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As a mainstream power storage and supply device, batteries are continuously upgraded. The microfluidic fuel cell has great development potential, and the paper-based microfluidic fuel cell is the latest achievement of its lightweight, which can be applied in the field of medical and biological detection. In this work, the cell models with various folding forms and unconventional absorption pads are creatively constructed, then the influence mechanism on cell performance is revealed by numerical simulation. Both transient and steady-state simulation methods are employed to monitor the whole process of paper-based microfluidic fuel cell. Conclusions show that the cell performance decreases with the increase of folding angle, the peak power density is as low as 1.71 mW/cm2, and the corresponding fuel utilization is only 2.73%. The changes in the absorbent pad shapes have little improvement on cell performance, thus the most direct way is increasing the absorbent pad volume. Moreover, materials with better water absorption capacity can increase the maximum current density to 28.70 mA/cm2, and the appropriate increase of operating temperature can also increase the peak power density to 2.36 mW/cm2, but the effect on the cell is significantly weakened if the temperature exceeds a certain limit. [ABSTRACT FROM AUTHOR]

The aim of this paper is to analyze through simulation how the energy efficiency of a single electrolysis stack at various loads is affected by shunt currents and to determine the energy-optimal load distribution between lines in a multiline electrolysis system under various magnitudes of shunt current losses. A dynamic energy and mass balance model of an industrial 3 MW , 16 bar alkaline water electrolyzer (AWE) process was developed using MATLAB. The optimization goal is to determine the power supply for each AWE line so that it can meet any hydrogen demand while minimizing the global specific energy consumption (SEC). The Particle Swarm Optimization (PSO) algorithm is used to minimize the objective function. According to the results of the single stack investigation, shunt current reduction could significantly improve the energy efficiency of partial-load operation. In addition, the optimization study revealed that whenever two or more lines are required to run in order to satisfy the hydrogen demand, the global SEC is minimized when the lines operate at equal loads. [ABSTRACT FROM AUTHOR]

Intermittent embedded devices and systems are widely used in various scenarios, but they often experience power failures due to unstable power supplies. Non-volatile memory (NVM) is gaining popularity in embedded systems due to its byte-addressability, low access latency, and high density. As a result, backups can be stored in NVM, and global data are directly manipulated in NVM in this architecture. However, NVM has limited write endurance and modifications to global data frequently occur which results in a significant number of writes. As a result, the extensive NVM accesses may lead to poor performance for intermittent programs. This paper presents an energy-efficient approach, called shadow-stack to minimize NVM write overhead while ensuring consistency. Furthermore, we propose a series of principles to assist programmers in rewriting the programs. And we prove the correctness of these principles using formal methods. Experimental results demonstrate that shadow-stack achieves an approximately 95.1%, 81.3%, and 76.6% improvement in NVM writes overhead compared with log-based, Coach, and Clank, respectively on average. Simultaneously, shadow-stack also significantly reduces energy and time consumption compared with log-based approach by up to 19.4 × and 6.87 × , Coach by up to 4.2 × and 2.46 × , and Clank by up to 3.4 × and 2.26 × respectively. [ABSTRACT FROM AUTHOR]

Energy extraction from renewable sources like hydrokinetic energy from the flowing water of rivers and canals is one of the affordable and clean energy generation technique. The current work is carried out towards performance enhancement of the Darrieus hydrokinetic turbine for open water channel utilization application. The investigation has been done using the flat and concave shape of blocking plate. Both blocking plates have been analyzed for different sizes as well as location at the upstream side of the turbine. The obtained results are reported after considering appropriate velocity correction. The blocking plates with projected width of 76 mm, 89 mm, 101 mm, 127 mm, 152 mm, and 203 mm are selected for the investigation. It is observed that 101 mm (Width Ratio , WR =0.36) with concave blocking plate provides maximum C p of 0.245 at 0.99 TSR. Also, the optimum region is found between 0.143 and 0.286 Distance Ratio (DR) from the top corner of the acrylic plate. The concave blocking plate enhance the performance more compared to flat blocking plate. The conclusion is made that, the performance with flat blocking plate with optimized width and location improve the power coefficient by 10.92% and that of concave blocking plate by 18.45%. • Energy extraction using Darrieus hydrokinetic turbine is one of the affordable and clean energy generation techniques. • The performance of the Darrieus water turbine has been compared with a bare rotor and with using two different types of blocking plates. • The concave and flat blocking plates have been experimentally analyzed, and its effect has been explored in the paper. • The different sizes of concave and flat blocking plates were placed at the upstream side of the Darrieus turbine to enhance the performance. • The paper also includes the optimum region of the optimized shape concave and flat blocking plates placed at the upstream location of the rotor. [ABSTRACT FROM AUTHOR]

Abstract With the revolution of the traditional economic and social pattern based on centralized fossil energy consumption, the regional integrated energy system (RIES) has gained rapid development in recent years for achieving higher energy efficiency. This paper expands the Demand Response (DR) concept to the RIES and presents an optimal operation model of RIES considering the DR mechanism on the energy price. In this paper, a comprehensive DR strategy combining energy price and different loads is firstly developed to exploit the demand flexibility of RIES in the DR model established. Based on the DR modeling of the RIES, an operation optimization model with environmental, economic benefits and energy supply reliability as objective functions has been firstly established in detail. Secondly, a complete scheduling scheme is built based on the energy consumption characteristics and system operation characteristic of the integrated energy system. The model presented could reduce the cost of system without causing a significant amount of environmental pollution, and improve the energy efficiency of the RIES efficiently. Besides, the scheduling strategy proposed could also provide support for the operation strategy of integrated energy system under the energy development. Hopefully, this paper will provide reference for future research and engineering projects on DR programs in the RIES. Highlights • The typical structure of the RIES is introduced. • A DR model suitable for the RIES considering different loads is established. • An optimal operation model of the RIES based on DR is established. • The load in the RIES is affected not only by energy price but also by other loads. [ABSTRACT FROM AUTHOR]

Industry poses one of the biggest challenges in the renewable energy transition. In this paper, fossil fuels in the European industrial sector are replaced by renewable energy using a novel tool, IndustryPLAN, a planning tool for the assessment of national industrial sectors. In a bottom-up approach, each industry sub-sector is addressed with energy efficiency and fossil fuel replacement measures based on best available and innovative technologies, and in a top-down approach, the fuel and electricity consumption per country is analysed and decarbonised. The results indicate that: 1. Known technologies can decarbonise most of the industrial sector; 2. Costs and efficiencies are improved by energy savings and electrification; 3. Limiting bioenergy consumption is a critical challenge, emphasising the key role of energy savings and electrification, and the alternative of using hydrogen or hydrogen-based electrofuels will make the transition more expensive and induce energy losses. A full transition to renewable energy and a decarbonised industry sector may be possible before 2050, however, this requires that all investments are sustainable from 2030 onwards and that grid electricity is fully decarbonised. This paper presents several pathways toward 100% renewable energy supply in the European industrial sector and discusses the implications of the outlined scenarios. • Four tangible 100% renewable energy scenarios for industry in EU27 + UK are established. • 100% renewable energy in industry is feasible before 2050. • Energy efficiency improvements are essential to limit biomass consumption. • Industry energy transition needs to be prioritised in short- and long-term planning. [ABSTRACT FROM AUTHOR]

