Abstract: The street lighting is one of major components in total energy consumption in cities. The paper is focused on a concept of street lamp control systems and function organization with remote monitoring, to reduce maintenance costs and energy consumption. A new approach to the definition of functional strategy organization for outdoor lighting systems is introduced in the paper. Proposed functional strategies are based on four efficiency classes of building automation and control systems (BACS) defined in the EN 15323 standard. They have been formulated, analysed and eventually implemented and verified in real experiment street lighting installation. This outdoor lighting system, designed by the authors, based on LonWorks (the ISO/IEC EN 14908) platform with a power line communication aimed to control high-pressure sodium lamps. The street lamps are integrated nodes of a building management system (BMS). The results of experimental tests for the proposed functional strategies, implemented with various control scenarios, show that they provide a great potential in reducing energy consumption by street lighting installations. In particular, the energy use can be reduced even by 45 % in comparison to conventional street lighting system, especially without the use of monitoring and control.

Abstract: Industrial energy efficiency represents a priority for European industrial competitiveness. Many studies offer contributions providing evidence of the existence of driving forces supporting the adoption of energy efficiency measures, but a structured approach to drivers for industrial energy efficiency is still lacking. Therefore, in the present study, we propose a definition of drivers, making emphasis on the industrial decision-maker perspective, that is needed for their classification here proposed. Focus is given to point out the difference between internal and external drivers, highlighting the major stakeholders responsible for their promotion. Drivers are further categorized into: regulatory, economic, informative, and vocational training. Moreover, we propose a framework describing the effect of drivers on barriers in the decision-making process, as well as a preliminary identification of the major stakeholders to promote drivers. The study opens several opportunities for further research in the area of industrial energy efficiency.

Abstract: Industrial activities are responsible for a significant share of both global delivered energy demand and CO2 emissions. Hence, a widespread adoption of energy-efficient technologies and practices represents a crucial means for sustainable production. Adopting a novel framework of drivers for energy efficiency describing the effect of drivers on barriers in the decision-making process steps and able to account for the nature of drivers and the stakeholders responsible for their promotion, we have performed an exploratory investigation into 61 manufacturing small- and medium-sized enterprises in Northern Italy. Our findings have highlighted the importance of information and economic drivers, showing the need for enterprises to be supported not only by public institutions but also by external stakeholders involved in the supply of energy-efficient technologies and practices such as industrial associations and groupings, as well as service and technology suppliers. Moreover, our study has highlighted an almost equal relevance of both internal and external drivers. According to our findings, the increase of awareness—generating the interest to energy issues and stimulated both by external and internal stakeholders—as well as financial issues have emerged as the most critical in the decision-making process to adopt an energy-efficient measure. A preliminary comprehension of the mechanisms relating drivers to barriers in the decision-making process brought additional value to the study, highlighting the most effective and specific means to overcome the existing barriers. We have also explored the effect of several firm characteristics, such as firm size and energy intensity offering suggestions for industrial decision-makers as well as policy-makers.

Abstract: Promoting pro-environmental behaviour among individuals could help to mitigate climate change. In this research, we tested the effect of self-determined motivation on pro-environmental behaviours related to household energy consumption. A questionnaire survey was conducted in Hong Kong (n = 1004) to examine the importance of self-determined motivation on pro-environmental behaviours that promote climate change mitigation. Our results indicated that incorporating self-determined motivation into a model of goal-directed behaviour (MGB) improved its predictive power and that both the intrinsic and extrinsic motivations of an individual were important predictors of pro-environmental energy consumption behaviour. The empirical results suggest measures that can be used by the government to motivate residents’ pro-environmental energy consumption behaviours and to achieve the goal of reducing greenhouse gas emissions for a metropolitan area in southern China.

