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[Display omitted] • Novel method to estimate total technical potential for improving energy efficiency. • Bottom-up sector energy model used to characterize energy demands and opportunities. • Technology-explicit analysis framework used to estimate integrated energy savings. • Application to Canada's pulp & paper sector indicates major savings are possible. • Technical potential to reduce natural gas use by 95% and net electricity by 54% Industrial energy efficiency has long been recognized as a critical tool for energy management and emissions reduction and is increasingly considered to be an energy resource in its own right. However, the complexity of most industrial sectors creates barriers for modellers, companies, and policymakers in understanding and achieving the overall potential for efficiency-driven energy savings. To address this gap, we have developed a novel method that combines disaggregated bottom-up sector energy modelling with analysis of a comprehensive set of technology-explicit energy efficiency measures. This approach overcomes the deficiencies of top-down analyses and better represents the complexities of multi-measure efficiency investments compared to piecewise studies of individual measures. In this study, we demonstrated application of our method to the case of the Canadian pulp and paper sector. Our analysis shows that the sector can reduce its natural gas and electricity use by 95% and 41%, respectively, by adopting economical efficiency measures. This equates to 71 PJ of natural gas and 44 PJ of electricity saved annually and would result in cost savings of $81 per tonne of output sector-wide. Notably, we find that efficiency and fuel switching have the technical potential to reduce natural gas consumption by 98% across the sector. Taken together, the results provide quantitative evidence that energy efficiency is an underestimated resource for cost-effective energy savings in the Canadian pulp and paper sector. Our analysis framework can be applied to any industrial sector in any region to provide insights regarding energy conservation strategies and policy design. [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 Software systems have a strong impact on the energy consumption of the hardware they use. This is especially important for cyber-physical systems where power consumption strongly influences the battery life. For this reason, software developers should be more aware of the energy consumed by their systems. Moreover, software systems should be developed to adapt their behavior to minimize the energy consumed during their execution. This can be done by monitoring the usage context of the system and having runtime support to react to those changes that impact the energy footprint negatively. Although both the hardware and the software parts of cyber-physical systems can be adapted to reduce its energy consumption, this paper focuses on software adaptation. Concretely, the paper illustrates how to address the problem of developing context-aware energy-efficient applications using a Green Eco-Assistant that makes use of advanced software engineering methods, such as Dynamic Software Product Lines and Separation of Concerns. The main steps of our approach are illustrated by applying them to a cyber-physical system case study. [ABSTRACT FROM AUTHOR]

As an important part of green eco-community planning, reasonable community energy planning requires accurate community load prediction. Hence, this paper focuses on the method of community load prediction. Given that community energy planning has great uncertainty and forward-looking requirements, this paper proposes an integrated method of buildings load prediction, which combines building simulation and scenario analysis. We apply scenario analysis to avoid simply adding up the loads which leads to overestimation. Establishment and calibration of the prototypical models are carried out. Using the proposed method, a case study is conducted to predict the cooling and heating load of a CBD in Shanghai. The results show that the energy system operates at relatively low efficiency and adjustment of area ratio of different building types is suggested. [ABSTRACT FROM AUTHOR]

Facing the challage of energy conservation and emission reduction in the building sector, most energy saving strategies of central heating only focus on the performance improvement of building envelope, ignoring the impact of energy use behavior. This paper proposed a building energy conservation strategy based on energy use behavior analysis, which provides a perspective for in-depth exploration of building energy conservation. After investigating a typical university in the northern China, the energy use behaviors were characterized and two different DeST energy consumption models before or after considering energy use behavior were established. By comparing the results calculated by these two models, the impact of energy use behavior analysis on building energy consumption was quantitatively analyzed. The results show that the heating energy consumption and carbon emission can be reduced by 23.28% and 23% respectively through the proposed strategy based on energy use behavior. Therefore, the analysis of energy use behavior can provide a theoretical basis for heating operators to make decisions on energy supply regulation. With central cooling and heating further popularizing in the future, the research methodology of this paper has more extensive reference value for energy conservation and emission reduction strategies in the building sector. [ABSTRACT FROM AUTHOR]

Abstract: Significant energy savings can be achieved in the pulp and paper industry through process integration. The aim of this paper was to investigate how much seasonal variations in the process influence the potential for making energy savings. The hot and warm water system in a market pulp mill has been evaluated from an energy point of view, using pinch analysis. Considerable energy-saving potential was found, 40.7MW, of which 16.5MW was in the form of steam savings. The steam savings represent 7% of the total steam consumption at the mill. New heat exchanger networks were redesigned using different approaches. The influence of seasonal variations was estimated from the calculated energy savings when monthly averages were used in the new heat exchanger networks. When seasonal variations were taken into account, the energy-saving opportunities fell by 2.5–5.0MW, depending on heat exchanger network design, compared with a steady-state scenario. Consequently, 88–94% of the theoretical energy savings could be realised. An economic evaluation indicates positive earnings from investment in a new heat exchanger network when seasonal variations were taken into account, even with low prices for the extracted steam and excess heat (5€/MWh) and with an annuity factor of 0.2. [Copyright &y& Elsevier]

• Accordingly, a flexible traction power supply system (FTPSS) composed of a TT and multi-port power hub and its coordinated control strategy are proposed for VU compensation and energy conservation in this paper. The main contributions can be summarized as follows: • Different from previous research, a power hub is installed in the TPSS to achieve power flow control among the utility grid, traction network, and DC grid. The FTPPS with the power hub can enable VU compensation for the utility grid, which also offers a friendly interface with distributed PV and ESS for on-site access. • A three-port VU compensation method based on active power flow control and reactive power injection is presented, which divides the system demand compensation capacity and reduces the performance requirements for power electronics, compared with traditional compensation methods. • A coordinated control strategy with a hierarchical structure is designed for FTPSS. The control strategy enables real-time power management to enhance energy utilization and mitigate VU in the system layer and coordinates multiple converters to realize the multi-function operation of the system in the converter layer. To mitigate voltage unbalance (VU) and eliminate the neutral sections while reducing the energy consumption of railways, a flexible traction power supply system (FTPSS) with the power hub is proposed. Different from conventional schemes, the proposed system provides a friendly interface to realize the on-site access of distributed photovoltaic (PV) generation along the railway line and concentrated integration of energy storage systems. The power flow is centrally managed by the power hub to reduce energy consumption and the proposed three-port VU compensation method is coupled with the power hub to suppress negative sequence current caused by trains. Considering the volatility of PV generation and traction loads, four operation modes including grid-connected, valley filling, VU compensation, and peak clipping mode, are proposed to dynamically regulate the operation of FTPSS. Moreover, a coordinated control strategy with a hierarchical structure is developed to enable the operation modes. The strategy is implemented with a global controller and multiple local controllers, which can realize real-time power management and flexible transition among different modes. Finally, different simulation and experimental case studies based on the field data are carried out to comprehensively verify the feasibility and effectiveness of the proposed FTPSS and control strategy. [ABSTRACT FROM AUTHOR]