The implementation of load management and demand response programs is motivating utilities to propose demand-side management to incentivize customers to modify their energy consumption during critical events, providing energy flexibility to the grid. With the widespread use of distributed energy resources, energy aggregators have grown significantly to manage the portfolio of residential buildings. This paper presents a control-oriented implementation to define the energy flexibility potential of a portfolio of residential buildings within the same energy aggregator. The data-driven methodology combines the resistance-capacitance thermal network model of the households with building integrated photovoltaics/thermal and air source heat pump models to assess the modification of the baseline of power demand at the energy aggregator level. The optimization is performed through a model predictive control (MPC) framework for day-ahead predictions. Parametric analysis and scenario investigation are exploited to define the optimal configuration for both the households and the grid operator. The presented methodology provides insight for energy efficiency and flexibility about the operating and design of energy aggregators in a demand response program. A Canadian virtual community is used as a case study to estimate the performance of the presented methodology. The optimization of load management at the aggregator level is presented for a representative demand response (DR) event during the winter season for two different energy pricing structures. Numerical results show the potential of the proposed methodology to guide the design and operation of virtual clusters integrating renewable technologies towards energy efficiency, showing a reduction of 40% in total energy consumption and a peak reduction of around 32%. [ABSTRACT FROM AUTHOR]

Research from economics and psychology suggests that behavioral interventions can be a powerful climate policy instrument. This paper provides a systematic review of the existing empirical evidence on non-price interventions targeting energy conservation behavior of private households. Specifically, we analyze four nudge-like interventions referred to as social comparison, commitment devices, goal setting, and labeling in 44 international studies comprising 105 treatments. This paper differs from previous systematic reviews by solely focusing on studies that permit the identification of causal effects. We find that all four interventions have the potential to significantly reduce energy consumption of private households, yet effect sizes vary immensely. We conclude by emphasizing the importance of impact evaluations before rolling out behavioral policy interventions at scale. [ABSTRACT FROM AUTHOR]

This paper presents the editorial for the Renewable and Sustainable Energy Reviews joint special issue devoted to the research work discussed and presented at the 11th Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES), held from the 4th September to the 9th September 2016 in Lisbon, Portugal and the 2nd South East European (SEE) SDEWES Conference held from June 15th to June 18th, 2016 in Piran, Slovenia. This special issue is in line with the journal's aim of publishing research from across the ever-broadening field of renewable and sustainable energy with a strong review element. Previous SDEWES conference special issues have gathered a significant knowledge base in the field of sustainable development that reflects the continuous research efforts of the SDEWES research community. Therefore, this editorial provides not only an overview of the papers published in this particular special issue, but also a wider overview of the current trends in the domain of sustainable and renewable energy. This year's special issue focuses particularly on the benefits of the bio-based economy, energy security issues, fossil fuel thermal plant alternatives and environmental constraints, district heating and cooling together with cross sector energy efficiency and energy conservation issues. Sustainable transport systems, the issue of fuel poverty in urban neighbourhoods and renewable energy to support development of peripheral rural areas, optimising passive building design for hot climates and solar-powered heating and cooling are further topics featured in this special issue. In the process of selecting papers for this special issue, the guest editors invited in total 23 extended manuscripts for consideration for publication. After a rigorous review process by expert reviewers overseen by the guest editors a total of 16 articles were accepted for publication. [ABSTRACT FROM AUTHOR]

Whether industrial agglomeration can promote an increase in energy efficiency is of great importance to not only China’s energy conservation and emissions reduction plans, but also China’s future sustainable development. This paper uses statistical data from 285 cities, from 2004 to 2013, to analyze the effect of industrial agglomeration on energy efficiency. The spatial autocorrelation tests show that there is significant spatial autocorrelation and spatial heterogeneity in urban energy efficiency. Although dynamic spatial econometric results show that industrial agglomeration can promote an increase in energy efficiency from a country level, there are significant differences at a regional level. In the east, the effect of industrial agglomeration on energy efficiency has a threshold effect, but in central and western areas, industrial agglomeration can promote the increase of energy efficiency, with the positive effect in western areas greater than that in central areas. Finally, based on the research, this paper puts forward concrete suggestions to enhance energy efficiency. [ABSTRACT FROM AUTHOR]

Adoption and improvement of energy efficiency is one of the recommended pathways to tackle the problems of growing energy demand and greenhouse gas emissions. However, studies show that rebound effects from energy efficiency improvements can erode anticipated energy savings. This paper elucidates the rebound effect arising from energy efficiency initiatives in Kenya. The study uses Index Decomposition Analysis to assess the drivers of Kenya's total primary energy supply. The paper then adopts the neoclassical growth model in the empirical analysis of energy and carbon rebound effects at the macro-economic level. Cobb-Douglas production function is further applied using Solow growth model and energy as a factor of production to approximate technological progress. Results of decomposition of energy supply show that energy intensity and affluence are the drivers with the most significant effect on energy supply while population has less critical effect. Average energy and carbon rebound effects show partial rebounds of 15.64% and 31.41%, respectively. These results imply that there is need to accelerate the pace of transitioning to green energy as the ultimate solution to minimizing environmental impacts arising from energy use and tackling climate change. • Carbon and energy rebound effects of energy efficiency initiatives is studied. • Decomposition analysis is used to investigate drivers of energy supply. • Energy intensity and affluence have most significant influence on energy supply. • Average estimates of carbon and energy rebound effects are partial rebound effects. [ABSTRACT FROM AUTHOR]

The building sector of the U.S. currently consumes over 40% of the U.S. primary energy supply. Estimates suggest that between 5% and 30% of any building's annual energy consumption is unknowingly wasted due to pathologically malfunctioning lighting and comfort conditioning systems. This paper presents analytical methods embodied within useful software tools to quickly identify and evaluate selected faults in air handling units (AHU) that cause large building energy inefficiencies. Algorithm for faults like stuck dampers and leaking dampers have been developed and tested in this particular case study. These damper fault detection algorithms can be applied to outdoor air and return air dampers both. The technical contributions of this work include expert rules that adapt to the Heating, Ventilation and Air-Conditioning (HVAC) equipment scale and operation and methods for sorting fault signals according to user-defined interests such as annual cost of energy inefficiencies. The combination of expert-rule based fault detection combined with first principles thermodynamic modeling is a unique contribution of this work that leads to quicker fault detection with minimal non-intrusive measurements. These contributions are particularly unique in their treatment of models and the careful consideration of user-interests in fault evaluation. As a first step to developing this general framework for fault detection, first-order faults such as stuck dampers and imbalanced airflows within several large air-handling units were targeted. The algorithms focused on detecting faults with minimal data and non-intrusive measurements. An example is presented of the potential energy savings in a large academic building that has been monitored. Real data from an academic building in Boston was collected from the building energy management system (BEMS) for the purpose of this study. Savings of around $3400/month or 18% of the monthly cost when a stuck damper fault occurred over an entire month in an air handler. Another fault that was investigated was that of leaking dampers which lead to savings of approximately $500/month or around 2.5% of the monthly energy expense. The savings would accrue if the fault were corrected; otherwise the occurrence of the fault causes a waste of money and energy predicted. The algorithms developed can be applied to large commercial office buildings, academic buildings, hospitals and other modern buildings in various climates as long as they have data collecting capabilities. [ABSTRACT FROM AUTHOR]

