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Abstract: Material flows and emissions in all the stages of production of zinc, copper, aluminum, cadmium, indium, germanium, gallium, selenium, tellurium, and molybdenum were investigated. These metals are used selectively in the manufacture of solar cells, and emission and energy factors in their production are used in the life cycle analysis (LCA) of photovoltaics. Significant changes have occurred in the production and associated emissions for these metals over the last 10 years, which are not described in the LCA databases. Furthermore, emission and energy factors for several of the by-products of the base metal production were lacking. This review article aims in updating the life cycle inventories associated with the production of the base metals (Zn, Cu), and defining the production paths and emission and energy allocations for the minor metals (Cd, Ge, In, Mo, Se, and Te) used in photovoltaics. [Copyright &y& Elsevier]

Abstract: Governments around the world try to stimulate the development and use of renewable energy technologies, like wind energy. While wind turbines are increasingly being implemented, however, a lack of social acceptance at the local level remains an important challenge for developers of wind power plants. This article aims to explore the relative importance of social and institutional conditions and their interdependencies in the operational process of planning wind power schemes. The article not only focuses on how negative local social conditions can frustrate public policy (cf. NIMBY syndrome), but also on how positive local social conditions can compensate for a negative public policy framework. We analyzed the cases of implementing wind power of two actors (the regional energy distributor and small private investors) in the municipality of Zeewolde, the Netherlands. Both cases illustrate that the formal institutional framework (formal rules, procedures and instruments) is neutral in a certain sense. Social conditions – management styles, interests and informal contacts – put meaning in this framework. The way stakeholders deal with the prevailing institutional structure clarifies social acceptance and therewith implementation. [Copyright &y& Elsevier]

Abstract: The oil-dependent electricity generation situation met in the Aegean Archipelago Islands is in great deal determined by increased rates of fuel consumption and analogous electricity production costs, this being also the case for other island autonomous electrical networks worldwide. Meanwhile, the contribution of renewable energy sources (RES) to the constant increase recorded in both the Aegean islands’ annual electricity generation and the corresponding peak load demand is very limited. To compensate the unfavorable situation encountered, the implementation of energy storage systems (ESS) that can both utilize the excess/rejected energy produced from RES plants and improve the operation of existing thermal power units is recommended. In the present study, a techno-economic comparison of various RES-ESS configurations supported by the supplementary or back-up use of existing thermal units is undertaken. From the results obtained, the shift of direction from the existing oil-dependent status to a RES-based alternative in collaboration with certain storage technologies entails – apart from the clear environmental benefits – financial advantages as well. [Copyright &y& Elsevier]

Understanding spatiotemporal patterns of energy infrastructure is foundational to characterizing environmental impacts and improving system resilience. We develop a systematic review of publicly available energy infrastructure datasets in the United States (US) to reveal the existing baseline data available for characterizing the energy system. Six fuel types that are used for electricity generation are examined: uranium, coal, natural gas, wind, hydropower, and solar. For each fuel, energy infrastructure data on fuel extraction, processing, storage, fuel transportation, power generation, and transmission and distribution of electricity to final energy product are reviewed. After screening, 146 unique datasets were evaluated for their spatiotemporal characteristics using a data quality assessment framework adapted for this study. The number of available datasets, their spatiotemporal resolution and coverage, the geographic extent and their completeness were found to be highly variable across the 19 different types of energy infrastructure examined. Connections between fuel supply, energy transportation infrastructure, and conversion through final energy product are not well characterized, making the construction of a complete, dynamic energy systems model challenging. Data suppliers may address this challenge by reporting supply-chain linking attributes; for example, unique identification numbers for each facility or segment of infrastructure could bridge datasets across the supply chain. Whereas government policies and reporting requirements largely dictate data format, inter-agency collaboration and harmonization of collection procedures and metadata requirements across regions could support more consistent datasets for each stage of the supply chain through power generation. • 146 fuel supply and electricity datasets evaluated with novel framework. • The number and comprehensiveness of datasets is variable across supply chains. • U.S. governments could consider concerted efforts to align reporting across agencies. [ABSTRACT FROM AUTHOR]