Abstract: In this paper, cuckoo optimization algorithm is implemented to solve energy production cost minimization in a combined heat and power (CHP) generation system. This problem is also known as combined heat and power economic dispatch problem, which looks for optimal values of power and heat generation of each CHP unit to minimize the total production cost. Cuckoo optimization algorithm is a new metaheuristic algorithm. It is inspired by the life of a bird family, called cuckoo, that special lifestyle of these birds and their characteristics in egg laying and breeding has been the basic motivation for development of this algorithm. Unlike of the some previous approaches, the effect of valve point is considered in the cost function and clearly formulated in the conventional polynomial cost function as absolute sinusoidal term. The proposed method is applied to three small (with three different test cases), medium, and large test systems in order to evaluate its efficiency and feasibility. The obtained results demonstrated a higher quality solution and superior performance of the proposed cuckoo optimization algorithm method in comparison with many existing methodologies.

Abstract: Indoor environmental conditions in classrooms, in particular temperature and indoor air quality, influence students’ health, attitude and performance. In recent years, several studies regarding indoor environmental quality of classrooms were published and natural ventilation proved to have great potential, particularly in southern European climate. This research aimed to evaluate indoor environmental conditions in eight schools and to assess their improvement potential by simple natural ventilation strategies. Temperature, relative humidity and carbon dioxide concentration were measured in 32 classrooms. Ventilation performance of the classrooms was characterized using two techniques, first by fan pressurization measurements of the envelope airtightness and later by tracer gas measurements of the air change rate assuming different envelope conditions. A total of 110 tracer gas measurements were made and the results validated ventilation protocols that were tested afterward. The results of the ventilation protocol implementation were encouraging and, overall, a decrease on the CO2 concentration was observed without modifying the comfort conditions. Nevertheless, additional measurements must be performed for winter conditions.

Abstract: Sustainable buildings have an important role in achieving sustainable development by improving energy utilization and environmental performance. Buildings are considered as the biggest single contributor to world energy consumption and greenhouse gas emissions. In Saudi Arabia, the significance of the building sector can be described on the basis of per capita electricity consumption, per capita carbon dioxide emissions, and the increasing number of buildings because of economic and population growth. Therefore, the country should consider establishing energy-efficient buildings to promote sustainable development. Efforts in developing energy-efficient technologies should increase for the national energy policy. This article comprehensively describes the current challenges and opportunities of energy consumption and various energy conservation options that are viable for the Saudi building sector. Current policy efforts for improving energy efficiency in Saudi buildings have been analyzed to enhance the sustainable development in the country. The study reveals that the energy conservation policy of the country has fairly improved in the past decades. However, the country has to focus on this area and perform urgent measures to adopt energy-efficient technologies in the building sector.

Abstract: This paper has two research objectives: first, it derives and analyses energy intensity trends for seven energy intensive manufacturing industries and the aggregate manufacturing sector in India for the period 1973–1974 to 2011–2012 and compares the same with best practice benchmarks. Second, based on Index Decomposition Analysis, it studies the extent to which the energy efficiency has contributed in the decoupling of industrial activity growth from growth in energy use. The study finds faster decline in energy intensity in all the seven industries during the recent years (1998–1999 to 2011–2012). Aluminium, cement and fertilizer industries are found to operate close to the global best-practice energy intensities with transformational changes in process technology. Iron and steel and pulp and paper are found to be lagging behind with only incremental transformation in technology in place. The decomposition results show that activity growth is the major driver of growth in energy demand with marginal impact coming from structural change. However, declining energy intensity has been able to neutralize a major portion of the growing energy demand resulting in decoupling trends, especially in recent years, with more energy efficiency-related voluntary and mandatory policies in place).