• A method for mapping energy/resource flows of manufacturing systems is proposed. • Key performance indicators highlighting the inefficiencies are developed. • The method supports defining corrective actions to improve production efficiency. • Case study results show a significant saving of energy and resources. The assessment and monitoring of energy and resource efficiency is an essential activity toward the implementation of sustainable manufacturing practices. Existing energy/resource assessment methods and tools are not based on a comprehensive approach, lack on the use of specific key performance indicators, are dedicated to expert stakeholders and do not provide useful suggestions for improving production systems. This paper proposes an innovative method, called Resources Value Mapping that aims to map and classify activities and related energy/resource consumptions according to lean philosophy principles (value-added, non value-added, waste). A user-friendly map and two efficiency indicators (Cost Index and Muda Index) are proposed to quantitatively support the identification of criticalities related to activities, processes, lines, plants, etc., and to successively guide the decision-making process during the improvement strategies implementation. The method has been used to analyze a manufacturing plant that produces cooking appliances. The case study demonstrated the applicability of the method in real industrial contexts and its effectiveness in identifying the energy/resource flows (electricity and compressed air), departments (sheet department) and lines (mechanical and hydraulic presses) for which the waste and non value-added consumptions are prominent. The analysis highlighted that less of 20% of the resources consumed during the process creates value, offering wide margins for improvement. Finally, it aided the definition of an action plan leading to relevant reduction of resource consumptions, economic savings and environmental benefits. [ABSTRACT FROM AUTHOR]

The increasing energy demand in harbour areas, coupled with the need to reduce pollutant emissions, has led to the development of renewable energy-based polygeneration systems to face the carbon footprint of ports and ships at berth. In this way, in the coming years, ports can be converted into modern energy hubs. From this point of view, this paper presents a new dynamic simulation model for assessing and optimizing the energy and economic impact of ports. Here, energy systems and renewable sources can be designed to be connected to national electricity and natural gas grids and can include also alternative fuels (hydrogen, biomethane, etc.) and thermal energy networks, as well as different biomass fluxes (to be exploited for energy aims). Energy availability/demands of near towns and port buildings/infrastructures, as well as on-shore power supply are also included in the dynamic assessments. Hourly weather data and different prices for all the considered energy carriers are taken into account hour by hour. A multi-objective optimization approach is also implemented in the model considering energy and economic indexes to be optimized. The whole model is implemented in a computer tool written in MATLAB. For showing the capability of the developed model, a novel case study referred to the port of Naples (South-Italy) is presented. Here, several renewable energy sources are considered, including an anaerobic biodigester for producing biogas from the organic waste of docked cruise ships. A combined heat and power system (fed by biogas) is implemented in the port energy hub also for supplying absorption chillers. PV panels, and marine power generators are also included. In the conducted analysis, optimization targets are the maximization of system self-consumption and self-sufficiency as well as the minimum simple payback period. The proposed system can effectively contribute to the decarbonization of the port energy demand and reduce harmful pollutant emissions. Results showed that very high rate of renewable energy produced on-site can be exploited (up to 84%) by the considered port facilities, ensuring increasing independency from utility power grid (self-sufficiency index up to 40%). By the obtained results and through the developed simulation/optimization tool, novel design and operating criteria can be achieved for future port energy hubs featured by renewables and bi-directional energy exchange between ships and port. [ABSTRACT FROM AUTHOR]

The deployment of electric vehicles (EVs) is rapidly progressing worldwide, and energy efficiency is an important indicator for both the economy and the environment. It is necessary to verify whether EVs are more energy efficient than internal combustion engine (ICE) vehicles. However, studies have yet to evaluate the energy efficiency of EVs using the data envelopment analysis (DEA) approach. To fill this research gap, this paper evaluated the energy efficiency of EVs for road passenger transportation using a slacks-based measure (SBM) approach in six European countries from 2012 to 2018. EVs have been separated from the entire transport sector and compared to ICE vehicles. In the case of EVs that use electricity as fuel, the primary energy supply must be used as energy input to reflect conversion loss during power generation. The primary energy supply was calculated by applying the power generation efficiency of each country for use as an energy input to reflect conversion loss. EVs were more energy efficient than ICE vehicles in four out of six countries but less energy efficient in two countries. Based on the measured slack results, the potential energy savings were quantified, and the main factors in reducing energy efficiency were identified. • The energy efficiency of EVs for road passenger transportation was analyzed. • A SBM model based on DEA was used for this analysis for the first time. • Primary energy supply was used as an input to reflect the energy conversion loss. • EVs were more efficient than ICE vehicles in Belgium, Germany, Norway, and the UK. • Large labor force (Greece) and energy consumption (Italy) led to low EV efficiency. [ABSTRACT FROM AUTHOR]

This paper discusses the application of distributed energy resources (DERs) at water resource recovery facilities (WRRF). The DERs considered include solar photovoltaic (PV) systems, biomass electricity generation, and energy storage systems (ESS). The financial and demand management implications of the deployment of various DER combinations are analyzed. The load profile of a single plant is studied in order to draw conclusions regarding the optimal size for energy storage solutions based on the goals of the WRRF. A case study of a Medium sized WRRF, located in a large metropolitan area, is used to compare different financial and technical implementation strategies. An ideal combination of DERs is determined based on analysis of various scenarios for nine distinct use cases. The overarching goal of this paper is to understand the potential of various combinations of DERs for managing peak demand and resilience at WRRFs. Elements in the financial models are compared to determine the combination that creates a financially viable project while providing tangible benefits in resilience and/or demand management to the WRRF. • Energy efficiency is key for urban regions to combat global warming. • Distributed energy resources (DERs) improve resiliency during power failures. • Energy efficiency is possible through deployment of DERs and better use of biogases • Distributed energy resources (DERs) improve resiliency during power failures. [ABSTRACT FROM AUTHOR]

Abstract In this paper we examine how decision makers can more precisely assess the costs of disruptive weather events and the value of resilient distributed energy systems such as combined heat and power (CHP). CHP makes up a small percentage of the energy infrastructure in the United States despite its substantial efficiency and resilience benefits. In part this is because the resilience value of CHP is not fully accounted for in energy infrastructure project cost screenings. To capture this benefit in investment decisions, we propose a framework for a metric called the Distributed Energy Resource Resiliency Value (DERRV) and discuss how such a metric might be applied to CHP. [ABSTRACT FROM AUTHOR]

Energy efficiency is a critical issue in data centre management, which is the foundation for cloud computing. The VM placement has a considerable impact on a data centre's energy efficiency and resource utilisation. The assignment of VMs to PMs is an NP-hard problem without an easy way to find an optimal solution, particularly in large-scale data centres. In this study, the VM placement problem is formulated as a constrained optimisation problem. The Genetic Algorithm (GA) is a suitable method for solving this problem in terms of the quality of the solution. However, GA is time-consuming to obtain an optimal solution in the large scale optimisation problem. Therefore, this paper focuses on accelerated GA for energy-efficient VM placement. As the most time-consuming element of the GA is the calculation of its fitness function, this paper simplifies this calculation through a new fitness function in GA. Simulation results of small-, medium-, and large-scale data centres demonstrate that our accelerated GA is faster than the standard GA and gives better quality of solution than the First Fit Decreasing (FFD) algorithm, respectively. The findings of our GA with the new fitness function reveal an 8% energy saving for our GA compared to FFD and a 66% reduction in our GA execution time compared to the standard GA with standard energy formula as a fitness function. The number of generations in our GA is reduced by about 50% in comparison with the standard GA. Moreover, we started with 3000 PMs in the large-scale dataset, and only 1086 PMs were actually used after running our GA. Therefore, we may switch off far more PMs for energy savings from our GA results than those from the standard GA. • Virtual machine placement problem formulated as a constrained optimisation problem. •It focuses on accelerated genetic algorithm for virtual machine placement. •Our algorithm can minimise residual resources using Taylor extension. •Our solution quality is better than FFD and standard genetic algorithm. •It reduces execution time and energy in large scale data centres. [ABSTRACT FROM AUTHOR]

