household energy consumption behavior in 2018. Estimated results indicated that households having energy-efficient AC tend to install larger-power size ones causing the electricity consumption of AC to increase. Oversized AC was the main driving force of rebound effects. Contrarily, the using time of AC was not the key influence factor on electricity consumption. Estimated results also indicated that households living in urban apartments, especially for those with large floor area, would have higher probability of choosing energy-efficient AC and would install a greater number of that.

Assuming that economic policy uncertainty (EPU) can significantly affect economic activities, the paper explored the nature of its effect on energy consumption in G7 countries (Canada, France, Germany, Italy, Japan, the UK, and the USA) over the period 1997–2019 using a panel nonlinear autoregressive distributed lag model. The presence of an asymmetric effect of EPU on energy consumption was tested by decomposing EPU into negative and positive changes and placing it in a multivariate setting. The results reveal that the asymmetric effect of EPU on energy consumption is limited to the short run. However, if energy policy fails to manage uncertainty, it could become significant in the long run. Energy consumption is statistically significantly affected by economic institutions and income in both the short and the long run. Higher real income per capita boosts energy consumption in the short run, but like energy technology innovation, it reduces energy consumption in the long run. In contrast, more economic freedom, which was used as a proxy for institutions, increases energy consumption regardless of the time frame. The results point to the energy policy challenges associated with energy consumption and sustainable energy practices.

In the USA and the European Union, buildings account for more than 40% of total energy use and a large proportion of buildings are energy inefficient. Countries address these inefficiency challenges with various initiatives and strategies. One of them relies on rating buildings with energy performance certificates, with the goal that awareness on energy consumption would lead to an efficient retrofit. In this article, we analyze the different methods chosen by the USA and France to rate multifamily buildings, i.e., the Energy Star score and the Diagnostic de Performance Energétique. We conduct a case study of a multifamily housing using a Design of Experiments to determine what inputs are the most influent on the output. In the French certificate, the results show that the climate, ventilation system, and building envelope are the most influent inputs on the energy consumption. In the USA certificate, the actual energy consumption and the climate are the most influent factors on the building score. We then discuss the significant differences in the two approaches, and the consequences in terms of accuracy, as well as how the DPE and ES scores are used as a tool in public energy policy to propose energy conservation measures and reduce energy consumption.

Smart city projects explore solutions to improve the sustainability of urban infrastructure. In Kalasatama, a new smart city district being built in Helsinki, a solution to excite the availability of electric demand management and other energy-related services for residents is being tested. The city has made installing a specified minimum set of home automation devices obligatory in each apartment in the district, with the intention that entrepreneurial companies would start to offer energy management solutions based on that automation. This case study examines the utilisation of home automation in energy management at a point in time when approximately one-third of the dwellings in the smart city district are complete. According to the results of the study, companies developing and building apartments in the area of Kalasatama do not seem to find the regulation concerning home automation to be directly beneficial. Also, the availability of energy management services, based on the home automation solution, seems to remain low for the residents of the district. Based on these findings, we propose that similar smart city projects should be subject to a wider dialogue between policymakers and prospective market participants in the project conceptualisation phase.

To explore the influence of natural gas price on the green efficiency of natural gas in China, this paper first assesses the levels of green efficiency of natural gas in 30 provinces. Then, we employ the panel data of 30 provinces from 2006 to 2017 to explore the nexus by employing the S-GMM method. We also investigate the regional heterogeneity, asymmetry, and mediating mechanism. The major conclusions are highlighted as follows: (1) the green efficiency of natural gas in China has increased remarkably and now shows significant differences among provinces; (2) the increase in the natural gas price can be positively related to the green efficiency of natural gas in China, a result that is robust in the robustness tests; (3) asymmetry and regional heterogeneity exist among the nexus between price and the green efficiency of natural gas, specifically, regions with lower economic development and lower green efficiency equip a higher coefficient of price; and (4) the gas price can promote the green efficiency of gas indirectly through the consumption effect and green technology effect. Several policy implications are presented in this study to improve the green efficiency of natural gas and achieve sustainable growth in China.