Greenhouse gas emissions from the burning of fossil fuels are one of the main causes of anthropogenic climate change. Large-scale deployment of renewable energy can play an immense role in transforming the global energy system and mitigating the emissions. This paper describes the development of a novel framework called MArket Penetration ModeLing of Renewable Energy Technologies in Electric Power Sector (MAPLET-PS). MAPLET-PS assesses the impacts of policy measures such as carbon price and financial incentives on the adoption of renewable energy technologies. The framework was used to develop a case study for the electric power sector of Alberta, a fossil-dominated province in Western Canada. The results show that implementing a carbon price on fossil fuel electric power sources and incentives for renewable energy, along with the phase-out of coal-fired electricity generation, can mitigate 29% of Alberta's electricity sector 2020 GHG emissions by 2050 and reduce GHG emissions from 46.5 Mt of CO 2 eq. in 2020 to 23.6 and 29.1 Mt of CO 2 eq. per year in 2030 and 2050, respectively, in Alberta. Moreover, these changes can increase the share of renewable energies from 12.5% in 2018 to 30% in 2050. These rates can be achieved by implementing a carbon price along with a 1000 $ incentive per kW new capacity development and 70 $ incentive per MWh electric power generation from renewable sources, from 2021 to 2025, primarily from wind turbines. • The analysis focuses on renewable electric power generation technologies. • A combined market penetration model is developed. • Electric power generation mix is modeled from 2020 to 2050. • Effects of carbon price and financial incentive on generation mix are analyzed. • Annual mitigation potential of greenhouse gases is evaluated. [ABSTRACT FROM AUTHOR]

Integration of renewable energy sources in the form of microgrids can increase the resilience of power systems and decrease their carbon footprints. However, renewable energy sources are intermittent in nature, and their availability can vary significantly with weather and the seasons. Energy storage can be used to make up for the resulting imbalance between supply and demand to a certain degree, but installing large-scale storage for this purpose can be uneconomical. Hence, other types of power sources are often still required, and in many systems this power is provided by diesel generators. The emerging small modular reactor (SMR) technologies can potentially replace these sources with cleaner options. These new reactors feature passive safety systems, long refueling intervals, and have provisions for load-following, allowing them to complement the renewable sources and provide a reliable, dispatchable, low-carbon solution for both electricity generation and district/process heat production. Key issues and approaches are examined and existing works are reviewed to show how SMRs can be integrated into microgrids effectively as a clean and sustainable energy supply. • Small modular reactors complement well with renewable resources in microgrids. • Small modular reactors can displace diesel gen-sets as low-carbon energy sources. • SMRs can provide both electricity and industrial process heat. • Load following by power maneuvers or controllable thermal loads is a key enabler. • SMRs having long refueling cycles improve northern and remote community feasibility. [ABSTRACT FROM AUTHOR]

We evaluated three Integrated Assessment Models (IAMs: IGSM, MERGE, MiniCAM) by: (i) comparing their global Primary Energy year-2000 initializations and projections for 2010 and 2015 to historical data; (ii) mapping their CO 2 emissions projections against observations; and (iii) examining model-output diagnostics. The IAMs underestimated historical primary energy consumption and initial/projected CO 2 emissions in both reference and stabilization scenarios (particularly for combustion fuels) but overestimated usage of non-biomass renewables, causing underestimates of future CO 2 emissions that, for the stabilization scenarios, are wildly optimistic. Mitigation technology breakdowns in the policy scenarios vary enormously across IAMs, suggesting that confidence in their projections might be misplaced, or that options for mitigation have greater scope than is supposed. Most increases in carbon-free technologies in the stabilization scenarios are already captured in the reference cases. Energy-conversion efficiencies in electricity generation improve over time, but, (except for gas-powered generation in IGSM), efficiencies in the policy scenarios are less than in the reference. Electrification results diverge widely: IGSM has little change over the 21st century, while MiniCAM and MERGE have major electrification increases in their policy scenarios. We suggest: 1) comprehensive model output suitable for secondary analysis should be more readily available; 2) directly comparable reference and policy-driven mitigation scenarios are essential for assessing mitigation measures; 3) model validation using historical, source-specific energy data is crucial for assessing model credibility; 4) separation of mitigation contributions into no-policy and policy-driven amounts is needed to assess the effectiveness of mitigation policies; and 5) detailed inter-model comparisons can provide important insights into model credibility. • Models have underestimated fossil-fuel emissions growth. • Models differ widely in the breakdown of future low-carbon technologies. • A large fraction of low-carbon emissions growth occurs in the absence of policy. • Biomass and carbon-capture-and storage (CCS) roles tend to be overestimated. • Electrification's role is minor relative to the role of low-carbon technologies. [ABSTRACT FROM AUTHOR]

