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Abstract: The pulp and paper industry is one of the most energy-intensive industries worldwide. In 2007, it accounted for 5% of total global industrial energy consumption and 2% of direct industrial carbon dioxide (CO2) emissions. An energy audit is a primary step toward improving energy efficiency at the facility level. This paper describes a plant-wide energy audit aimed at identifying energy conservation and CO2 mitigation opportunities at a paper mill in Guangdong province, China. We describe the energy audit methods, relevant Chinese standards, methods of calculating energy and carbon indicators, baseline energy consumption and CO2 emissions of the audited paper mill, and nine energy-efficiency improvement opportunities identified by the audit. For each of the nine options, we evaluate the energy conservation and associated CO2 mitigation potential. The total technical energy conservation potential for these nine opportunities is 967.8terajoules (TJ), and the total CO2 mitigation potential is equal to 93,453tonnes CO2 annually, representing 14.4% and 14.7%, respectively, of the mill’s total energy consumption and CO2 emissions during the audit period. [Copyright &y& Elsevier]

Abstract: Adoption of energy efficient technologies is considered a key sustainability strategy for reducing greenhouse gas emissions in global industries. This article aims to assess costs of energy savings and carbon reduction from applying energy efficiency technologies in the US pulp and paper sector. Applicable efficiency measures were identified and their cost effectiveness was evaluated in two historical years – 1994 and 2006. Potential savings of final energy use resulting from applicable sustainability options were estimated as 707 PJ in 1994 and 1064 PJ in 2006, respectively, corresponding to approximately 32% of the sector''s annual final energy use in 1994 and 62% in 2006. The associated carbon-emission reduction was 8.1 million ton of carbon (MtC) in 1994 and 11.8MtC in 2006, corresponding to 26% and 45% of sector''s total energy-related carbon emissions in 1994 and 2006, respectively. Using the concepts of cost of conserved energy and cost of carbon reduction, we estimated that cost effective sustainability options contributed to final energy savings in the range of 15–25% of the annual energy use, and carbon-emission reduction from 14% to 20% of annual carbon emissions from the sector. [Copyright &y& Elsevier]

The customers of textile wet processing plants have committed to reduce their greenhouse gas emissions from outsourced manufacturing activities. The textile brands directly use specific energy consumption values to analyze and set steep, time-bound emission intensity reduction targets for the energy intensive textile wet processing plants. However, the direct use of specific energy consumption values to evaluate energy savings can be misleading. In this paper, the authors propose a methodological framework to systematically evaluate energy performance and monitor energy savings in the textile wet processing plants. Further, the approach was extended to analyze the energy performance monitoring practices and identify energy conservation measures. The proposed framework was developed based on thorough analysis of the manufacturing process of textile wet processing plants and the principles of ISO 50001. A textile wet processing plant was chosen as a case study for illustrating the effectiveness of the framework using multiple regression method. Bottom up approach for benchmarking was used and yet significantly simplified by the introduction of an innovative parameter "program mix factor" and thereby evaluate "equivalent specific energy consumption". The predicted values for specific energy consumption were found to be within a close error range of ±10 % of the actual data. The proposed methodological framework is therefore innovative, simple and yet comprehensive to conduct internal benchmarking in textile wet processing plants. The textile brands are suggested to use equivalent specific energy consumption instead of specific energy consumption for energy performance monitoring of their textile wet processing plant suppliers. The authors also conducted a survey in fifteen textile wet processing plants to assess the prevailing energy monitoring practices. The results of the survey suggests that only 20 % of the plants are practicing basic level energy performance monitoring, while the remaining 80 % are at minimal level. • Textile wet processing plants were analyzed to identify the parameters required to normalize specific energy consumption • A simplified methodological framework was developed for the textile wet processing plants and the textile brands • The framework serves as a useful tool to evaluate, monitor the realistic energy performance & identify conservation measures • The textile brands are suggested to use equivalent specific energy consumption to monitor energy performance • The study identified the low levels of energy monitoring practices in textile wet processing plants in South Asian countries [ABSTRACT FROM AUTHOR]

Abstract Water pumping systems are widely used in industrial and civil applications. During their operational life, they consume energy and materials (mainly for installation and replacement of components). The aim of this paper is to optimize the pump operations in order to save energy and enlarge the operational life of the pumps and their components. This paper addresses the multi-period (e.g. 24-hours time horizon) optimization of pumping systems. To this end, we have developed a simulation-based optimization approach including novel relevant technical features of a generic but realistic pumping system, namely cavitation and overflow. The proposed multi-period optimization differs further from the classic static optimization (i.e. at the design stage), proposing a new dynamic approach in which pump activation is steered dynamically for an optimal management of the variability of water inflow. Furthermore, the problem includes constraints on the number of pump activations allowed to reduce material strain. The performances of different meta-heuristic optimization algorithms (e.g. genetic algorithm, simulated annealing and particle swarm optimization) for solving the problem are compared. The numerical results show that energy savings are possible with the dynamic approach and that particle swarm optimization and simulated annealing algorithms provide the most suitable solutions for this problem. Highlights • Three algorithms are compared to minimize energy pump consumption. • The pump model includes energy, cavitation, overow and activation frequency. • Static and dynamic optimizations are investigated. • The dynamic optimization can reduce the energy consumption by 6.5%. [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]

Energy conservation in a highly resource restricted environment of Wireless Sensor Networks (WSNs) is a crucial task. This issue can be efficiently tackled by adopting the mechanism of clustering in sensor networks. The primary objective of any of the designed clustering protocols for WSNs is to obtain energy efficiency and to lengthen the network life duration. This achievement is made through the election of a single deserving node as a head node called cluster head. This paper suggested an evolutionary approach based clustering protocol named Modified-Invasive Weed Optimization Based Clustering Algorithm (M-IWOCA) for WSNs. M-IWOCA focuses on the selection of fittest node as a cluster head to enhance the network's lifetime as well as to address the issue of energy conservation in sensor networks. A fuzzy inference model is designed to evaluate the fitness of each node in the network. Simulation results for M-IWOCA depict significant reduction in dead nodes per round and results in minimizing the energy utilization of the sensors. Moreover, M-IWOCA enhances the network stability period by 45% in comparison to Artificial Bee Colony (ABC) protocol and by 18% in comparison to Quantum Artificial Bee Colony (QABC) protocol. [ABSTRACT FROM AUTHOR]