On-bill schemes are innovative financial frameworks for supporting energy renovation based on private capital. Direct intervention of public authorities may not be necessary. The pivotal role is assumed by energy utilities which are the originators of the business and act as market aggregators. On-bill schemes are based on a simple principle, namely the utility supports the energy renovation of final users by providing the upfront capital to repay on the utility bill. This implies that energy supply and renovation services are provided by the same company. This could be a limitation since the user may be obliged to stay with the same energy supplier for all the duration of the on-bill scheme. Even more complications can arise when the dwelling is sold or rent to another tenant. For such a reason it is important to find solutions for the possible decoupling of energy supply and energy renovation services. The present paper introduces an innovative business model which involves Distribution System Operators or other designated entities acting as market facilitators supporting the decoupling between energy supply and building energy renovation services. To characterise precisely the business ecosystem and the relations among the different actors, the Value Flow Model is employed. • On-bill schemes are useful tools for supporting deployment of energy efficiency measures. • Innovative business models allow to remove relevant market barriers. • The involvement of DSOs can improve the flexibility of on-bill schemes. [ABSTRACT FROM AUTHOR]

This paper presents a case study on optimal options for distributed energy resource (DER) technologies to reduce greenhouse gas emissions in a large retail shopping centre located in Sydney, Australia. Large retail shopping centres take the largest share of energy consumed by all commercial buildings, and present a strong case for adoption of DER technologies to reduce energy costs and emissions. However, the complexity of optimally designing and operating DER systems has hindered their widespread adoption in practice. This paper examines and demonstrates the value of DER in reducing the carbon footprint of the shopping centre by formulating and solving a multiobjective optimisation problem using the Distributed Energy Resources Customer Adoption Model (DER-CAM) tool. An economic model of the shopping centre is developed in DER-CAM using on-site-specific demand, tariffs, and performance data for each DER technology option available. Four key optimal DER technology investment scenarios are then analysed by comparing: (1) solution trade-offs of costs and emissions, (2) the cost of reduced emissions attained in each investment scenario, and (3) investment benefits with respect to the business-as-usual scenario. The analysis shows that a moderate investment in combined cooling, heat and power (CCHP) technology alone can reduce annual energy costs by 8.5% and carbon dioxide-equivalent emissions by 29.6%. A larger investment in CCHP technology, in conjunction with on-site solar photovoltaic (PV) generation, can deliver nearly 72% reductions in emissions at a 47% increase in total energy costs. The study demonstrates the effectiveness and flexibility of this type of modelling approach for the analysis, design, and ongoing assessment of new DER technologies under changing market conditions, supporting a more robust adoption of DER technologies in the commercial building sector. [ABSTRACT FROM AUTHOR]

The use of photovoltaic power plants is rapidly expanding, despite the continued growth in the production of traditional mineral resources. This paper analyses photovoltaic panels (PVP) in order to identify the best values of their various nominal (rated) parameters in terms of lifetime and efficiency. The authors have created a database of one-sided PVPs from 100 to 450 W power range, which includes PVPs from 72 manufacturing companies around the world. The paper analyzes 1300 mono- and polycrystalline, heterostructural and thin-film PVPs. The following PVP parameters were analyzed: efficiency, temperature coefficients of power, short circuit current, open circuit voltage, square per power, mass per power, number of cells, operating temperature and lifetime. The results obtained can be widely applied in simulating the operating modes of photovoltaic power plants and will improve the accuracy of feasibility studies of the implementation of autonomous power supply systems. • Parameters of photovoltaic panels (PVPs) is necessary for modeling and analysis of solar power systems. • The best and the median values of the main 16 parameters among 1300 PVPs were identified. • The results obtained help to quickly and visually assess a given PVP (including a new one) in relation to the existing ones. • The median and the best parameters will reduce the time of feasibility studies for the implementation of autonomous photovoltaic power plants. • According to the medians of parameters, the most efficient are heterostructural PVPs, the least efficient are thin-film PVPs. [ABSTRACT FROM AUTHOR]

Southeast Asia is a significant stakeholder in the global action against climate change, given its growing population, rising greenhouse gas emissions, and vulnerability to climate change impacts. Public policy makers in this region are faced with the challenge of transitioning to cleaner energy sources to enable the attainment of Paris Agreement goals, while also expanding access to affordable and reliable energy supplies. Southeast Asia has one of world's fastest growing rates of greenhouse gas emissions due to rising fossil fuel combustion, second only to South Asia. As such, it is imperative to decouple its energy consumption from emissions growth. This paper reviews Southeast Asia's energy sector trends, with a focus on electricity supply and demand vis-à-vis global decarbonization efforts. Based on global and regional best practices, the paper highlights the crucial role that governments and public policy can play in accelerating the region's clean energy transition, namely through the establishment of mandatory long-term climate and renewable energy targets and binding policies; use of iterative and adaptive power system planning; support for effective market development; financing of pioneering investments and trunk infrastructure; and support for a just and equitable transition. • Countries of Southeast Asia need to accelerate the clean energy transition. • Governments and public policy play a key role in the energy transition. • Policy prescriptions provided based on global and regional best practices. [ABSTRACT FROM AUTHOR]

This paper presents an innovative approach for the understanding and control of grid-connected hybrid micro-generation systems (HMS) without energy storage, to supply electricity to a group of homes designated as 'Sustainable block'. The initiative is based on an effort to integrate non-conventional renewable energies (NCRE) through distributed generation (DG) projects intended for remote and rural communities in Chile and South America, where electricity supply is both expensive and often times unreliable. This may be due to equipment malfunction, line faults and/or harsh climatic conditions or other natural phenomena like earthquakes, all of which can undermine the electric power distribution networks. Here a systems thinking (ST) and cybernetics approach is employed which looks at grid-connected microgrids supplying power to local loads as intrinsically dynamic, complex adaptive systems (CAS). Moreover, such systems can be viewed and approached as a complex sociotechnical system, wherein the energy users ought to play a crucial role as 'active loads' within the sustainable block to which the grid-tie microgrid is coupled. Building upon this theoretical framework, a set of coordination and supervisory control strategies for renewable microgrids is presented based on homeostatic control (HC) principles introduced by Schweppe et al. Homeostatic control of power systems. In: Fourth energy monitoring and control system conference. Norfolk, VA: November; 1979. The approach is intended to study and eventually develop new forms of sustainable renewable energy technologies (RETs) for DG of electricity and heat, working in parallel with the grid and offering new choices and benefits to energy users everywhere. A concrete theoretical model is proposed and the algorithms depicting the strategies are explained and compared through simulation analysis. Unlike what is available in the literature on sustainability, and looking at what is missing in regards to HMS as sustainable energy systems (SES), this paper offers an entirely new and significant perspective in terms of design and operation of such systems. First the concepts of sustainability and SES applied to HMS are explored, finding that the large majority of the mainstream analysis reviewed on the subject is focused on socio-economic, environmental, and regulatory issues rather than on the systemic, technical and operational aspects of such systems, as this paper does, and how HC, energy efficiency (EE), and a novel approach to energy supply and consumption equilibrium based on homeostasis can help build more sustainable HMS. Results are presented which confirm the hypotheses underlying the strategies employed and the model predictability, showing that SES are indeed possible and feasible. Discussion and recommendations are also offered stressing the fact that sustainability is essentially a systemic property and operational in nature, rather than explained by exogenous factors. [ABSTRACT FROM AUTHOR]

