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Paper industry is one of major material and energy users in Finland, material costs being far bigger than energy costs. Energy saving is promoted in Finland by an energy service centre, subsidies and energy service companies (ESCOs). Material savings in production processes are typically used to reduce costs while life cycle material efficiency rather would require focusing, e.g. on product design. This could be promoted by total producer responsibility, economic instruments and environmental permits. For industrial sites with limited resources, MASCOs’ (Material Saving Companies) services could manage material savings, e.g. by funding the investments, planning and running the project. Authorities should put more emphasis on material auditing and information on material saving technologies and logistics. Material savings should also be included into the environmental permitting procedures. Materials saving services are developing and the projected Finnish material efficiency service centre could support new businesses. This article is based on a literature review and interviews of persons in paper producing companies and environmental authorities. We also analyse experiences of the first MASCO project in Finland. [Copyright &y& Elsevier]

Abstract: In this study the possibilities of making a cost-effective heat exchanger retrofit in a simulated thermo mechanical pulp and paper mill are analysed using advanced composite curves. The use of advanced composite curves is a fairly new method developed in Chalmers University, and they have not previously been used to analyse a mechanical pulp and paper mill. The simulated mill used as an example in this study has one TMP (thermo mechanical pulping) line, one paper machine, debarking and auxiliary systems. The results show that the advanced curves give valuable information on the system and provide guidance as to where to look for improvement potential. The relative costs of different improvements are in line with traditional knowledge of improvement costs. [Copyright &y& Elsevier]

Energy efficiency can make energy access more affordable by reducing the electricity cost burden on households and businesses. Improving products' energy efficiency helps reduce monthly energy bills— freeing up funds that can feed back into the economy, thus stimulating economic growth. To demonstrate these benefits, this paper conducts a cost-benefit analysis (CBA) and a national impact analysis (NIA) for implementing an energy-efficiency standards and labeling (EESL) program for refrigeration products in Uganda. The CBA compares the costs versus the benefits of investing in energy-efficient products for consumers: It shows that the most cost-effective products have an efficiency level 35 % higher than baseline products sold on the market. By choosing these products, consumers save, on average, US$76 over the lifetime of the product. The NIA assesses the impact of an energy-efficiency standard set at that level and shows potential cumulative savings of US$595 million (2023–2040) for households and small businesses. These savings translate into additional purchasing power for households and investments for small businesses, leading to increased living standards and economic development. This paper describes the importance of implementing energy efficiency policies and programs in emerging economies where affordability of electricity hinders electricity access. This paper provides a rigorous approach of using CBA and NIA assessments to demonstrate the economic savings for the consumers and the nation to implement EESL programs for major electric equipment. • Energy efficiency increases consumer's welfare. • In Uganda, it can save consumers US$76 over the lifetime of the product. • This represents cumulative savings of US$595 million (2023–40) at the national level. • Energy efficiency policies is critical for electricity access affordability • The paper provides a Regulatory Impact Assessment replicable in other countries. [ABSTRACT FROM AUTHOR]

Highlights • We investigate a redundancy allocation problem for a cold-standby system with degrading components. • We consider performing periodic inspection and preventive maintenance for the degrading cold-standby components. • The proposed optimization problem has three parts of decision variables: component choices, the number of redundant components, and the length of periodic inspection interval. • We use approximation methods when evaluating the system reliability (objective function) and expected cost. • A modified genetic algorithm involving dual mutation and random keys technique is developed to solve the proposed problem. Abstract In this paper, a redundancy allocation problem for cold-standby systems with degrading components is studied. We consider performing a policy of periodic inspection and preventive maintenance on the cold-standby components. Components in cold-standby mode are assumed to suffer from performance degradation when exposed in extreme standby environments for a long-term storage. Except the online working components, other cold-standby components are periodically inspected and preventively maintained to retain them in or restore them to an acceptable condition. The situation, that the cold-standby components are restored like new but their failure rates increase, is considered. In this paper, we develop a model to determine an optimal combination of the component choices, the number of redundant components, and the length of periodic inspection interval, so as to maximize the system reliability while meeting the resource limits, such as cost and weight. As it is difficult to obtain a closed-form expression of the objective function for the optimization problem, an approximated objective function is proposed. The approximation is also used for evaluating the expected cost of periodic inspection and maintenance. We then develop a modified genetic algorithm to solve the optimization problem. Finally, a numerical example is presented to illustrate the effectiveness of the proposed model and the solution methodology. [ABSTRACT FROM AUTHOR]

Non-Volatile Memory (NVM) has been widely used in hybrid memory architecture due to the promising advantages like high density and low power consumption. Most of existing page replacement methods focused on prolonging the life time of NVM memory systems, which either consider the energy cost or deal with consistency errors caused by system failures. This paper proposes a page replacement method based on NVM–DRAM hybrid main memory systems for low power and consistency guarantee, called Energy-Aware Page Replacement (EAPR). The energy consumption of page access in DRAM and NVM is modelled considering the memory access like reading, writing and idle. EAPR utilizes page grouping policy to improve the migration efficiency between NVM and DRAM. Page groups are chosen to migrate according to their energy-related substitution degrees. To guarantee the consistency during page migration, this paper designs two consistency guarantee schemes in page replacement phase and transaction committing phase. Instead of deleting logs directly, our approach guarantees the consistency of hybrid memory systems by modifying the data structures of logs after the transactions of applications are submitted. Based on existing benchmarks, we conduct extensive experiments to evaluate the proposed method. Experimental results show that EAPR can reduce the energy consumption up to 40.19% compared with the existing page replacement algorithms, and also guarantee the consistency of transactions in NVM–DRAM hybrid memory systems. [ABSTRACT FROM AUTHOR]

In the present context, energy access to remote rural households through local energy generating systems has been recognized as a cost effective and extent efficient option. With increased emphasis on eco-friendly technologies and high fuel cost associated with conventional energy generation, the use of renewable energy resources (small hydro, biomass, solar, wind energy etc.) are being explored. The present paper is focused on the optimal sizing of a stand-alone Integrated Renewable Energy System (IRES) which comprises the resources of micro hydro power (MHP), biogas, biomass, solar and wind energy. Initially, a demand response (DR) strategy based on energy consumption scheduling of appliances has been suggested and modelled in the paper. This strategy aims to minimize the peak hourly energy consumption of the study area. Further, different combinations of system components without and with DR strategy were considered and optimized for power reliability criteria of 0% and 5% unmet load. It has been found that significant amount of savings in system sizes and costs are obtained with DR strategy compared to system without DR. [ABSTRACT FROM AUTHOR]