• TIP-EMS enhances EV energy efficiency by integrated prediction and energy management. • Significant driving economy boost; 1.6%-4.2% better than state-of-the-art PEMS. • TIP-EMS shows robust performance with varying prediction weight adjustments. To enhance the energy efficiency of electrified vehicles (EVs), developing effective energy management strategies (EMS) for hybrid storage systems is essential. Predictive EMS (PEMS) that foresee future vehicle speeds have demonstrated substantial potential in boosting EMS performance. However, traditional PEMS models, employing a sequential approach of speed prediction followed by energy allocation, are hampered by cumulative errors. These errors from the initial speed predss this issue, this paper introduces a novel solution: the trainable integrated preiction negatively impact the efficiency of subsequent energy management. To addrediction and energy management strategy (TIP-EMS). Contrasting with conventional sequential PEMS, TIP-EMS features a dual-branch, integrated neural network, which is fully trainable. This network processes driving status inputs via attention layers, with one branch dedicated to energy management objectives using a reinforcement learning (RL) algorithm, and the other to vehicle speed prediction. Both branches are trained simultaneously, but post-training, only the RL branch is activated for energy management. Implemented with a soft actor-critic RL algorithm, TIP-EMS is applied to a fuel cell EV for optimized energy management. The validation involved training TIP-EMS using 27 driving profiles, which developed its prediction and energy management capabilities, followed by tests in untrained scenarios. The results show that TIP-EMS surpasses conventional sequential PEMS by up to 4.2% in scenarios where prediction accuracies are comparable, highlighting the efficacy of the trainable integrated mechanism. In addition, TIP-EMS exhibits superior energy conservation compared to non-predictive RL strategies. Lastly, TIP-EMS exhibits robustness to adjustments in the weight given to the prediction objective, further confirming its practical applicability. [ABSTRACT FROM AUTHOR]

This paper reports the use of low cost off-the-shelf components to develop a wireless energy monitoring system for the purpose of non-intrusive appliance load monitoring. The system comprises hardware design where a standard open source WiFi-connected embedded system board is used as the core component, an analog front end for interfacing between the voltage and current sensors and the embedded board and also a server to store data for further processing. The software side consists of algorithms for performing data partitioning and Naive Bayes classifier. Non-intrusive appliance load monitoring (NIALM) is a methodology used to disaggregate total power consumption into individual electrical appliance power usage. In this paper, the average power consumptions of electrical appliances are obtained from the system setup through the identification of switching ON or OFF events of appliances. The Naive Bayes classifier is deployed for appliances’ classification. This work demonstrates the feasibility of utilizing low cost and standard components to develop a wireless energy monitoring system. It is also observed that the developed classifier algorithm is able to classify individual electrical appliances with satisfactory accuracy level using few training examples. The novelty of this paper is that it developed a data set consisting of 4 types of appliances from the application of embedded networking device. This paper also shows that satisfactory classification accuracies can be achieved using few training examples with generic classifiers (Naive Bayes) and one feature (the average power). It provides an example of how NIALM can offer feedback to appliances’ energy consumption and therefore promote energy efficiency. [ABSTRACT FROM AUTHOR]

Network end-user devices such as laptops and desktop PCs are often left powered ON 24/7 while they remain idle most of the time. The main reason behind this is maintaining network connectivity for remote access, VoIP, instant messaging and other Internet-based applications. The Network Connectivity Proxy (NCP) emerged as a quite promising strategy for significantly reducing network energy waste by allowing devices to sleep without losing their presence over Internet. It impersonates presence of devices during their sleeping periods at all layers of TCP/IP stack. The NCP can successfully proxy basic networking protocols (e.g., ARP, PING, DHCP, etc.) but faces challenges in proxying TCP sessions and proprietary closed-source applications with encrypted packets. To overcome the limitations of NCP concept, this paper proposes a new strategy for reducing network energy waste through intelligent coordination among a user's devices (e.g., smartphone, laptop, desktop PC, etc.). In the proposed system, a user's daily used devices autonomously and seamlessly communicate with a centralized control server that decides which user device will maintain presence of applications at a given instant. To allow devices to sleep and wake them up whenever necessary, the proposed system also uses a light-weight Home Gateway Proxy (HGP) with very basic set of practically realizable features. The communication framework for HGP is designed to achieve auto-discovery, seamless networking and communication features. This paper also practically evaluates the proposed system and estimates energy saving for fixed as well as mobile network devices. [ABSTRACT FROM AUTHOR]

The cost of heat savings in buildings increase as more heat savings are achieved and hence, alternatives other than savings typically become more economically feasible at a certain level of heat reductions. The challenge addressed in this paper is to identify when the cost of heat savings become more expensive than the cost of sustainable heat supply, so society does not overinvest in heat saving measures. This study first investigates the heat saving potentials for different countries in Europe, along with their associated costs, followed by a comparison with alternative ways of supplying sustainable heating. Furthermore, the levelised cost of supplying sustainable heat is estimated for both a single technology and from an energy system perspective. The results are analysed by assessing various parameters such as socio-economic costs and energy efficiency improvements in the national energy systems. The results demonstrate the economically feasible levels of heat savings and heat production for various European countries, highlighting differences in their national conditions and energy systems. The findings in this paper indicate that overinvestments in heat savings can be avoided by saving heat until a level around 30–50% of projected heat demands and supplying the remaining heat demand with sustainable heat sources. [ABSTRACT FROM AUTHOR]

This paper aims to present a novel smart grid adaptive energy conservation and optimization engine for smart distribution networks. The optimization engine presented in this paper tries to minimize distribution network loss, improve voltage profile of the system and minimize the operating cost of reactive power injection by switchable shunt Capacitor Banks using Advanced Metering Infrastructure data. Moreover, it performs Conservation Voltage Reduction (CVR) and minimizes transformer loss. To accurately weight the optimization engine objective function sub-parts, Fuzzification technique is employed in this paper. Particle Swarm Optimization (PSO) is applied as Volt-VAR Optimization (VVO) algorithm. Substantial benefits of the proposed energy conservation and optimization engine include but not limited to: adequate accuracy and speed, comprehensive objective function, capability of using AMI data as inputs, and ability to determine weighting factors according to the cost of each objective sub-part. To precisely test the applicability of proposed engine, 33-node distribution feeder is used as case study. The result analysis shows that the proposed approach could lead distribution grids to achieve higher levels of optimization and efficiency compared with conventional techniques. [ABSTRACT FROM AUTHOR]