The electrical installations to supply power for heavy loads usually are three-phase and have several cables in parallel. One reason for this choice has been the mechanical difficulties that arise when cables are too large. The shape or arrangement of cables within the conduit, beds, cable trays, or other assembly systems for cables can make each cable have a different impedance and, therefore, cause uneven distribution of the current between the cables of the same phase or circulating currents that appear in the neutral conductor. Using the Finite Element Method (FEM) or applying the solution of analytical equations, one can better understand this problem and, thus, propose solutions. This paper implements the analytical methodology, analyze it through the FEM, and take measurements in the laboratory. Thus, the method will be validated and then applied to the study of a proposed case. The purpose of this study is to present a methodology that can contribute to maximize cable ampacity and to improve the shelf life and the energy efficiency of the installation. [ABSTRACT FROM AUTHOR]

In the present paper, life cycle analysis of coal-based synthetic natural gas (SNG) is performed for heat supply and electricity generation in China with a full consideration of energy efficiency, environmental pollutions and greenhouse gas emissions. Several different technical routes of SNG are studied in detail and the emissions of SO 2 , NO x , CO 2 and energy efficiency are all calculated. For comparisons, technical routes of ultra supercritical and coal-fired power generations are also analyzed together with a direct use of coal for heat supply. Our results show that the cogeneration of heat and electricity is a suitable technical route for SNG utilization. Comparing with ultra-supercritical and coal-fired power generations, technical routes based on SNG could significantly reduce the emissions of pollutants (especially for heat supply) with an acceptable level of the energy efficiency. After synthesis of SNG, our life cycle analysis suggests that SNG should be transported to the energy demand center for further power generation locally. [ABSTRACT FROM AUTHOR]

Understanding the energy metabolism of national economies is nowadays crucial for policymakers in order to define effective policies and to properly set energy efficiency targets. Energy accountings based on the traditional Production-based accounting method (PBA) allows to understand how primary energy is directly extracted, traded, transformed and used within each economy. On the other hand, Consumption-based accounting method (CBA) allows to understand the ultimate economic purposes of such energy flows. The information provided by the joint application of these approaches may provide useful and complementary insight on the national energy metabolism, allowing to identify hotspots for potential interventions from both the supply and demand side. This paper reviews PBA and CBA energy accounting methods, presenting a possible way for the joint use of their results, consistently represented by means of one unique Sankey diagram. This will be useful to have a comprehensive insight on the energy metabolism of national economies, supporting analysts and policymakers in the identification of energy efficiency hotspots. The method is applied to South Africa and to the neighbor country of Botswana, based on data provided by IEA energy statistics and the EORA26 Multi-Regional Input-Output model, taking into account non-renewable fossil energy (raw coal, crude oil and natural gas) and considering the reference year 2013. Results suggest that the joint use of PBA and CBA methods may provide useful information on the hidden energy links among national economies, helping analysts and policymakers in defining alternative energy efficiency policies. For this reason, the Authors argue that results of CBA should be provided alongside energy statistics based on the traditional PBA approach. [ABSTRACT FROM AUTHOR]

Emissions of GHG from the transport sector and how to reduce them are major challenges for policy makers. The purpose of this paper is to analyse the level of greenhouse gas (GHG) emissions from ships while in port based on annual data from Port of Gothenburg, Port of Long Beach, Port of Osaka and Sydney Ports. Port call statistics including IMO number, ship name, berth number and time spent at berth for each ship call, were provided by each participating port. The IMO numbers were used to match each port call to ship specifications from the IHS database Sea-web. All data were analysed with a model developed by the IVL Swedish Environmental Research Institute for the purpose of quantifying GHG emissions (as CO 2 -equivalent) from ships in the port area. Emissions from five operational modes are summed in order to account for ship operations in the different traffic areas. The model estimates total GHG emissions of 150,000, 240,000, 97,000, and 95,000 tonnes CO 2 equivalents per year for Gothenburg, Long Beach, Osaka, and Sydney, respectively. Four important emission-reduction measures are discussed: reduced speed in fairway channels, on-shore power supply, reduced turnaround time at berth and alternative fuels. It is argued that the potential to reduce emissions in a port area depends on how often a ship revisits a port: there it in general is easier to implement measures for high-frequent liners. Ships that call 10 times or less contribute significantly to emissions in all ports. [ABSTRACT FROM AUTHOR]

In recent years, the volume of data has grown exponentially. Big data analytic platforms for the smart grid have enormous potential since they play an essential role in the decision-making process and help to prevent disasters or instabilities in the grid. Vehicle to Grid (V2G) technology has become a buzzword in the industry. It is posited as a forthcoming technology to be grasped in a distant, ultimately green, and future. However, this view is now being challenged as V2G is being deployed at a large scale. The severe challenges of rapid population growth, ecological pollution, and energy deficiency have encouraged the design of smart grids and electric transport systems, especially electric vehicles containing central energy utilization systems in a smart city. This paper proposes a robust and distributed approach to balance supply and demand. This study have constructed a unique framework to manage the ambiguous performances of vehicles and supplied energy resources in a smart city. Furthermore, it analyze the influence of network topology by evaluating the strength of solid network motifs using predictive analysis for the whole system. [ABSTRACT FROM AUTHOR]

Drawing on agency theory and absorptive capacity literature, this paper empirically analyzes factors of adoption and barriers to adoption of four crosscutting, ancillary energy efficiency measures (EEMs) for non-residential buildings (efficient lighting, building insulation, heating system replacement, and optimization of heating system operations). The empirical analysis employs a large representative sample of organizations in the German trade, commerce and services sector. Results from econometric analyses provide evidence for a negative effect of principal–agent relationships (landlord-tenant; owner-user of energy supply equipment; parent-subsidiary) and for a positive effect of organizational attributes that contribute to absorptive capacity (energy manager in place; energy audit conducted; experience with decentralized low carbon energy). However, the significance of these effects varies by measure. For non-adopters, heterogeneity of crosscutting ancillary EEMs has little impact on the ranking of barriers to adoption. The most relevant barriers for all EEMs are rented spaces, high investment costs, and other priorities; least relevant are technical risk to production and risk to product quality. Finally, we find little evidence for differences in the factors of adoption and barriers to adoption between manufacturing and non-manufacturing organizations. These findings are robust to alternative model specifications. [ABSTRACT FROM AUTHOR]

Using renewable energy as wood chip or improving wood chip heating process are different usual ways to reduce carbon dioxide emission. The more uncharted path to reduce it is to limit energy consumed to produce wood-based fuel as wood chips or pellets. Wood chipping is the first step of each wood fuel production process. Chipping wood knowledge is also important for improving wood chipper efficiency. This paper compares two methods for determining cutting energy of a disc chipper and evaluates influence of anvil position on chipper efficiency. Cutting force is measured by the anvil bending during chipping and disc chipper energy supply is calculated by multiply the torque applied by the Power Take Off (PTO) to the shaft of the chipper by the shaft speed. In our study, a large set of chipping conditions are tested on a disc chipper with different species, log diameters, infeed volume rates and anvil vertical position. Cutting force measured from anvil's strain represents one impact for each half disc turn because the disc has two knives, whereas chipper energy supply is similar to a sinus curve. Cutting force depends of wood specie, diameter, infeed volume rates and anvil vertical position. Higher the wood infeed volume rate and diameter are, higher the cutting forces are. A disc chipper efficiency is estimated as the ratio of the cutting energy and the chipper energy supply. [ABSTRACT FROM AUTHOR]

