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Abstract This paper is an Editorial for the special issue (SI) of Renewable and Sustainable Energy Reviews (RSER) devoted to the 12th Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES), held from the 4th to 8th October 2017 in Dubrovnik, Croatia. The key focus of RSER is to publish critical thinking across the wide field of renewable and sustainable energy. The journal publishes either pure review papers or research papers with a precise review element. Overall, the guest editors invited 36 papers presented on 12th SDEWES conference, of which 17 were accepted after rigorous peer review process. The SDEWES conferences present a continuous effort in gathering high level scientists and research papers across the field of sustainability and by now the amount of accumulated knowledge, through conference papers and special journal issues, is significant. Each SDEWES journal editorial presents a wider overview of special issue journal papers in order to maintain the continuation of knowledge generation on the main sustainability topics. The main topics covered in this RSER editorial include renewable energies with special focus on integration, markets and roadmaps, energy efficiency in buildings, industrial process and transport, bio based economy focused on bio based chemicals and biofuels, energy storage focused on batteries, thermal and geological storages and various sustainability assessments in several sectors and technologies. All were considered in light of the Circular Economy. [ABSTRACT FROM AUTHOR]

Abstract The purpose of the paper is to establish national carbon emissions prices for the People's Republic of China, which is one of the world's largest producers of carbon emissions. Several measures have been undertaken to address climate change in China, including the establishment of a carbon trading system. Since 2013, eight regional carbon emissions markets have been established, namely Beijing, Shanghai, Guangdong, Shenzhen, Tianjin, Chongqing, Hubei and Fujian. The Central Government announced a national carbon emissions market, with power generation as the first industry to be considered. However, as carbon emissions prices in the eight regional markets are very different, for a variety of administrative reasons, it is essential to create a procedure for establishing a national carbon emissions price. The regional markets are pioneers, and their experience will play important roles in establishing a national carbon emissions market, with national prices based on regional prices, turnovers and volumes. The paper considers two sources of regional data for China's carbon allowances, which are based on primary and secondary data sources, and compares their relative strengths and weaknesses. The paper establishes national carbon emissions prices based on the primary and secondary regional prices, for the first time, and compares both national prices and regional prices against each other. The carbon emission prices in Hubei, Guangdong, Shenzhen and Tianjin are highly correlated with the national prices based on the primary and secondary sources. Establishing national carbon emissions prices should be very helpful for the national carbon emissions market that is under construction in China, as well as for other regions and countries worldwide. For purposes of establishing a single indicative price for carbon emissions in China, the empirical results suggest that the Arithmetic Mean of the National Primary and Secondary prices leads to the optimal prices for carbon emissions in China. Highlights • The paper establishes national carbon emissions prices for China. • The paper considers primary and secondary regional carbon allowance data sources. • The paper establishes national carbon emission prices using primary and secondary regional data. • National carbon emissions prices will be helpful for China's carbon emissions market. • Arithmetic mean of national primary and secondary carbon emission prices is optimal. [ABSTRACT FROM AUTHOR]

Global warming, and the energy crisis, both caused by the unregulated overconsumption of fossil fuels, are some of the main problems humanity has to face along with freshwater shortage. The importance of safe access to freshwater and various forms of energy to the survival of modern societies is undeniable. Water- and energy-related technologies are independent, but thermal energy storage can bind such technologies. Salts, which are well-known phase-change materials that can be used as thermal energy storage media, can be extracted from the brine produced by desalination plants, which is usually rejected into the environment. Evaporation, electrodialysis, membrane distillation-crystallization, and adsorption/desorption are suitable techniques for extracting salts from brine in conjunction with desalination. Obtained salts can be used as phase change materials in thermal energy storage units. Salt-based thermal energy storage units can be integrated into concentrated solar power plants, geothermal power plants, fossil fuel, and biomass fuel power plants, load-following nuclear power plants, and various industrial processes for energy production and optimization. Although there are many papers on molten salt-based thermal energy storage, the direct utilization of salts extractable from the brine produced by desalination plants for thermal energy storage units has not been thoroughly investigated. In order to provide a guide for researchers in investigating such systems, this paper reviews salt extraction technologies in conjunction with desalination, applications of salt-based phase change materials in thermal energy storage, and challenges and perspectives of binding desalination plants with energy production or optimization systems using thermal energy storage. • Desalination plants produce brine which can be used to obtain salts. • Salts are phase change materials that can be used in thermal energy storage. • Salt-based thermal energy storage units can be used in various applications. • Co-generation of water and electricity is possible using thermal energy storage. • Developing thermal energy storage technology demands a multidisciplinary approach. [ABSTRACT FROM AUTHOR]

Building envelope parameters and geometric configurations can considerably influence the building energy performance. However, determining the best trade-offs of different building shape and envelope configurations to yield near-optimal design alternatives with respect to their energy performance is not a straight-forward task. Consequently, different methods have been utilized to optimize building envelope parameters and geometric configurations to achieve better energy performance. The objective of this paper is to provide an extensive review of the optimization methods and their application in energy-efficient architectural building design to better identify the potentials and applicability of different optimization methods. This paper reviews the optimization research, where building envelope parameters and geometric configurations are considered remarkably as the optimization independent variable(s) and building energy consumption/demand is included as an objective in the optimization process. The associated derivative-free and derivative-based optimization methods and their application in energy-efficient building design are included in this review. In addition, decision-making approaches are discussed for multi-objective optimizations. Current optimization tools are demonstrated. Finally, crucial considerations, including limitations and suggestions for the related future studies are concluded. [ABSTRACT FROM AUTHOR]

The development of cleaner and renewable energy sources are necessary so that fossil fuel dependency and global warming can be reduced. Present communication is an attempt to explore the available literature on Photovoltaic Thermal (PVT) air collectors and PVT air collector integrated greenhouse drying system. Solar drying is one of the best method to preserve crops for a long time. In developing and under developed countries; per capita electricity production is low; therefore the electricity uses for heating purpose cannot be economically and environmentally justified option. In previous studies, it was found that forced drying is better in terms of controlling drying parameters and PVT air collector is better than standalone PV module in terms of energy storage. In present review paper, combination of PVT air collector and drying system has been discussed. Moreover, thermal modelling of PVT air collector integrated greenhouse drying system has been presented in detail. Average thermal efficiency, electrical efficiency and overall thermal efficiency for PVT air collector are found to be 26.68%, 11.26% and 56.30% respectively at 0.01 kg/s mass flow rate of air. This review paper may be very helpful for researchers and scientists to develop thermal models for different hybrid solar systems. [ABSTRACT FROM AUTHOR]