Abstract: A key factor deciding the capacity to increase the sustainability of final products is the energy efficiency. The energy embodied in a product is an aggregation of all of the energy embodied in the products' components and subsystems, expended through its manufacturing processes and logistical activities. Currently, accurate estimation of this energy metric is hindered due to the unavailability of energy use data traceable to individual processes and equipment associated with the product's assembly. In this paper, we propose using minimally-required energy to compute energy efficiency of a product assembly process. Based on the proposed approach, efficiency metrics established on the process, product, material and equipment characteristics have been presented at the assembly activity and equipment level. A case study has been presented for a hybrid laser welding process to demonstrate the computational methods used to arrive at these efficiency metrics. Major contributions of this paper are the metrics development and exemplifying the metrics through an actual assembly process (hybrid laser welding) case study. We will explain how these metrics can provide industries with a capability to identify opportunities to improve their sustainability performance across their assembly processes. [Copyright &y& Elsevier]

The objective of this paper is to investigate the energy conservation and resource utilization in the smelting process of ferrochrome pellets. Based on the laws of mass and energy conservation, the material and energy flows model has been established in the smelting process of steel belt sintering-submerged arc furnace. To better understand the smelting process from disorder state to order state under energy conservation and resource utilization, the synergy model related to the material and energy has been developed. The state change depends on the fluctuations to the energy critical point. The fluctuations are defined as order parameters, which satisfy all the smelting processes. The value of synergy degree is set as the evaluating indicator to assess the smelting process. The results show that the energy efficiencies of three smelting equipments are 42.89%, 66.17% and 61.44%, respectively. Also, the energy efficiency of the smelting process is 49.15%. The value of synergy degree is 0.584. Several suggestions for the smelting process are proposed based on the synergy model. The synergy degree of the suggestions is 0.632. The present work has a potential to improve the smelting process in efficiency. • Establish material and energy flows in steel belt sintering-submerged arc furnace. • Define order parameters affecting the synergy relationship on smelting processes. • Set the synergy degree as evaluating indicator for energy and resource saving. • Propose and validate suggestions according to the synergy analysis model. [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 Security of energy supply and the threat of climate change are the key challenges that define the further development of EU energy systems. The security of supply problem follows other problems such as energy and material scarcity, import dependency and waste generation. These problems can be alleviated via development of a low-carbon, sustainable, competitive and resource-efficient economy. One of the pillars of this approach is a circular economy and "closing the loop" approach. Integrated waste management system can close the loop, not only material-wise, through material recovery, but also energy-wise, by using energy from waste to drive whole waste management and recovery chain. Such approach is utilized in this paper through tracking of each energy vector and calculating coverage of energy needs inside the analysed systems. Energy analysis is accepted approach for sustainability assessment of the various products and systems, where primary energy consumption approach is mostly used. By combining these two approaches, the impact of closing the loop material- and energy-wise on the sustainability of the recycled materials is assessed by analysing to which degree can the embodied energy of recycled materials be reduced. The results of the analysed city case study show that energy recovery can satisfy up to 60/50% (in 2020/2030) of the total energy needs of the analysed system; in 2030 38% of waste routed to energy recovery (from which 25% to anaerobic digestion and the rest to the incinerator) satisfies around 50% of energy needs. This internal (partial) coverage of systems energy needs can additionally reduce embodied energy of recycled materials, and increase their sustainability (primarily lowered by material recovery) by 11–67% at the same time. From these results it can be concluded that energy recovery of waste could help to "close the loop" in the whole waste recovery mindset. Highlights • Evaluation method of the energy recovery role in the circular economy is elaborated. • Energy recovery influence on the embodied energy of recycled material is analysed. • Sequential, time-dependent, city-based, energy analysis is conducted. • Influence of legislation and time changes on waste management system are analysed. • Impacts of closing the loop on the energy side of the recovery chain are identified. [ABSTRACT FROM AUTHOR]

Highlights • Parameters of 60 electricity-saving measures and 16 abatement measures are compiled. • Synergies of electricity use in China's chemical sector at grid level are assessed. • Efficient use of power can cut 154 Mt CO 2eq , 295 kt SO 2 , 322 kt NO x and 64 kt PM 2.5. • North and Northwest grids have the largest economic benefits on emissions reduction. • Grid with high electricity price is more sensitive to price change than other grids. Abstract Industry is a large electricity user. China's chemical industry (globally the largest based on sales) contributes 7% to China's GDP, while it consumes 11% of the total electricity consumption in industry and is responsible for 40% of total CO 2eq , 40% of SO 2 , 59% of NO x and 18% of PM-emissions of the chemical industry emissions. The heterogeneity of GHG and air pollutant emissions across electricity grids (within a country) is rarely included in analyses. In this paper, electricity conservation supply curves are developed (distinguishing the grids) to estimate the cost-effective and technical potentials of electricity conservation in China's chemical industry. The emission factors per grid for GHG (i.e. CO 2 , CH 4 and N 2 O) and air pollutants (i.e. SO 2 , NO x and PM 2.5) are calculated and used to quantify the emissions mitigation achieved by electricity saving technologies in the chemical industry for the period 2012–2035. Results show that significant multiple benefits can be obtained by implementing electricity efficiency measures. There are large differences among the six grids in terms electricity savings and emissions abatement of GHG and air pollutants. 83% of the total electricity saving potential is contributed by the North, Northwest and Central grids, equal to 32% of baseline electricity consumption in 2035. In 2035, 129 Mt of CO 2 , 33 kt CO 2eq of CH 4 , 571 kt CO 2eq of N 2 O, 235 kt of SO 2 , 275 kt of NO x and 52 kt of PM 2.5 in these three grids can be avoided as a result of electricity savings (a reduction of 31–33% compared to baseline emissions). When decision-makers set targets for energy saving and emission reduction, the multiple benefits and grid heterogeneity should not be ignored. [ABSTRACT FROM AUTHOR]