This paper introduces a novel tool for industrial customers to perform a cost-benefit analysis regarding the implementation of Demand Response (DR) strategies in their facilities with the final goal of softening the impact of RES intermittency in the grid. The dynamic simulation tool focuses on assessing the participation of industries in reserve energy markets in the same conditions as generators offering capacity reserve, energy reserve or both of them and taking into account all the technical restrictions of production processes as well as possible extra costs due to the implementation of DR (additional labour cost, productivity losses, etc.) Main innovations of the methodology are the DR assessment carried out per process and the introduction of the “margin of decision” as a decision making strategy for the energy consumer. Along the paper, the methodology behind this tool is introduced step by step in order to show how the technical, economic and environmental analyses are performed. At the end, it is included the application of the methodology to a real paper factory in Germany. Results of the dynamic simulation tool are provided and discussed, showing the potential of the paper manufacturing in DR programmes as well as the benefits associated to it. [ABSTRACT FROM AUTHOR]

Use of biomass for energy purposes has many advantages, but it is not always profitable due to the characteristics of biomass. In order to improve the utilization of biomass it is necessary to create optimal conditions which require employment of several methods and technologies. This paper describes developed approach for consideration of options for the optimal utilization of available biomass potential under the current conditions (technological, economic, environmental and social). The developed approach is focused on support for decision making process on community level. Proposed approach includes mapping of biomass potential with defining both potential primary storage locations and potential locations of plant using geographic information system technologies. Also, it includes determining the optimal amount of biomass that can be justifiably used for energy purposes under current conditions by using the mathematical optimization with objective function related to maximizing net present value quotient. Four groups of technologies that can be used for biomass valorisation have been considered in the paper; biofuels production, thermal power plants, district heating and cogeneration. The proposed approach has been applied (as a case study) on Municipality of Ivanjica located in South-West region of Serbia. Municipality of Ivanjica is characterized by both significant forest area and significant forest biomass potential. There are 30 potential primary storages locations and 57 potential plants locations determined by geographic information system. However, only one of potential locations of plant and two of potential primary storage locations (6% of available potential) are determined by mathematical optimization as optimal and could be used under current conditions. [ABSTRACT FROM AUTHOR]

This publication is considered the most promising path leading to the creation of energy-efficient engineering solutions for various buildings. This path begins with the first design calculations. The foundation for creating cost-effective heating and ventilation systems is carried out at the stage of forming the heat and mass balances of the premises as building components. Besides drawing the heat and mass balances must be closely connected with the study of the geometric parameters of premises and the thermal performance of the building envelope. In this paper a special way of heat load computing of heating and ventilation systems is considered. It is shown that considered method allows refining the calculations of heat losses of the building. The application of the proposed method to determine the transmission heat losses with the elemental approach is considered. The calculating method of ventilation heat losses with different variations of accounting the infiltration component is shown. Way of the joint account of heat energy consumption factors in a single mathematical apparatus is presented. The method of optimizing of heat loads during extreme operating conditions is reviewed. The paper shows further way application of accurate method in the design of buildings and the results of calculations. Some conclusions are suggested as a conclusion of this article. [ABSTRACT FROM AUTHOR]

Energy efficiency improvements in the shipping industry are being driven by economics, compliance and customer requirements. Whilst various technological and operation improvements are known and available, with many being demonstrated to be cost effective and with savings reported in the industry, their take up in the world fleet remains low. This low take-up can be considered due to many different barriers, as explored in various research studies. However the aim of this paper is first to understand how these barriers are created by considering how ship operations function day-to-day within the context of mainstream business practice. A holistic view of operations is required and is presented in this paper, including consideration of business focus areas in parallel with the functions of technical, operational and commercial stakeholders. With this laid-out, gaps within existing operations are discussed in relation to areas for practical improvements. From here, non-prescriptive mechanisms to enable a desired future are proposed; including the integration of mandates, processes and systems. Case studies are given throughout the paper using hull and propeller maintenance as a recurring example of a typical decision making processes and best practices. [ABSTRACT FROM AUTHOR]

A critical step in the design of a Net-Zero Energy building is the reduction of energy consumption, so that consumption can be cost-effectively offset by renewable energy production. In this paper, we present a method to inform the design of Net-Zero Energy buildings through the identification of influential energy efficiency measures. A regression-based global sensitivity analysis is used to quantify the relative importance of both individual design parameters and bilinear interactions between parameters. This allows for the identification of the specific two-way interactions between parameter pairs, rather than an evaluation of the influence of interactions for each parameter in a lumped manner as is commonly used in building performance simulation. The relative importance of both building control and architectural design parameters are assessed, and are used to help evaluate the importance of utilizing an integrated design method for reducing building energy consumption. The case-study building investigated is a primary vaccine warehouse, a vital part of the vaccine cold chain in the developing world. As this building type has not received adequate attention in the field of building performance simulation, this paper makes a significant contribution towards an improved understanding of the energy efficient design of these warehouses. [ABSTRACT FROM AUTHOR]

This paper estimated the cost curve of energy saving and CO 2 emissions reduction in China's iron and steel sector. Forty-one energy saving technologies which are widely used or popularized are selected, their investments, operation costs, energy savings and CO 2 abatement are collected and the data in 2010 are taken as a baseline. Then energy conservation supply curve and CO 2 conservation supply curve under two different discount rates are calculated in the paper. These 41 technologies result in a saving contribution of 4.63 GJ/t and a CO 2 abatement contribution of 443.21 kg/t. Cost-effectiveness of technologies was analyzed based on the fuel price and an estimated CO 2 price. When comparing the result with the promoted technologies during the 12 th five-year-plan, we found that some promoted technologies are not cost-effective in current situation. Three scenarios are set through changing the diffusion rate of technologies and the share of BOF and EAF, based on this energy saving potentials of technologies in 2020 and 2030 are forecasted. At the same time, we compared the change of the CSC depending on the year and the energy saving potentials in three scenarios of 2020 and 2030, respectively. [ABSTRACT FROM AUTHOR]

Technology evaluation of vehicle powertrains is the basis for policymakers and automotive manufacturers to make technical decisions. However, there is a research gap in comparative studies on different powertrain technologies under uniform assumptions (dynamic performance and test-driving cycles) for light-duty vehicles in China. To fill these gaps, this paper proposes an innovative technology evaluation model of the powertrains for the energy-saving cost-effectiveness of powertrains. The results are as follows: as the electrification degree of the powertrain technology increases, its curb mass and direct manufacturing cost increase, while its comprehensive fuel consumption gradually decreases. Changes in curb mass and direct manufacturing cost are the combined effect of powertrain electrification upgrades and engine simplification. ICEV has limited fuel-saving potential and poor cost-effectiveness. HEV can achieve more significant fuel savings with minor cost increases and has the highest cost-effectiveness. PHEV50, REEV180, and BEV400 have high fuel economies, but their cost-effectiveness is poor due to the high cost of the battery system. In the short term, the Chinese government should encourage automotive manufacturers to increase their research and development investment in HEVs to replace ICEVs. In the long term, the government should promote battery technologies to reduce the direct manufacturing cost of NEVs. [Display omitted] • A technology evaluation model of the powertrains (TEMP) is built. • The vehicle characteristics of different powertrain technologies with a detailed breakdown of components are calculated. • The energy-saving potential and cost-effectiveness of different powertrains are evaluated. • Some policy suggestions for promoting the development of powertrains are proposed. [ABSTRACT FROM AUTHOR]