The recent global energy crisis has provoked a need to explore alternate energy sources including run-of-the-river hydropower projects. To derive maximum payback for a given investment, finding the most advantageous siting of power plants is imperative. If a selection of potential sites misses some of the apparently indistinct sites with significant power potential, there is a chance of acquiring only partial benefits out of these investments. A review of the existing methods for evaluating power potential of a river is discussed in this paper with their limitations along with a new proposed approach. The new approach can be used to evaluate different installation schemes along a river to assess run-of-the-river hydropower potentials using geospatial data techniques to select sites exhibiting higher total hydropower potential. The case study of Kunhar River, located in the northern part of Pakistan, presents the applicability of the approach. Open source Advanced Spaceborne Thermal Emission (ASTER)’s digital elevation model (DEM) and regional hydrologic gauged data are used for identifying the best locations for hydropower plants, demonstrating this approach is substantially more cost effective and robust compared to other field based assessment. Replicating the proposed approach for other locations is easy following the step-by-step method presented in this paper and giving consideration to the limitations described. This study may provide guidelines for the development of cost-effective and energy efficient hydropower projects. The use of this approach is most advantageous in the preliminary assessment phase of a project to narrow the scope of the detailed study focusing only on the higher potential sites. [ABSTRACT FROM AUTHOR]

Cameroon has an abundant reserve of energy resources, such as crude oil, natural gas, hydropower, biomass, solar, wind and geothermal energies. However, these resources are still weakly valorised. The country relies mainly on hydropower energy for electricity generation (73%) with persistent power outages throughout the country especially in the dry seasons when water levels are low. Electricity access is about 65–88% in urban areas and around 14% for rural populations. Cameroon has experienced a strong economic growth (growth rate of 5.9% in 2015), accompanied by a rapid increase in electricity demand (1455 MW in 2014). Electricity needs are expected to continue rising over the next decade to reach 5000 MW by 2020 and 6000 MW by 2030. This paper seeks to address energy issues (reliability, accessibility and security) in Cameroon and brings to light the potential and meaningful contributions of renewables in solving energy concern. In order to achieve this objective, an overview, of the energy sector (energy source, access, demand, supply and distribution) is given followed by a review of renewable energy potential, policy, benefits and barriers. In addition, this paper introduces the energy roadmap to achieve a universal access to electricity, which will pave the way for the country emergence by 2035. It is found that energy sector of Cameroon holds promising possibilities of development and diversification given the country's energy potential. With adequate policy, standards, regulations, awareness, capacity building and off-grid renewable energy investments measures, it is possible for Cameroon to meet the future energy targets and ensure meaningful development throughout the country. [ABSTRACT FROM AUTHOR]

Any electronic equipment contains silicon chips. Modern society, the Knowledge Society, has been possible through the development of low-cost silicon chips. Some researchers, however, have been claiming that “Moore's law” for silicon chip design and production of integrated circuits will remain valid only for the next 1 or 2 decades due to energy limitations. Thus, we cannot produce these chips as efficiently as before. The objective of this paper is to present and discuss this claim in terms of energy, information and communications technologies (ICT), computer engineering, knowledge and knowledge engineering, and electronics views. It also appears that the use of some advanced production techniques could extend the use of silicon chips. The author has been unable to find any study yet that has addressed the effect of this issue on the future of intelligence, knowledge and knowledge engineering and management. Hence, this may cited as an original feature of the present paper. [ABSTRACT FROM AUTHOR]

Lighting system design is a significant component of building and is considered as an important aspect when addressing sustainability of buildings. Achieving sustainability in buildings would tackle through energy conservation and waste savings. In most of the industrialised countries, rising energy costs make indoor artificial lightings as a significant contributor. Thus, visual comfort within the indoor environment could be affected by an energy-saving strategy. This paper organises a systematic state of the art review of indoor lighting simulation related to the buildings research. Simulation allows artificial objects and dynamical role variations to optimise the maximal use of lighting systems in buildings. Thus, it allows equivalent lighting system design and the synthetic environment in a virtual world. This strategy makes it possible to design and select the subjective state of the physical and virtual well-being of the visual comfort in the buildings. The main objective of this paper is to find out the most popular simulation tool adopted for the simulation of lighting in the building prototypes by various researchers. The simulation platforms are categorised in simple tools and integrated tools. The survey comprises of seventy papers which were thoroughly reviewed. It is observed that various relevant studies were carried out by different researchers in the energy savings and lighting in buildings and their prototypes were found during the survey. This research can positively aid the researchers and energy managers in deciding the feasible simulation tool for simulating their respective prototypes. [ABSTRACT FROM AUTHOR]

Disposal of paddy residue has turn out to be a huge problem in north-west Indian states, resulting farmers prefer to burn the residues in-situ. Paddy residue management is of utmost important as it contains plant nutrients and improves the soil-plant-atmospheric continuum. Burning biomass not only pollutes environment and results in loss of appreciable amount of plant essential nutrients. The objectives of the review paper is to access the amount of residue generation, its utilization in-situ and ex-situ, emphasize harmful effects of residue burning on human health, soil health and environment of north-west states of India specially in Punjab and Haryana. This paper also discusses the possible strategies, financial and socio-economic evaluation of the paddy residue management technologies and accentuates the assessment of range of potential policy instruments which would offer avenues for sustainable agriculture and environment. Timely availability of conservation agriculture (CA) machinery is of utmost significance to manage the paddy residues in-situ. Collection and transportation of voluminous mass of paddy residue is cumbersome, therefore, ex-situ residue management is still not an economically viable option. The agricultural waste opens vivid options for its versatile usage and is possible if residue is collected and managed properly. It is a prerequisite for surplus residues to be used for CA. There is an urge to create awareness among farming communities to incline them to understand importance of crop residues in CA for sustainability and resilience of Indian agriculture. [ABSTRACT FROM AUTHOR]

In the last decade several scientific papers have dealt with the damages fossil fuels did to our environment. Carbon dioxide has been blamed the chief culprit since it is produced by the automobile fleet that uses diesel or gasoline as a fuel. As a result, several countries are implementing public policies aimed at the replacement of fossil fuels by renewable ones, such as biodiesel. Brazil has become one of them, since the biodiesel production has increased from 736 m 3 to 3,419,838 m 3 in less than ten years. Therefore, this paper intends to briefly review the literature on the history, evolution, and the environmental aspects of biodiesel in Brazil in order to show its positive economic impact on the Brazilian economy, in addition to showing how important this biofuel is to the environment by providing an overview of its advantages when compared to fossil diesel. [ABSTRACT FROM AUTHOR]

The main aim of this review article is to review of DEA models in regarding to energy efficiency. This paper reviewed and summarized the different models of DEA that have been applied around the world to development of energy efficiency problems. Consequently, a review of 144 published scholarly papers appearing in 45 high-ranking journals between 2006 and 2015 have been obtained to achieve a comprehensive review of DEA application in energy efficiency. Accordingly, the selected articles have been categorized based on year of publication; author (s) nationalities, scope of study, time duration, application area, study purpose, results and outcomes. Results of this review paper indicated that DEA showed great promise to be a good evaluative tool for future analysis on energy efficiency issues, where the production function between the inputs and outputs was virtually absent or extremely difficult to acquire. [ABSTRACT FROM AUTHOR]