Abstract: Monitoring the progress of the European Union and its Member States towards the EU’s energy efficiency target is a crucial part of the mandatory process as defined in the Energy Efficiency Directive 2012/27/EU. In this paper, we conduct index decomposition analyses to show the effects of both policies and autonomous developments driving the changes of primary energy consumption for the European Union (EU28) and its Member States for the time period of 2000 to 2014, with a comparative analysis of Germany and Poland. These analyses are based on the logarithmic mean Divisia index methodology and primarily on data compiled by Eurostat. They are carried out on two levels, i.e. on the level of total primary energy consumption as well as on the level of primary energy consumption related to electricity generation. The first level examines the influences of changes in final energy consumption and changes within the energy conversion sector on primary energy consumption. With the second level, we provide insights into the effects of changes in electricity consumption and production. According to our first-level analysis, the consumption of primary energy in the EU28 is primarily influenced by an increased share of electrical energy and the counteracting effect of rising efficiency in electricity generation, induced by an increasing share of renewable energies. Furthermore, the reduction of final energy consumption had a significant decreasing influence on primary energy consumption in the European Union. The second level of our analysis regarding electricity generation shows that the increasing effect on primary energy consumption due to the rising consumption of electricity was mainly compensated by substituting nuclear and thermal power plants by renewable energy technologies.

Abstract: Smart-metering allows electricity utilities to provide consumers with better information on their energy usage and to apply time-of-use pricing. These measures have been shown to reduce electricity consumption and induce time-shifting of demand. Less is known about how they affect residential energy efficiency investment behaviour. We use data from a randomised-controlled trial on a sample of almost 2500 Irish consumers, conducted over a 12-month period to investigate the effect of smart-metering and residential feedback on household investment behaviour. The results show that exposure to time-of-use pricing and information stimuli, while reducing overall and peak usage, can also have the unintended effect of reducing investment in energy efficiency measures within the home. Our findings indicate that households exposed to treatment were less likely to adopt any energy saving measure (23–28 % on average), and those households adopted less energy saving features than those in the control group (15–21 % on average). This result highlights the potential for behavioural interventions to have unintended consequences on behaviours other than those specifically targeted. Furthermore, it underlines the importance of examining a wider range of outcomes and allowing longer time-scales when evaluating this type of experiment.

Abstract: The European Union in line with its climate and energy strategy has presented a renewed ambition for the post-2020 period, towards 2030, through the Clean Energy for All Europeans policy package proposals. A new binding target of minimum 30% for energy efficiency improvements is in the horizon, as well as the identified need for a stronger governance framework to support its delivery. This research contributes to a better understanding of energy efficiency governance by analysing a set of indicators covering aspects related to institutional, human, financial, and political dimensions. The results obtained provide a more detailed perspective on the European Union level and Member State governance capacities. These indicate the need to develop institutional capacities related to the transposition of legislation and directives. In parallel, the disparities between individual Member State governance capacities should be considered when devising and implementing future policies. The implications for policymakers include the need for a more robust governance monitoring and reporting system, including the development of transparent and comparable indicators, as well as a more comprehensive assessment of the impact of good governance on delivering energy efficiency improvements.

Abstract: Industrial waste heat may be one of the answers to future energy demands. Depending on the temperature, industrial waste heat may be used to produce electricity or meet cooling or heating demands at different temperature levels. However, in order to estimate the influence the waste heat may have in future energy systems, the magnitude of the industrial waste heat in the different countries need to be estimated. For Germany, so far, only top-down analyses of the waste heat potential exist, using key figures derived from other studies in other countries. In this paper, the first bottom-up approach for estimating the industrial waste heat potential in Germany is presented. For this approach, an algorithm to evaluate and test the mandatory emission report data from German production companies was developed. In a second step, round about 81,000 data sets have been evaluated to calculate a conservative and lower boundary value for the industrial waste heat. As this conservative, lower boundary based on the collected data from the German industry, the waste heat volume was evaluated as 127 PJ/a or 13 % of the industrial fuel consumption. Results were used to derive key figures with which the missing share of the data was approximated.

Abstract: The energy in buildings is influenced by numerous factors characterized by non-linear multi-interrelationships. Consequently, the prediction of the energy performance of a building, in the presence of these factors, becomes a complex task. The work presented in this paper utilizes risk and sensitivity analysis and applies artificial neural networks (ANNs) to predict the energy performance of buildings in terms of primary energy consumption and CO2 emissions represented in the Building Energy Rating (BER) scale. Training, validation, and testing of the utilized ANN was implemented using simulation data generated from a stochastic analysis on the ‘Dwellings Energy Assessment Procedure’ (DEAP) energy model. Four alternative ANN models for varying levels of detail and accuracy are devised for fast and efficient energy performance prediction. Two fine-detailed models, one with 68 energy-related input factors and one with 34 energy-related input factors, offer quick and multi-factored estimations of the energy performance of buildings with 80 and 85% accuracy, respectively. Two low-detailed models, one with 16 and one with 8 energy-related input factors, offer less computationally intensive yet sufficiently accurate predictions with 92 and 94% accuracy, respectively.