The challenges currently facing the EU in the energy sector include increasing import dependence, limited diversification, high and volatile energy prices, decarbonization, and slow progress in energy efficiency. EU energy policy has provided a wide range of measures to achieve an integrated energy market and sustainability of the building sector. Various incentives and financial instruments have been promoted and financed by governments to help consumers in energy retrofit processes. These include direct investments and fiscal, financial, and market instruments. Public measures have been widely studied but private initiatives have not. In this study, the energy-efficiency mortgage (EEM) is investigated as a credit scheme to attract young people to a real estate market for sustainable buildings, characterized by high sale prices. A choice experiment (CE) was modelled to investigate the preferences of potential young buyers of a new home. The results of this exploratory survey showed an appreciation of the purchase of new A-rated properties according to the Energy Performance Certificate, compared to those that need to be retrofitted or not retrofitted. Consumers like the option of a home energy efficiency renovation being fully managed by a third party (i.e., following the one-stop shop model). The key appeal of energy efficiency for consumers ranges from its ability to support better energy management, to better property value management. The EEM seems to be a promising tool to stimulate investments in energy efficiency and to promote the accessibility and affordability of housing in the sustainable housing market. The results of this study can help private financial institutions to propose appropriate credit plans, which limit the risk of default by the borrower. They can also help public incentive policymakers to propose complementary instruments to EEM.

About 70 years have passed since highly energy-efficient heat pump water heaters (HPWHs) were introduced to the US market, having come to Europe even earlier. Market adoption has been promoted through extensive if not coordinated publicly sponsored R&D, demonstrations, energy-performance ratings, tax credits, utility rebates, regional initiatives, mandatory standards, whole-building electrification initiatives, and extensive advocacy. Despite being cost-effective in most applications, the result has fallen far short of expectations, with HPWHs reaching only 1% of overall residential water heater sales, corresponding to 104,000 units sold into a total market of about nine million units in 2020, while still virtually unknown in commercial and industrial settings. There is evidence that premature commercialization resulted in market-spoiling that avoidably dampened consumer demand, even as the technology improved. US consumers have also faced a “boom-and-bust” environment—evidenced by many manufacturers entering and exiting the market. This muted progress parallels a patchwork policy landscape and a host of persistent market barriers, both real and perceived. By contrast, the relative success of residential, commercial, industrial, and municipal HPWHs in many countries across industrialized Europe, Asia, and the Middle East has been accompanied by greater public–private coordination and more effective industrial policy and incentives. Looking forward, water heaters are increasingly recognized as demand-flexible thermal “batteries” to allow more complete use of surplus renewable energy. This, together with a more focused and coherent policy strategy, may provide new opportunities in the USA for the technology to finally establish its value and make a material contribution to decarbonization.

Industry is the largest consumer of energy and CO 2 emission sector. Recognizing the heterogeneity of total factor CO 2 emission performances between various industrial sub-sectors is crucial for governments, to enable the compilation of effective industrial CO 2 emission reduction policies. To determine the CO 2 emission characteristics throughout the industry sectors, Liaoning province was selected as typical heavy industry province for analysis. Based on the input-output data of 37 industrial sub-sectors from 2003 to 2012, the industrial total factor CO 2 emission efficiencies and performances were analyzed through data envelopment analysis (DEA) and the Malmquist-Luenberger productivity index. The results show that most sub-sectors have low total factor CO 2 emission efficiencies, which indicates that it is difficult for Liaoning's industry to reduce carbon emissions. The total factor CO 2 emission performance of the overall industry declined by 1.85% per year during the study period; this decrease was mainly related to a lack in implementing technical changes. However, efficiency change showed a progressive trend. These findings indicate that to realize carbon reduction in heavy industry provinces within China, it is necessary to focus on expediting technical change. Keywords Industrial CO 2 emissions. Total factor CO 2 emission performance. Data envelopment analysis (DEA). Malmquist-Luenberger productivity index. Heavy industrial province Abbreviations DEA Data envelopment analysis ML Malmquist-Luenberger TFCEP Total factor CO 2 emission performance TC Technical change EC Efficiency change PTEC Pure technical efficiency change SEC Scale efficiency change TFCEE Total factor CO 2 emission efficiency