Approximately 3 billion people, most of whom live in Asia, Africa, and the Americas, rely on solid fuels (i.e. wood, crop wastes, dung, charcoal) and kerosene for their cooking needs. Exposure to household air pollution from burning these fuels is estimated to account for approximately 3 million premature deaths a year. Cleaner fuels – such as liquefied petroleum gas, biogas, electricity, and certain compressed biomass fuels – have the potential to alleviate much of this significant health burden. A wide variety of clean cooking intervention programs are being implemented around the world, but very few of these efforts have been analyzed to enable global learning. The Clean Cooking Implementation Science Network (ISN), supported by the U.S. National Institutes of Health (NIH) and partners, identified the need to augment the publicly available literature concerning what has worked well and in what context. The ISN has supported the development of a systematic set of case studies, contained in this Special Issue, examining clean cooking program rollouts in a variety of low- and middle-income settings around the world. We used the RE-AIM (reach, effectiveness, adaptation, implementation, maintenance) framework to coordinate and evaluate the case studies. This paper describes the clean cooking case studies project, introduces the individual studies contained herein, and proposes a general conceptual model to support future planning and evaluation of household energy programs. [ABSTRACT FROM AUTHOR]

Abstract: This paper deals with the method of how to regenerate the potential energy for a hybrid hydraulic excavator (HHE). After studying the structure and working cycle of the HHE, two energy regeneration systems are considered. Then, the control strategy and parameter matching for the proposed energy regeneration system (ERS) are discussed. United simulations with AMEsim and MATLAB/simulink for the conventional control system and two ERSs are carried out in this paper. An estimated 41% of the total potential energy could be regenerated at the lowering of the boom in accumulator-motor-generator system while the recovery efficiency in the motor-generator system is only about 17%, and it is also shown that the accumulator-motor-generator energy regeneration system (AMGERS) features better speed control of the boom and response characteristics than the motor-generator energy regeneration system (MGERS), hence, the AMGERS is a good configuration for the HHE at present. [Copyright &y& Elsevier]

Abstract: There are many kinds of methods to estimate the energy requirement or fuel consumption in the optimal design and minimize the life cost of a building. The bin method is one of the most popular ways to estimate the energy performance of a building, which is based on the hourly-based outdoor dry-bulb temperatures of all days in a whole year. There is lack of information about the bin weather data in China. In this paper, the ambient temperature bin data for 26 cities in China are generated. Based on the method used in this paper, the bin data can be calculated with the long-term daily weather record or TMY weather data, the deviation between them is acceptable. The bin data given in this paper may have the positive impact on building energy conservation in China. [Copyright &y& Elsevier]

Abstract: The renewable energy industry is growing rapidly amidst rising concerns about oil depletion and climate change. Renewable energy is seen by many as part of the appropriate response to these concerns and some national Governments have put programs in place to support the wider use of sustainable energy systems. This has led to a rapid increase in demand for renewable energy specialists who are able to design, install and maintain such systems. Most engineers are not trained to use these renewable energy technologies and most are not aware of the principles of sustainability. There is therefore an urgent need to develop and implement new courses that prepare engineers, scientists and energy planners to work with renewables to produce sustainable energy generation systems. Renewable energy education is a relatively new field and previously it formed a minor part of traditional engineering courses. These days it has an identity of its own, with special techniques, standards and requirements which are not normally encountered in other disciplines. Attempts to add one or two units of study on renewables into traditional science and engineering degrees are unlikely to produce graduates with sufficient knowledge or understanding to use renewables effectively. Modern renewable energy education includes a study of the technology, resources, systems design, economics, industry structure and policies in an integrated package. This prepares the graduates to design sound systems from amongst the range of options available. There are more pitfalls in the use of renewables than there are in using the more mature conventional technologies and systems. Designers, installers and service personnel need to be particularly aware of the industry and the characteristics of the various firms and their technologies. Over the past decade several new approaches have emerged to renewable energy education that seek to address the needs of the 21st century for sustainable energy supply systems. This paper will describe the aims, philosophy, structure and outcomes of several of these initiatives. It includes courses in renewable energy science, renewable energy engineering, renewable energy policy and planning and renewable energy technician training. The paper will also describe some aspects of the training of researchers in cooperation with the renewable energy industry. [Copyright &y& Elsevier]

Abstract: The minimum energy broadcast routing problem was extensively studied during the last years. Given a sample space where wireless devices are distributed, the aim is to perform the broadcast communication pattern from a given source while minimising the total energy consumption. While many papers deal with the 2-dimensional case where the sample space is given by a plain area, few results are known about the more interesting and practical 3-dimensional case. In this paper we study this case and we present a tighter analysis of the minimum spanning tree heuristic in order to considerably decrease its approximation factor from the known 26 to roughly 18.8. This decreases the gap with the known lower bound of 12 given by the so-called 3-dimensional kissing number. [Copyright &y& Elsevier]

Abstract: The objective of this study is to conduct a realistic prediction of the potential energy saving for using water cooled air conditioners in residential buildings in Hong Kong. A split type air conditioner with air cooled (AAC) and water cooled (WAC) options was set up for experimental study at different indoor and outdoor conditions. The cooling output, power consumption and coefficient of performance (COP) of the two options were measured and calculated for comparison. The experimental results showed that the COP of the WAC is, on average, 17.4% higher than that of the AAC. The results were used to validate the mathematical models formulated for predicting the performance of WACs and AACs at different operating conditions and load characteristics. While the development of the mathematical models for WACs was reported in an earlier paper, this paper focuses on the experimental works for the AAC. The mathematical models were further used to predict the potential energy saving for application of WACs in residential buildings in Hong Kong. The predictions were based on actual building developments and realistic operating characteristics. The overall energy savings were estimated to be around 8.7% of the total electricity consumption for residential buildings in Hong Kong. Wider use of WACs in subtropical cities is, therefore, recommended. [Copyright &y& Elsevier]