This paper provides a comprehensive review on the status of renewable energy developments and hydrogen economy in the Middle East and North Africa region. This region is heavily reliant on fossil fuels for its domestic energy supply and is also considered a global energy exporter. In this regard, an overview of the current state of energy sector in the region is provided. Moreover, the region possesses great potential for renewable energy exploitation due to its climatic advantages. Therefore, the current status of renewable energy utilization within the region's various countries is reviewed by presenting several operational renewable energy-based plants and future projects for deployment of renewable power in the region. Green hydrogen is an important sustainable clean fuel, and its utilization is essential for both environmental preservation and energy security. Thus, the status of hydrogen production and utilization in the region is discussed considering the various operational systems and future hydrogen generation projects. The concept of source, system and service is also incorporated which considers the utilization of clean energy sources for sustainable hydrogen production through environmentally benign pathways. The potential deployment opportunities for the renewable hydrogen production are also discussed based on available renewable sources in the region. Moreover, this paper discusses the challenges of increasing renewable energy utilization in the region. Furthermore, this paper provides a road map for achieving renewable hydrogen economy including a reduction in domestic utilization of oil and gas sources, subsidization of renewable production sector, and financial support to hydrogen production and transportation infrastructure. • Providing an overview of the status of energy sector in the region. • Providing an overview of the status of renewable energy utilization in the region. • Discussing the challenges and opportunities of renewable and hydrogen energy development in the region. • Providing a road map for renewable hydrogen development in the region. [ABSTRACT FROM AUTHOR]

Smart grid engineering is the key for a beneficial use of widespread energy resources, it is a modernized electrical grid that uses analog or digital information and communications technology. Renewable energy itself a thrust area of research due to its availability, applicability and environmental friendly nature and the application of smart grid in renewable energy makes it vast and more promising. This fusion enables the efficient use of renewable energies which is a key challenge for now. The present review paper attempts to investigate the role of smart grid in the renewable energy. The introductory section sets the role of renewable energy and distributed power in a smart grid system. Subsections cover the concept and availability of renewable energies, renewable energy power calculation formulae, smart grid concepts and its feasibility, case studied as performed by different researchers around the World, discussion and future recommendations and finally the conclusions from the study. To achieve this, articles from different sources such as internet, reports, conferences and journals of Elsevier, Springer, Tailor and Franacis, Wiley and many more have been collected and reviewed. This paper concludes that renewable energies can be used efficiently and in a smart way by using the smart grids. However, the smart grid technology is not mature enough and needs more research on the same. [ABSTRACT FROM AUTHOR]

Reduction of energy consumption is a major concern in vapor compression cooling systems, especially in areas with very hot weather conditions. In hot weather conditions, performance of these systems decrease sharply and electrical power consumption increases considerably. Evaporative condensers enhance the heat rejection process by using the cooling effect of evaporation and therefore improve energy-usage efficiency. This paper presents an extensive review of the state of the art of evaporative condensers used in residential cooling systems: refrigeration, air-conditioning, and heat pump systems. The paper primarily concentrates on the energy consumption of residential cooling systems worldwide and its related problems. In addition, the paper covers the operation principles of evaporative-condensers, theory of heat rejection, and water evaporation rate. Finally, comparison between different types of condensers is presented. It is found that by using evaporative-cooled condenser instead of air-cooled condenser, the power consumption can be reduced up to 58% and the coefficient of performance can be improved by about 113.4% with systems of different cooling capacities ranging from 3 to 3000 kW. [ABSTRACT FROM AUTHOR]

Total energy consumption per capita of any country is a critical input for the economic and social development. But nowadays, the current energy production systems are not sustainable and they are not environment friendly. Increased fossil energy consumptions in manufacturing, transportation and standard of living in the growing population have the highest impact on the environment in terms of global warming potential and air pollution. Also fossil fuel prices are increasing because of shortening of fossil fuel sources. Sustainable development improves standard of life economically and environmentally over the long term in a way that must be supported by the industrial structure of the country. In order to sustain energy availability and keep environment livable for future generations, finding new alternatives is necessary. Increased awareness of society about environmental issues and fossil energy sources depletion support new clean alternatives. These alternatives are one of the important and determinant policy areas for the countries, and should include both short and long term energy policies. This paper discusses the environmental pollution caused by energy consumption, and the role of conventional and renewable energy technologies as one component of the effective sustainable development and solution. Also, renewable energy potential of Turkey for assessment of the green energy systems is investigated in terms of sustainable development, environmental impact and prices. All the given results in this paper will be useful to researchers, engineers, decision and policy makers in industry and government. [ABSTRACT FROM AUTHOR]

Demand-side management (DSM) is an effective means to construct low-carbon electricity system, improve energy efficiency and fastly enhance the sustainable development of economy. DSM in China has entered a period of rapid development. A series of policies and regulations related to DSM have been issued by some national ministries in China. However, some problems exist in the implementation of DSM. In view of that, the current situation of DSM development in China is analyzed in this paper from the three aspects of policies and regulations related to DSM, DSM organizational management and DSM development of representative regions. Following that, the challenges faced in DSM implementation are discussed and feasible measures are proposed based on the challenges. This paper is conducive to give impetus to the development of DSM in China. [ABSTRACT FROM AUTHOR]

The nexus between trade openness and energy demand is hot topic of discussion among academicians and researchers, and numerous studies are available in existing literature while investigating the nexus between trade openness and energy demand. This paper explores the relationship between energy consumption, trade openness and economic growth in case of Thailand. In doing so, we have applied Bayer and Hanck cointegration approach to test whether the long run relationship exists between the variables. Our results confirm the presence of cointegration between the variables. Energy consumption stimulates economic growth. Trade openness adds in economic growth. The causality analysis reveals that energy consumption Granger causes economic growth and in resulting, economic growth Granger causes energy consumption. Trade openness and energy consumption are interdependent i.e. trade openness Granger causes energy consumption and in return, energy consumption Granger causes trade openness. This paper openness up new directions for policy making authorities in Thailand to design a comprehensive energy and trade policies to sustain economic growth for long run. [ABSTRACT FROM AUTHOR]

The health and performance of students and teachers are influenced by the internal environment of school buildings such as noise levels, indoor temperature, air quality and light. Providing good internal environmental conditions with minimum energy for schools has long been a concern in school design guidelines around the world. The growing necessity to save energy in an uncertain future and to provide a good indoor environment in schools suggests that school designers should approach design more holistically in order to offer a better internal environment and to reduce the gap between design and performance. This paper investigates design issues in UK schools through case study analysis and a review of the literature. The main reasons for these design issues can be attributed to the lack of optimisation of different internal environment factors and their relation with energy consumption; the lack of understanding occupants’ response to the environment; the lack of building adaptability and the inappropriate application or use technology. This paper urges school designers to look at these factors holistically in order to overcome these problems in the future design of UK schools. This study also suggests an Environmental Circle to look at the interrelation between comfort factors through their sub factors in a holistic manner in order to prevent any conflict between. [ABSTRACT FROM AUTHOR]