SMEs are considered the backbone of a nation’s economy as they contribute to exports, GDP, and employment. These firms face several challenges and aim to keep up their production targets and ensure the desired quality of products. In the process, they lose sight of energy consumption and emissions. Their electrical energy consumption is also considerable—in 2015, 13% or more (i.e., equivalent to 74 exajoules (EJ)) of the cumulative global energy demand was consumed by SMEs. Indian SMEs fail to take even simple energy-saving measures and lack effective implementation of such measures; SMEs account for almost 45% of GHG emissions annually. Previous studies have provided frameworks for implementing energy-efficient measures (EEM) and listed ways to ascertain their maturity in this regard. However, very little validation of these frameworks, reasons for low adaption of EEM, and actions required have been studied. Energy audit of an energy-intensive industry—washing units of jeans factories—revealed the areas requiring attention and the causes of high energy consumption. Interviews with operational managers and heads of units showed that they are non-adaptive to environmental requirements. A systems dynamics model was developed, and three scenarios were created to demonstrate the plausible energy savings and introduce learning among managers. The study proposes a changed KPI, the means to evaluate returns, and mental models for decision-making.

Across nations, unprecedented electricity utilisation arising partly from growing population especially in developing economies, rising environmental abuses and accelerating depletion of natural resources are increasingly challenging the existence of global family, thereby bringing to fore the need to care for and consume resource sustainably. Access to electricity is a requirement for a good standard of living. This research examines contemporary issues regarding what motivates households to consume energy sustainably using smart meter technology widely adjudged a critical tool in electricity/energy management as a proxy for sustainable electricity consumption behaviour. A sample size of 150 households was determined statistically. The questionnaire served as a data collection instrument from respondents. Snowball and judgemental sampling techniques were utilised to recruit participants from undermetred semi-urban areas in Southeastern Nigeria. The structural equation modelling technique was applied to analyse the dataset with the aid of SmartPLS software. The findings indicate that attitude, subjective norms and perceived behavioural control signifcantly influence behavioural intentions; however, the direct influence of perceived behavioural control on sustainable energy consumption behaviour was not supported. Furthermore, behavioural intention correlates signifcantly with sustainable energy consumption behaviour. Potential implications of the findings to policy and practice were pointed out.

The thermal performance of two geothermal earth-to-air heat exchangers (EAHEs) installed at the guest apartment building of the Universidad de Quintana Roo was analyzed. Both EAHEs are composed of 6-m-long, 0.1524-m-diameter polyvinyl chloride pipes buried 1 and 2 m deep. To reduce either heat gain or loss at the EAHE outlet, this section of the pipe was thermally isulated with a 0.0508-m layer of polyurethane foam. Thermocouples were placed at the inlet and the outlet of each EAHE to measure the corresponding temperatures. The EAHE has been tested under the climatic conditions of Chetumal, Quintana Roo, Mexico, where the climate is mild in the months of December to February and warm the rest of year. The experimental work was conducted in January and August, the coldest and warmest months. The results show that for the warmest month, the use of EAHE is advantageous during the day because the output temperature is reduced up to 4∘\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{\circ }$$\end{document}C. In addition, it has been found that the EAHE inlet air temperature is lower than that of the outlet at night, indicating an undesired effect. Thus, use of the EAHE is encouraged only in the daytime during summer in Chetumal, Quintana Roo. On the other hand, for the coldest month, the EAHE helps to raise the temperature up to 5 ∘\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{\circ }$$\end{document}C to improve comfort at night.