Fuel poverty is a recognized and increasing problem in several European countries. A growing body of literature covers this topic, but dedicated analysis for Portugal are scarce despite the high perception of this condition. This paper contributes to fill this knowledge gap focusing on a European southern city while bringing new datasets and analysis to the assessment of this topic; consumer groups identification and to policy discussion. Daily electricity smart meters' registries were combined with socio-economic data, collected from door-to-door surveys, to understand the extent and the determinants of energy consumption for two contrasting consumer groups (herein called fuel poverty and fuel obesity groups). The analysis is based on the amount and annual profile of electricity consumption and was complemented with building energy simulations for relevant building typologies in those groups, to identify heating and cooling thermal performance gaps. The existence of these gaps allowed confirming and/or discarding the initial hypothesis of the poverty or obesity conditions. Results disclose socio-economic variables, as income, and consumers' behavior as key determinants of electricity consumption. It was identified a severe lack of thermal comfort levels inside households of both groups, either in cooling (98% for fuel poverty and 87% for fuel obesity) and heating seasons (98% for fuel poverty and 94% for fuel obesity). Major conclusion refers that electricity consumption cannot be used alone to segment consumer groups. This assessment may serve to support energy policy measures and instruments targeted to different consumers' groups. For example, distinct campaigns and differentiated incentives may apply to achieve energy efficiency and reduction while keep or improve indoor comfort levels. [ABSTRACT FROM AUTHOR]

This paper introduces three methods of energy saving in the application of the full fresh air dehumidifier. Condensing heat recovery, cold recovery of condensed water, fresh air heat and cold recovery. Condensation heat recovery technology is relatively mature, and its development trend is combined with other energy-saving methods. It is feasible to use condensation water recycling to save energy, and in the eastern and southern parts of the energy saving effect is better. Adopting the plate heat exchanger or heat pipe heat exchanger to carry out the fresh air hot and cold recovery can reduce the cooling load 20%~30% of the refrigeration system and improve the dehumidifying capacity unit energy consumption of the full fresh air dehumidifier 15% or more. This kind of recycling has great energy saving potential. [ABSTRACT FROM AUTHOR]

Under the background of energy internet and low-carbon power, integrated energy system (IES) has become an important carrier of energy conservation and emission reduction. The IES utilizes innovative energy management mode to coordinate various energy sources such as natural gas, electric energy and heat energy. It is composed of energy production, conversion, storage and consumption subsystems, which emphasizes breaking the isolation of energy subsystems through reasonable scheduling, realizing energy cascade utilization and improving energy utilization efficiency. In this paper, an energy management model with two-stage scheduling before day and in real time is proposed aiming at the collaborative optimization of generator-load-storage of IES. Firstly, the first stage is the day-ahead economic dispatch, which aims to realize the power distribution of units in the system. The day-ahead economic dispatching model takes the maximization of economic benefits, the maximization of exergy efficiency and the minimization of carbon emission cost as the optimization objectives, so as to make the day-ahead global optimal dispatching decision. Secondly, the second stage is real-time optimal scheduling, which aims at real-time power adjustment of the previous scheduling plan. The real-time optimal scheduling model takes the minimum interactive power deviation punishment cost, wind abandonment punishment cost and user satisfaction loss cost as optimization objectives, so as to balance the energy supply and load demand deviation between planned output and actual output. Thirdly, according to the characteristics of the model, Non-dominated Sorting Genetic Algorithm-II (NSGA-II) is used to solve the first-stage day-ahead economic scheduling, and YALMIP toolbox is used to solve the real-time optimal scheduling model. Finally, based on the established model, a typical IES is selected for case simulation, which verifies that the proposed method can effectively improve the economy of system operation. • A two-stage energy management framework for IES is designed. • A multi-objective economic dispatching model is established. • A collaborative optimization model in real-time scheduling is established. [ABSTRACT FROM AUTHOR]

[Display omitted] • The influencing factors on energy efficiency of data center are reviewed. • Energy efficiency metrics are classified according to different priorities. • Appropriate metrics should be selected according to data center function for optimization. • Metrics are analyzed by hierarchy according to the degree of sustainable development. • Challenges and gaps are highlighted and suggestions are given for future works. The rapid development of the Internet requires data center infrastructures to be extended to a large scale with a higher power capacity and a reduction in energy consumption and carbon emissions. It is of great significance for this application to reduce energy consumption, capital cost and carbon emissions while ensuring a safe and reliable data center operation. Evaluation metrics have been considered an effective method to assess the energy efficiency of data centers and have been widely used in various data centers for many years. This work reviews the latest progress of data center evaluation metrics development in recent 20 years. Energy efficiency metrics are summarized based on energy conservation, eco-design and data center security, with the advantages and disadvantages and their correlations discussed. The applicability of each metric is analyzed. The influencing factors of energy efficiency of data centers discussed include site selection, IT equipment, power supply and distribution systems, cooling systems, building structure, and temperature control. The results show that the current evaluation metrics are valuable for the assessment of energy saving of data centers. However, more comprehensive and multi-scale evaluation metrics combining energy consumption, eco-design and data center security are needed to accelerate the progress towards carbon neutrality. In this paper, the hierarchy analysis of metrics is carried out according to sustainability, and metrics in line with sustainable development should be used preferentially. [ABSTRACT FROM AUTHOR]