Improving energy performance has been recognized as an effective measure to promote the energy saving and emission reduction and to realize the sustainable development. Methods of improving energy performance towards sustainable manufacturing are numerous and scattered, resulting in insufficiency from the perspective of overall strategies and system integration. After the intensive selection of advanced literatures, about 166 research papers directly related to energy performance improvement are analyzed. A comprehensive review and analysis from multi-perspectives of energy monitoring, evaluation, optimization and benchmarking are performed, which is conducive to understand the energy consumption pattern and take effective energy-saving measures. This paper establishes a framework of energy performance integrated method, and four energy management methods and their energy models in energy monitoring, evaluation, optimization and benchmarking phase are analyzed and summarized. Besides, the proposed framework analyzes potential applications and key advantages, and some challenges and potential opportunities for energy performance improvement methods are discussed. This study will provide a significant foundation for energy-efficient production through various methods application. • Performing a review on methods of improving energy performance. • Constructing a framework of methods of improving energy performance. • Summarizing advances in energy monitoring, evaluation, optimization and benchmarking. • Discussing challenges and opportunities of improving energy performance. [ABSTRACT FROM AUTHOR]

Bangladesh is a small country with its large population struggled with several challenges over the last few decades, including overpopulation, power grid disruptions, floods, and global warming. Sufficient rate of energy production is must for a developing country, but quickly expanding population and overall economic growth interrupt the energy sector. Renewable energy plays a vital role to contribute in this sector. For becoming an agricultural country biomass is an important sustainable energy source for this country. Organic crop residues, animal waste, and municipal solid waste are the most accessible biomass energy sources in this country. On the other hand, by using the membrane gas separation technology the quality biogas can be improved and it helps the environment from the toxic CO 2 which is a major element of biogas. This study represents the extension, potential and innovations identified with the utilization of biomass assets. Besides the improvement of biogas also discussed in this paper. This paper also represents the various initiatives conducted by the government that are all relevant to biomass energy. This work further can be studies to innovate different biomass technology and to improve the quality of biogas. [Display omitted] • Biomass is an alternative and sustainable renewable energy source in Bangladesh. • Thermal and bio-chemical methods are widely used for changing over biomass to energy. • Government plan is to produce electricity by utilizing natural gas, liquid fuel, and peat. • Membrane gas separation technology is used to increase the quality of gas. [ABSTRACT FROM AUTHOR]

Variability in the predicted cost of energy of an ocean energy converter array is more substantial than for other forms of energy generation, due to the combined stochastic action of weather conditions and failures. If the variability is great enough, then this may influence future financial decisions. This paper provides the unique contribution of quantifying variability in the predicted cost of energy and introduces a framework for investigating reduction of variability through investment in components. Following review of existing methodologies for parametric analysis of ocean energy array design, the development of the DTOcean software tool is presented. DTOcean can quantify variability by simulating the design, deployment and operation of arrays with higher complexity than previous models, designing sub-systems at component level. A case study of a theoretical floating wave energy converter array is used to demonstrate that the variability in levelised cost of energy (LCOE) can be greatest for the smallest arrays and that investment in improved component reliability can reduce both the variability and most likely value of LCOE. A hypothetical study of improved electrical cables and connectors shows reductions in LCOE up to 2.51% and reductions in the variability of LCOE of over 50%; these minima occur for different combinations of components. [ABSTRACT FROM AUTHOR]

The vulnerability of electric potential generation from water resources has been evidenced due to uncertainties of climatic origin and energy planning. Changes in rainfall regimes are multifactorial phenomena difficult to model. Rainfall is the main natural way of restoring the reservoir levels of hydroelectric power plants. The reduction in rainfall levels may increase in the coming years, resulting in a probable change of the energy matrix configuration of the state of Minas Gerais (MG). This could reduce the share of renewable sources increasing dependence on the importance of energy from fossil fuels, which are the immediate primary sources of energy available. Prior examinations have portrayed the depletion of hydroelectricity in Brazil, or its macro-regions, however this work tries to supply a more focused look at the effects on the electricity and social sectors of the state of Minas Gerais. The study developed in this paper aims to investigate the hydrological potential alteration impacts and consequences on the energy matrix of the state, the greenhouse gas emissions and the social reflexes of these changes due to scenarios motivated by climate change. The investigation intends to show the importance of the water-energy-emissions nexus for energy planning and decision-making, in order to evaluate the best options for dealing with adverse and potentially destabilizing conditions. The results of the analyses show that while hydropower demand was 5.24 Mtoe in 2015, in 2030 the supply of hydropower will be 5.81 Mtoe and 4.72 Mtoe, for the conservative and severe scenarios, respectively. In addition, the effect of climate change may require an increase in the share of non-renewable sources in the energy matrix, which could increase CO 2 e emissions from 4.2% to 7.4% by 2030, compared to the levels in 2016. • Reduction in rainfall levels will change the energy matrix configuration of MG state. • Population growth will boost demand for energy. • It is shown the importance of the water-energy-emissions nexus for energy planning and decision-making. • The energy matrix may considerably increase the CO 2 e emissions by 2030, compared with 2016 levels in the MG state. [ABSTRACT FROM AUTHOR]

Abstract Urban areas provide strategic settings for attaining more sustainable urban systems. This paper provides fivefold contributions to the literature based on the Sustainable Development of Energy, Water and Environment Systems City Index. A comprehensive benchmarking of 120 cities is undertaken of which the first three cities are found to be Copenhagen, Stockholm, and Helsinki. Uncertainty and sensitivity analyses are conducted by comparing the original ranking with those based on Monte Carlo simulations and three aggregation schemes with and without the use of the geometric mean. The ranking of cities that take place in the 95% confidence interval and strong coefficients of correlation are found to suggest aspects of index robustness. As the third contribution, a scenario that represents the cross-sectoral strategy of utilizing residual energy in the urban vicinity from the industry, thermal power generation, wastewater, and urban biowaste is applied to 60 cities. The integration of data from the Pan-European Thermal Atlas provides additional practical value to local decision-makers who can assess possible improvements in city performance through such an approach. Fourth, 13 city pairs of 3 or more cities with the same above or below average performances across the dimensions of the index are identified as another means of supporting policy-learning opportunities. The fifth contribution synthesizes the original results of the research work to discuss the need for integrated urban transitions and proposes a vision for cities to envision the sustainable development of urban energy, water and environment systems. The research work provides analytical support to cities in a time when local actors are tasked with a mission that is nothing less than leading the transition to net-zero emissions by mid-century. Highlights • An original benchmarking of 120 cities with a composite indicator is provided. • Uncertainty and sensitivity analyses of the city rankings suggest assessment quality. • A scenario that is representative of a cross-sectoral strategy is evaluated for 60 cities. • Pairs with similar performance across the dimensions of the index are identified. • The implications are discussed based on the need for integrated urban transitions. [ABSTRACT FROM AUTHOR]