Abstract: In this work, a parametric cost-benefit analysis concerning the use of integrated gasification combined cycle (IGCC) technology (with and without carbon capture and storage) is carried out. For the analysis, the IPP optimization software is used in which the electricity unit cost from various power generation technologies is calculated. For comparison purposes, the Rankine cycle (with heavy fuel oil or coal as fuel) and the combined cycle (with natural gas or gasoil as fuel) technologies are also examined. The parametric study carried out, using a range of load factors from 50% to 90% and a range of efficiencies for IGCC technology between 40% and 55%, yields encouraging results for the viability of this emerging technology. [Copyright &y& Elsevier]

Abstract: The distributed energy resources (DER) comprise several technologies, such as diesel engines, micro turbines, fuel cells, photovoltaic, small wind turbines, etc. The coordinated operation and control of DER together with controllable loads and storage devices, such as flywheels, energy capacitors and batteries are central to the concept of MicroGrid (MG). MG can operate interconnected to the main distribution grid, or in an islanded mode. This paper reviews the researches and studies on MG technology. The operation of MG and the MG in the market environment are also described in the paper. [Copyright &y& Elsevier]

Abstract: Tidal energy has been used for centuries. Tidal current and rise and fall of tides were both put to work. They provided power for flour mills, saw mills, breweries, etc. Tide mills dotted several regions of Europe from The Netherlands to Spain and from Wales to England. Immigrants brought the technique to the “New World” to the United States and Canada. But they could not withstand the development of more efficient power production and faded away. Though some subsisted well into the 20th century, most of those still in existence offer mainly a tourist interest. However, they may well be considered the forerunners of the power-generating tidal power stations. These are not numerous—except mini plants in China—but with the price of oil soaring a renewed interest as developed. Of all existing stations, the Kislaya Guba station has not the largest; but the only one completely built by women, and it celebrates this year its 40th birthday. [Copyright &y& Elsevier]

Abstract: Limited fossil resources and severe environmental problems require new sustainable electricity generation options, which utilize renewable energies and are economical in the meantime. Concentrating solar power (CSP) generation is a proven renewable energy technology and has the potential to become cost-effective in the future, for it produces electricity from the solar radiation. In China, the electricity demand is rapidly increasing, while the solar resources and large wasteland areas are widely available in the western and northern part of China. To change the energy-intensive and environment-burdensome economical development way, Chinese government supports the development of this technology strongly. These factors altogether make China a suitable country for utilizing CSP technology. In this paper, the potential of CSP in China was studied and strategies to promote development of this technology were given. [Copyright &y& Elsevier]

Abstract: Today''s environmental policies are largely devoted to fostering the development and implementation in Europe of renewable energy technologies, such as grid-connected photovoltaic solar energy, which are being actively promoted by European Union countries. This article describes an environmental decision-support system (EDSS) for selecting optimal sites for grid-connected photovoltaic power plants. This system combines multicriteria analysis and the analytic hierarchy process with geographical information systems (GIS) technology and at the same time takes into account environment, orography, location, and climate factors. [Copyright &y& Elsevier]