High energy efficiency for low operating cost of desalination can be obtained from operational optimizations as well as component-wise innovations. This paper is concerned with an energy-efficient operation for reverse osmosis (RO) desalination process involving a joint control of multiple modules. Energy resource considered for desalination is of two types: intermittent solar energy and steady grid energy. With solar energy, the energy efficiency is measured by total permeate production obtained while the solar energy is available. With grid energy, the energy efficiency is measured by the power consumed to get unit permeate production rate. Achieving maximum energy efficiency is equivalent to solving constrained optimization. For the constrained optimization, obligatory constraints are given by the permissible ranges of trans-membrane pressure on RO membrane and total dissolved solids of permeate, and optional constraint is given by the permissible range of permeate production rate. Constraints as well as the objective function are modeled by the empirical second order equations in terms of control variables of multiple modules. Jointly optimal values of the control variables are found by the sequential quadratic programming. Experimental results obtained by the jointly optimal control demonstrate superior performances as compared to those acquired by marginally optimal control schemes. [ABSTRACT FROM AUTHOR]

The use of data envelopment analysis (DEA) in China’s regional energy efficiency and carbon emission efficiency (EE&CE) assessment has received increasing attention in recent years. This paper conducted a comprehensive survey of empirical studies published in 2006–2015 on China’s regional EE&CE assessment using DEA-type models. The main features used in previous studies were identified, and then the methodological framework for deriving the EE&CE indicators as well as six widely used DEA models were introduced. These DEA models were compared and applied to measure China’s regional EE&CE in 30 provinces/regions between 1995 and 2012. The empirical study indicates that China’s regional EE&CE remained stable in the 9th Five Year Plan (1996–2000), then decreased in the 10th Five Year Plan (2000–2005), and increased a bit in the 11th Five Year Plan (2006–2010). The east region of China had the highest EE&CE while the central area had the lowest. By way of conclusion, some useful points relating to model selection are summarized from both methodological and empirical aspects. [ABSTRACT FROM AUTHOR]

The fast growing Revenue Passenger Kilometers and the relatively lagged energy supply of aviation industry impels the airlines to improve energy efficiency. In this paper, we focus on evaluating and analyzing influencing factors for airline energy efficiency. Number of employees and aviation kerosene are chosen as the inputs. Revenue Ton Kilometers, Revenue Passenger Kilometers and total business income are the outputs. Capital stock is selected as the dynamic factor. A new model, Virtual Frontier Dynamic Slacks Based Measure, is proposed to calculate the energy efficiencies of 21 airlines from 2008 to 2012. We verify two important properties to manifest the advantages of the new model. Then a regression is run to analyze the influencing factors of airline energy efficiency. The main findings are: 1. The overall energy efficiency of Malaysia Airlines is the highest during 2008–2012.2. Per capita Gross Domestic Product, the average service age of fleet size and average haul distance have significant impacts on the efficiency score. 3. The difference between full-service carriers and low-cost carriers has no significant effects on airline energy efficiency. [ABSTRACT FROM AUTHOR]

• Optimization-based comparison of natural gas liquefaction processes is proposed. • Broad process flowsheet complexity and natural gas processing scales are considered. • The AP-X process has the lowest energy consumption and cost for 8 MTPA plants. • The single mixed refrigerant process has the highest profit for small-scale plants. • Energetically better processes may not provide a higher economic return. The demand for liquified natural gas grows as it is an energy resource that has more flexible means of transport than non-liquefied natural gas, and is more eco-friendly than other fossil fuels. This paper focused on comparing five different mixed-refrigerant liquefaction processes to determine which one is the most efficient in energetic and economic terms for four different natural gas processing scales (20,000 kg/h and 2, 4, and 8 MTPA of natural gas feed). Simpler processes with one or two refrigerant cycles (single mixed refrigerant, propane pre-cooled mixed refrigerant, and dual mixed refrigerant) and more complex processes with three cycles (mixed fluid cascade and AP-X) were analyzed. All processes were simulated in Aspen HYSYS, and the energy consumption was optimized by a communication between the simulator and an optimization algorithm based on Particle Swarm Optimization coded in MATLAB. The economic analysis was performed using the CAPCOST technique and the rule of six-tenths for upscaling. In the best-optimized scenario, the results show that the most complex process, AP-X, consumes the lowest amount of energy (0.2367 kWh/kg-LNG) while the simplest one, the single mixed refrigerant, consumes the highest value (0.2561 kWh/kg-LNG). In the economic analysis, the results indicate that energetically better processes may not provide a higher economic return even on large scales. [ABSTRACT FROM AUTHOR]

Heating and cooling of residential buildings is accountable for a significant share of the EU's final energy consumption. In order to determine the current condition of the building stock and to implement appropriate measures and requirements to improve energy efficiency of buildings, a detailed analysis of existing buildings is essential. This paper aims at describing characteristics of the building stock of Salzburg by analysing energy performance certificates. Therefore, the building stock is grouped into archetypes based on the construction period, building condition (not-retrofitted and retrofitted) and building type (single-family house and multi-family house) and then analysed regarding energy need for space heating, energy carrier, heat emission system, share and U-values of building elements and window to wall ratio. The analysis of the data demonstrates that the structure and naming conventions within the EPC-database pose hurdles for a correct investigation of the data. A comprehensible and distinct notation as well as versioning is inevitable for the sake of avoiding a loss of information and enabling international comparability. An analysis of energy carriers of the archetypes reveals, that a significant share of buildings still uses fossil fuels like oil and gas for energy supply, although electricity (heat pumps) and district heating are on the rise for buildings constructed in recent periods as well as for retrofitted buildings, with heat pumps being the most important energy carrier for new single-family houses amounting to a share of 65 % and district heating for new multi-family houses amounting to a share of 46 %. A detailed observation of the thermal performance of buildings and building elements reveals high potential and practicability not only for energy efficient new buildings, but also retrofitted buildings throughout all construction periods and for both, single-family houses and multi-family houses (e.g. median U-values for retrofitted ceilings/roofs range from 0.17 to 0.26 W/(m2K) compared to a median of 0.14 W/(m2K) for not-retrofitted ceilings/roofs from the most recent construction period). The conducted analysis provides detailed statistical information on the Salzburg building stock and hence a robust basis for further studies regarding the thermal performance of the building stock and future scenarios by means of urban building energy modelling approaches. Furthermore, based on this information, policies for energy efficient buildings can be improved and adapted according to current circumstances. [ABSTRACT FROM AUTHOR]