Abstract Photovoltaic/thermal (PV/T) systems are emerging as an important branch of solar technology, which combines photovoltaic panels and solar collectors in a single unit to generate electricity and heat from uninterruptible solar energy. Energy systems are typically examined from two aspects of energy and exergy. The exergy of these systems is of great importance because it focuses on the quality of the energy. Due to the unequal quality of electrical and thermal energy, it is clear that the exergetic performance of these systems gives a clearer view of their efficiency compared to their energetic one. The purpose of this paper is to provide a comprehensive review of the researches conducted in the field of the exergy for various types of PV/T systems in the last decade. According to our study, the largest attention was directed at investigating the exergy of water-based, air-based and nanofluid-based PV/T systems, and the exergy examination of other types, especially thermoelectric-based PV/T systems, was rarely performed. Also, a comparison between different PV/T systems shows that using nanofluids, concentrators and optical filters could improve the exergy efficiency of PV/T systems. Highlights • A detailed review of the exergetic performance of PV/T systems is provided. • Exergy efficiency of different PV/T systems is compared. • Factors affecting the exergy efficiency of photovoltaic/ thermal systems are investigated. [ABSTRACT FROM AUTHOR]

Due to the rapid increase in the global demand for renewable energy and uneven, seasonal distribution of bulky biomass resources, developing decentralized and mobile biomass thermochemical conversion systems are critical, particularly to accommodate the energy needs of rural residents in developing countries and remote communities. This paper establishes the fundamental concepts of decentralized and mobile thermochemical biomass conversion systems and addresses the necessity and advantages of such systems. This article comprehensively examines the potential of various biomass and non-biomass waste streams for co-processing in such systems and summarizes the latest progress in pretreatment technologies, conversion pathways, product separation and purification, and applications. Moreover, this paper compares the designs and specifications, operation status, drawbacks, and benefits of existing systems from household to industrial-scale. It also summarizes the latest studies on the socioeconomic and environmental impacts of such systems. The key challenges in the future research and development of such systems are discussed, including systems integration and simplifications, interaction mechanism of mixed waste during co-processing, development of cost-effective catalysts, and investigation of biochar applications. Also, our recommendation is to re-visit the direct-combustion technology under a modern technological and environmental perspective. Moreover, it is necessary to promote education and training for the development of dedicated skills to support the operation and maintenance of conversion systems at secondary or higher levels. • Key concepts of decentralized and mobile biomass conversion systems are established. • Systematic comparison of decentralized and mobile systems from household to industrial scale. • Up-to-date review on co-processing, reactor design, and cost-effective catalysts. • Mobile systems show great potential in helping developing countries and off-grid communities. • Necessity for high level education to promote the decentralized biomass conversion is emphasized. [ABSTRACT FROM AUTHOR]

This review offers a state of the field examination of cookstove implementation efforts with a focus on stakeholder engagement and persistently low rates of adoption. Literature from related fields, such as sanitation and public health, indicate that perspectives in sustainable energy are narrow, and point to a new approach for sustainable energy and development engagement, one that does not solely rely on overcoming habitualized behaviors of adult women. Should stakeholder perspectives be expanded, and coupled with partnerships that include local, youth-oriented educational institutions, better uptake of efficient cooking technologies may be realized. This paper argues that youth, current and future users of cookstoves, are systematically overlooked at all points along the cookstove value chain, and that their continued exclusion from implementation efforts is to the detriment of cookstove research and practice. This paper calls for their purposeful inclusion in development efforts through collaborations with Education for Sustainable Development providers whose work is complementary to the cookstove and sustainable development communities' aims and aspirations. This represents a new line of research in sustainable household energy, one that includes a diversity of perspectives and the inclusion of all stakeholders. • Overview of current and past cookstove implementation efforts and research. • Discussion of complementary public health field successes as model for cookstoves. • Proposed research agenda including youth-focused sustainability education. • Substantiates prior calls for more inclusive perspectives in the cookstove sector. [ABSTRACT FROM AUTHOR]

Renewable-based energy systems have the potential to vastly increase the use of land devoted to energy, thus drastically changing landscapes and habitats, since conventional, fossil-based energy systems use a very small proportion of earth's land surface. Land use affects ecosystems, biodiversity, and geochemical cycles. It also affects people's well-being due to effects on views, noise, recreation, and quality of life. This means strong and transparent metrics to assess land use for energy systems are needed. This review considers some of the most influential papers and metrics in this category, namely ecological footprint, land use intensity and power density, attempting to make them transparent in terms of data used and calculations performed. The literature frequently relies heavily on assessments that are decades old, many dating from the 1980's. The lack of transparency in the methods and even confusion in the units has led to the published metrics being applied incorrectly. Even within the same paper, the calculation is often performed several different ways, leading to errors and confusion on several orders of magnitude. An assessment of land use by major electricity production technologies and fuels as well as an explanation and guide to commonly used metrics is provided. • Estimates of land use by power generation technologies vary by orders of magnitude, with inconsisten methodologies. • The energy transition will cause drastic changes to land use, which provides barriers to adoption of renewables. • Storage has relatively high use of land, which has so far been almost unexplored in the literature. • Natural gas has lowest land use but there is potential for renewables to improve land use profile via mixed-use development. • Further development of land use metrics including ecosystem services is needed for betterfor better sustainability assessments. [ABSTRACT FROM AUTHOR]

The arriving optimum improvement of a thermodynamic system of energy conversion such as a combined cycle power plant (CCPP) is complicated due to the existence of different factors. Energy and exergy analysis is utilized as effective methods to determine both the quantity and quality of the energy sources. This paper reviews the latest thermodynamics analysis on each system components of a CCPP independently and determine the exergy destruction of the plant. A few layouts of the CCPP plant from different locations considered as case studies. In fact, the most energy losses occurred in the condenser compared with the plant components. It found that in the combustion chamber (CC) the highest exergy destruction occurred. The ambient temperature causes an evident decrement in the power production by the gas turbine (GT). The result has proved that besides energy, exergy analysis is an efficient way to the assessment of the performance of the CCPP by recommending a more advantageous configuration of the CCPP plant, which would lead to reductions in fuel required and emissions of air pollutants. [ABSTRACT FROM AUTHOR]

Seawater desalination is an important option for addressing the world's water supply challenges. Current desalination plants use enormous quantities of energy and cause a number of environmental issues. Renewable energy options, mostly solar and geothermal systems, have been examined in detail to supply the energy needed for water desalination. The co-location benefit of energy derived from the ocean to power seawater desalination processes is appealing. However, the promise and potential of ocean-based power generation for desalination systems has not been investigated in detail. The development of such systems has been limited due to technological and economic limitations of energy harvesting and transport as well as device maintenance under water. In this paper, we review the state of the art of ocean energy in desalination. It explores different sources of energy from the ocean that include electricity generation, as well as mechanical force and thermal energy and salinity gradients that can also be directly harnessed for powering the desalination processes. We also examine recent advances in scaling up for commercial deployment, and discuss relevant cost, environmental and social concerns. The great potential of ocean energy for seawater desalination in terms of diverse energy forms, flexible integration methods and various deployment strategies can provide important environmental, water and social benefits for seawater desalination, thus promote sustainability in water-energy nexus. The use of ocean energy in desalination applications could benefit the future development of ocean energy technology in renewable energy sector. [ABSTRACT FROM AUTHOR]