• A new model is employed to estimate the carbon efficiency and carbon abatement cost of China's coal-fired power plants. • The change of carbon abatement cost is associated with input change and technical change. • The potential for carbon efficiency improvement for China's coal-fired power plants is substantial. • Non-state-owned power plants possess higher carbon efficiency and lower abatement cost relative to state-owned ones. In this paper, we propose a new model to investigate the carbon efficiency and carbon abatement cost of coal-fired power plants in China based on the directional distance function with endogenous directional vectors (DVs). We further decompose the change of carbon abatement cost into two contributing factors, i.e., input changes and technical change. The empirical analysis is based on a recent panel dataset comprising 616 Chinese coal-fired power plants from 2011 to 2012. The results show substantial potential for carbon performance improvement in China's coal-fired power plants, with higher carbon efficiency (CE) and lower carbon abatement cost (CAC) associated with non-state-owned enterprises. The decomposition analysis shows that the change in carbon abatement cost is mainly attributed to technical change. However, imposing DVs exogenously can get the opposite results and have a significant impact on the distributions of the estimated results. The findings of this paper provide new insights for better understanding the recent dynamics of the carbon performance of China's coal-fired power plants and have important policy implications. [ABSTRACT FROM AUTHOR]

Abstract: This paper categorises different concentrating solar power (CSP) hybrid options into light, medium and strong hybrids and discusses the combination of CSP with coal, natural gas, biomass and waste materials, geothermal, and wind. The degree of hybridisation depends on the interconnection of the plant components. Light hybrids create only limited synergies, such as the joint use of a substation, and their cost reduction potential is therefore limited, while strong hybrids share major plant components, such as steam turbine and condenser, and can better match their energy output with electricity pricing. The hybridisation options for CSP with different energy sources are plentiful ranging from feedwater heating, reheat steam, live steam to steam superheating with some options better suited for a specific energy source combination than others. The synergies created in hybrid plants can lead to cost reductions of 50%, better energy dispatchability as well as revenue maximisation. Several CSP hybrid studies exist for coal, natural gas and biomass but these are often investigating a specific hybrid concept. This paper considers several options at a higher level and also includes geothermal and wind which is novel. While the paper focuses on Australia the approach taken and concepts discussed are transferable to other countries. [Copyright &y& Elsevier]

Abstract: This paper analyses the cost effectiveness of the implementation of some of the Best Available Technologies (BATs) and Innovative Technologies (ITs) in the European industry up to 2030. This is done using a bottom-up model that considers the main processes involved in each facility. The model described in the paper assumes the retrofitting/upgrade of each European facility with a BAT or IT as soon as the criterion for a capital budgeting decision is met. The paper details the effect on the savings in energy and CO2 emissions by European industry, assuming different levels of requirement in the payback period used as main capital-budgeting decision criterion. This approach reveals the full potential that some technologies under research (as the ones considered in the Ultra–Low CO2 Steelmaking project and Carbon Capture and Storage technologies, as well as other technologies that are not widely deployed (Direct Reduced Iron technologies), may have in the European industry. The starting point of the simulation is adjusted so that the CO2 emissions of each facility in the model have a counterpart in the emissions recorded for the benchmarking exercise of the European Union Emissions Trading Scheme. The results show that, by 2030, for a payback period of two years, the margin of improvement in CO2 emissions is around 20%. Whereas, by 2030, for a payback period of six years, the margin of improvement in CO2 emissions is in the range between 50% and 65%. [Copyright &y& Elsevier]

Abstract: Energy flow from the primary energy to the final energy use varies depending on which device is used for the heating and cooling energy service. This paper presents economic analyses of medium capacity space heating and cooling systems from three perspectives – primary energy, final consumer, and social cost perspective. From the analysis results of primary energy and final consumer perspective, electric heat pump (EHP) system is found to be superior to the gas engine driven heat pump (GHP) system for the energy consumption and cost-effectiveness due to its higher system efficiency. However, the result of social cost perspective shows the GHP system is superior to the EHP system considering incurred incremental electricity generation capacity construction cost and avoided gas storage tank construction cost due to a new installation of each system. And this paper suggests three analysis methodologies – the primary energy, final consumer, and social cost perspective – can be used for developing various measures and policies for integrated demand side management. [Copyright &y& Elsevier]

Abstract: The textile industry is a complicated manufacturing industry because it is a fragmented and heterogeneous sector dominated by small and medium enterprises (SMEs). There are various energy-efficiency opportunities that exist in every textile plant. However, even cost-effective options often are not implemented in textile plants mostly because of limited information on how to implement energy-efficiency measures. Know-how on energy-efficiency technologies and practices should, therefore, be prepared and disseminated to textile plants. This paper provides information on the energy use and energy-efficiency technologies and measures applicable to the textile industry. The paper includes case studies from textile plants around the world and includes energy savings and cost information when available. A total of 184 energy efficiency measures applicable to the textile industry are introduced in this paper. Also, the paper gives a brief overview of the textile industry around the world. An analysis of the type and the share of energy used in different textile processes is also included in the paper. Subsequently, energy-efficiency improvement opportunities available within some of the major textile sub-sectors are given with a brief explanation of each measure. This paper shows that a large number of energy efficiency measures exist for the textile industry and most of them have a low simple payback period. [Copyright &y& Elsevier]

Abstract: Improvement of energy efficiency has been accepted as one of the most cost-effective approaches towards sustainable economic development and reduction of the continuously increasing energy consumption internationally. South Africa, being among the developing countries, is not an exception even though historically low energy prices and the lack of appropriate policies have created an energy intensive economy. This paper examines the factors affecting the trends in energy efficiency in South Africa from 1993 to 2006 and particularly the impact of structural changes and utilisation efficiency of the country''s energy intensity. Identifying and understanding the driving forces are necessary ingredients in the development of appropriate policy-making. This paper also provides disaggregation of the energy efficiency trends in the main sectors of the economy. We determine that structural changes of the economy have played an important and negative role in the increasing economy-wide energy efficiency. On the other hand, the energy usage''s intensity was a contributing factor to the decreasing trend of energy efficiency. We suggest that differentiated price policies may be required if South Africa is to create an effective energy efficiency policy. [Copyright &y& Elsevier]

Abstract: Construction or modernization of a wastewater treatment plant (WWTP) with membrane bioreactor (MBR) technology requires the selection of an optimal configuration and design. The objective of this paper is to evaluate a stand-alone MBR in comparison to a hybrid MBR, i.e., a combination of a conventional activated sludge (CAS) process and an MBR. This paper evaluates two different hybrid MBR configurations, i.e., in series and in parallel, and a stand-alone MBR. The impact of these MBR configurations on operation, performance, energy consumption and economy is evaluated. A hybrid MBR operated in series provides certain operational flexibility, ensures more stable conditions for the activated sludge leading to a more stable MBR operation at energy and cost efficient conditions. Nevertheless, determination of the optimal plant configuration depends on the particular local situation such as the presence and condition of old infrastructure, availability of equalization tanks and space requirement. [Copyright &y& Elsevier]