Abstract: This paper reviews crucial role of building performance simulation (BPS) – dynamic analysis of the inextricable linkage of building''s energy demand for HVAC and other building''s technical systems sustainable energy supply and renewable energy sources (RES) availability to reach building''s zero energy status. Reviewed are BPS advances in buildings energy efficiency optimization, solar, geothermal and other renewable energy sources integrated implementation, as well as hybridization and mixed distributed energy generation, co- and tri-generation for building''s greening and sustainable neighborhoods, settlements, as well as “high performance” Zero Energy Cities Planning. As an introduction, outlined is the intrinsic harmony of the traditional village houses balanced use of renewable materials and energy sources and presented are feasibility study results on the sustainable Zero Energy ECO Settlement at the Mediterranean Sea proceeded by the description of the site''s sustainability''s constrains assessment. Architectural design and building''s dynamic behavior and energy efficiency optimization resulting in minimization of thermal and lighting loads, precede to the multidisciplinary engineering investigation and preliminary design of sustainable Zero Energy Buildings confirming feasibility of settlement''s sustainable energy and water supply by the reliable implementation of solar PV and wind technologies, including PV powered sea water desalination. Further, interwoven with presentation of a few case studies, paper outlines advances in BPS and Co-simulation. Reviewed are optimization of mixed, natural and mechanical ventilation via CFD integrated with architectural modeling; BPS and Co-simulation approach to the “total building performance optimization” encompassing multifunctional facades, day-lighting, IE&AQ and HVAC systems operation offering an enormous potential for energy saving by residential/municipal RES integrated renovation. Stressed has been that it is impossible to reach sustainability without harmonious interdisciplinary interacting, without balance between materiality and spirituality, science and art, technology development and cultural and other human values improvement, without ethics of sustainability. [Copyright &y& Elsevier]

Abstract: This paper will summarise the European Strategy for Energy and Climate Change. In current international negotiations Europe has proposed a 20% reduction in GHG (greenhouse gases) in the developed countries by 2020 or 30% should there be an international agreement in the domain. However it is important to define measures to achieve the targets. One of the principal tools is to improve energy efficiency under the energy efficiency action plan, which will help to achieve a 20% energy saving by 2020. On the other hand, the amount of energy from renewable sources consumed in Europe will have to rise from its current level of 8.5%–20% by 2020. These are ambitious but achievable targets. Nonetheless, these can only be achieved through strong investment in areas of the knowledge triangle which strengthens research and innovation in the energy sector in Europe. The paper covers European Energy and Climate Change Policy, the European Strategic Energy Technology plan, the consequences of the Lisbon Treaty, European and national Road maps to a low carbon economy, the Energy Efficiency Plan for 2011 and finishes with a brief consideration of the EU’s energy infrastructure priorities. [Copyright &y& Elsevier]

Abstract: The procedure of development of energy management system applied to an existing company (Serbian car producer “Zastava”) is shown in the paper. The aim of the paper is to provide a guideline for entrepreneurs in metal-working industry in implementing energy management system. First of all, paper includes: critical analysis of existing energy management system (energy matrix), principles of effective energy management organization (with energy manager and energy team in its structure) and energy management politics. Based on the results of energy auditing and performed technological and economical feasibility studies several energy saving measures related to different energy sources (steam, hot water, compressed air, electricity and water) were proposed, implemented and valuated. The proposed measures are not exclusively related to car assembly industry; they can be easily applied to other metal-working facilities with minor modifications. Such energy management system reduces energy costs and increase profitability of a factory. [ABSTRACT FROM AUTHOR]

Abstract: Fossil fuel based power generation is and will still be the back bone of our world economy, albeit such form of power generation significantly contributes to global CO2 emissions. Solar energy is a clean, environmental friendly energy source for power generation, however solar photovoltaic electricity generation is not practical for large commercial scales due to its cost and high-tech nature. Solar thermal is another way to use solar energy to generate power. Many attempts to establish solar (solo) thermal power stations have been practiced all over the world. Although there are some advantages in solo solar thermal power systems, the efficiencies and costs of these systems are not so attractive. Alternately by modifying, if possible, the existing coal-fired power stations to generate green sustainable power, a much more efficient means of power generation can be reached. This paper presents the concept of solar aided power generation in conventional coal-fired power stations, i.e., integrating solar (thermal) energy into conventional fossil fuelled power generation cycles (termed as solar aided thermal power). The solar aided power generation (SAPG) concept has technically been derived to use the strong points of the two technologies (traditional regenerative Rankine cycle with relatively higher efficiency and solar heating at relatively low temperature range). The SAPG does not only contribute to increase the efficiencies of the conventional power station and reduce its emission of the greenhouse gases, but also provides a better way to use solar heat to generate the power. This paper presents the advantages of the SAPG at conceptual level. [Copyright &y& Elsevier]

Abstract: This paper takes a close look at the China national standard GB50189-2005, Design Standard for Energy Efficiency of Public Buildings, which was enforced on July 1, 2005. The paper first reviews the standard, then compares the standard with ASHRAE Standard 90.1-2004 to identify discrepancies in code coverage and stringency, and recommends some energy conservation measures that can be evaluated in the design of public buildings to achieve energy savings beyond the standard. The paper also highlights several important features of 90.1-2004 that may be considered as additions to the GB50189-2005 standard during the next revision. At the end the paper summarizes the latest developments in building energy standards and rating systems in China and the US. [Copyright &y& Elsevier]

Abstract: This paper reports the outcome of the project on “Capacity building in formulating harmonized policy instruments for the promotion of Renewable Energy and Energy Efficiency in the ASEAN member countries”. With the growing concerns about green house gas (GHG) emission and consequent climate change, renewable energy sources have become more attractive option for electricity generation around the world. Studies have been made on the status of renewable energy potential and utilization, major barriers in promoting renewable energy in ASEAN countries, major energy policies to overcome barriers, and existing renewable energy and energy efficiency policies in ASEAN countries. Paper concludes that ASEAN has not utilized its renewable energy resources anywhere near to the potential. Analysis found that the key factor that has to be amended is “policies and regulations in renewable energy and energy efficiency” at both country level and regional level. But, ASEAN is not yet ready for the full harmonization of the policies. However, it recommends that, with the project outputs it is possible to focus on the specific policy instruments common to most of the member countries, such that it could use to augment ASEAN Plan of Action for Energy Cooperation (APAEC) initiatives. [Copyright &y& Elsevier]

Abstract: Within recent years, energy policies have imposed a number of targets at European and national level for rational use of energy (RUE), renewable energy sources (RES) and related CO2 reductions. As a result, a wide variety of policy instruments is currently implemented and hence the question arises: how can these instruments be designed in a way to reach the maximum policy target with the minimum public money spent? The objective of this paper is to derive a methodology for obtaining efficient policy portfolios promoting sustainable energy systems depending on the policy target and show corresponding results from case studies in Austria, Germany and Poland. The investigations were carried out by application of Invert simulation tool, a computer model developed for simulating the impacts of various promotion schemes for renewable and efficient energy systems. With this tool, the CO2 reductions and related public expenses have been calculated for various policy mixes. In the building-related energy sector, it turned out that in all investigated regions support schemes for supply side measures are the most cost-efficient instruments. However, their potential is restricted and for achieving higher levels of CO2 reduction, promotion of demand side measures is indispensable. The paper shows that for a comprehensive comparison of policy portfolios, there are always two dimensions to be considered: efficiency and effectiveness. The more effective, i.e. the higher the implementation rate of a scheme, the more essential becomes the efficiency criteria. [Copyright &y& Elsevier]

Abstract: Based on different current long-term energy scenarios the paper discusses the future perspectives of hydrogen in the German energy system as a representative example for the development of sustainable energy systems. The scenario analysis offers varying outlines of the future energy system that determine the possible role of hydrogen. The paper discusses the possibilities of expanding the share of renewable energy and the resulting prospects for establishing clean hydrogen production from renewable energy sources. Emphasis is given to the questions of an ecologically efficient allocation of limited renewable energy resources that can only be assessed from a systems analysis perspective. Findings from recent studies for Germany reveal a strong competition between the direct input into the electricity system and an indirect use as fuel in the transport sector. Moreover, the analysis underlines the paramount importance of reducing energy demand as the inevitable prerequisite for any renewable energy system. [Copyright &y& Elsevier]