International sustainability ranking systems generally set criteria in order to monitor global achievement of universities in terms of sustainability. However, current sustainability ranking systems do not provide specific consumption thresholds according to the different buildings’ function or characteristic and the comparison among universities lacks of precise criteria. Thus, this paper proposes different energy clusters enabling a meaningful comparison among campuses within the international rankings. Energy profiles of two university campuses—Politecnico di Torino (Italy) and Hokkaido University (Japan)—similar for climate, surface, and population have been collected for 4 years as a relevant case study. Five different clusters of homogeneous consumption have been identified: cluster 1 (around 1 GJ/m ² /year) includes the Art departments, cluster 2 (2 GJ/m ² /year) includes the Science faculties, cluster 3 (3 GJ/m ² /year) includes the hospital and the medicine departments, cluster 4 includes the Data Centre (9 GJ/m ² /year), and cluster 5 includes special research facilities with consumption over 10 GJ/m ² /year. Findings show how comparisons between different buildings should also take into account the electrification rate (dependence on electricity) and the leveling rate (variation of consumption during a year), which variations are directly related to the main building function (e.g., hospitals/data centers have high values, while arts or humanities departments have low values for both rates). The proposed energy cluster approach and the introduction of proper weights for energy performances based on the proposed clusters can significantly enhance the accountability and comparability of different campuses’ energy profiles, contributing to a better evaluation of universities’ energy performances.

The goal of this paper is to analyze the equilibrium of the Italian market of white certificates (WC) during the 2006–2021 period by relying upon granular data of prices, traded volumes, demand, supply, and information on regulatory interventions. It emerges that market forces, represented by an infinitely inelastic demand curve and a convex supply function, describe the trends of prices and traded volumes up to mid-2016, while they do not during the following biennium. We suppose that the remarkable and sharp fluctuations of the WC price observed in 2016–2018 are due to decreasing returns that energy companies face in energy efficiency investments and to exogenous shocks caused by poorly designed regulatory interventions. It turns out that the equilibrium is the results of interactions between market forces and public intervention, as well as their related failures, aiming to a self-sustainable mechanism oriented to technological innovation.

In recent years, energy efficiency has been considered an extremely cost-effective way to reduce greenhouse gas emissions. China is a country with the world's largest coal consumption and heavy reliance on thermal power generation. Therefore, the relationship between the coal consumption constraint policy (CCCP) in China and electrical energy efficiency is a topic worthy of study. Based on the panel data of 30 provinces in China during 2005-2016, this paper employs the difference-in-differences (DID) to examine the impact of CCCP on electrical energy efficiency in China. The results indicate that the implementation of the CCCP reduces electrical energy efficiency in the pilot provinces. Based on the mechanism tests, the cost effect outweighs the innovation effect, which is why CCCP decreases electrical energy efficiency. The results of the heterogeneity analysis show that the influence of CCCP is more significant in the provinces with weak law enforcement and small hydropower investment and northern provinces. This study suggests that the Chinese government can promote corporate technological innovation by improving the environmental compensation system and increasing environmental law enforcement to improve electrical energy efficiency. Meanwhile, renewable energy projects should be the focus of future investment. Supplementary information: The online version contains supplementary material available at 10.1007/s12053-022-10023-2.

Nowadays, transportation electrification represents one of the most significant changes to reduce the pollution production rate. Unfortunately, in a TWEV (two-wheel electric vehicle), particularly in the case of a motorcycle wheel hub motor, there are different constraints by using an electric driving chain. They include an autonomy reduction caused by the lack of a control system to maintain a good powertrain efficiency according to the operating parameters variation, principally in the motor. In consequence, the efficiency decreases significantly by the relationship between speed proposed by the driver and the torque required by the vehicle. Those parameters can be used in order to make an efficiency optimization based on present road/weather conditions. Regrettably, this kind of control (optimal control) requires a representative model with low computation time and easy implementation. In this paper, a convex geometrical representation of an electric motor power efficiency is proposed. This representation helps to reduce the optimization compilation time without strong accuracy losses in order to propose sophisticated co-driving profiles. Its advantages over the high mathematical complexity representation are evaluated with an electric vehicle urban speed profile and an efficiency optimization compatible with the requirements of real-time operation.