A fundamental problem in the management of energy usage is the inability to clearly predict any possible energy saving opportunities. The cost of both under or overestimating potential returns on investment can be prohibitive to a decision maker. In recent years the simulation of energy usage using existing manufacturing simulation tools has increased in popularity among researchers, but it is decision makers who need to see the benefits of this discipline. This paper proposes an interactive manufacturing energy management toolkit which makes use of existing productivity simulation models for the prediction of energy usage. An interactive Microsoft ® Excel ® based toolkit is developed to control Lanner's WITNESS ® discrete-event simulation software using Microsoft ® Visual Basic ® for Applications. The toolkit has the ability to predict potential areas where energy saving opportunities can be made within a complex manufacturing line, and is accessible from management presentations and proposals. The interactivity of the toolkit provides an environment which facilitates efficient hypothesis testing. The paper includes an industrial case study where the approach was used to quantify theoretical savings from certain energy usage reduction scenarios within a complex automotive engine manufacturing line. [ABSTRACT FROM AUTHOR]

Coal mining not only produces, but also consumes a large amount of energy. Coal production has an extremely high energy efficiency potential, and benchmarking is critical to discover this potential. To address problems such as ambiguity of coal production (e.g. underground mining), benchmarking range and absence of both indicators and standards for energy efficiency benchmarking, this paper makes use of product-based and process-based benchmarking. These two techniques are used to construct a benchmarking system for coal production with high energy efficiency, and improve the standards used at the eight coal mines owned by the Yankuang Group. Comparison and analysis of benchmarking in enterprises indicates that energy use during raw coal production could be reduced by 22.77%. Across China energy savings from coal production could reach 15.98–32.98 Mtce, with an equivalent 42–87 Mt of CO 2 emissions saved. Lastly, this paper provides measures to improve coal production energy efficiency. [ABSTRACT FROM AUTHOR]

Significant increases in industry energy efficiency are crucial for the transformation of the world's energy systems. Many production sites offer high energy savings capabilities, and if these are accompanied by short periods of economic amortization, companies should be willing to act. This case study provides a novel and extended energy assessment for plastics processing plants including primary energy, greenhouse gas emissions, and energy costs. The research distinguishes between the standard form of separate individual energy assessments and provides a more innovative holistic approach taking all relevant energy flows within the production system into account. Dynamic simulation offers a quick and effective way to predict the results of the possible energy saving measures highlighted in this analysis. The paper presents validated energy consumption simulations based on realistic processing conditions for two injection molding factories in different climatic zones. The results show that combining a number of separate energy saving measures can reduce the primary energy demand by around 26% for a German plant under temperate climate conditions and 20% for a Western Australian plant under Mediterranean conditions. However, when the separate energy saving measures are holistically combined the reduction in energy use significantly increases to 41% and 43% respectively. This holistic energy strategy involves incorporating better cogeneration and waste heat recovery options. For small and medium sized companies in particular major energy infrastructure investments may often be considered too expensive without examining the extended benefits from a holistic energy assessment perspective. In contrast, a holistic framework, like the one suggested in this paper could provide a number of new options for increasing energy efficiency that individually might normally not be accepted under conventional economic rate of return analysis. [ABSTRACT FROM AUTHOR]

Legislation targeting business carbon emissions typically excludes the significant portion of the economy comprised of small- and medium-sized enterprises (SMEs). As an alternative many governments have developed voluntary programs to assist SMEs to reduce emissions and increase their energy efficiency. To maximise benefits associated with such programs, this paper seeks to provide insights into key factors contributing to the design of successful voluntary energy efficiency programs for SMEs. This is achieved by comprehensively analysing the factors that impacted the uptake of energy savings measures by 202 SMEs which participated in the ClimateSmart Business Cluster Program (commencing in 2009). Expanding on previous research that has mostly focus on identifying inhibiting factors (barriers) to the uptake of energy savings measures, this paper offers a comprehensive assessment of barriers and motivating factors (motivators). A unique finding of this research is that SMEs experienced many different barriers and motivators while participating in the program, inferring great complexity to achieving the critical aim of reducing carbon emissions. Based on these findings, this paper argues that voluntary government energy efficiency programs should be flexibly designed and implemented to accommodate the many and various barriers. Motivating factors should be emphasised and barriers identified upfront so that the program can be tailored to the often idiosyncratic needs of SMEs. [ABSTRACT FROM AUTHOR]

A sustainable energy system can be treated as a development of the distributed generation concept. It meets energy demands locally from renewable energy or/and high-efficiency polygeneration production technologies, and is characterized by energy and cost efficiency, reliability, and environmental-friendliness. Distributed energy systems typically use renewable energy resources to supply all energy demands, such as heat, cooling, and electric power in an integrated way. However, it seems that too much emphasis is placed on power and associated renewable energy-based power technologies for dealing with sustainability issues in public discussion and the research community. Often, equally important thermal energy (heat and cooling) and polygeneration are ignored. Polygeneration is an energy-efficient technology for generating simultaneously heat and power as well as other energy products in a single integrated process. Energy efficiency contributes significantly to CO 2 emission reduction. This paper discusses the role of polygeneration in a distributed energy system and the contributions of polygeneration to the development of sustainable energy systems. The paper also stresses that efficient decision support tools for sustainable polygeneration systems are important to achieve sustainability. First, the joint characteristic of a polygeneration plant that defines the dependency between different energy products is reviewed. Then, typical methods for dealing with polygeneration systems are reviewed. The review attempts to highlight the complexity of polygeneration systems and potential of polygeneration systems to adjust output of different energy products. Next, the challenges of sustainable polygeneration energy systems are discussed. Then some practices for operating polygeneration plants are discussed. [ABSTRACT FROM AUTHOR]

The expected savings from energy efficiency projects are divided into two, direct savings and indirect savings. Direct savings refer to savings obtained through the personal effort of an individual implementing some energy efficiency measures. Indirect savings are achieved through information transmission of energy efficiency measures from an individual to his/her neighbours. In this paper information transmission is seen as human contribution for energy savings through interactions within the social network. This paper formulates a mathematical model that calculates an expected energy cost savings model that consists of direct and indirect savings. Indirect savings are made through social interactions of people in a network over time. Direct savings calculations are based on the Homeflex time of use tariff of South Africa. A case study of thirty-six households is used to illustrate the impact individuals have on the rest of their network in transferring information about the energy efficiency measures they have implemented. The results show that social interactions can improve energy efficiency savings and consequently reduce electricity cost. [ABSTRACT FROM AUTHOR]