Abstract: Considering the increased interest of stakeholders in climate change and a low-carbon economy, this article has investigated and identified several contributions of the ISO 50001 in support of the adoption of green supply chain management (GSCM). In this context, energy efficiency and reduced CO2 emissions are critical. Therefore, the proposal for and the requirements of ISO 50001 can generate useful insights on how to structure green and low-carbon supply chains, hence helping to address the challenges posed by climate change.

Abstract: Many countries, Switzerland included, envisage an energy transition characterised by the increased production of renewables. One challenge faced by these nations is that peak household electricity demand often does not correspond with the peak production of renewables such as photovoltaics (PV) and wind. Load-shifting via the use of smart appliances provides one option to better match renewable electricity production with household electricity demand. However, load-shifting requires the adoption of smart grid and smart metering technologies, which the public often views as a form of surrender to a lack of control and data security issues. Thus, load-shifting might encounter social disapproval. This paper analyses how control over the use of appliances and data security perceptions influence the social acceptance of load-shifting programmes via a social psychological online experiment (N = 250) by taking the example of the dishwasher. Results suggest a significant causal influence of the level of control over appliance on the acceptance of a load-shifting programme. In situations where participants perceived a lack of control over their appliance, acceptance levels dropped significantly. Regarding data security, experimental manipulation has been unsuccessful; therefore, no valid conclusions can be drawn regarding this factor. These results indicate the presence of serious concerns regarding the control of appliances when people are asked to consider a load-shifting programme. The development of a deeper understanding of these concerns may help utilities to create more successful, socially accepted load-shifting programmes and communication strategies.

Abstract: The percent of energy consumed by plug load equipment in commercial buildings is on the rise. Research conducted in the past has included surveying plug load equipment, measuring plug load electricity consumption and equipment operating patterns, and studying plug load reduction solutions in office buildings, but plug load energy use across other building types is poorly understood. A university campus, which houses many building types, presents a unique opportunity to understand plug load profiles across building types. In this study, an equipment inventory was performed in 220 buildings on Stanford University’s campus, totaling 8,901,911 ft2 of building space and encompassing lab buildings, office buildings, recreation facilities, public space, and service buildings. Within these buildings, 110,529 pieces of plug load equipment were recorded. Energy consumption estimates were developed from published values and used to evaluate the aggregate plug load energy consumption of this equipment by equipment type and by building type. In total, it is estimated that the plug loads from these buildings consume nearly 50 million kWh per year and comprise 32% of the electricity consumption of the buildings surveyed. This data can be used to better target energy conservation efforts throughout multiple sectors.

Abstract: Downhill conveyors are important potential energy sources within conveyor belt systems (CBSs). Their energy can be captured using regenerative drives. This paper presents a generic optimisation model for the energy management of CBSs that have downhill conveyors. The optimisation model is able to optimally schedule three configurations of a case-study CBS that is connected to the grid and operated under a time-of-use tariff. The three suggested drive configurations showcase potential energy savings/incomes that can be obtained from implementing: (a) variable speed control, (b) internal use of downhill conveyor energy and (c) the export of energy to the grid. The results show that a CBS with a daily energy consumption of 924 kWh can be reconfigured and controlled to reduce consumption by 53 or 100 % or be made to generate 1984 kWh, depending on the configuration. Analysis of the investment in each of the three configurations is assessed using a life-cycle cost and payback period (PBP). The daily operation simulation results show that the use of regenerative drives and variable speed control is able to provide energy savings in CBSs. The cost analysis shows that the configuration that enables sale of energy to the grid is the most profitable arrangement, for the case study plant under consideration. The sensitivity analysis indicates that the PBPs are more sensitive to the annual electricity price increases than changes in the discount rate. Combining regenerative drives and optimal operation of CBS generates energy savings that give attractive PBPs of less than 5 years.