Abstract There is an upcoming "P&A wave" of wells that need to be permanently plugged and abandoned, especially in mature, offshore areas such as the North Sea and Gulf of Mexico. It is important to ensure that plugged wells do not leak after abandonment, as there could be several potential leak paths such as microannuli in plugged wells. To ensure well integrity after abandonment, permanent well barriers must extend across the full cross section of the well. That includes establishing barriers in all annuli, which could however be quite time-consuming and thus costly. This paper is a review of challenges and technologies for P&A of offshore wells, with an emphasis on cost-effective solutions while establishing permanent well barriers. An overview of cement and other plugging materials is given, as well as a discussion of different types of potential leak paths and failure mechanisms in permanently plugged and abandoned wells. Moreover, recent technology developments such as utilizing shale as barrier for P&A are described. A discussion on the special considerations related to P&A of subsea wells is also included. [ABSTRACT FROM AUTHOR]

Highlights • Calculation of life cycle costs and payback periods of building intervention packages. • Calculation of financial gap between nZEB and cost optimality. • Study covers single and multi-family house buildings for 2 periods and climate zones. • Ranking of intervention packages based on cost effectiveness and energy efficiency. Abstract Nearly zero energy buildings (NZEBs) constitute one of the main pillars of the energy policy of European Union (EU). Greece has recently established a clear definition for NZEB, however the interdependence between cost-optimality and the energy performance of NZEB has not been adequately studied. The present work includes a cost effectiveness analysis among different energy efficiency interventions for the existing residential Greek building stock. To this end, the calculation of the investment as well as the operating and maintenance cost for a wide range of energy efficiency measures were carried out. All calculations were based on the methodology defined in the Directive 2010/31/EU on the energy performance of buildings, while the economic evaluation assumptions were based on the EN 15459-1 standard. The goal is the determination of the most cost effective (cost-optimal) measures that are applicable for two different building types; Single Family House (SFH) buildings and Multi-family House (MFH) apartment blocks, taking into account the period of their construction and the climate zone they belong to. Furthermore, the scope of the paper includes also the assessment of the gap between these measures and the NZEB thresholds. The analysis showed that in various cases and depending on the exact national NZEB definition, NZEBs are located beyond cost optimality. [ABSTRACT FROM AUTHOR]

Abstract: The spark spread, or price differential between electricity cost and fuel cost, may be used to indicate whether a combined heating and power (CHP) system shows a cost benefit in a certain situation over a conventional separate heating and power system. This paper extends the spark spread concept to address the emission of CO2 and the consumption of primary energy by introducing two parameters: the emissions spark spread (ESS) and the primary energy spark spread (PESS). ESS and PESS are evaluated in 16 US cities for three different CHP system efficiencies, and compared to the minimum ESS and minimum PESS required for a CHP system to potentially reduce CO2 emissions (CDE) or primary energy consumption (PEC). Since the fuel mix used in electricity production, which varies with location, affects the amount of CDE or PEC due to the use of a CHP system, this paper also presents the ratios ESS/ESSmin and PESS/PESSmin that could be used for a simple analysis of the potential of a CHP system based on CDE and PEC. [Copyright &y& Elsevier]

Abstract: The electricity demand in Iran has increased steadily in recent years. This is mainly due to the rapid growth in the number of high-rise air-conditioned buildings and the rapid use of electrical appliances in residential and commercial sectors. This paper investigates the annual energy required for cooling per unit area and the total energy cost per unit area for each type of air conditioning systems in different climates in Iran. The paper also investigates the effects of changing the coefficient of performance (COP) of absorption chillers on cost saving. This study found that using absorption chillers for cooling will increase the amount of energy usage per unit area; however the energy cost per unit area will decrease. In addition this research indicates that for each 0.1 increment in COP of absorption chillers, there is at least 50USD/m2 saved cost. [Copyright &y& Elsevier]

Highlights • A distributed generation planning model in active distribution network is proposed. • Demand side management and network reconfiguration are taken into consideration. • The proposed planning model is converted to a three-layer programming model. • A hybrid solving strategy is developed to solve the model. • The total cost over the planning horizon can be reduced 3.8% under the new model. Abstract This paper proposes a novel distributed generation (DG) planning methodology in active distribution network considering both demand side management and network reconfiguration. The objective function of the planning model is to minimize the total cost over the planning horizon, including investment cost of DG, operation and management cost of DG, fuel cost of DG, active management cost of DG, and demand side management cost. The constraints contain not only traditional DG investment and electrical restrictions (for instance, limitation of DG penetration, constraint of nodal voltage, constraint of branch capacity, etc.), but also the various restrictions of active management measures including regulating the on-load tap changer of transformer, controlling the output power of DG, demand side management and network reconfiguration. It is a large-scale mixed integer nonlinear programming model, which cannot be effectively solved by a single algorithm. Based on the idea of decomposition and coordination, the planning model is converted to a three-layer programming model. A hybrid solving strategy is developed to solve the model, in which differential evolution algorithm is used to determine the type, location and capacity of DG, and tree structure encoding-partheno genetic algorithm and primal–dual interior point method are applied to simulate the operation of active distribution network and find out the optimal operation state for each scenario. Case studies are carried out on a 61-bus active distribution network in East China, and results show that the total cost over the planning horizon can be reduced about 3.8% when demand side management and network reconfiguration are considered. [ABSTRACT FROM AUTHOR]

Highlights • Analysis of possible energy savings in the German chemical industry. • Uncertainty analysis of costs and potentials of energy saving measures. • Evaluation of marginal cost curves of energy savings with uncertainties. • Determination of important model parameters using sensitivity analysis. Abstract In 2014, 19.3% of Germany’s industrial final energy consumption could be allocated to the chemical industry. Energy efficiency measures with focus on the chemical industry could thus contribute to reaching the German goal of reducing greenhouse gas emissions. To achieve this goal, energy planners and industries alike require an overview of the existing energy efficiency measures, their technical potential as well as the costs for realizing this potential. Energy efficiency opportunities are commonly presented in marginal cost curves, which rank these measures according to specific implementation costs. Existing analyses, however, do not take uncertainties in costs and potentials sufficiently into account. The aim of this paper is to create a marginal cost curve of energy efficiency measures for the chemical industry in Germany, while quantifying the uncertainties of the results and identifying the most influential input parameters. The identification of energy efficiency measures and the quantification of the associated technical potentials and costs were identified based on literature data and own assessments. Based on these findings a cost curve was created for the current technical potential. This potential was found to be 24.4 PJ per year, of which 23 PJ had negative lifetime costs. To investigate the uncertainties of these results, Monte Carlo simulations were performed to quantify the standard deviations of the implementation potential and costs. Furthermore, a sensitivity analysis, based on Morris Screening and linear regression, was conducted in order to identify the most influential model input parameters. With the applied approach, it was shown that uncertainties have a non-negligible impact on the final energy saving potential and costs, as well as the shape of marginal cost curves. The standard deviation of the energy saving potential was found to be 3.1 PJ. Furthermore, it is possible to systematically prioritise efforts in refining data. [ABSTRACT FROM AUTHOR]