Solar photovoltaics (PV) are on the rise even in areas of low solar insolation. However, in developing countries with limited capital, land scarcity, or with geographically isolated agrarian communities, large solar infrastructures are often impractical. In these cases, implementation of low-density PV over existing crops may be required to integrate renewable energy services into rural communities. Here, using Indonesia as a model system, we investigated the land use, energy, greenhouse gas emissions, economic feasibility, and the environmental co-benefits associated with off-grid solar PV when combined with high value crop cultivation. The life cycle analyses indicate that small-scale dual land-use systems are economically viable in certain configurations and have the potential to provide several co-benefits including rural electrification, retrofitting diesel electricity generation, and electricity for processing agricultural products locally. A hypothetical full-density off-grid solar PV for a model village in Indonesia shows that electricity output (1907.5 GJ yr−1) is much higher than the total residential consumption (678 GJ yr−1), highlighting the opportunity to downscale the PV infrastructure by half to lower capital cost, to co-locate crops, and to support secondary income generating activities. Economic analysis shows that the 30-year net present cost of electricity from the half-density co-located PV system (12,257 million IDR) is significantly lower than that of the flat cost of diesel required to generate equivalent electricity (14,702 million IDR). Our analysis provides insights for smarter energy planning by optimizing the efficiency of land use and limiting conversion of agricultural and forested areas for energy production. • A "crop-centric" approach can integrate renewable energy services into rural communities in developing countries with limited capital and land. • Combining solar PV and agriculture improves land use efficiency, minimizes the energy and carbon footprint of agriculture, and offsets PV costs. • The lifetime cost of solar PV electricity was less than the cost of diesel electricity in off-grid, rural areas of developing countries. [ABSTRACT FROM AUTHOR]

The aim of this research is to analyse the impact of renewable energy (RE) technologies and sector coupling via analysing the transition pathways towards a sustainable energy system in Chile. Four energy transition scenarios for the power, heat, transport and desalination sectors were assessed using the LUT Energy System Transition model. The current policy scenario was modelled and compared with three best policy scenarios. The results showed that the transition to a 100 % renewable-based energy system by 2050 is technically feasible. Further, such an energy system would be more cost-efficient than the current policy scenario to reach carbon neutrality by 2050. The results also indicate that Chile could reach carbon neutrality by 2030 and become a negative greenhouse gas emitter country by 2035. In a 100 % renewable-based energy system, solar photovoltaics (PV) would contribute 86 % of electricity generation, which would represent 83 % of the total final energy demand for the year 2050. This would imply the use of about 10 % of the available techno-economic RE potential of the country. Three vital elements (high level of renewable electrification across all sectors, flexibility and RE-based fuel production) and three key enablers (solar PV, interconnection and full sectoral integration) were identified in order to transition to a fully sustainable energy system. Chile could contribute to the global sustainable energy transition and advance to the global post-fossil fuels economy through the clean extraction of key raw materials and RE-based fuels and chemicals production. • Transitioning to a 100 % RE system would be more cost-efficient from 2035 onwards. • A fully defossilised energy system in Chile is technically feasible. • Electrification on all sectors, flexibility and RE-based fuels are vital elements. • Solar PV, interconnection and full sectoral integration are key enablers. • Chile could become a negative GHG emitter country by 2035. [ABSTRACT FROM AUTHOR]

BIPV windows integrate solar cells within window glazing and do not only retain the functionality of conventional windows but also provide other benefits such as electricity generation and thermal insulation. BIPV windows are categorized into single glazed BIPV windows, double glazed BIPV windows with/without ventilation and vacuum BIPV windows depending on the configurations of the glazing. The electricity generation, thermal performance and optics of BIPV windows are reviewed in this paper. The results of this study showed that the total heat gain through BIPV windows are less than conventional windows in summer and hence the electricity used by air-conditioning in summer would be reduced. In addition to the electricity produced by BIPV windows, there are great potentials to reduce building energy consumption significantly in hot climate areas. The development and performance of BIPV blinds which integrate solar cells with blinds are also reviewed. BIPV blinds are grouped into outdoor PV blinds, indoor PV blinds and middle PV blinds according to the position of blinds relative to the windows. Future research directions are also suggested for this research domain. • The BIPV windows are grouped according to the configurations of the glazing. • The power generation, thermal performance and optics of BIPV windows are reviewed. • The development and performance of BIPV blinds are also discussed. [ABSTRACT FROM AUTHOR]