In this study, the feasibility of constructing multi-energy complementary systems in rural areas of China is examined. First, the rural energy structure and energy utilization in the eastern, central, and western regions of China are analyzed, and the development and utilization modes of multi-energy complementary systems in different regions are evaluated based on the differences in the resource endowment in different regions. Second, the input-output status of the multi-energy complementary mode in different regions is analyzed. Then, based on the assumption of technical feasibility, the feasibility of the multi-energy complementary system is analyzed in terms of various dimensions, such as economic, energy conservation, environmental protection, and social benefit. Finally, an empirical study is conducted by comparing the proposed multi-energy complementary system with traditional energy supply system. The results show that the development of a multi-energy complementary system in each region is feasible from the perspective of multiple dimensions to reduce environmental pollution, create employment opportunities, and improve the economy. Moreover, the system can significantly reduce the peak-valley difference and improve energy efficiency. • This paper analyzes the differences in energy structure in the different regions of China. • Construct a multi-energy complementary system in each region. • Demonstrate the feasibility of constructing a multi-energy complementary system. [ABSTRACT FROM AUTHOR]

Between 1989 and 2011 the aviation traffic has been growing 4.6% per year. The increase on aviation traffic had consequences in terms of greenhouse gases (GHGs) and local pollutant emissions (e.g. carbon monoxide – CO, hydrocarbons – HC, nitrogen oxides – NO x ). In order to minimize this problem, the evaluation of sustainable alternatives to current fuel (jet fuel A) has been discussed but their impact on emissions is still unclear. The main research goals of this paper are: (i) to evaluate if the well-to-wake energy consumption in aviation can be reduced with alternative fuels as liquid natural gas (LNG) and/or liquid hydrogen (LH 2 ) and (ii) to assess if alternative fuels can be used in aviation to minimize carbon dioxide emissions and local pollutants. In this analysis two types of flights were evaluated: short flights (<5000 km) and long flights (>5000 km) for six typical aircrafts. We verified that LH 2 from SMR can provide between 13% and 21% less environmental and social impacts than jet fuel A, in the same aircraft. [ABSTRACT FROM AUTHOR]

Abstract: As a major contributor to productivity and employment in China, the petroleum refining industry consumes approximately 15% of industrial fuel oil and 10% of industrial coal. Given this energy-intensive characteristic, cost-effective investments for energy-efficient technologies may be a useful strategy to improve the competitiveness of China's refining industry. More importantly, this approach may alleviate the environmental problems China faces. This paper addresses the challenges posed by a highly complex refining system, incomplete industrial information, and the absence of a widely accepted evaluation method. This study models and analyzes the energy-savings potential for refining and conversion processes in the context of technological change. The results indicate that upgrading process heaters have been a priority during recent years, but heat recovery and advanced process control systems will gradually begin to dominate the technological marketplace in the long term. Current technology policies will result in approximately 2.7 × 108 GJ of energy savings by 2020, keeping the average energy consumption of refineries within 57 kg oil equivalent (kgoe)/t-feed. If a cap-and-trade scheme is introduced in the future, a further reduction of up to 10% can be achieved. Various specific barriers that impede the realization of potential goals are also addressed in this study. [Copyright &y& Elsevier]

Abstract: Economic growth in China needs lots of energy to support, but how to obtain a sufficient energy supply is now a problem. Meanwhile, environmental pollution caused by energy consumption is a problem that urgently needs to be solved. In order to adapt China’s fast developing economy, and on the basis of current policies, paying more attention to energy saving and environmental protection is more important. Therefore, to reasonably analyze China’s regional environmental efficiency and its determinants has practical significance. This article uses the Super-SBM model under undesirable outputs to measure regional environmental efficiency in China, and then explores influential factors of China’s environmental efficiency between 1991–2001 by means of the Tobit regression model. The empirical results show that during the sample period, the overall average level of China’s environmental efficiency is low, and the gap between different provinces and areas is large. The eastern area’s efficiency is obviously superior to the central and western area, which shows the necessity at present to optimize regional integration and promote innovation of energy conservation and emission reduction technology. At the same time, the “Eleven-Five ” year plan clearly states the energy saving and consumption reducing index, which motivates a great increase in China’s overall environmental efficiency, and promotes the fast development of resource conservation and environmentally friendly societal construction. The analysis of the influence factors by the Tobit model shows that fiscal decentralization and technology progress can increase environmental efficiency on the whole while economic scale and regional difference can also influence the efficiency. However, these factors’ influence is not the same in different areas. Finally, based on the research results, this paper gives policy recommendations on reducing pollution emissions and increasing China’s environmental efficiency. [Copyright &y& Elsevier]

Abstract: IEA has done an organization with the attendance of USA, Germany, Italy, Norway etc. to innovate the solar space heating systems. These countries lay the foundations of “Solar Combisystems” by presenting the extent of TASK 26. In this paper, an experimental study has done to improve the existing solar space heating systems in Turkey. Experimental system has built up by devising thermal stratified boiler and internal working parameters, external system parameters have been measured between December 2010 and May 2011. The system includes two closed flow cycle. There are three control units to control flow cycles which are placed into the system. Also system presents new approach on floor heating method by using copper finned-copper flow tubes for space heating. The new approach in design and application state has a positive impact on the energy flow of the system. The results show that energy saving ratio is performed between 59% and 89% monthly. The system, supplies the energy demand of the space that is needed to provide comfort conditions. Also fractional solar consumption (FSC) change is investigated daily, monthly and annually. Annual FSC value of the established system is approximately 83%. [Copyright &y& Elsevier]

Abstract: The need for high boiler operating performance requires the application of improved techniques for the rational use of energy. The analysis presented is guided by an effort to find possibilities for ways energy resources can be used wisely to secure a more efficient final energy supply. However, the biggest challenges are related to the variety and stochastic nature of influencing factors. The paper presents a method for modeling, assessing, and predicting the efficiency of boilers based on measured operating performance. The method utilizes a neural network approach to analyze and predict boiler efficiency and also to discover possibilities for enhancing efficiency. The analysis is based on energy surveys of 65 randomly selected boilers located at over 50 sites in the northern province of Serbia. These surveys included a representative range of industrial, public and commercial users of steam and hot water. The sample covered approximately 25% of all boilers in the province and yielded reliable and relevant results. By creating a database combined with soft computing assistance a wide range of possibilities are created for identifying and assessing factors of influence and making a critical evaluation of practices used on the supply side as a source of identified inefficiency. [Copyright &y& Elsevier]