Abstract: Warm-mix asphalt (WMA) has been gaining popularity in the asphalt industry primarily because of its ability to lower the energy required to blend asphalt mixes, which in turn results in less fuel consumption, slower aging of the asphalt binder and reduced emission of greenhouse gases. This paper evaluates the effects of different quantities of a WMA additive known as Sasobit® on the required heat energy and the amount of CO2 produced to increase the temperature of two aggregates from three sources and one binder from 25 °C to the point of mixing. The results showed that incorporating 1% Sasobit® can potentially reduce the required heat energy and amount of CO2 produced by 2.8% and 3.0%, respectively, for all aggregate types and sources investigated. The paper also presented design charts that enable energy policy makers and engineers to select the appropriate Sasobit® content to produce the most cost effective asphalt mixture with less environmental impact. The design charts show that 1.6% Sasobit® content is the most suitable proportion to be blended into the asphalt binder without compromising pavement resistance against fatigue failure. Two similar aggregates from different sources may exhibit similar specific gravities, but their specific heat capacities can vary widely. These differences have a significant effect on the required heat energy, asphalt production cost and the amount of emissions released into the environment. [ABSTRACT FROM AUTHOR]

Abstract: Industrial energy programs such as energy audit programs and long-term agreements (LTAs) are one of the most common means of promoting energy efficiency in industry. As a result of the European Energy End-Use Efficiency and Energy Services Directive from 2006, the Swedish Government Bill proposed a national energy program towards industrial small- and medium-sized enterprises (SMEs) using more than 500MWh energy annually. The aim of this paper is to present the structure and design of the program, adopted in 2010, the logics in brief behind the structure, as well as an ex-ante evaluation of the program’s cost-effectiveness. The paper is aimed towards the part of the program involving industry, i.e. not the part involving companies within service and sales etc. The proposed design primarily includes a subsidized energy audit with some minor LTA-elements, such as the need to report results from the energy audit, to present a plan over which measures to conduct, and after three years present which measures that were implemented. The ex-ante evaluation of the program shows a cost-effectiveness of 0.25–0.50Eurocents/kWh, yielding savings of about 700–1 400GWh annually. [Copyright &y& Elsevier]

Abstract: Traditionally, life cycle assessment (LCA) is mostly concerned with product design and hardly considers large systems, such as buildings, as a whole. Though, by limiting LCA to building materials or building components, boundary conditions, such as thermal comfort and indoor air quality, cannot be taken into account. The life cycle inventory (LCI) model presented in this paper forms part of a global methodology that combines advanced optimisation techniques, LCI and cost-benefit assessment to optimise low energy buildings simultaneously for energy, environmental impact and costs without neglecting the boundary conditions for thermal comfort, indoor air quality and legal requirements for energy performance. This paper first outlines the goal and scope of the LCI. Then, the partial inventory models as well as the overall building inventory model are presented. Finally, the LCI results are shown and discussed for one reference dwelling for the context of Belgium. [Copyright &y& Elsevier]

Abstract: The paper presents a full cost-benefit analysis of a deposit–refund program for beverage containers in Israel. We examine all cost elements of the program – storage, collection, and treatment costs of empty containers, and all potential benefits – savings in alternative treatment costs (waste collection and landfill disposal), cleaner public spaces, reduction of landfill volumes, energy-savings externalities associated with use of recycled materials, and creation of new workplaces. A wide variety of data resources is employed, and some of the critical issues are examined via several approaches. The main finding of the paper is that the deposit–refund program is clearly economically worthwhile. The paper contributes to the growing body of literature on deposit–refund programs by its complete and detailed analysis of all relevant factors of such a program, and also specifically in its analysis of the savings in alternative waste management costs. This analysis reveals greater savings than are usually assumed, and thus shows the deposit–refund program to be highly efficient. [Copyright &y& Elsevier]

Abstract: The purpose of this paper is to conceptually analyze the cost-effectiveness of voluntary energy efficiency programs targeted at the industrial sector. In the paper a broad methodological framework for such an assessment is outlined, and this is applied empirically to discuss the potential cost-effectiveness of the ongoing Swedish energy efficiency program PFE. The focus lies on the presence of asymmetric information and bounded rationality, and the paper discusses how these factors may influence the cost-effectiveness of these types of programs. We also highlight the impact of the self-selection mechanism on the program''s cost-effectiveness. The results show that the presence of information inefficiencies and asymmetries represents one of the major motives for policy intervention in the industrial energy efficiency field, but the substitution of energy management systems for electricity taxes—such as that achieved in the Swedish PFE program—does not necessarily address these asymmetries entirely cost-effectively. First, the presence of firm-government information asymmetries implies that electricity taxes could do a better job in energy-intensive companies while an energy management system could be more effective in companies with a low energy-intensive production process due to the lack of prior experience of energy efficiency measures. The current set-up of PFE induces the reverse situation. Second, although firm-internal information asymmetries may well exist in the participating energy-intensive companies—implying that energy management systems could do a good job in detecting cost-effective measures—this is likely to be even more true for the non-participating companies (again due to their comparatively low accumulated knowledge in the energy efficiency field). It should however also be acknowledged that this analysis is static, and in the long-run voluntary energy efficiency programs may lead to significant learning impacts and—given the public good characteristics of this new knowledge—to important spillover effects. [Copyright &y& Elsevier]

Abstract: Energy efficiency is one of the most potent and cost effective ways of meeting the demands of sustainable development. It has in fact been referred to as the best energy resource. Way back in 2005 the South African Department of Minerals and Energy (DME) published its Energy Efficiency Strategy in support of some of the objectives enlisted in the 1998 White Paper on Energy Policy. The Strategy set a national target for energy efficiency improvement of 12% by 2015 against the baseline year 2000. The document further predicted that, with a business as usual model of energy usage, at the projected rate of national economic development, there would be a need to invest in new power generating capacity by around 2007. Despite the policy foresight and seemingly enthusiastic efforts, though, the dawn of 2008 saw the country gripped in an electric power crisis, with a capacity shortfall of over 10%. This paper looks at what could have gone wrong, examines energy efficiency policies and measures in other countries and how these lessons could be adopted to the South African context. [Copyright &y& Elsevier]