To solve the problem of data inconsistency between electricity consumption and value added in Taiwan, the approach of cross-dataset calibration was proposed in this study. The datasets of electricity consumption from Taiwan Power Company were calibrated using the tax information statements from the Ministry of Finance, which are compiled for an entirely different purpose. These two datasets were integrated to reclassify electricity consumption into 19 sectors and 96 divisions. The calibrating process consists of five steps: date rollback, address data cleaning, integration, industry identification, and electricity consumption analysis. The calibrated results indicate that the data inconsistency mainly came from the low-voltage commercial electricity, especially for the small-sized enterprises in the service sector. The electricity consumption of wholesale and retail trade was calibrated upward by 19,073 GWh, while that of other service was calibrated downward by 16,350 GWh. We suggest that the calibration should be conducted at regular intervals to ensure that future policies are based on reliable data.

Deploying green energy is, directly and indirectly, related to energy- and environment-related sustainable development goals (SDGs). This study uses the stochastic impact by regression on the population, affluence, and technology (STIRPAT) model to examine the relationship between CO2 emissions, energy efficiency, green energy index (GEI), and green finance in the top ten economies that support green finance. The results show that green bonds are a suitable method to promote green energy projects and reduce CO2 emissions significantly. At the same time, there is no causal linkage between these variables in the short term. Therefore, to achieve sustainable economic growth for environmental issues, governments should implement supportive policies with a long-term approach to boost private participation in the investment of green energy projects. This policy may be applicable during and in the post the COVID-19 era when green projects have more difficulties accessing finance.

A review of the methods of obtaining water in the Canary Islands (Spain) is presented, dividing the islands into two groups: the eastern islands and the western islands. This division is due to the different origins of water resources, with western islands using mainly underground sources, while the eastern ones main source is seawater desalination. Water sources define the way in which water is obtained, as well as the energy expenditure to obtain it. In this review, the energy consumption of different methods of drinking water collection is studied, as well as the resources that make up the energy mix in the Canary Islands. In addition, a projection is made for drinking water consumption and energy consumption related to water use in the archipelago up till the year 2035, in order to observe the expected trends in these sectors.

The existing power systems as well as the smart grids utilize a number of advanced computing, networking, and measurement technologies that improve their planning and operation targeting to a full automated system in terms of monitoring and control. As power systems become more complicated, they face a combination of known and unknown vulnerabilities and threats that are more targeted and sophisticated. Among them, the malicious activity, influencing the measuring devices, is of major importance since it can instantaneously result in the physical operation and reliability of the grid. Conventional and smart energy meters incorporated to power systems are the most vulnerable measuring devices. The problem of conventional or smart energy meter manipulation targeting to the influence of power system operation and reliability is known as the energy theft (ENT) problem. This problem has become of major importance in many countries all over the world. The energy theft mainly occurs in the transmission and distribution levels. In order to reduce the impact of the energy theft, there are many methods that have been proposed in the literature. This paper presents a review of smart metering in the European Union (EU) along with a classification and contribution analysis of the most cited ENT problem solutions published in the literature, while a bibliographic analysis concerning the impact of most cited authors, affiliations, and references is also conducted.