Abstract: China’s rapid economic growth causes a sharp increase in the demand for electricity. Electricity price in China is generally controlled at a low level by the government, leading to a substantial electricity subsidy. Electricity subsidy is the focus of energy price reform. It is also most closely linked with residential life and is a very sensitive issue to residents. This paper adopts the price-gap approach to estimate the scale of electricity subsidy and finds that in 2010, residential electricity subsidy in China amounted to 467.17 billion CNY (Chinese yuan), accounting for 1.17 % of GDP in that year. Subsequently, the paper estimates the impacts of residential electricity subsidy reform on the welfare of residents using the compensating variation (CV) measurement. The results show that if residential electricity price rises by 50, 100, 150, and 191 %, the CV should be 288.5, 394.2, 451.1, and 467.2 billion CNY, respectively. The residential electricity subsidy reform also has a moderating role in the rebound effect of electricity consumption. The direct rebound effect in China’s residential electricity consumption is 20 %. Electricity subsidy reform will raise terminal electricity price and restrain residential electricity consumption. Therefore, electricity subsidy reform should be an effective measure to mitigate the rebound effect.

Abstract: There is growing interest among policy makers and others regarding the role that industrial energy efficiency can play in mitigation of climate change. For over 10 years, the US Environmental Protection Agency (EPA) has supported the development of sector-specific industrial energy efficiency case studies using statistical analysis of plant level on energy use, controlling for a variety of plant production activities and characteristics. These case studies are the basis for the ENERGY STAR® Energy Performance Indicators (EPIs). These case studies fill an important gap by estimating the distribution of efficiency using detailed, sector-specific, plant-level data. These estimated distributions allow Energy Star to create “energy-efficient plant benchmarks” in a variety of industries using the upper quartile of the estimated efficiency distribution. Case studies have been conducted for 14 broad industries, 2 dozen sectors, and many more detailed product types. This paper is a meta-analysis of the approach that has been used in this research and the general findings regarding the estimated distribution of performance within and across industries. We find that there are few sectors that are well represented by a simple “energy per widget” benchmark that less energy-intensive sectors tend to exhibit a wider range of within-industry efficiency than energy-intensive sectors, but changes over time in the level and range of energy efficiency do not reveal any single pattern.

Abstract: The aim of this research is to investigate the effectiveness of vertical vegetation in terms of energy savings for a residential facility situated at KAIST campus. The research has been established through analyzing different building orientations to find out the most suitable combination of vegetation and orientation for reduced heating and cooling energy consumption. A simulation model has been developed where leaf area index, one of the contributing plant physiological parameters for improving building thermal performance, has been incorporated as per seasonal variations. This allowed observing thermal performance patterns of green wall throughout the year. Approximately 60 % savings in heating energy and 31 % increase in overall energy efficiency were achieved with the non-insulated studied building case, and the results showed extreme weather conditions lead to greater energy savings in winter. In cooling season, plant layers were found to be less effective in terms of facade thermal performance especially during relatively higher temperature period, with an average of 17 % cooling energy savings. The North-oriented green wall was observed to be the most effective in increasing heating energy efficiency, while the East-oriented wall was observed to be greatest in cooling energy savings. A higher LAI value proved to be beneficial in improving both heating and cooling energy performance for the studied building.