Improving energy efficiency in mobile hydraulics is paramount and feasible via machine electrification, but all actuators' power in standard systems must flow through the electric motors, which is unfeasible for medium-to-high power applications. Therefore, this paper leverages the idea of splitting the transferred power between the hydraulic and electric domains to save energy while downsizing the electric motors. A novel layout of a hybrid excavator is presented, validated using high-fidelity simulations, and compared to the state-of-the-art, load-sensing machine. The results show the expected system's functioning and efficiency benefits (fuel savings close to 28% compared to the original excavator). Almost 60% of the energy is transferred to the actuators hydraulically minimizing the power rating of the electric machines in favor of the system's cost and compactness. Future research will focus on controlling the hybrid system to maximize energy savings and make it easily applicable to different fluid power machines. • Electrification enhances energy efficiency and recovers energy in mobile hydraulics • The main actuators become individual electro-hydraulic drives using speed control • A centralized hydraulic power supply supports the individual electric motors • Splitting hydraulic and electric power downsizes the electric machines (less costs) • The hybrid excavator saves fuel up to 28% and uses small electric motors [ABSTRACT FROM AUTHOR]

Energy demand has been increasing worldwide and the building sector represents a large percentage of global energy consumption. Therefore, promoting energy efficiency in buildings is essential. Among all building services, Heating, Ventilation and Air Conditioning (HVAC) systems are significantly responsible for building energy use. In HVAC, ventilation is the key issue for providing suitable Indoor Air Quality (IAQ), while it is also responsible for energy consumption in buildings. Thus, improving ventilation systems plays an important role not only in fostering energy efficiency in buildings, but also in providing better indoor climate for the occupants and decreasing the possibility of health issues in consequence. In the last decades, many energy-efficient ventilation methods are developed by researchers to mitigate energy consumption in buildings. This paper reviews scientific research and reports, as well as building regulations and standards, which evaluated, investigated and reported the development of energy-efficient methods for ventilation in buildings. Besides energy-efficient methods such as natural and hybrid ventilation strategies, occupants’ behaviours regarding ventilation, can also affect the energy demand in buildings. Therefore, the influence of occupants’ behaviour on the energy use and the correlation between ventilation and the occupants’ health and productivity were also considered. The review showed that ventilation is interrelated with many factors such as indoor and outdoor conditions, building characteristics, building application as well as users’ behaviour. Thus, it is concluded that many factors must be taken into account for designing energy-efficient and healthy ventilation systems. Moreover, it should be mentioned that utilizing hybrid ventilation in buildings integrated with suitable control strategies, to adjust between mechanical and natural ventilation, leads to considerable energy savings while an appropriate IAQ is maintained. [ABSTRACT FROM AUTHOR]

Energy efficiency in industries is one of the dominating challenges of the 21st century. Since the release of the eco-design directive 2005/32/EC in 2005, great research effort has been spent on the energy efficiency assessment for energy using products. The ISO (International Organization for Standardization) standardization body (ISO/TC 39 WG 12) currently works on the ISO 14955 series in order to enable the assessment of energy efficient design of machine tools. A missing piece for completion of the ISO 14955 series is a metric to quantify the design of machine tools regarding energy efficiency based on the respective assembly of components. The metric needs to take into account each machine tool components' efficiency and the need-oriented utilization in combination with the other components while referring to efficiency limits. However, a state of the art review reveals that none of the existing metrics is feasible to adequately match this goal. This paper presents a metric that matches all these criteria to promote the development of the ISO 14955 series. The applicability of the metric is proven in a practical case study on a turning machine. [ABSTRACT FROM AUTHOR]

Hybridization of heavy off-highway working vehicles brings considerable energy savings in the form of a downsized internal combustion engine (ICE) by means of reduced no-load losses. In this paper, a novel energy saving opportunity in working hydraulics at the end of long booms of working vehicles is proposed. In traditional off-highway working vehicles, the working hydraulics is supplied through pipes, hoses, and valves by a hydraulic pump located near the main engine. A significant amount of energy is lost in long pipelines and hoses as well as in valve throttles. A new topology is introduced to supply the power along the long boom; the power for a hydraulic actuator is supplied by an integrated electro-hydraulic energy converter (IEHEC), which is located at the boom end. The electrical energy to the converter is supplied through electrical cables, which have negligible losses compared with a conventional fluid power supply with long pipelines. The converter transforms the electrical energy into hydraulic energy at the end of the boom, and may also recover energy for additional energy savings. [ABSTRACT FROM AUTHOR]

Even though industry consumes nearly half of total energy production, the relative share of total energy consumption related to heating and operating buildings is growing constantly. The motivation for this study was to reveal the differences in electricity use and district heating consumption in school buildings of various ages during the working day and also during the night when human-based consumption is low. The overall aim of this study is to compare the energy (electricity and heating) consumption of six school buildings in Kuopio, Eastern Finland. The selected school buildings were built in different decades, and their ventilation and building automation systems are also inconsistent. The hourly energy consumption data was received from Kuopion Energia, the local energy supply company. In this paper, the results of data analysis on the energy consumption in these school buildings are presented. Preliminary results show that, generally speaking, new school buildings are more energy-efficient than older ones. However, concerning energy efficiency, two very new schools were exceptional because ventilation was on day and night in order to dry the building materials in the constructions. The novelty of this study is that it makes use of hourly smart metering consumption data on electricity and district heating, using modern computational methods to analyse complex multivariate data in order to increase knowledge of the buildings’ consumption profiles and energy efficiency. [ABSTRACT FROM AUTHOR]

• The new power supply structure resulting from the new policy has been considered. • The new models project the inefficient points onto a more realistic efficient frontier. • The new models have the power to allocate the shared resources. • Results show that the power production stage is allocated less shared resources. • The power sale stage's efficiency is lower than the one of power production stage. To relieve the problems of energy shortage and environmental pollution, many countries have implemented a variety of policies to improve the energy efficiency of the power industry. To understand the impacts of such policies on energy efficiency, this paper constructs novel network data envelopment analysis models to recognize the policy-induced structural changes in the power system. Compared with previous studies, the new models project the inefficient points onto a more realistic efficient production frontier, considering how the distribution proportion of shared resources will change when the power system, modeled as a power generation stage and a power sale stage, is led by the latter stage. Our empirical study on China's power system shows that the province of Guangdong and the eastern region of China perform best, and all power production stages perform better than the corresponding power sale stages. The development of the two power subsystems in the four regions is unbalanced. More than half of the power supply systems choose to allocate more proportion of the shared resources to the sale stage rather than use a more balanced distribution between the two stages. [ABSTRACT FROM AUTHOR]

Thermal Energy Storage (TES) has been a topic of research for quite some time and has proven to be a technology that can have positive effects on the energy efficiency of a building by contributing to an increased share of renewable energy and/or reduction in energy demand or peak loads for both heating and cooling. There are many TES technologies available, both commercial and emerging, and the amount of published literature on the subject is considerable. Literature discussing the combination of thermal energy storage with buildings is however lacking and it is therefore not an easy task to decide which type of TES to use in a certain building. The goal of this paper is to give a comprehensive review of a wide variety of TES technologies, with a clear focus on the combination of storage technology and building type. The results show many promising TES technologies, both for residential and commercial buildings, but also that much research still is required, especially in the fields of phase change materials and thermochemical storage. [ABSTRACT FROM AUTHOR]