Abstract: Import of a huge proportion of electrical energy from the Southern African Power Pool, and the geographical location and population distribution of Botswana stimulated the need to consider renewable energy as an alternative to imported power. The paper describes a systematic experimental study on a mini-solar chimney system. Particular attention is given to measurements of air velocity, temperature and solar radiation. The results for the selected 5 and 6 clear days of October and November, respectively, are presented. These results enable the relationship between average insolation, temperature difference and velocity for selected clear days to be discussed. [Copyright &y& Elsevier]

Abstract: Green power products may be seen as a means of fostering renewable energy sources (RES) because they create and channel consumer demand for environmentally sound power generation. Turkey also has a large potential for renewable energy exploitation in a number of areas. Clean, domestic and renewable energy is commonly accepted as the key for future life, not only for Turkey but also for the world. The renewable energy contribution in the total primary energy production is insignificant. The alternative and renewable energy systems have been neglected so far in Turkey but must be included in the new energy programs. In this context, Renewable Energy Law was enacted in 2005 in order to encourage renewable-based generation in competitive market conditions. Supporting mechanisms such as feed-in tariffs and purchase obligation are defined in the law, in conformity with the EU legislation and practice. These mechanisms are envisaged to facilitate the development of power plants based on RES. [Copyright &y& Elsevier]

Abstract: The integration of biomass gasification with SOFCs offers the potential of highly efficient and renewable power generation, primarily in modular solutions. SOFC seems to be the most promising fuel cell technology of biomass gasifier producer gases. Solid oxide fuel cells, because of their high operating temperature, do not require pure hydrogen as fuel, exhibiting high fuel flexibility. Sufficient amounts of cereal, cotton, corn, olive, coffee or palm tree residues are available in Mediterranean areas, while the climatic conditions are favorable for energy crops cultivations. Their residues can be utilized for electricity production by modular biomass gasification-based solid oxide fuel cells (SOFC). [Copyright &y& Elsevier]

Abstract: Electricity generated from renewable sources, which has shown remarkable growth worldwide, can rarely provide immediate response to demand as these sources do not deliver a regular supply easily adjustable to consumption needs. Thus, the growth of this decentralized production means greater network load stability problems and requires energy storage, generally using lead batteries, as a potential solution. However, lead batteries cannot withstand high cycling rates, nor can they store large amounts of energy in a small volume. That is why other types of storage technologies are being developed and implemented. This has led to the emergence of storage as a crucial element in the management of energy from renewable sources, allowing energy to be released into the grid during peak hours when it is more valuable. The work described in this paper highlights the need to store energy in order to strengthen power networks and maintain load levels. There are various types of storage methods, some of which are already in use, while others are still in development. We have taken a look at the main characteristics of the different electricity storage techniques and their field of application (permanent or portable, long- or short-term storage, maximum power required, etc.). These characteristics will serve to make comparisons in order to determine the most appropriate technique for each type of application. [Copyright &y& Elsevier]

Abstract: A concise overview on recent research work on sun-tracking system is presented. Also, an experimental investigation on the effect of using multi-axes sun-tracking systems on the electrical generation of a flat photovoltaic system (FPVS) was carried out to evaluate its performance under Jordanian climate. Multi-axes (N–S, E–W, vertical) electromechanical sun-tracking system was designed and constructed. The measured variables were compared with that at fixed axis. It was found that there was an overall increase of about 30–45% in the output power for the North–South axes (N–S)-tracking system compared to the fixed PV system. Also, it was found that the N–S axes sun tracking is the optimum. [Copyright &y& Elsevier]

Abstract: The paper presents some outputs of renewable energy power plants in Brazil, focusing in the case of wind energy. The information data are mainly acquired from a project developed by the authors with financial resources of Electric Energy National Agengy (ANEEL), United Nations Development Program (PNUD) and Ministry of Science and Technology (MCT). It was used as the socio environmental impacts to evaluate the acceptance aspect, using as examples some case studies implemented in Brazil and the previous experience of the authors. [Copyright &y& Elsevier]