Abstract: This paper examines recent temporal and spatial trends and forecasts in energy consumption, energy efficiency and energy costs in the transport sector across Europe. It explores the links between these trends and forecasts with individual actions and intentions concerning the reduction of energy in transport. It examines some of the differences between stated actions and intentions and investigates the effect of socio-economic factors (including age, gender and income) on stated actions and intentions. The paper draws on three Special Eurobarometer surveys from 1984, 1993 and 2002 to examine temporal and spatial trends in individual actions and intentions. Data from the 2002 Eurobarometer survey are explored in more detail to investigate some of the relationships between socio-economic factors (including age, gender and income) and the level of action and intention concerning the reduction of energy use in transport. [Copyright &y& Elsevier]

Abstract: Coal fired power generation will continue to provide energy to the world for the foreseeable future. However, this energy use is a significant contributor to increased atmospheric CO2 concentration and, hence, global warming. Capture and disposal of CO2 has received increased R&D attention in the last decade as the technology promises to be the most cost effective for large scale reductions in CO2 emissions. This paper addresses CO2 transport via pipeline from capture site to disposal site, in terms of system optimization, energy efficiency and overall economics. Technically, CO2 can be transported through pipelines in the form of a gas, a supercritical fluid or in the subcooled liquid state. Operationally, most CO2 pipelines used for enhanced oil recovery transport CO2 as a supercritical fluid. In this paper, supercritical fluid and subcooled liquid transport are examined and compared, including their impacts on energy efficiency and cost. Using a commercially available process simulator, ASPEN PLUS 10.1, the results show that subcooled liquid transport maximizes the energy efficiency and minimizes the cost of CO2 transport over long distances under both isothermal and adiabatic conditions. Pipeline transport of subcooled liquid CO2 can be ideally used in areas of cold climate or by burying and insulating the pipeline. In very warm climates, periodic refrigeration to cool the CO2 below its critical point of 31.1°C, may prove economical. Simulations have been used to determine the maximum safe pipeline distances to subsequent booster stations as a function of inlet pressure, environmental temperature and ground level heat flux conditions. [Copyright &y& Elsevier]

Emergent smart energy distribution systems offer new approaches in the sustainable management of energy consumption, even at household level. The smart grid and smart house paradigms provide the necessary infrastructure to improve the efficiency of the distribution system and at the same time offer benefits for the consumers, too. In this paper the control of an intelligent household refrigerator is introduced, which can autonomously react to hourly energy tariffs by shifting its operating periods to less expensive time slots, thus it greedily minimizes the energy bill of the consumer. As a “side effect”, the energy consumption is decreased during peak periods, which is the primary purpose of the utility provider, and also decreases the CO 2 emission. The proposed controller adaptively learns the dynamic behavioral model of the appliance, and utilizes this model in a predictive control scheme. The proposed method is evaluated utilizing a realistic household refrigerator model and real pricing data. The operation is also validated by a real hardware implementation, which confirms that the control algorithm can be implemented using inexpensive embedded hardware devices. According to experiments using real pricing data, the proposed model predictive control can save 9% of the energy bill and can decrease the peak energy consumption by as much as 76%. [ABSTRACT FROM AUTHOR]

In this paper, optimal design/operating conditions are presented by considering the cost-effectiveness and operability of a single-stage ammonia/water absorption refrigerator (AAR) via exergy analysis. Chemical exergy change constitutes complexity with respect to exergy analysis of absorption systems. In the study, Gibbs free energy is considered in the exergy analysis to precisely evaluate the absorption and rectification processes including chemical exergy change. The theoretical maximum exergy efficiency of AAR and the influence of its design/operating conditions on exergy efficiency/destructions are investigated under an ideal condition. The analysis indicates the importance of the evaporator outlet liquid (bleed) ammonia mass fraction and the desorber temperature. A condition of bleed mass fraction control is illustrated. In addition, the study involves performing a sensitivity analysis of design parameters (pinch temperatures) with respect to exergy efficiency and optimal desorber temperature. Finally, design conditions that maximize exergy efficiency per cost are derived relative to the sum of thermal conductance as a cost parameter. The study demonstrates the potential for downsizing the AAR without reducing exergy efficiency. The results indicate that approximately 39% total thermal conductance reduction, maintaining nominal efficiency, or 19% total thermal conductance reduction with an exergy efficiency increase of 16% are expected when compared to those in a commercial AAR. [ABSTRACT FROM AUTHOR]

This paper presents a study coming from an academic and industry partnership with the goals of exploring potential uses for UAS in distribution system operation and maintenance, establishing baseline costs and capabilities via equipment field tests, and simulating the cost benefits of increased maintenance. Existing UAS technology is shown to be capable of providing situational awareness for disaster response as well as increasing the number of maintenance inspections and speeding them up. [ABSTRACT FROM AUTHOR]

Reversible logic has captured significant attention in recent time for its reduced power consumption property which is one of the main concerns of digital logic design. Reprogram ability, higher speed, higher density, non-recurring engineering (NRE) costs, massive parallel operations and many other favoring factors have made prominent use of the Field-Programmable Gate Array (FPGA) in today's electronics world. In this paper, the most significant part of an FPGA, the Plessey Logic Block is designed in reversible manner with optimal parameters. On the way to design the proposed reversible Plessey Logic Block, each individual components such as reversible D-Latch, reversible Decoder, reversible Multiplexer, reversible Master-Slave Flip-Flop, reversible RAM are designed separately.. The proposed design of the individual parts is primarily optimized for the number of gates, garbage outputs, quantum cost and delay. In addition, area and power are optimized to ensure the power efficiency of the circuits. Two 4 × 4 reversible gates, namely HNF (Hafiz-Naz-Flip-Flop) gate and HND (Hafiz-Naz-Decoder) gate, are proposed to achieve the optimization goal. Moreover, proposed algorithms, lemmas and theorems certify the novelty of the proposed design. Compared to previous works, the proposed counter parts of Reversible Plessey Logic Block require less number of gates, garbage outputs, quantum cost and the delay. Finally, the proposed Reversible Plessey (4 × 2) Logic Block is compared with existing designs. The comparative result proves the efficacy and novelty of the proposed design showing improvement 51.62% in terms of number of transistor, 73.57% in terms of area (mm 2 ) and 34.12% in terms of power (mW) with respect to the corresponding metrics of the best design in literature. [ABSTRACT FROM AUTHOR]

The electricity system balancing is becoming increasingly challenging due to the integration of Renewable Energy Sources (RES). At the same time, the dependency of electricity network on gas supply system is expected to increase, as a result of employing flexible gas generators to support the electricity system balancing. Therefore the capability of the gas supply system to deliver gas to generators under a range of supply and demand scenarios is of a great importance. As potential solutions to improve security of gas and electricity supply, this paper investigates benefits of employing flexible multi-directional compressor stations as well as adopting a fully integrated approach to operate gas and electricity networks. A set of case studies for a GB gas and electricity networks in 2030 have been defined to quantify the value of an integrated operation paradigm versus sequential operation of gas and electricity networks. The results indicate there are significant overall system benefits (up to 65% in extreme cases) to be gained from integrated optimization of gas and electricity systems, emphasizing the important role of gas network infrastructure flexibility in efficiently accommodating the expected expansion of intermittent RES in future power systems. [ABSTRACT FROM AUTHOR]