Energy management systems are considered as appropriate instruments to identify and realize energy efficiency potentials in industrial plants. Studies point out a largely untapped potential for energy efficiency in industry through the adoption of systematic energy management. We suggest introducing qualitative and quantitative modelling tools into energy management to facilitate a focused process to set priorities and identify effective measures. This paper describes the case of voestalpine Austria Draht GmbH, an Austrian wire rolling mill. voestalpine Austria Draht GmbH at present is implementing a knowledge based energy management system. Within the work described in this paper, first an overview of energy flows using Sankey diagrams was elaborated. Then a qualitative systems analysis was developed for the plant and a gap analysis done for priority areas. Subsequently physical input–output models for several energy intensive units were prepared. The paper describes the models for the cooling water system and product cooling. This study revealed a significant potential to save electricity by optimizing the control of cooling water pumps along the milling train and to recover heat from the final products. 2 GWh of electricity can be saved annually. The biggest single energy loss in the mill is the heat from air cooling the products on hook conveyors. These heat flows contain about 30–50 % of the energy input for heating up the billets. Following a theoretical analysis of the potential, a demonstration plant was developed and pilot tests were run to characterize the realistic potential of heat recovery on the hook conveyor. Based on the test results, feasibility studies for large scale plants were carried out. As a result, 0.8 GWh of heat can be recovered annually. The method was found useful because it helped to structure the existing information with a reasonable effort mostly by the operators themselves in their work and to build a conceptual model of energy flows and energy efficiency of the total plant. [ABSTRACT FROM AUTHOR]

In this paper, a mathematical model is formulated to quantify the social impact an individual has on his/her community when he/she performs any energy efficiency project and transmits that information to his/her neighbours. This model is called the expected power savings model; it combines direct and indirect expected power savings of the energy efficiency project for each individual within the network. The indirect savings are quantified through the social interactions people in the network. The example used in this paper illustrates the effectiveness of the model by identifying the households who should have free solar water heaters installed in their residential houses based on their influence through interactions in their community. Two case studies are considered in this paper, single and multiple sources case studies. In the multiple source case study, the results show that it is not necessarily the people with the highest connections who provide the maximum expected power savings. [ABSTRACT FROM AUTHOR]

This paper describes the results of energy efficiency enhancement in 23 numbers of 210 MW coal fired power plants spread over India. Energy efficiency improvement of major auxiliary equipment with different plant load factors are summarized here with improved performance. The effect of plant load factor on all major auxiliary equipment and improvement in performance of auxiliary equipment are discussed in this paper. Operation of the plant at improved plant load factor reduced the specific auxiliary power from 11.23% at 70% PLF to 8.74% at 100% PLF that reduced the net auxiliary power by 9.1 MU/year that is an equivalent reduction of CO2 emission by 9500 t/year. Optimizing the excess air, controlling the furnace ingress, enhanced energy efficiency of individual equipment by proper maintenance, etc., improves the plant capacity and reduces the overall auxiliary power by about 1.5-2.1% of gross energy generation i.e., equivalent CO2 reduction of 23,000-32,400 t/year and release an additional power of about 3.5 MW (for a typical one 210 MW power plant) into grid. [ABSTRACT FROM AUTHOR]

Abstract: Direct-LTE communication underlying a cellular infrastructure, or more commonly known as device to device (D2D), is discussed in this paper. When enabling D2D communication in the system, one can see several benefits compared to the conventional infrastructure based communication, such as improved energy efficiency, increased overall system throughput and decreased traffic load in the network. The aim of this paper is to give an energy efficiency perspective of D2D communication to assist all major mobile stakeholders to perceive the benefits when facilitating D2D communication in the network. This paper is tutorial in nature, initially elaborating on the fundamental concept surrounding D2D communication towards technical perspective, business opportunities and open challenges when considering deployment. Furthermore, a simulation study of a typical D2D use case is carried out that includes the energy efficiency perspective; we use 3GPP Long Term Evolution Advanced (LTE-A) as a baseline technology and candidate for launching D2D communications. [Copyright &y& Elsevier]

Abstract: Heat transfer intensification for shell and tube heat exchangers is an efficient technique to increase energy saving when retrofitting heat exchanger networks (HENs). Such intensification has been widely studied in the process industry in recent years from the point of view of individual heat exchangers. By implementing intensified techniques in existing exchangers, higher heat transfer coefficients can be achieved, leading to higher heat exchange duties in the existing matches, which can improve the overall energy recovery without the necessity to change the HEN configurations [1–3]. The conventional intensification techniques include tube-side enhancements (internal tube fins, twisted-tape inserts, and coiled-wire inserts), and shell-side enhancements (external tube fins, and helical baffles). Combining several enhancement techniques can achieve higher energy saving compared with single technique implementing. However, existing papers rarely considered different intensification techniques in the same case to compare their performances and examine combinations. It is difficult to identify which intensification technique is more suitable in a certain exchanger, or which combinations of intensification techniques are expected to contribute the most positively to the compound augmentation. Thus, this paper focuses on the recent advances on tube-side and shell-side enhancement techniques, and investigates their performances to obtain substantial economic benefits in intensified heat exchangers. [Copyright &y& Elsevier]

Abstract: Machining is one of the major activities in manufacturing industries and is responsible for a significant portion of the total consumed energy in this sector. Performing machining processes with better energy efficiency will, therefore, significantly reduce the total industrial consumption of energy. In this paper, a framework is presented to validate the introduction of energy consumption in the objectives of process planning for CNC machining. The state of the art in process planning and energy consumption in manufacturing research is utilised as a basis for the framework. A mathematical representation of the logic used is presented followed by two sets of experiments on energy consumption in machining to validate the logic. It is shown that energy consumption can be added to multi-criteria process planning systems as a valid objective and the discussion on using resource models for energy consumption estimation concludes the paper. These experiments represent a part test procedure machining proposal for the new environmental machine standard ISO 14955 Part 3. [Copyright &y& Elsevier]

The energy conversion efficiency of coal utilization is a focal point in modern energy management practices and in academic literature. This paper explores life cycle energy efficiency of coal (LEEC), which encompasses six distinct stages from the design of coal mines to the comprehensive reuse of resources. First, the study analyzes improvements to the evaluation of efficiencies in energy systems. Secondly, it proposes a multi-stage energy efficiency analysis and constructs an innovative LEEC model for coal exploitation and utilization. Thirdly, the energy efficiency of coal exploitation and utilization was evaluated, and found that total efficiency in China increased from 33.11% in 2010 to 37.69% in 2014, saving 126 Mtce of energy. Finally, this study found that mine design is the most important stage in improving energy efficiency, followed by the coal processing stage. Moreover, we found that coal processing has an indirect contribution to other stages in the life cycle utilization of coal, such as reducing transportation capacity. The primary research contribution is the development of a comprehensive LEEC model for the entire life cycle of coal, rather than just single-stage evaluation. This lays the foundation for further studies on energy efficiency of industrial chains and across entire systems. • Exploration of energy efficiency across the entire coal life cycle. • The energy efficiency of coal exploitation and utilization increased annually. • Analysis shows the implicit contribution of coal processing to life cycle. • Mine design is a crucial stage for overall life cycle energy efficiency. [ABSTRACT FROM AUTHOR]