Abstract: Public indoor swimming pools are a very popular type of sports facility. They need to ensure good indoor air quality and thermal comfort of the occupants (TCO) while reducing their energy consumption. The objectives of this study are to develop a numerical code, based on the zonal method; to investigate the indoor airflow patterns; and to determine the TCO in the indoor swimming pool. The numerical simulation, performed using the TRNSYS software (version 17), is validated against intensive field measurements, carried out in the public indoor swimming pool located at Bishop’s University (Sherbrooke, Quebec, Canada), of the temperature, velocity, and relative humidity of the air as well as the surface temperature of the walls, ceiling, and floor. The developed code is then used to study the indoor flow patterns and to evaluate the TCO using three indexes: the humidex chart, the predicted mean vote (PMV), and the predicted percentage of dissatisfied (PPD). The results show a hot-humid rather uncomfortable atmosphere is prevailing in the occupied parts of the studied indoor swimming pool. The calculated airflow rates show that, due to the position of the ventilation inlets and outlets, most of the ventilation air circulates in the upper part of the building causing an insufficient air renewal in the occupied parts of the studied indoor swimming pool.

Abstract: The residential sector is responsible for 29% of the total energy consumption of the UK, with 62% of this energy being used for space heating. Heat loss through the fabric of building elements is a crucial factor in the energy efficiency of homes, and a wide number of studies have looked at physical interventions to improve the energy efficiency of existing buildings, commonly called retrofit. This research considers the impact of window coverings on reducing heat loss from homes, a measure that is not commonly considered an energy efficiency intervention. Although the amount of glazing varies widely between homes, all windows are a significant factor contributing to heat loss. While physical changes such as double and triple glazing can improve the energy performance of buildings, the impact of curtains and blinds is not well characterised. Previous research into window coverings has been undertaken using laboratory tests, such as hotbox and small climatic chamber environments. This study presents the impact of window coverings on heat loss within a unique whole house test facility. This allows for a better replication of a real heating system and the effects that it has on localised heat transfer. This gives a more detailed picture of in situ performance, similar to that which may be found in the field.

Abstract: Energy master plans are important tools for an effective and sustainable land governance. On the other hand, the stakeholder role in setting priorities for planning energy interventions is dramatically increasing, also in the light of recently issued European directives. The priorities of energy-saving measures of the Sicilian energy and environmental master plan were originally established with the application of typical economic indicators (the cost of saved energy and the cost of avoided pollutant emissions). During the prioritization process, there was a minor contribution from stakeholders who were not directly involved in the priority-setting process but were only asked to express their opinions according to the in-force regulations. Based on more active stakeholder involvement in hierarchizing a given set of actions, as required by the recently issued directives, the University of Palermo, which participated in the development of this master plan, assessed an ex post evaluation of these established economy-based priorities, by means of the application of a multi-criteria decision analysis (MCDA) tool. The resulting changed priorities, which lead to a better policy allocation of the regional budget for energy efficiency in the building sector, confirm the preeminent role played by the stakeholders in the development of energy plans, further supported by a sensitivity analysis.

Abstract: Previous research often regard household and individual as synonymous actors, although the overall household electricity consumption is the aggregate of diverging actions by individual household members. We disentangle the impact of actor-specific predictors on household and individual electricity consumption, employing regression models to data of 204 Austrian multi-person households. Predictors add more to the explained variance of household and individual electricity consumption if they are located at the same actor level as the dependent variable. While household electricity consumption is best predicted by the household context and value/knowledge factors, individual electricity consumption depends foremost on habit and whether a person stays at home during the day. The study exemplifies that future research and interventions need to decompose actor levels to better understand and target the drivers of private electricity consumption. Methodological challenges in measuring individual and household consumption behaviour are discussed.

Abstract: This paper analyzes the drivers for and barriers to the adoption of energy efficient technologies among a sample of firms based in Viet Nam, the Philippines, and Moldova. The current debate on the fight against climate change emphasizes the need to adopt environmentally friendly measures at the global level. We therefore need to better understand the obstacles to the adoption of energy saving measures, especially in developing countries. By applying discrete choice modeling techniques, we find that firms’ internal management and organizational factors rather than top-down or other external market conditions increase firms’ likelihood to invest in energy efficient technologies. Moreover, experience in the adoption of energy efficient technologies and the commitment of top management are also crucial in this regard.