Abstract: This paper presents a MCO (multi-criteria optimisation) of regional biomass supply chains for the conversion of biomass to energy through the simultaneous maximisation of economic performance and minimisation of the environmental and social FPs (footprints). The energy supply-chain model contains agricultural, pre-processing, processing, and distribution layers. An integrated model, previously developed by the authors, for regional biomass energy network optimisation is used as a basis, and now extended for simultaneous assessment of the supply-chain performance based on LCA (Life cycle assessment). Several total FPs are introduced for “cradle” to “grave” evaluation, which, besides direct, comprises also indirect effects caused by products’ substitutions. In the MCO approach, the annual profit is maximised against each FP generating different sets of Pareto optimal solutions, one for each FP. With this approach the aggregation of different environmental and/or social pressures is thus avoided. The results indicate that total FPs enable the obtaining of more realistic solutions, than in those cases when only direct FPs are considered. More profitable and less environmentally harmful solutions can be gained with significant reduction in total carbon and total energy FPs. [Copyright &y& Elsevier]

Abstract: Solar energy technologies offer a clean and renewable energy source, and are essential components of a sustainable energy future. The current paper presents a method for technical–economic optimization of an autonomous photovoltaic system. The principal objective of this study is to find the optimum characteristics of a photovoltaic system, able to accomplish the energy requirements of a given load distribution, for a specific site. Mathematical models are exploited to analyze the working of the photovoltaic system. These models present an estimation of the recovered solar energy anywhere and anytime, an evaluation of the electric energy produced by a photovoltaic generator and a determination of the storage unit characteristics. Then, the optimizing step is done based on lack of energy to generate probability (LEGP), percentage of the surplus of energy produced (PSEP) and the cost of the kilowatt-hour produced (C kWh). A case study has been presented to determine the optimal system configuration used to satisfy the requirements of a typical residential home located in Sfax, Tunisia. [Copyright &y& Elsevier]

Abstract: Numerous studies have focused on improving energy efficiency in commercial buildings. Engineers and researchers have developed complex methods to improve energy efficiency, but buildings are often managed by non-specialised technicians who need understandable and cost-effective actions to implement in their buildings. This paper presents basic actions on which to base improvements in energy efficiency in commercial buildings in operation. Furthermore, obtained results and details of the implementation of these techniques in various buildings in the Universitat Politècnica de València are presented. [Copyright &y& Elsevier]

Abstract: This paper re-examines the causal relationship between energy use and Gross Domestic Product (GDP) in the United States for the period 1960–2005. To that end, we use Markov-switching vector autoregressive (MS-VAR) models, rather than vector autoregressive (VAR) models, which allows for regime shifts. These models are capable of detecting changes in the relationship between variables; in addition, the coefficients of the model are time dependent and they depend on the states of the variables. Therefore, in contrast to VAR and vector error correction models (VECM), which assume a stable relationship, the relationship between the variables could be different in the separate regimes. Results from the estimation of MS models show changes in the pattern of causality relationship between GDP and energy use. That is, we found evidence of bidirectional Granger causality (GC) between the variables in the first regime, while there is no GC between the variables in the second regime. The first regime consists of 1971–1975, 1977–1982, 1989–1995, and from 2001 to the end of the sample. This regime includes the energy crises in 1970s, the recessions in the early 1980s, 1990s, and the recession in 2001. [Copyright &y& Elsevier]

Abstract: Zhejiang is a major province of energy consumption, but poor in energy resources. The inherent and complete dependence on importing energy makes energy security extremely difficult, which draws more attention to the energy conservation in Zhejiang. A great many factors of which the relations are complex affect the energy conservation. By introducing System Dynamics analysis, which has a unique advantage of analyzing the multiple and complex feedback system, this paper aims to analyze energy conservation in Zhejiang, and finally comes to some conclusions of values towards governments’ policies. [Copyright &y& Elsevier]

Abstract: To make the deployment of carbon capture possible, it is highly needed to develop original solutions that induce low energy penalty and that are easy to operate. This paper aims at presenting the DMX™ process developed at IFP Energies nouvelles based on special solvents which are characterized by the formation of two immiscible phases for given temperature and CO2 loading conditions. The concept of demixtion is briefly described in terms of physico-chemical properties, its interest and all required steps for appropriate process development are discussed. The corresponding process is presented and a technico-economic analysis is given. It is shown than one can reach a reboiler duty as low as 2.1 GJ/t CO2 which is significantly lower than the 3.7 GJ/t CO2 of the 30wt.% MEA reference process. It is also discussed that the energy consumption at reboiler cannot be the only parameter to consider for comparison with other processes and some further information about the DMX™ process are given. Operational issues are particularly discussed. In that sense, the performances of the DMX-1TM solvent in terms of degradation and corrosion are shown. Similarly a particular focus is made on the liquid/liquid separation which is a key aspect of the DMX™ process. [Copyright &y& Elsevier]

Abstract: Along with high-speed economic development and increasing energy consumption, the Chinese Government faces a growing pressure to maintain the balance between energy supply and demand. In 2009, China has become both the largest energy consumer and CO2 emitting country in the world. In this case, the inappropriate energy consumption structure should be changed. As an alternative, a suitable infrastructure for the implementation of renewable energy may serve as a long-term sustainable solution. The perspective of a 100% renewable energy system has been analyzed and discussed in some countries previously. In this process, assessment of domestic renewable energy sources is the first step. Then appropriate methodologies are needed to perform energy system analyses involving the integration of more sustainable strategies. Denmark may serve as an example of how sustainable strategies can be implemented. The Danish system has demonstrated the possibility of converting into a 100% renewable energy system. This paper discusses the perspective of renewable energy in China firstly, and then analyses whether it is suitable to adopt similar methodologies applied in other countries as China approaches a renewable energy system. The conclusion is that China’s domestic renewable energy sources are abundant and show the possibility to cover future energy demand; the methodologies used to analyse a 100% renewable energy system are applicable in China. Therefore, proposing an analysis of a 100% renewable energy system in China is not unreasonable. [ABSTRACT FROM AUTHOR]