The global construction industry is expected to experience an average growth of 3.6% annually in construction outputs throughout 2018 to 2022. The surge of new building developments will create substantial demand for energy and therefore run the risk of higher carbon emissions. With the rising concern over climate change, it is imperative for buildings to have energy-saving strategies in place. Many research has discussed the use of energy efficient technologies as a solution, but overlook the role of energy-saving behaviour during the post-occupancy stage. Occupants' energy-saving behaviour is important in ensuring the optimisation of building technologies. A large part of human behaviour is characterised by habit, which is learned sequences of an act that have become automatic responses to specific ques and are functional in meeting certain needs. The study aims to establish the link between the behaviour of building occupants and their underlying habits. Adopting the Habit Theory as a premise, the study formulates a framework on strategies for behaviour change interventions that captures the underlying motivations to exhibiting energy-saving behaviour. The Effective Theory-Building design process was applied, which engages an axiomatic system to purposefully generate theory, evaluate its utility, and provide an effective representation of the observed phenomena. The theoretical framework addresses how energy-saving behaviour is cultivated through conditions of habits. This shows that the building occupant's behaviour is important for enabling energy efficiency and that it can be construed and explained by repetitive habitual actions of energy-saving practices. To have the greatest effect on a building's energy performance, building managers must examine the nuanced ways that habitual actions may shape the occupants' energy-saving behaviour and consider intervention strategies for changing habits. The paper provides a deeper understanding of building occupants' energy-saving behaviour from a sociotechnical perspective and creates a paradigm for future studies of building energy management. [ABSTRACT FROM AUTHOR]

Graphical abstract Decreased energy usage for the same grind size and therefore: lower wear rate of replaceable components and lower operating cost. Highlights • Cylindrical shaft spacers are used to separate the IsaMill™ grinding discs. • Alternative conical spacers have now been tested at lab, pilot and full scale. • In an operating IsaMill™, the new configuration reduced specific energy by 13–17%. • Further specific energy savings are possible at finer grind size targets. • The benefit can be realised as finer grind size or decreased power consumption. Abstract The IsaMill™ was specifically developed to address the energy efficiency issues associated with grinding to fine and ultrafine sizes. It has been doing this successfully for nearly 25 years in more than 125 installations. Recent efforts by Glencore Technology to further improve the energy efficiency of the IsaMill™ have resulted in the development of a new IsaMill™ shaft spacer design. The spacer was developed through laboratory, pilot and full scale testing prior to being commercialised. Full-scale results indicate that the new configuration was able to reduce the specific energy consumption by 13–17% in an M1000 gold application grinding to a P80 of 18 µm. The spacers were also shown to have no adverse impact on the shape of the product particle size distribution. This paper discusses the development process of the new spacers through lab, pilot and full scale trials, operating results and processing implications. [ABSTRACT FROM AUTHOR]

Highlights • Examine the coal use, CO 2 and pollutant emissions characteristics of China's wind-coal power system. • Model the impacts of wind penetration on them with high resolution output data. • Suggest future dispatch study from economical and environmental perspectives. Abstract China's power supply structure is dominated by coal-fired power. As China's renewable power expands, coal-fired power units are required to improve flexibility to balance power system. However, more flexible operation of coal power units increases energy consumption and pollutant emissions. This paper examines the energy efficiency, CO 2 and pollutant emissions characteristics of China's generic wind-coal combined power generation system, and discusses pollution-minimizing dispatch strategies by modeling three hypothetical scenarios of wind-coal combined power generation systems. For day-scale analyses, we find expected displacement rates of coal consumption and CO 2 emission decrease by wind fraction rate, indicating reduced energy savings from wind power per unit of increase in wind capacity. For NO x emission, we find that expected displacement rate reaches maximum value of 112% when wind fraction rate is equal to 0.27.For week-scale analysis, we simulate the coal consumption rate and emission factors with and without an operation of shutdown and startup of coal power units in the system. We suggest future study on dispatch decisions of startup/shutdown of coal power units to optimize power generation economically and environmentally. [ABSTRACT FROM AUTHOR]

Abstract With the continuous development of wireless networks, energy conservation and energy efficiency are becoming key factors in improving the network lifetime. In multi-antenna wireless networks, the energy conservation problem can be addressed using the trade-off between the transmit power and the circuit energy consumption. In this paper, we propose a cross layer protocol, MAC-LEAP, that selects the best transmission policy based on Multiple-Input Multiple-Output (MIMO) in both single-hop and multi-hop wireless networks. Various data transmission algorithms are presented in which many factors are considered in order to find the best transmission policy between each pair of nodes. An RTS/CTS handshake is used to exchange the required information to select the best transmission policy prior to data transmission. Moreover, we introduce a MIMO-based framework in Network Simulator 3 (ns-3) in which the wireless nodes may be equipped with more than one antenna. Using extensive simulations in ns-3, we compare the performance of MAC-LEAP with traditional protocols in terms of the network lifetime and the number of received packets. The simulation results show that MAC-LEAP outperforms the traditional protocols in both single-hop and multi-hop networks for various transmission distances and target Bit-Error-Rates (BER). [ABSTRACT FROM AUTHOR]