Abstract: Energy efficiency (EE) is rapidly growing in many markets today, but its its cost-effectiveness and potential for growth are being hotly debated. These controversies impede public and private investment in efficiency programs, products, and services. As the stakes rise, the debate has heated up and the need grows to clarify the disagreements and disputes. We review the arguments of skeptics and advocates on 10 key questions concerning energy efficiency, attempting to answer three overriding questions: does an EE gap exist, how big is the gap, and how can the gap be shrunk? We tackle 10 areas of contention: the significance of market failures, the efficiency of investment levels, energy intensity as a measure of efficiency, the treatment of naturally occurring EE, the application of discount rates, accounting for transaction costs, treatment of the rebound effect, the practice of EE delivery, the integration of EE into utility business models, and opportunities for EE growth. Research needs in each of these areas are also described. By examining the divergent views of skeptics and advocates and by addressing the limitations of current knowledge, policymakers and stakeholders can make better-informed decisions supported by more defensible analysis.

Abstract: In this work, we investigate the effect of the thermal insulation by leather wastes (wet-blue chrome shavings and buffing dust) and carpentry wastes (wood shavings and sawdust) on the energy consumption of a model building using the average climatic data of the city of Casablanca (Morocco). For this study, we used the dynamic thermal simulation tool “TRNSYS 16” which predicts the thermal behavior of building and systems associated with it. Using this software, we evaluated the effect of the above material wastes on thermal comfort and building energy consumption. The type and the thickness of the materials were considered as variants to choose the better solution. The average temperatures of building supposed thermally insulated compared to those obtained without insulation clearly show the thermal insulation ability of tested materials during the cold and warm periods of the year. Increasing the thickness of the insulator makes locals increasingly comfortable. Because of their performance, leather and carpentry wastes can compete with conventional insulating materials such as polystyrene and cork.

Abstract: Improving the energy efficiency of conventional energy services is an essential way to cope with global CO2 emissions mitigation. To date, energy efficiency improvement (EEI) has been broadly introduced exogenously in integrated assessment models (IAMs) by virtue of the autonomous energy efficiency improvement (AEEI) coefficient; however, it is usually good at capturing the EEI driven by non-price factors, while weak in describing the EEI induced by policy incentives. In this paper, we introduce an endogenous EEI (EEEI) mechanism in an IAM, called E3METL, to explore the impacts of EEEI on the global macro-economy, CO2 emission paths, and timing of carbon mitigations. The results reveal that (1) introducing EEEI significantly improves gross world product (GWP) gains, and this positive effect is partly offset when carbon restriction policies are implemented; (2) RD (3) EEEI may perform as one of supporting factors to delay the actions of carbon reduction; moreover, the introduction of EEEI lowers the optimal carbon tax level by 7.8 % on average, as compared to the no EEEI case.

Abstract: The energy efficiency of a building depends to a large measure on the characteristics of its envelope insulation. In the special case of internal gain dominated buildings, excessive building insulation may prevent the heat loss through the walls (anti-insulation effect), and thus generate the need for energy-intensive active systems to remove this thermal load. Detailed energetic simulations of a typical office building in Malaga (Spain), Dubai (UAE), and El Dorado (USA) show this anti-insulation effect and its dependency on climatic, constructive, and use factors. Results indicate that buildings in a predominantly cooling environment but within a certain range of heating degree days (HDD) will display this behavior: with very few to no HDD, the building’s energy consumption becomes insensitive to insulation increase (Dubai case); with a low number of HDDs the building becomes sensitive to anti-insulation (Malaga), and once a threshold is passed (El Dorado), the building’s energy consumption decreases with increased insulation. In order to further explore these limitations, simulations in 132 global locations of the building response to a step change in insulation are carried out. Results indicate that buildings in the Koppen climate zones Csa and Csb (Mediterranean climate), in locations with less than 2000 HDD and between 2000 and 5000 cooling degree days (CDD) are most susceptible to this anti-insulation behavior; however, quantitatively, the efficiency loss in these areas due to the insulation increase does not exceed 1 % of the overall energy consumption for the particular building studied and thus remains of limited importance.