In the last decade the demand of power in India has increased manifold, therefore Government has announced the National Solar Mission of generating 100 GW of solar power up to 2022. Around 60% of the total National Solar Mission target is allotted to the national/international large-scale solar power developers/investors. Hence, it becomes important to know the ground reality of large-scale solar PV developers/investors. This paper deeply analyzes the key barriers and bottlenecks faced by solar power developers in achieving the target and their growth. This article also suggests some motivational factors of solar energy which play an important role in attracting large solar players around the world to invest in Indian subcontinent. It concludes by highlighting some key policies of the Government that can help in addressing some identified barriers in order to ensure a secured sustainable energy future of India. [ABSTRACT FROM AUTHOR]

This paper investigates the precedents, policies and factors relevant to a successful energy regime transition which may be applied in the Japanese case, through a review of national leaders in renewable energy deployment. The examples of Germany, Italy and Spain are of particular note for their progress along the transition pathway toward a low carbon energy regime. Transition theory is used as a framework to enable this assessment, and exogenous impacts specific to Japan such as recent and ongoing market liberalization and the Fukushima nuclear incident are considered as pertinent factors which impact upon the transition landscape. Through a comparative assessment of policy approaches, technologies deployed, and social factors impacting upon deployment, lessons are drawn for comparison with current Japanese transition progress, identifying factors critical to the future estimation of the Japanese transition pathway. Future energy transition pathway projections will need to incorporate policy approaches and mechanisms as well as being cognizant of Japan's geographic and cost-competitive RE resource deployment limitations. These limitations alongside existing generation assets (including nuclear energy) are expected to have a significant impact upon Japan's transition from the current pre-development phase toward take-off, acceleration and the stabilization of a new, low-carbon energy regime. [ABSTRACT FROM AUTHOR]

Despite its vast natural resources, African is facing serious challenges in sustainable development in an energy sector, if addressed with dispatch could not only check its indispensable needs, but also mitigate some global phenomenon at stake, such as desertification, environmental degradation and green house emission. This paper reviews the prospects of four major renewable energy sources-hydro, solar, wind and biomass- for each of the three leading countries in Africa namely South Africa, Egypt and Nigeria. Based on literature survey of energy efficiency, all the three countries encourage energy efficiency in varying degrees. In the course of this review, several national energy policy frameworks of these countries were looked into, especially on how African countries could overcome the persistent energy crisis in the continent by utilizing the naturally gifted renewable energy sources. This could only be achievable if proper technology, awareness and skills for harnessing the resources are provided. Also lingering energy challenges such as energy efficiency measures, needs for grid extension, energy storage technology and seasonal variation were carefully highlighted. [ABSTRACT FROM AUTHOR]

Analyzing of the effects and the determinants of the energy paradigm changes on influencing the economic growth in European Union starts from the assumption that the economy is highly dependent of energy consumption in achieving of the economic growth and welfare for population. Consequently, the changes in the energy paradigm imply significant transformations in the production structures and their evolution. The aim of the paper is to present and evaluate the effects and determinants of the energy paradigm changes on assuring economic growth in European Union, by using the panel data approach and its subsequent techniques. In this respect, there was considered the evolution of nine economic variables across 30 countries, representing the EU member States during the examined period, plus Iceland and Norway, in order to revile direct and irrefutable connections among these variables in shaping the new energetic paradigm in European space. The results obtained during the research confirm that all nine variables are determinant and significant elements in shaping a new and proactive energy policy and it undoubtedly contribute in achieving of the sustainable economic development [ABSTRACT FROM AUTHOR]

Lighting accounts for over 20% of electricity use in the residential sector of Cameroon. Due to the unreliable and inadequate energy supply in the country, there is a need for the efficient utilization of the available energy. This paper presents the current different technologies used for artificial lighting including the economic and environmental benefits associated with a switch from incandescent lighting to compact fluorescent lamp (CFL) and light emitting diode (LED) in residential dwellings in Buea, Cameroon. The study employed a survey of 100 residential dwellings in Buea. Results of the survey revealed that artificial lighting in dwellings is achieved through the use of the following technologies: incandescent lamps, CFLs and fluorescent tubes. The economic assessment for the substitution of incandescent lamps with CFL and LED considering an average daily lighting duration of six hours was also conducted using the net present value (NPV), benefit cost ratio (BCR), the simple payback period (PBP) and a life cycle cost analysis (LCC). The economic assessment revealed an NPV that ranges from $47 to $282.02, a BCR of 1.84 and a PBP of 0.17 year for the substitution of current incandescent lamps in dwellings with CFL while the substitution of incandescent lamps with LED revealed an NPV of the range $89.14 to $370, a BCR of 3.18 and a PBP of 1.92 years. The LED and incandescent technologies emerged with the lowest and highest LCC respectively. Substituting incandescent lamps with CFL and LED results in a reduction in lighting related greenhouse gas (GHG) emissions from dwellings by 66.6% and 83.3% respectively. From the results, a transition towards efficient lighting in the residential sector of Cameroon possesses great economic and environmental benefits. There is need for the government of Cameroon to expedite the uptake of LED through the formulation and implementation of favourable policies. [ABSTRACT FROM AUTHOR]

The resource nexus consists of a framework to address interlinkages between natural resources and systems that provide water, energy, food and waste management. It transcends traditional assessments conducted in "silos", raising trade-offs and synergies that are rarely acknowledged. The nexus framework is intrinsically context-specific, as each respective region has particularities in terms of critical interlinkages. Brazil is the world's eighth largest economy [1] and is heavily reliant on natural resources. This paper considers Brazil to be a textbook case for nexus research that identifies critical interlinkages that are neglected by literature, which is typically based on single-resource analysis. It proposes a research agenda to advance resource nexus assessments and improve resource governance in Brazil. We propose a novel method for nexus research, systematically reviewing geographical context-specific papers in relevant single nexus dimensions and establishing resource interlinkages that characterise research gaps and policy priorities. We found that 36% of practices reviewed involve more than one resource at a time, characterising interlinkages not analysed by the literature. Lastly, selected quantitative indicators were used to identify critical interlinkages by analysing the representativeness of practices in the national context, and the relevance of synergies or trade-offs for Brazil. Critical interlinkages in Brazil were found to be irrigation for energy crop expansion (water, food and energy); transport biofuels and fuelwood (water, energy, food); deforestation for new pasture (water, energy, food); and hydropower generation (water and energy). These are, therefore, priorities for future nexus research and for efforts to address synergies and trade-offs in resource governance. • The nexus framework assesses and emphasizes critical interlinkages across natural resources. • Critical interlinkages embedded in resource use practices were identified. • Interlinkages between water, waste, energy and food in resource use and management practices were identified. • A research agenda around resource interlinkages in Brazil was developed. [ABSTRACT FROM AUTHOR]