Abstract: Low carbon cities. What, exactly, are we talking about? Are we talking about lifestyles, activities, or enterprises? Are we talking about individual or group voluntary behavior change or a policy framework that seeks to encourage behavior change by regulatory force? Faced with an enormous literature that mixes related topics like sustainable development/climate change/energy conservation/low carbon, it is not surprising to hear about local governments’ or planners’ “climate change initiatives”. This paper describes/reflects on how officials in Broward County, Florida, are dealing with issues of awareness, governance, measurement, and instruments for challenges arising from the combined threats of energy depletion and climate change. The overriding objective of this paper is to provide some pith for the discussion of planning for low carbon cities. To this end, we describe and reflect on the planning management responses of Broward County, Florida, USA – as an illustrative local government – in dealing with climate change challenges (CCC), energy conservation (EC) and greenhouse gas reduction (GHG). Both description and reflection are important as it is primarily the latter that provides the critical perspective necessary for assessing both potential and effect. The paper is organized into five sections. The first two sections address the “contextual” questions raised above: what is the level of knowledge and/or awareness among the collection of planners and/or local governments; and, what are/is appropriate responses of different levels of government. In the next section, we review overall levels of knowledge and awareness of basic science and policy dimensions, with particular attention paid to (a version of the) US planning profession. This is followed by a discussion of “theoretical” prescriptions for actions at different levels of government. The third and fourth sections focus on Broward County. The third section describes the county and presents a current measurement of its carbon footprint (at least at the level to which it can be measured). The fourth section describes the operational response of Broward County government. The final section returns to the original questions of knowledge and appropriate types of responses and argues that while the Broward response is generally effective in certain aspects, the current policy paradigm contains both strengths and weaknesses, which are generally outlined and discussed. [Copyright &y& Elsevier]

Abstract: This paper assesses the energy and water consumption practices of existing housing in Saudi Arabia, with the ultimate aim of establishing guidelines for delivering sustainable residential buildings in the near future. In order to achieve this aim the current status of a typical Saudi residence (i.e. an apartment complex) is investigated in terms of energy and water consumption using simulation software packages. The paper then examines the prospects for applying various measures to the typical Saudi residence to manage energy and water use more sustainably. This research identifies several design-related faults common to Saudi Arabian house design. These faults contribute to an inefficient use of energy and domestic water resources. Finally, the paper puts forward a set of recommendations and guidelines, design-related and otherwise, to enhance the sustainability of future Saudi residential buildings. [ABSTRACT FROM AUTHOR]

Highlights • Non-intrusive techniques are proposed to infer occupancy from existing HVAC sensors. • Reheat energy use is reduced by more than 38% with better nighttime setback schedules. • Derived a comprehensive set of candidate anomalous zones using unsupervised learning. • Proposed approach can be readily applied to any commercial building with a BMS. Abstract The Heating Ventilation and Air Conditioning (HVAC) system of commercial buildings traditionally runs on a fixed schedule that does not take occupancy into account despite its huge variation over space and time, thereby wasting a lot of energy in conditioning empty or partially-occupied spaces. Occupancy information is essential to eliminate wasteful energy use with imperceptible impact on building operations and human comfort. This paper investigates the application of non-intrusive techniques to obtain a rough estimate of occupancy from coarse-grained measurements of sensors that are commonly available through the building management system. Various static and adaptive energy-efficient schedules are developed based on this approximate knowledge of occupancy at the level of individual zones. Our experiments in three large commercial buildings confirm that the proposed techniques can uncover the recurring occupancy pattern of the zones, and schedules that incorporate these occupancy patterns can achieve more than 38% reduction in reheat energy consumption while maintaining indoor thermal comfort. [ABSTRACT FROM AUTHOR]

Abstract: In the last years, wireless sensor networks (WSNs) have gained increasing attention from both the research community and actual users. As sensor nodes are generally battery-powered devices, the critical aspects to face concern how to reduce the energy consumption of nodes, so that the network lifetime can be extended to reasonable times. In this paper we first break down the energy consumption for the components of a typical sensor node, and discuss the main directions to energy conservation in WSNs. Then, we present a systematic and comprehensive taxonomy of the energy conservation schemes, which are subsequently discussed in depth. Special attention has been devoted to promising solutions which have not yet obtained a wide attention in the literature, such as techniques for energy efficient data acquisition. Finally we conclude the paper with insights for research directions about energy conservation in WSNs. [Copyright &y& Elsevier]

Abstract: The rebound effect presents a major flaw in to energy conservation policies that aim to reduce energy consumption through energy efficiency development. Economics and energy related disciplines have thus far developed tools to measure such a phenomenon. This paper attempts to explain this seeming paradox using a thermodynamic-evolutionary theoretical framework in addition to the traditional economic approach. We here propose that evolutionary systems, such as biological or even economic systems, may rearrange themselves in a more complex fashion under the pressure of an increasing flux of energy, driven by the higher conversion rate of greater efficiency. Higher complexity, due to a greater energy density rate, counteracts the positive effects of energy efficiency. We investigated this hypothesis in the context of the road freight transport system and the productive structure. The qualitative analysis in this paper, further substantiated by figures, provides a link between the dynamics of production patterns and the effect of efficiency in the light of the macro-economic effects of increased energy demand. The analysis departs from a rigorous investigation of the actual energy efficiency evolution in the road freight transport system to develop through a survey of the subsequent worldwide economic revolution in the production system. It is then shown how outsourcing, the key feature of globalization, can be identified as the main source of traffic density growth. Finally, four paradigms are used to stress how the shift in the production system must be considered a leap in structural complexity that consequently serves to increase the frequency of components’ interactions. [Copyright &y& Elsevier]

Abstract: This paper addresses the issue of improving the energy efficiency of processors by eliminating trivial operations. The paper provides a new classification of trivial operations and quantifies their relative frequency in desktop and embedded applications. It then presents a hardware technique to remove trivial operations as early as at the decode stage of the pipeline to save energy. This paper shows that 13.6% and 8.6% of the instructions are identity-trivial in the selected applications in the SPEC CPU2000 and EEMBC1.1 benchmark suites, respectively. Early detection and elimination of trivial operations reduce the average energy consumption of the core pipeline by 9% and 6%, respectively. [Copyright &y& Elsevier]

Abstract: Constructing an indicator to measure the effectiveness of energy management is important for energy agencies and authorities. This paper uses multiple linear regression method and data envelopment analysis to examine the effectiveness of energy management. First, the regression method using environmental factors is used to calculate the predicted energy usage intensity of each evaluated building. Data envelopment analysis is then employed to calculate overall energy efficiency, using the predicted energy usage intensity as output and the observed energy usage intensity as input. Data envelopment analysis can be further applied to measure the overall energy efficiency in details by examining environmental factors and management factors. Finally, the energy consumption of buildings can be measured to evaluate the effectiveness of energy management. Buildings examined as a case study in this paper are government office buildings in Taiwan. The results show that most of the buildings evaluated to report a higher predicted energy usage intensity have successfully used efficient energy management methods in energy saving. [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]