The Passive House is a performance-based efficiency standard for new buildings. The factors that lead to very low heating and cooling demands include compact shape, favourable orientation and size of windows, good insulation, optimised thermal bridges, high-performance glazing, insulated window frames, airtightness, mechanical ventilation with heat or energy recovery, cool colours and solar control. Many of these components can also be used in retrofits of existing buildings, although Passive House levels of energy efficiency are often hard to achieve in renovation. EnerPHit is a voluntary standard for high-efficiency retrofits that is based on the use of typical Passive House components. It pursues economic efficiency and simultaneously addresses thermal comfort, indoor air quality, climate protection and hygrothermal performance. This paper is the first fully comprehensive publication of the foundations upon which the EnerPHit criteria were developed. Furthermore, we present five EnerPHit example buildings, including energy consumption data, costs and solutions for the challenges that arose in the practical implementation: a multifamily residence in Frankfurt, Germany, two row houses in Hereford, the UK and New York, USA, a school in Innsbruck, Austria, and a high-rise in Gothenburg, Sweden. Where measured performance data are available, they confirm very low energy consumptions of the refurbishments. The corresponding investments can be profitable.

Energy efficiency technologies have been promoted worldwide by policymakers and government and non-governmental institutions to decarbonize economies. In such context, Colombian government forecasted a total energy savings of around of 9% at the end of 2021 by promoting energy efficiency technologies across the different economic sectors. However, such efficiency goals may not be fully achieved due to the existence of the rebound effect. The rebound effect has the potential not only of entirely suppressing the energy savings expected but also of generating additional energy demand, a phenomenon known as backfire effect. Although the rebound effect has been extensively studied for developed countries, there is no empirical evidence of this phenomenon for South American countries. Hence, this study measures the direct rebound effect for all energy services consuming electricity in the household sector in Colombia along the period 2005–2013 by applying econometric techniques in a panel data for 15 states around the country. The results suggest a national rebound effect of 83.4% and values ranging across regions between 64.7 (Atlantico) and 78.9% (Meta). Our study points out that the rebound effect in Colombia follows a geographic patter, with high values at the interior of the country, which is relevant to various stakeholders in order to make informed decisions. Policymakers will gain knowledge on the role of the rebound effect in planning sustainability goals, whereas academics and practitioners will benefit of novel data regarding the role of the rebound effect in Latin American economies. Given the significance of our finding about rebound effect in a Latin American country, we conclude with some recommendations aimed at relevant stakeholders.

We measure energy intensity efficiency of 104 countries by classifying them into both five income groups and four groups. Along measurement of energy intensity efficiency, we investigate the impact of GDP and CO2 emissions on intensity efficiency. In this study, since fossil fuels have a close relationship with not only GDP but also CO2 emission, the energy efficiency and energy intensity efficiency model of fossil fuels including CO2 emissions are presented together. We put CO2 emissions as a constraint variable as well as a combined product with the desired output. Unlike energy efficiency, energy intensity efficiency was higher in the group with higher income. This was the same in both results, with CO2 emissions as a constraint and a combined product. In particular, when countries’ heterogeneity was controlled by converting five groups to four groups by the mean–variance approach, the energy intensity efficiency of each group was more clearly different. The energy intensity efficiency improved most when income improvement and environmental regulations were simultaneously imposed in all five income groups. Therefore, to improve energy intensity efficiency, reduction of CO2 emissions is necessary not only in high-income countries but also in low-income countries.

It is widely recognized that fuel poverty is a multidimensional social problem triggering significant adverse consequences to households. This paper aims at developing approaches and algorithms to identify the fuel poor households in a region, which is a prerequisite to implement effective tackling policies, by utilizing the collected microdata within the framework of the EU-SILC survey. In this context, emphasis is given on the examination of key subjective indicators to monitor the evolution of fuel poverty in Greece over the last decade. Furthermore, they are utilized to formulate composite indicators aiming to describe the problem of fuel poverty, including its depth, more precisely. The results of the analysis showed that 4 out of 10 households in Greece face some type of fuel poverty, while the problem for 1 in 3 of them has more structural characteristics. Based on these findings, two different logistic regression models are developed that seek to correlate the probability of a household suffering from fuel poverty with specific and easily identifiable characteristics. The types of the dwelling, if it is privately owned or rented, the location of residence, the household’s income, the level of education of the head of the household, etc., were identified as the main drivers of fuel poverty in Greece.