Recently, wireless sensor networks (WSNs) have been widely recognized as a promising technology for enhancing various aspects of smart grid and realizing the vision of next-generation electric power system in a cost- effective and efficient manner. However, recent field tests show that wireless links in smart grid environments have higher packet error rates and variable link capacity because of dynamic topology changes, obstructions, electromagnetic interference, equipment noise, multipath effects, and fading. To overcome these communication challenges, in this paper, we propose a data capacity-aware channel assignment (DCA) and fish bone routing (FBR) algorithm for WSN-based smart grid applications. The proposed DCA framework deals with the channel scarcities by dynamically switching between different spectrum bands and employs a network for organizing WSN into a highly stable connected hierarchy. In addition, the proposed FBR mechanism provides robust loop free data paths and avoids high transmission cost, excessive end-to-end delay and restricts unnecessary multi-hop data transmission from the source to destination in the network. Thus, it significantly reduces the probability of data packet loss and preserves stable link qualities among sensor nodes for load balancing and prolonging the lifetime of wireless sensor networks in harsh smart grid environments. Comparative performance evaluations show that our proposed schemes outperform the existing communication architectures in terms of data packet delivery, communication delay and energy consumption. [ABSTRACT FROM AUTHOR]

In Recirculating Aquaculture Systems (RAS), water is continuously treated and recirculated as opposed to being discharged untreated into the environment as in other type of fish production systems; the design and production parameters will determine the overall energy consumption. This energy-intensive nature hampers their sustainability and cost-effectiveness. This paper proposes a combination of two methods (i.e. Life Cycle Assessment (LCA) with energy audits) to: improve environmental performance of RAS, identify energy consumption and thus, its environmental and monetary effects in order to seek cost reduction. The proposed methodology was proved with a case study focused in a pilot-scale RAS unit used in codfish ( Gadus morhua ) production, located in the Basque coastal area (northern Spain). Feed and juvenile production/transportation, oxygen transportation and energy consumed during the whole experiment were considered as inputs for the assessment. Energy consumption was measured both continuously by an energy meter embedded in the RAS unit as well as with a portable energy analyzer to measure each of the energy-consuming devices independently. Although the system required an average of 29.40 kWh/kg fish for successful system operation, the energy consumption varied by season presenting maximum and minimum periods of 40.57 and 18.43 kWh/kg fish, respectively. Main consumers included the heat pump, followed by the main and secondary pumps, respectively. Energy audit's results show the success in identifying the devices that consumed the largest amount of energy, and recorded data served to feed the Life Cycle Inventory and perform a more complete and precise LCA. Fossil fuel based on-farm electricity for the on-growing of fish was shown to be the most environmentally unfriendly input; it was the major impact producer in the assessed impact categories. It showed a temporal variability depending on the water temperature, which resulted to be the main factor linked to the energy use. This aided performing a precise assessment including system-specific scenarios. The combination of LCA and on-farm energy audit represents a useful tool to secure a more complete assessment with a periodic assessment to design a less energy intensive, profitable and sustainable system; likewise, it increases the speed and transparency of governance and decision-making, taking into account the time-based fluctuation of the energy consumption throughout the production cycle. [ABSTRACT FROM AUTHOR]

In Wireless Sensor Networks (WSNs) to address the duality between the cost-effective energy efficiency and the reliable data delivery is a relevant issue. This paper presents a novel bio-inspired routing protocol, named CB-RACO, that combines the Ant Colony Optimization (ACO) meta-heuristic with the computationally cheap and distributed community detection technique Label Propagation (LP). CB-RACO creates communities in the WSNs and meets the balance of energy consumption by routing data inside-communities through swarm intelligence. As a consequence, CB-RACO demands low memory and overhead in construction and maintenance of routing paths. Additionally, CB-RACO achieves high data delivery reliability through a data retransmission strategy based on acknowledgments between communities. We simulated CB-RACO in large-scale scenarios according to the goodput, delivery delay and energy consumption metrics. The results have shown that the proposed approach may provide significant improvement in comparison to ant-based strategies that do not rely on community structures. [ABSTRACT FROM AUTHOR]

Energy and water management has become a necessary part of industrial production for manufacturers to reduce their environmental impact and production cost because of increasingly serious resources crisis, strict environmental regulations and consumers’ demand for sustainable products. However, due to the complex operation processes and high investment cost, the existing energy, water and production management systems are not applicable and profitable for small and medium-sized manufacturers which are featured as poor capital flow and worker capability. In this paper, we develop a cost-effective energy and water management system, embedded in the production system. In addition to provide the production manager and workers in small and medium-sized manufacturers with an easy-to-operate way to conduct planning and supervision as well as complete production and information collection, the proposed system can find out the production process and team with low energy and water efficiencies by monitoring consumption in a low-cost way. The production manager can accordingly take technology improvement on specific process and enhance environmental training on specific workers to reduce consumption and increase profit. The monitoring results can also be used for financial accounting, cleaner production inspection and environmental products certification. [ABSTRACT FROM AUTHOR]

The increase in average lifespan and huge costs for health treatments have resulted in cost effective solutions for healthcare management. Wireless Body Area Network (WBAN) is a promising technology for delivering quality healthcare to its users. Low power devices attached to the body have limited battery life. It is desirable to have energy efficient routing protocols that maintain the required reliability value for sending the data from a given node to the sink. The current work proposes two protocols: Optimized Cost Effective and Energy Efficient Routing protocol (OCER) and Extended-OCER (E-OCER). In OCER, optimization using Genetic Algorithm (GA) is applied to the multi-objective cost function with residual energy, link reliability and path loss as its parameters for selecting the most optimal route from a given body coordinator to the sink. Distance between any two sensor nodes is reduced by applying multi-hop approach. E-OCER extends the work of OCER by considering inter-BAN communication. Performance of OCER is compared with other existing energy aware routing protocols by considering different parameters. A comparison of the performance of E-OCER with OCER is made to study the effect of on-body sensors communication on the energy consumption and throughput of the network. This paper also provides a comprehensive energy model to calculate the total energy consumption of the network. In addition to the radio transmission and receiving energy, other basic energy consumption sources viz. processing energy, sensor sensing, transient energy and transmission/reception on/off energy have also been taken into account. The results show an improved performance of the proposed protocols in terms of energy efficiency. [ABSTRACT FROM AUTHOR]

Soft open points (SOPs) are power electronic devices installed to replace normally open points in active electrical distribution systems. SOPs can provide active/reactive power flow control and voltage regulation under normal operating conditions as well as fast fault isolation and supply restoration under abnormal conditions. The application of SOPs can improve the controllability of distribution systems, thus further enhances the economy, flexibility and reliability of the grid. In this paper, considering the long-term operation characteristics of distributed generation, a mixed integer non-linear optimization problem is formulated to optimally determine the siting and sizing of SOPs based on the typical operation scenarios generated by Wasserstein distance. It is then transformed to and solved as a mixed integer second-order programming model. Finally, case studies on the IEEE 33-node system and Taiwan Power Company distribution system are used to verify the effectiveness and efficiency of the proposed method. [ABSTRACT FROM AUTHOR]