Improving energy efficiency helps achieve energy conservation and emission reduction. Examining whether China's SO2 trading emission system (TES) reform can enhance energy efficiency will provide empirical evidence for the institutional benefit of market-oriented environmental regulation in environmental governance. This paper employs the difference-in-differences (DID) method to examine the effect of SO2 TES on energy efficiency using panel data from 285 Chinese cities from 2003 to 2018. The empirical results indicate that: (1) SO2 TES significantly promoted green total factor energy efficiency and reduced energy intensity. This conclusion is still valid after the prerequisite assumption test and robustness test. (2) SO2 TES significantly promotes local energy efficiency and has significant spatial spillover effects on surrounding cities. (3) Promoting green technological progress, resource allocation, and curbing energy consumption, are the primary mechanisms for SO2 TES to improve energy efficiency. (4) SO2 TES's improvement in energy efficiency comes more from eastern, developed, small, resource-based, and non-old industrial cities. • SO2 trading emissions system (TES) improves energy efficiency. • TES has a spatial spillover effect on nearby cities. • Green innovation, resource allocation and energy saving effects are the channels. • The effect of the TES on energy efficiency is heterogeneous. [ABSTRACT FROM AUTHOR]

Fifteen years after the publication of the article entitled "Energy Education: breaking up the rational energy use barriers" in 2004, what were the paths taken and scientific contributions made towards a rational energy use as regards energy education? This paper aims to answer this question by collecting data on the Web of Science database to identify publications citing the aforementioned article using different levels of approach. The selected papers were structured in clusters utilizing software for such a purpose, which allowed organizing and listing reviewed works from which a cluster of keywords has been structured to identify the most frequently cited terms. Once found, the following step was to perform a content analysis to allow organizing authorship and contributions. During this process, the term "barriers" in the context of rational energy use was not restricted to its class, but it was present in the analysis of other terms that constitute other classes. Energy education is presented as one of the ways to make society more aware and active while taking actions towards rational energy use. However, to achieve greater effectiveness of such an educational process, the human aspect requires special attention through a clearer definition of personal values, attitude, and behaviour because of its importance for activities aimed at energy issues. • Energy education is crucial for energy rational use. • Other approaches for energy education were identified. • Individual's psyche influence on energy rational use. • Several barriers permeate energy and its use. • Energy education enables energy planning. [ABSTRACT FROM AUTHOR]

With the growing urbanization and environmental concerns over buildings' energy consumption and carbon footprint, the demand for energy-efficient building design is greater than ever. This paper addresses these concerns by presenting a novel method for estimating and optimising the thermal load (i.e. total energy load for heating and cooling) of a building within a real environment, provided by high-resolution LiDAR data, while considering long-term climatological parameters, estimated direct and anisotropic diffuse irradiance, shadowing from surroundings, and terrain topography. In the optimisation part of the method, the building's design is optimised regarding the estimated thermal load. The estimation was validated with the well-established EnergyPlus software. In experiments, a rectangular building's design was optimised on a flat and urban dataset. The effect of a building's design parameters on thermal load was inspected as well. On average, the proposed method improved a building's net heat gain by over 103 kWh/m 2 and reduced its thermal load by 234.18 kWh/m 2 when compared with the initial building design. [ABSTRACT FROM AUTHOR]

• The combination of active and passive strategies saves 13.5 % of the building cost. • This paper studies the economic payoff of making energy-efficient choices in a residential building over its life cycle. • This paper uses energy simulation tools along with Life Cycle Costing to study economic benefits. • This paper identifies opportunities and challenges for the realization of energy-efficient procedures. The residential building sector is very energy-intensive. With population growth and a rise in the number of homeowners, the effect is bound to worsen. A wave of green and sustainable strategies is on the rise, hoping to moderate some of the adverse effects on the environment. The construction industry is continually evolving into becoming more energy conscious. However, one of the biggest obstacles is a lack of awareness and a fear of initial costs among contractors, homeowners, and clients alike. The purpose of this research is to explore the potential of current Life Cycle Cost Analysis (LCCA) procedures as an evaluation tool for green building strategies by conducting energy simulations for different energy conservation measures (ECMs). This paper aims to establish the tradeoff between initial investment and long-term benefits for different energy conservation measures. Energy simulation models and life cycle cost models were developed. The developed models have been applied to a case of an apartment in a multi-family building. This research shows that a combination of passive and active energy conservation measures results in the lowest lifecycle cost. The results show a 13.5 % saving of the building cost employing a combination of passive design and active strategies. [ABSTRACT FROM AUTHOR]

Energy saving strategies are vital for long term viability and commercial success of buildings. Buildings in the US today consume 41% of the total primary energy. Complex buildings consume significantly higher energy than typical office buildings and present challenges to energy savings due to their operational requirements. This paper presents an economic analysis on energy saving technologies implemented in a complex manufacturing building. The return on investment is determined by using the payback analysis and life cycle cost analysis. The results indicate that energy saving technologies achieved a total energy cost savings of 14%. The savings were achieved by using high efficiency HVAC equipment and advanced fluorescent lighting systems. When applied to similar types of buildings, energy saving strategies considered will increase economic and environmental benefits to owners. [ABSTRACT FROM AUTHOR]

In order to achieve greater energy sustainability, the European Union has begun the reform process of the energy policy. Two main lines have been raised: electricity generation with renewable energy and energy saving. The raising cost of energy makes indoor lighting techniques as one of the most important contributors for energy saving in most of the industrialized countries. Therefore, the history of indoor lighting is not exclusively linked to the development of new light sources, having impact on energy saving and sustainability. The aim of this paper was to study and analyse the evolution and milestones of indoor lighting from incandescent bulbs to the modern light-emitting diodes (LEDs) and organic lighting emitting diodes (OLED) going through intermediate milestones like fluorescent lamps (FL) and/or techniques in lighting induction lamps. As main conclusion of this review, it has been found that indoor lighting techniques with their energy efficiency have opened new perspectives for optimizing the energy conversion and this in turn will play a major role in people's quality of life and well-being. [ABSTRACT FROM AUTHOR]