Hydrogen is acknowledged as a potential fuel as it can be used as an energy carrier, a storage medium, in fuel cells and as a fuel as well and offers carbon-free solutions. This paper investigates three renewable energy based configurations for hydrogen production. The renewable energy sources considered in this study are solar PV, geothermal power generation and biomass gasification. The proposed study also presents a novel configuration of biomass gasification for hydrogen production via multistage water gas shift reactors. The solar PV and geothermal energy based hydrogen production systems are analysed employing the EES software while the hydrogen production system employing biomass gasification is simulated employing Aspen Plus. All three designed configurations are proceeded through numerous parametric analyses to investigate the system behavior and effect on system efficiencies. The hydrogen production using biomass gasification technique provides with the energetic and exergetic efficiencies of 53.6% and 49.8% and the efficiencies for the geothermal power generation based hydrogen production system are found to be 10.4% and 10.2% respectively. The exergetic and energetic efficiencies of hydrogen production system employing solar PV system are found to be 17.45% and 16.95%, respectively and the system is designed to produce 1.13 mol/s of hydrogen. Furthermore, the results of the parametric studies and sensitivity analyses are presented and discussed. • This paper investigates three renewable energy techniques for hydrogen production. • The considered renewable energy sources are solar PV, geothermal and biomass. • Biomass gasification offers energy and exergy efficiencies of 53.6% and 49.8%. • The energy and exergy efficiencies of geothermal hydrogen are 10.4% and 10.2%. • The exergy and energy efficiencies of solar PV based H 2 are 16.95% and 17.45%. [ABSTRACT FROM AUTHOR]

The concept of supply chain resilience continues to attract both industry and research experts in the field of energy. These stakeholders continue to tackle disruptions to supply chain systems through the introduction of strategy options for resilience. A better understanding of broader dimensions of potential disruptions to supply chains caused by uncertainties has become eminent, especially as currently experienced during the global COVID-19 pandemic. The effects of the outbreak in disrupting supply chains in the energy sector will, in the next decade, continue to be a likely concern for industry and research stakeholders. Balancing the increasing need for energy security to meet the continuous growth in energy demand through shortage reduction and increased uptime using optimization is the core of this research. This review paper provides an insight into recent studies in the field of natural gas supply chain resilience as a major player in the energy mix, and the continued disruption and subsequent shutdowns of plant nodes, which results in emission loss to the environment. This paper is motivated by the disparity between demand and supply triggered by the disruption of supply chain networks. Referenced in this paper are scientific work on supply chain resilience of biomass, water, power systems, and natural gas. Findings show that existing studies favor fewer system-based strategies in optimizing for resilience. This review concludes that an optimization is a useful tool to continuously achieve resilience in supply chain production, storage, and transportation activities. • Review of the resilient supply chain. • Presentation of various disruptions impacting the supply chain. • Highlighting losses and shortages recorded during shutdowns. • Presentation of natural gas and other energy supply chains. • Emphasizing the development of the resilient supply chain system for natural gas through optimization. [ABSTRACT FROM AUTHOR]

CO 2 emissions from fossil fuel energy and its potential influence on climate change is one of the biggest environmental sustainability challenges. The process industries are a major contributor to CO 2 emissions and thus have a major role to play in trying to greatly reduce them. This paper focuses on individual processors and what they can achieve in moving towards zero CO 2 emissions form energy use. It uses a number of case-studies to highlight technical approaches that may be applied to reduce CO 2 emissions, such as gas turbine CHP and renewables. It argues that these approaches need to be looked at in a broader holistic sense and highlights the limitations of these approaches for providing major reductions in CO 2 emissions. Furthermore, the dominant neo-classical economic system continuously drives economic growth which often counteracts any reductions achieved. There is only so much an individual processor can be expected to do, as there are factors and barriers outside the direct control of an individual processor that influence their carbon footprint, such as cost and availability of energy sources. Many of these factors are socio-economic, thus modifications to the dominant neo-classical economic paradigm are required to facilitate and move individual processors towards majorly reducing their carbon footprints form energy usage. [ABSTRACT FROM AUTHOR]

The paper deals with thermo-mechanical exergy analysis of the electricity production by recovering from natural gas pressure reduction station. In this study we present an energy and exergy assessment and modeling of PRS systems for their system analysis, performance evaluation and optimization. A comprehensive case study is conducted in Marmara 1.3 MW pressure reduction station (PRS) in Tekirdag, Turkey and actual thermal data are collected and employed for analysis. Using actual system data, an assessment of the pressure reduction station system performance, energy and exergy efficiencies, and exergy destructions in the system is conducted in this regard. The exergy destructions in the overall PRS are quantified and illustrated. It is observed through analysis that the exergy destructions in the system particularly take place as the exergy of the fluid lost in the turbo expender, the heat exchanger losses of the system. For system performance analysis and improvement, both average energy and exergy efficiencies of the overall PRS are investigated and determined to be 71.96% and 78.25%, respectively. [ABSTRACT FROM AUTHOR]

Given the exponential cost decline trend of solar energy generation technologies, and the targeted tax incentives and loan guarantees for renewable energy in the American Recovery and Reinvestment Act of 2009, and other policy measures, solar energy generation has been enjoying rapid growth in the United States. This paper examines the incorporation of solar renewable energy into generation portfolios, and the effects of natural capital – specifically the geospatially calculated potential solar energy generation as measured by potential average annual kilowatt-hours per square meter per day − and respective state mandated “renewable portfolio standard” targets on utility-scale solar energy generation. Findings suggest that a state's natural solar energy potential is a predictor of solar energy generation development, and further this relationship is significantly moderated by state-specific renewable energy portfolio standard targets. [ABSTRACT FROM AUTHOR]

World’s human population is increasing rapidly day by day and has been reached to 7.324 billion by 2015. This rapid increase in the population is expanding energy demands and led to an energy crisis throughout the world, leading to the search for alternative sources of energy. Biofuels are an attractive solution for offsetting fossil fuels for a number of different reasons. There are various potential feed stocks for biodiesel production. From an economic and social perspective edible seed oil should be substituted by non-edible, lower cost and reliable seed oil for biodiesel production. We reviewed in this paper previously declared potential plant sources of biodiesel reported in Pakistan. Various related aspects of these feed stocks has been reviewed from numerous current publications, including oil extraction techniques, fatty acid composition profile (FAC) of non-edible seed oils, biodiesel standards and characterizations. We concluded from our review that the easy availability of non-edible plant resources in various parts of the world pave ways for its use in biodiesel production. It can supplant the dependency on edible plant seed oil resources and to tackle with the devastating crises of energy in Pakistan and worldwide. [ABSTRACT FROM AUTHOR]

This research paper is the 2nd part of field investigation about renewable energy education in different engineering departments in state and private universities in Jordan. The prime objective is focused on assessing the influence of some students’ related characteristics, namely age, gender, department and university on their levels of knowledge and awareness regarding existing energy situation and renewable energy potential. To achieve such goal, common statistical methods such as ANOVA, Chi-square test & Post hoc comparisons were used for data analysis. The study in hand investigated two aspects of energy knowledge are considered, i.e. energy situation and renewable energy sources. The principal findings of this research showed consistent significant difference in the level of energy knowledge among students with respect to university, but insignificant difference in the level of energy knowledge pertaining to age. On the other hand, gender and department showed inconsistent findings: both were significant with respect to the first aspect, but insignificant with respect to the second aspect. This is due to the fact that some universities have taken necessary steps and introduced new courses related to energy conversion and renewable energy technologies in close cooperation with some universities in Europe. Others such as German-Jordan University went further by introducing new engineering stream which specialized in renewable energy. It is deemed that such programs will reduce the existing gap in energy education and local renewable energy industries as well as disseminating energy efficiency and renewable energy technologies in the country. However, there is still an urgent need to develop energy and renewable energy education and training in order to provide the desired skillful engineers and technicians to support related industries in the local and regional markets. [ABSTRACT FROM AUTHOR]