Conventional machine tools are still widely used for a large group of small machining companies, mainly in countries with emerging economies. There is a wide variety of high-efficiency electric motors for machine tools in machining; however, most conventional machine tools are driven by three-phase squirrel-cage induction motors (SCIM). This type of machines in small companies deserves a systematic study on energy efficiency. Therefore, the main purpose of this work is to propose a methodology to assess the energy efficiency of conventional lathes with three-phase squirrel-cage induction motors. A case study was conducted with the proposed methodology that demonstrated that the energy efficiency can be depicted by constructing characteristic curves for each machine tool. The control of depth of cut (ap) is a sufficient condition for the construction of the characteristic curves of a conventional lathe. As a result, it was concluded that at the shop floor environment, the final user could install a digital wattmeter to read the electric power and analyze, from the characteristic curves, whether the machining operation is running on an efficient mode. The machine tool manufacturer can also incorporate a wattmeter into conventional lathes with squirrel-cage induction motors to measure and report the efficiency status during the machining operation.

This study evaluates the effect of energy efficiency and conservation on the Ghana National Grid. The motivation of this research study derives from the overwhelming lack of energy efficiency and conservation practices by consumers in Ghana while the existing generation continues to deplete with the increasing population and their growing energy needs. A survey was conducted on existing generation plants to assess their capacities and average power contributed to the national grid over a 6-month period. Energy efficiency and conservation awareness questionnaires was also administered to selected consumers to test their knowledge in energy efficiency and conservation. An energy audit and demand management program was established and implemented for a set of households, which were later audited, after a 3-month period to ascertain improvements in their energy consumption pattern. The study revealed that the implementation of energy efficiency and conservation measures led to a maximal reduction of energy consumed by 5.14% which is highly significant and subsequently led to positive economic and environmental implications. The study also found out that most of the respondents are unaware of energy efficiency and conservation measures; they make abusive use of non-efficient electrical appliances and do not implement any energy efficiency and conservation measures. The study recommended the development of policies and strategies to conduct mass education, to ensure the implementation of energy efficiency and conservation measures, and also to encourage the use of energy-efficient appliances. Successful implementation of the proposed recommendations contribute significantly to meeting the energy challenge in developing countries and subsequently sustain business while alleviating poverty.

Resource scarcity and anthropogenic climate change require the reduction of performance gaps in existing buildings. In addition to unexpected user behavior, performance gaps are primarily caused by the technical gap due to operational errors in building technology. The main objective of this paper is to quantify model input uncertainty incorporating uncertain boundary conditions in terms of operational errors using thermo-dynamic building performance simulations and to identify the most relevant input parameters for the performance gaps in air conditioning systems by means of sensitivity analyses. Model input uncertainty is stochastically determined using Monte-Carlo Simulations to calculate the target values “primary energy demand” as well as “over- and under-temperature degree hours” for an office building. Selected parameters are simulated in a specific uncertainty and sensitivity analyses using the Sobol’ and Jansen estimators, which distinguish between a direct influence on the target variables and interactions between the parameters. The methodology requires a selection process, which is carried out as part of relative uncertainty and relative sensitivity analyses. Furthermore, the operational errors are compared with construction factors as well as building physics inputs and design parameters for building technology systems to show their reciprocal effects as part of a comprehensive investigation. The main findings of this paper are that operational errors in air conditioning systems play an essential role in decreasing energy efficiency and thermal comfort, but do not warrant the significance of certain construction factors as well as setpoints in building technology. Moreover, the impact of operational errors on thermal overheating of the building investigated is minor compared to other targets that cause greater model input uncertainty.

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