Some new application scenarios for Wireless Sensor Networks (WSNs) such as urban resilience, smart house/building, smart agriculture and animal farming, among others, can be enhanced by adding multimedia sensors able to capture and transmit small multimedia samples such as still images or audio files. In these applications, Wireless Multimedia Sensor Networks (WMSNs) usually share two conflicting design goals. On the one hand, the goal of maximizing the network lifetime by saving energy, and on the other, the ability to successfully deliver packets to the sink. In this paper, we investigate the suitability of several WSNs MAC protocols from different categories for low data rate WMSNs by analyzing the effect of some network parameters, such as the sampling rate and the density of multimedia sensors on the energy consumption of nodes. First, we develop a general multi-class traffic model that allows us to integrate different types of sensors with different sampling rates. Then, we model, evaluate and compare the energy consumption of MAC protocols numerically. We illustrate how the MAC protocols put some constraints on network parameters like the sampling rates, the number of nodes, the size of the multimedia sample and the density of multimedia nodes in order to make collisions negligible and avoid long queuing delays. Numerical results show that in asynchronous MAC protocols, the receiver-initiated MAC protocols (RI-MAC and PW-MAC) consume less energy than the sender-initiated ones (B-MAC and X-MAC). B-MAC outperforms X-MAC when the sampling rates of multimedia nodes is very low and the polling periods are short. PW-MAC shows the lowest energy consumption between the selected asynchronous MAC protocols and it can be used in the considered WMSNs with a wider range of sampling rates. Regarding synchronous MAC protocols, results also show that they are only suitable for the considered WMSNs when the data rates are very low. In that situation, TreeMAC is the one that offers the lowest energy consumption in comparison to L-MAC and T-MAC. Finally, we compare the energy consumption of MAC protocols in four selected application scenarios related to Smart Cities and environment monitoring. [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]

Improving energy efficiency is one of the most effective ways to reduce energy waste and achieve carbon neutrality, but it may also bring the energy rebound effect and thus fail to achieve the desired energy conservations. In this paper, we examine the energy rebound effect of Beijing at the level of overall economy, industry and sector based on the Cobb-Douglas production function and the idea of Solow residual, so as to clarify the true impact of technological progress on energy-saving target. Results suggest that: (1) The overall economy of Beijing shows partial rebound effect in most years and appears backfire effect in some years, but the degree of the rebound effect has been gradually mitigated; (2) The energy rebound degree of the tertiary industry is higher than that of the secondary industry on the whole, but the rebound effect of the secondary industry fluctuates more obviously; (3) Energy savings at the sector level is also not ideal, and in most cases, sectors with low energy efficiency have a higher rebound effect than sectors with high energy efficiency. Based on these results, suggestions are provided to alleviate the energy rebound effect of Beijing. • The energy rebound effect of Beijing are quantified at the level of overall economy, industry and sector. • The overall economy of Beijing appears backfire effect and partial rebound effect. • The energy rebound effect of the tertiary industry is higher than that of the secondary industry in most years. • Sectors with low energy efficiency may have higher rebound effects. [ABSTRACT FROM AUTHOR]

The paper presents a method for assessing the environmental and the energy performance of museum buildings, demonstrating that conservation, human comfort, and energy efficiency are mutually compatible when based on rational planning, interdisciplinary cooperation, and extensive knowledge of museum buildings and collections. The operative tool assists the decision makers in optimizing planning actions during the energy and environmental retrofit, maintenance and management, to: (i) extend the lifetime of heritage; (ii) identify the conservative risks and quantify the factors responsible of damage phenomena; (iii) improve the building performance; (iv) minimize consumptions and costs, (v) establish appropriate procedures and policies; and (vi) program the retrofit. To merge different aspects, we use the SOBANE strategy (screening, observation, analysis, expertize) to organize efficiently, economically, and durably the risk management and, consequently, the retrofit actions. The methodology has been structured in four levels of investigation: (i) “screening” for assessing the museum performance; (ii) “observation” for detecting causative factors, present and potential risks; (iii) “analysis” for quantifying the environmental and energy risks with detailed investigations and long-term measurements; and (vi) “expertize” to provide guidelines for implementing and prioritizing appropriate solutions to solve specific problems related to prevention, human comfort, and energy efficiency. This methodology neither meant to be exhaustive or definitive, but simply aims to serve as a reference for technicians and conservators, who require clear and easy procedures and applicable solutions. [ABSTRACT FROM AUTHOR]

With the energy consumption of wireless networks increasing, visible light communication (VLC) has been regarded as a promising technology to realize energy conservation. Due to the massive terminals access and increased traffic demand, the implementation of non-orthogonal multiple access (NOMA) technology in VLC networks has become an inevitable trend. In this paper, we aim to maximize the energy efficiency in VLC-NOMA networks. Assuming perfect knowledge of the channel state information of user equipment, the energy efficiency maximization problem is formulated as a mixed integer nonlinear programming problem. To solve this problem, the joint user grouping and power allocation (JUGPA) is proposed including user grouping and power allocation. In user grouping phase, we utilize the average of channel gain among all user equipment and propose a dynamic user grouping algorithm with low complexity. The proposed scheme exploits the channel gain differences among users and divides them into multiple groups. In power allocation phase, we proposed a power allocation algorithm for maximizing the energy efficiency for a given NOMA group. Thanks to the objective function is fraction form and non-convex, we firstly transform it to difference form and convex function. Then, we derive the closed-form optimal power allocation expression that maximizes the energy efficiency by Dinkelbach method and Lagrange dual decomposition method. Simulation results show that the JUGPA can effectively improve energy efficiency of the VLC-NOMA networks. [ABSTRACT FROM AUTHOR]

The paper deals with issues on the improvement of the refrigeration supply system of a petrochemical enterprise in Western Siberia. Using a low-temperature potential of the environment allows for saving on some productions up to 50% of energy resources. It also describes variants of refrigeration supply schemes using new energy-efficient technologies. [ABSTRACT FROM AUTHOR]

The assessment of fixed asset investment projects of energy conservation is based on a scientific and systematic approach to analyze the energy production, consumption and management and helps to analyze whether the use of energy is in line with the national and local industrial policies and whether the project design meets China׳s energy saving design outlines and industry standards. The level of energy consumption is compared to the domestic and international advanced levels regarding the project energy use and process analysis, in all aspects of energy production and energy consumption, taking technically feasible, economically reasonable and environmentally and socially responsible measures and effective and rational use of energy, to reduce consumption and losses and to stop waste, while investigating if the project has a certain advanced and rational use of energy. This study provides a full consideration of whether there is a scientific and rational use of energy to avoid low-level repetition construction, to avoid blind expansion trends, and to promote the upgrading of industrial structure. This paper takes as an example a gas turbine power plant in Shenzhen as an assessment case study of the potential energy savings. The project is expected to have an annual power supply of 37.89×10 8 kW h and an annual heat supply of 5.43×10 4 GJ. The consumption of power generation in tons of coal equivalent units is expected to reach 208 g per kW h. The comprehensive annual average thermal efficiency is 77.16%, and the average heat-to-power ratio is 40.65%. These technical indicators are thought to be one of the best compared to similar level projects in the country. [ABSTRACT FROM AUTHOR]