Resources scarcity and electricity demand have been dramatically increasing. Wastewater is recognized as one of resources for water, energy and plant fertilizing nutrients. Nevertheless, current wastewater treatment technologies have limitations due principally to their energy- and cost-intensive for achieving the conversion target of wastewater recovery. It is desired to develop a new technology to generate alternatives to conventional energy sources in a sustainable manner. An innovative technology based on the use of microbial fuel cells (MFCs) has been proved as a critical pathway for bioconversion processes towards electricity generation, then for addressing energy and environmental problems. Three special features including energy saving, less sludge production and less energy production make MFCs outstanding compared with the existing technologies. Multiform wastewaters could be efficiently degraded through advancing MFCs alone or integrating MFCs with other processing units. However, the low power density and the high operating cost of MFCs have greatly limited their applications on large-scale problems, and then result in some debates and doubts about their development and applications. Therefore, this paper objectively discussed the problems and applications of MFCs in wastewater treatment. Moreover, the integration of MFCs with other treatment processes was presented to verify the practicality and effectiveness of MFCs in contaminants removal. Furthermore, the primary challenges and opportunities for scaling-up and future applications of MFCs in wastewater were analyzed. [ABSTRACT FROM AUTHOR]

Availability of and access to water and energy are key ingredients for economic and social development. Unfortunately, more than a billion people still lack access to both safe freshwater and basic energy services. Future predictions show that the situation may become worse with about a 40% increase in energy demand and 30% increase in water demand by 2040. In addition, water and energy are highly interdependent, with water needed in all phases of the energy lifecycle and energy needed in all phases of the water lifecycle. While recent years have seen an increasing number of studies on the water-energy nexus, the research is focused on scattered individual areas of the nexus, each important in their own right. However, there is now a need to synthesize these efforts and identify the most important elements needed for a holistic water-energy nexus methodology. This paper focuses on the benefits to be gained from and the drawbacks of ignoring various water-energy interlinks for policy makers and planners in their goals to meet long term resource security. Several possible combinations of socio-economic and climate change scenarios make these goals even more challenging. The lessons learnt from reviewing different integration methodologies and studies are compiled into a list of key recommendations. It is found that current integration efforts are often biased towards the energy sector and its water requirements. There is still a need for better representations of the water infrastructure and corresponding linkages with the energy sector. There is also a need to harmonize the energy and water systems from both a technical and policy perspective. This calls for compatible disaggregation of spatial and temporal elements in both systems as well as designing model outputs to allow evaluation of the synergies and tradeoffs of multi-scale, cross-sector policies. [ABSTRACT FROM AUTHOR]

Solid biomass and waste are major sources of energy. They account for about 80% of total primary energy consumed in Nigeria. This paper assesses the biomass resources (agricultural, forest, urban, and other wastes) available in Nigeria and the potential for biofuel production from first, second, third and fourth generation biomass feedstocks. It reviews the scope of biomass conversion technologies tested within the country and the reports on the technology readiness level of each. Currently, most of the emerging biofuels projects in Nigeria utilize first generation biomass feedstock for biofuel production and are typically located many miles away from the petroleum refineries infrastructures. These feedstocks are predominantly food crops and thus in competition with food production. With significant availability of non-food biomass resources, particularly in the Niger Delta region of Nigeria, and the petroleum refineries located in the same area, it is pertinent to consider expanding use of the petroleum refinery׳s infrastructure to co-process non-food biomass into bio-intermediate oil for blending with petroleum. This not only addresses the potential food versus fuel conflict challenging biofuel production in Nigeria, but also reduces the cost of setting up new bio-refineries thus eliminating the transportation of ethanol to existing petroleum refineries for blending. In view of this, it is recommended that further research be carried out to assess the feasibility of upgrading existing refineries in Nigeria to co-process bio-based fuels and petroleum products thus achieving the targets set by the Nigeria Energy Commission for biofuel production in the country. [ABSTRACT FROM AUTHOR]

Cogeneration is one of the methods to improve energy efficiency, reduce energy consumption and control environmental pollution. Downsizing the cogeneration system, improving its overall efficiency and incorporating it for meeting multiple objectives have been the topics of interest in the last three decades. A polygeneration system is a modified version of a cogeneration system, in which more than two objectives (i.e heat, power, cooling, production of energy or fuels) are achieved. This paper discusses the research and developmental activities that have been recently carried out in the area of trigeneration and polygeneration systems. [ABSTRACT FROM AUTHOR]

In this paper we present a green growth model with energy and pollution. A structural VAR approach is used to test its empirical implications for the Italian economy. Data span over the 1961–2010 period. Our model develops the original contribution by Adom and Kwakwa (2014) [2] aimed at identifying the long-run forces driving the dynamics of a set of variables. Specifically, we identify the long- and short-run structural shocks of the variables of interest by means of restrictions from theory. Our results show that (1) the estimated conditional correlations of energy intensity and pollution per capita are positive for both supply and demand shocks; and (2) the impulse responses show a persistent increase of both energy intensity and pollution per capita to supply shocks. The main insight is that the VAR residuals are combinations of structural supply and demand shocks. [ABSTRACT FROM AUTHOR]

The development of distributed energy system is one of the important measures to promote energy production and innovation of energy utilization patterns of China. Combined with development status of distributed energy resources in China, this paper introduces the development emphasis and main goals of three distributed generation industries from natural gas, photovoltaic and distributed wind power, then describes the policies about distributed generation from three aspects: subsidy standard, grid connection and electrovalence mechanism. Moreover, it analyzes policy options and management experience in developing distributed generation of several typical developed countries, such as America, Germany, Japan and Denmark. Finally, aiming at further development of distributed generation in China, related recommendations on policy options are put forward from four aspects: policies, regulations, financing channel and development pattern. [ABSTRACT FROM AUTHOR]

This paper aims to show the current context of Small Hydro Power Plants (SHPs) in Brazil, presenting and discussing the institutional acts, regulations for growth of the SHP, public and private policies for the sector and growth prospects. After the restructuring of the Brazilian electricity sector, a series of laws, decrees and resolutions were developed with the purpose of regulating the sector in favor of SHPs. In 2001, the number of SHPs in Brazil was 303 with an installed capacity of 855 MW. Over the years, with the changes in the sector and, in 2010, the number of buildings has reached 387, with an installed capacity of 3428 MW. Today, they are 475 SHPs in operation with the generation capacity in the country, around 4799 MW, representing 3.49% of all Brazilian energy matrix. It is estimated that in 2020 the installed capacity will be approximately 6500 MW, but there is more potential available in the country for SHPs, that has great technical and environmental characteristics. It is concluded that more attention must be given by the government policies of the electricity sector to reach in the future the full the potential of SHPs available in Brazil. [ABSTRACT FROM AUTHOR]