Abstract: One of the central variables in bottom-up energy efficiency and saving calculations is the energy consumption baseline. In the evaluation of energy efficiency measures, developing this baseline is a challenging task, which may involve serious problems, especially if the energy service of the analysed subject has changed while the energy efficiency measure was being implemented. In this paper we present a formalised concept of the process of developing the baseline that is flexible enough to deal with various difficulties, such as changes in the levels of the energy services involved. We also discuss the most relevant options for deriving the necessary variables. [ABSTRACT FROM AUTHOR]

Abstract: The energy saving opportunity of supermarket refrigeration systems using subcooler between the medium-temperature (MT) refrigeration system and the low-temperature (LT) refrigeration system has been identified in the previous work. This paper presents a model-based comprehensive analysis on the subcooler design. The optimal subcooling control is discussed as well. With optimal subcooler size and subcooling control, the maximum energy savings of integrated two-temperature supermarket refrigeration system using R404A or R134a as working fluid can achieve 27% or 20%, respectively. The load ratio of MT to LT system and the operating conditions have considerable impact on the energy savings. [ABSTRACT FROM AUTHOR]

Abstract: With environmental protection and energy source posing as the biggest issue of the global problems, human beings have no choice but to reduce energy consumption. One way to accomplish this is to increase the efficiency of energy consumption and sufficiently exploit the low-grade energy in our lives. Low-grade energy recovery devices are of significance to meet the needs for energy conservation and green environment requirements such as fresh air pre cooling/heating, water heating, drying clothes and humidifying. These devices are also free of motion parts, non-corrosive and environmentally friendly. Various low-grade energy recoveries powered cooling, heating, drying and dehumidifying systems have been tested extensively; however, these systems are not yet ready to compete with the well-known vapor-compression system. The objective of this paper is to provide fundamental knowledge on the low-grade energy usage systems and present a detailed review on the past efforts in the field of low-grade energy recovery and usage subsystems. Lots of attempts have been made by the researchers to improve the performance of the low-grade energy recovery or usage subsystems. It is seen that, for successful operation of such systems, combination of diverse technologies is essential for more effective and multi-purpose applications. [Copyright &y& Elsevier]

Abstract: Biogas engine-driven heat pump air conditioner is a new-style system which includes biogas engine-driven heat pump, primary heat exchanger, second heat exchanger, sprayed room and fans, pumps, etc. In summertime, the air can be reheated by the waste heat water from the biogas engine in the system, while the air can be reheated and humidified by the waste heat water in winter. Reducing or displacing electrical heating requirements can achieve the great opportunity for significant energy savings. This paper, therefore, aims to improve the energy performance of the AC system by using the waste heat from the biogas engine. The mathematic model was used to research the BHPAC. Explicitly, we investigated the influence of various factors including the outdoor air temperature and humidity in summer and winter. Results show that the biogas engine-driven heat pump air conditioner can save more energy than the electrical power heat pump. In summer, the minimum for percentage of primary energy saving for BHPAC is over 25%. With the outdoor air dry-bulb temperature and the relative humidity rises, the saving energy percentage rises. In winter, the minimum for percentage of primary energy saving for BHPAC is 37%. The more the outdoor air relative humidity of the outdoor air decreases, the more the BHPAC saves energy. It is proved that the system which is a highly actively fully utilizing energy technology has good partial load characteristic and good effects of energy saving. [ABSTRACT FROM AUTHOR]

Abstract: Since energy consumption in process industries accounts for a great proportion of China''s total energy consumption, energy conservation becomes the practical choice to reduce the conflict between energy demand and energy supply in China, and therefore, promoting energy conservation is the long-term solution to China''s energy and environment problems from the source. In this paper, based on the introduction of the concept of energy consumption status in China''s key energy-consuming process industries, the main technical bottlenecks and resource-environment problems were analyzed with special emphasis on energy utilization efficiency, energy consumption mode, and waste emission. As for the measures to resolve these problems, at the policy level, policies and programs of Chinese government related to energy conservation were introduced in combination with China''s circular economy structure. At the technical level, the key technologies and research progress to improve energy utilization efficiency, reducing energy consumption, as well as utilizing the resource of discharged wastes were reviewed. Finally, three typical cases of the development of circular economy at three levels, namely the chemical industry, metallurgical industry, and electric power industry, were studied for the enforcement of circular economy and energy conservation in China''s process industries. [Copyright &y& Elsevier]

Abstract: A survey of the key issues associated with the development in the Chinese iron and steel industry and current situations of energy consumption are described in this paper. The apparent production of crude steel in China expanded to 418.78 million tonnes in 2006, which was about 34% share of the world steel production. The iron and steel industry in China is still one of the major high energy consumption and high pollution industries, which accounts for the consumption of about 15.2% of the national total energy, and generation of 14% of the national total wastewater and waste gas and 6% of the total solid waste materials. The average energy consumption per unit of steel is about 20% higher than that of other advanced countries due to its low energy utilization efficiency. However, the energy efficiency of the iron and steel industry in China has made significant improvement in the past few years and significant energy savings will be achieved in the future by optimizing end-use energy utilization. Finally, some measures for the industry in terms of the economic policy of China''s 11th five-year plan are also presented. [Copyright &y& Elsevier]

Abstract: Significant energy savings can be achieved in some manufacturing enterprises through process integration. But in certain cases, the optimization of energy utilization should be combined with many items, such as the rational structures of energy consumption, the influence of seasonal variations, and application of waste heat recycling technologies, etc. This paper shows an example for process synthesis extending traditional pinch analysis according to the situation of energy utilization in different seasons. Seen from the optimization analysis, the energy consumption will decrease apparently through the heat integration over the year and the adjustment of the consumption structure of energy. [ABSTRACT FROM AUTHOR]

Abstract: We have been developing technologies for energy saving in the residential sector. Recently, we have been concentrating our resources specifically into the development of polymer electrolyte fuel cell (PEFC) cogeneration systems. The system has excellent energy saving characteristics. However, the total amount of energy saved depends on how the system is operated. The characteristics of residential energy consumption are more complicated than in industrial use and depend on individual living patterns. It is therefore not easy to develop a control method for a system that can be generally applied across a wide variety of residential use. In this paper, we propose a system configuration and operation planning method developed for a residential PEFC cogeneration system. Using an operation planning method we developed, we demonstrate that our system provides higher energy savings than the conventional method. The energy saving rates are 15.9% under a large heat demand, 18.4% under a relatively high electrical demand and low heat demand, 1.3% under relative low electrical and heat demands. [Copyright &y& Elsevier]