The paper presents cost-optimal energy performance improving measures conducted in deep renovations of typical Finnish (cold climate) brick apartment buildings, built in the 1960’s. The study discusses the effects of different renovation measures on the energy performance and economic viability in a selected building. Energy performance is studied from the primary energy consumption’s perspective and cost-effective renovation measures to meet higher energy performance criteria are also studied. The cost-optimal renovation concepts to meet different energy performance criteria were determined from over 2 billion potential renovation measure combinations by using sophisticated simulation-based multi-objective optimisation (SBMOO) analysis, utilising the advanced Pareto-Archive NSGA-II genetic algorithm, as the main research method. The SBMOO analysis was used to minimise the primary energy consumption and the net present value of life-cycle cost over a 25-year discount period simultaneously. The results indicate that the cost optimum renovation solutions of the brick apartment building stock provide the same energy performance criteria as the current national minimum energy performance requirements of new apartment buildings. According to the study, the investments should be focused on high performance renewable energy production systems, which deliver the best return on investment. External financial support mechanisms are also required to encourage apartment building owners to conduct deep renovations towards nearly zero-energy apartment buildings. [ABSTRACT FROM AUTHOR]

Energy management strategy and battery capacity are the primary factors for the energy efficiency of range-extended electric buses (REEBs). To improve the energy efficiency of REEBs developed by Tsinghua University, an optimal design method of global optimization-based strategy is investigated. It is real-time and adaptive to variable traction battery capacities of series REEBs. For simulation, the physical model of REEB and key components are established. The optimal strategy is first extracted by the power split ratio (PSR) from REEB simulation result with dynamic program (DP) algorithm. The power distribution map is obtained by series simulations for variable battery capacity options. The control law for developing optimal strategy are achieved by cluster regression for power distribution data. To verify the effect of the proposed energy management strategy, characteristics of powertrain, energy efficiency, operating cost, and computing time are ultimately analyzed. Simulation results show that the energy efficiency of the global optimization-based strategy presented in this paper is similar to that of the DP strategy. Therefore, the overall energy efficiency can be significantly improved compared with that of the CDCS strategy, and operating costs can be substantially reduced. The feasibility of candidate control strategies is thereby assessed via the employment of variable parameters. [ABSTRACT FROM AUTHOR]

Smart grids (SGs) have a central role in the development of the global power sector. Cost-benefit analyses and environmental impact assessments are used to support policy on the deployment of SG systems and technologies. However, the conflicting and widely varying estimates of costs, benefits, greenhouse gas (GHG) emission reduction, and energy savings in literature leave policy makers struggling with how to advise regarding SG deployment. Identifying the causes for the wide variation of individual estimates in the literature is crucial if evaluations are to be used in decision-making. This paper (i) summarizes and compares the methodologies used for economic and environmental evaluation of SGs (ii) identifies the sources of variation in estimates across studies, and (iii) point to gap in research on economic and environmental analyses of SG systems. Seventeen studies (nine articles and eight reports published between 2000 and 2015) addressing the economic costs versus benefits, energy efficiency, and GHG emissions of SGs were systematically searched, located, selected, and reviewed. Their methods and data were subsequently extracted and analysed. The results show that no standardized method currently exists for assessing the economic and environmental impacts of SG systems. The costs varied between 0.03 and 1143 M€/yr, while the benefits ranged from 0.04 to 804 M€/yr, suggesting that SG systems do not result in cost savings The primary energy savings ranged from 0.03 to 0.95 MJ/kWh, whereas the GHG emission reduction ranged from 10 to 180 gCO 2 /kWh, depending on the country grid mix and the system boundary of the SG system considered. The findings demonstrate that although SG systems are energy efficient and reduce GHG emissions, investments in SG systems may not yield any benefits. Standardizing some methodologies and assumptions such as discount rates, time horizon and scrutinizing some key input data will result in more consistent estimates of costs and benefits, GHG emission reduction, and energy savings. [ABSTRACT FROM AUTHOR]

Lighting accounts for a significant amount of electrical energy consumption in office buildings, up to 45% of the total consumed. This energy consumption can be reduced by as much as 60% through an occupant-dependent lighting control strategy. With particular focus on open-plan offices, where the application of this strategy is more challenging to apply due to differences in individual occupancy patterns, this paper covers (1) to which extent individual occupancy-based lighting control has been tested, (2) developed, and (3) evaluated. Search terms were defined with use of three categories, namely ‘occupancy patterns’, ‘lighting control strategy’, and ‘office’. Relevant articles were selected by a structured search through key online scientific databases and journals. The 24 studies identified as eligible were evaluated on six criteria: (1) study characteristics, (2) office characteristics, (3) lighting system characteristics, (4) lighting control design, (5) post-occupancy evaluation, and (6) conclusions, and this was used to answer the research questions. It was concluded that the strategy has not been tested yet with field studies in open-plan offices, but that it needs further development before it can be applied in these type of offices. Although lighting currently tends to be controlled at workspace level, many aspects of the strategy can be further developed; there is potential to further increase energy savings on lighting within open-plan office spaces. Individual occupancy-based lighting control requires further validation, focussing on the factors influencing its energy savings, on its cost effectiveness, and on its acceptability for users. [ABSTRACT FROM AUTHOR]

The European Energy Efficiency Directive requests the application of high quality and cost effective energy audits across Europe. The potential of up to 20% of energy savings shall be realized to follow the strategy of smart, sustainable, and inclusive growth. A number of barriers must be tackled to implement the Directive, especially among small and medium sized enterprises (SMEs). A large number of cost effective energy efficiency measures remains unimplemented because of financial reasons, a lack of information, and limited in-house skills. Information measures, audits, capacity buildings are suggested as potentially effective measures to support implementation of energy efficiency measures. Within the work described in this paper, an auditing approach was developed, focusing on modelling the energy consumption of an SME. The model of the energy consumption is built using simple MS Excel tools, dividing the process into unit operations and attributing annual consumption to these units, from measurements or by calculation. Consumption is linked to drivers of consumption and corresponding losses, thus developing an understanding of the origin of energy consumption, priorities, and the potential for reduction. The approach simultaneously addresses the needs for the identification of measures, capacity building, information and awareness raising. The auditing approach was tested with 280 companies in Austria, Bulgaria, Cyprus, Italy, Romania, Slovakia and Spain. A wide range of energy efficiency measures was identified and implemented, partly consisting of no-cost options, but partly also innovative technical solutions. Over EUR 10 million investments with a simple payback time of less than three years were triggered. 6500 toe per year of primary energy savings were realized, as well as greenhouse gas emission reductions of 13,500 tonnes per year. [ABSTRACT FROM AUTHOR]