Abstract: In the last years, the growing demand for air conditioning has caused a significant increase in demand for primary energy resources. Solar-powered cooling is one of the technologies which allows to obtain, by using the renewable solar source, an important energy saving compared to traditional air conditioning plants. The paper describes different technical installations for solar cooling, their way of operation, advantages and limits. The objective of the present study has been to analyze the technical and economic feasibility of solar absorption cooling systems, designed for two different application fields: industrial refrigeration and air conditioning. The possibility to replace or integrate the existing plants is studied, by considering the refrigeration requirements of a company, which works in meat manufacturing, and the heating and cooling demands of a hotel located in a tourist town in Italy. In the first case, the system comprises an absorption chiller coupled to solar flat plate collectors, whereas the second application is about a hybrid trigeneration plant, known as thermo-solar trigeneration; this option allows having greater operational flexibility at sites with demand for energy in the form of heating as well as cooling, for example in a hotel. In this way the authors could compare different results obtained by a technical and economic experimental analysis based on existing users and evaluate the advantages and disadvantages in order to suggest the best solution for the two studied cases. [Copyright &y& Elsevier]

Abstract: In every reflectance-based application like broadband matching, circuit modeling, etc., a nonlinear equation following from energy conservation, the Feldtkeller equation, must be solved, in order to obtain real networks. In the literature, however, there is no analytic solution available but only numerical solutions. Consequently, the resulting error depends on the accuracy of the numerical tools. In this paper, an analytic solution is proposed, which is based on the modified ABCD-parameters of a lossless reciprocal two-port network. An algorithm is presented and examples are included to illustrate the implementation of the analytical method. [Copyright &y& Elsevier]

‘Multi-zone thermodynamic engine model’ is a generic term adopted here for the type of model also referred to as quasi-dimensional, two-zone, three-zone, etc.; based on the laws of mass and energy conservation and using a mass burning rate sub-model (as opposed to a prescribed mass burning rate) to predict the in-cylinder pressure and temperature throughout the power cycle. Such models have been used for about three decades and provide valuable tools for rapid evaluation of the influence of key engine parameters. Numerous papers have been published on the development of models of varying complexity and their application. The current work is not intended as a comprehensive review of all these works, but presents an overview of multi-zone thermodynamic models for spark-ignition engines, their pros and cons, the model equations and sub-models used to account for various processes such as turbulent wrinkling, flame development, flame geometry, heat transfer, etc. It is suggested that some past terminology adopted to distinguish combustion models (e.g. ‘entrainment’ versus ‘flamelet’) is artificial and confusing; it can also be difficult to compare the different models used. Naturally, different models use varying underlying assumptions; however, the influence of several physical processes has frequently been incorporated into one term, not always well documented or clearly described. The authors propose a unified framework that can be used to compare different sub-models on the same basis, with particular focus on turbulent combustion models. [Copyright &y& Elsevier]

Abstract: Distillation is a largely used separation operation, but at the same time it is intensively energy consuming. Distillation columns need huge amount of energy due to evaporation steps involved; more than half of the process heat distributed to plant operations ends up in the reboilers of distillation columns. ∞/∞ analysis is a framework that allows studying distillation systems, checking the feasibility, detecting multiple steady states and getting the influence of the distillate flow rate and recycle streams on purities in early stage of process design. Also, ∞/∞ analysis is useful to evaluate new alternatives for existing processes and to propose energy-efficient alternatives by process integration. Process intensification is an issue of constant interest, providing strategies to develop more effective and cheaper technologies with lower environmental impact. The originality of this paper lies in the applicability of this framework to kinetically controlled reactive distillation including hybrid systems. TAME synthesis is used as an illustrative example. Energy savings obtained by using reactive distillation are evaluated comparing with the traditional system consisting of reactor and distillation columns. The solution proposed, subsequent to the validation by rigorous simulation, offers a 20% decrease in the number of stages and a reboiler energy saving of 10%. [Copyright &y& Elsevier]

Abstract: In this paper we present a general formalism for the family of adaptive filter algorithms with selective partial updates. Based on this, the mean-square performance analysis of this family of adaptive filters is presented in a unified way. This analysis is based on energy conservation arguments and does not need to assume a Gaussian or white distribution for the regressors. We demonstrate through simulations that the results are useful in predicting the performance of this family of adaptive filters. [Copyright &y& Elsevier]

Abstract: In this paper, “energy efficiency” studies, done in a big industrial facility’s pumps, are reported. For this purpose; the flow rate, pressure and temperature have been measured for each pump in different operating conditions and at maximum load. In addition, the electrical power drawn by the electric motor has been measured. The efficiencies of the existing pumps and electric motor have been calculated by using the measured data. Potential energy saving opportunities have been studied by taking into account the results of the calculations for each pump and electric motor. As a conclusion, improvements should be made each system. The required investment costs for these improvements have been determined, and simple payback periods have been calculated. The main energy saving opportunities result from: replacements of the existing low efficiency pumps, maintenance of the pumps whose efficiencies start to decline at certain range, replacements of high power electric motors with electric motors that have suitable power, usage of high efficiency electric motors and elimination of cavitation problems. [Copyright &y& Elsevier]

Abstract: In the present scenario of energy demand overtaking energy supply, top priority is given for energy conservation programs and policies. As a result, most existing systems are redesigned or modified with a view for improving energy efficiency. Often these modifications can have an impact on process system configuration, thereby affecting process system reliability. The paper presents a model for valuation of process systems incorporating reliability that can be used to determine the change in process system value resulting from system modification. The model also determines the break even system availability and presents an algorithm for allocation of component reliabilities of the modified system based on the break even system availability. The developed equations are applied to a steam power plant to study the effect of various operating parameters on system value. [Copyright &y& Elsevier]