Abstract: Hybrid renewable energy systems (HRES) are becoming popular for remote area power generation applications due to advances in renewable energy technologies and subsequent rise in prices of petroleum products. Economic aspects of these technologies are sufficiently promising to include them in developing power generation capacity for developing countries. Research and development efforts in solar, wind, and other renewable energy technologies are required to continue for, improving their performance, establishing techniques for accurately predicting their output and reliably integrating them with other conventional generating sources. The paper describes methodologies to model HRES components, HRES designs and their evaluation. The trends in HRES design show that the hybrid PV/wind energy systems are becoming gaining popular. The issues related to penetration of these energy systems in the present distribution network are highlighted. [Copyright &y& Elsevier]

Abstract: Prices of oil and other fossil fuels have proven a powerful incentive for the alternative energy hunters. The alternatives include the various forms of ocean energy that, often considered uneconomical for electricity generation, have become attractive and competitive. Many sites throughout the world have been considered, at one time or another, suitable for implantation of a tidal power station, but very few have witnessed implementation of often ambitious plans. The Rance River tidal power plant, near St Malo in Brittany (France) is an exception. It is celebrating in 2006, 40 years of durable, loyal and productive service. [Copyright &y& Elsevier]

Abstract: Solar photovoltaic (PV) hybrid system technology is a hot topic for R&D since it promises lot of challenges and opportunities for developed and developing countries. The Kingdom of Saudi Arabia (KSA) being endowed with fairly high degree of solar radiation is a potential candidate for deployment of PV systems for power generation. Literature indicates that commercial/residential buildings in KSA consume an estimated 10–45% of the total electric energy generated. In the present study, solar radiation data of Dhahran (East-Coast, KSA) have been analyzed to assess the techno-economic viability of utilizing hybrid PV–diesel–battery power systems to meet the load requirements of a typical commercial building (with annual electrical energy demand of 620,000kWh). The monthly average daily solar global radiation ranges from 3.61 to 7.96kWh/m2. NREL''s HOMER software has been used to carry out the techno-economic viability. The simulation results indicate that for a hybrid system comprising of 80kWp PV system together with 175kW diesel system and a battery storage of 3h of autonomy (equivalent to 3h of average load), the PV penetration is 26%. The cost of generating energy (COE, US$/kWh) from the above hybrid system has been found to be 0.149$/kWh (assuming diesel fuel price of 0.1$/L). The study exhibits that for a given hybrid configuration, the operational hours of diesel generators decrease with increase in PV capacity. The investigation also examines the effect of PV/battery penetration on COE, operational hours of diesel gensets for a given hybrid system. Emphasis has also been placed on unmet load, excess electricity generation, percentage fuel savings and reduction in carbon emissions (for different scenarios such as PV–diesel without storage, PV–diesel with storage, as compared to diesel-only situation), cost of PV–diesel–battery systems, COE of different hybrid systems, etc. [Copyright &y& Elsevier]

Abstract: This paper utilizes monthly average daily global solar radiation and sunshine duration data to study the distribution of radiation and sunshine duration over Saudi Arabia. The analysis also includes the renewable energy production and economical evaluation of a 5MW installed capacity photovoltaic based grid connected power plant for electricity generation. The study utilizes RetScreen software for energy production and economical assessment. It is found that the global solar radiation varies between a minimum of 1.63MWh/m2 yr–1 at Tabuk and a maximum of 2.56MWh/m2 yr–1 at Bisha while the mean remained as 2.06MWh/m2 yr–1. The duration of sunshine varied between 7.4 and 9.4h with an overall mean of 8.89h. The specific yield was found to vary from 211.5 to 319.0kWh/m2 with a mean of 260.83kWh/m2. The renewable energy produced each year from 5MWp installed capacity plant was varied between 8196 and 12,360MWh while the mean remained as 10,077MWh/yr–1. The economical indicators like internal rate of return, the simple payback period, the years to positive cash flows, the net present value, the annual life cycle savings, the profitability index and the cost of renewable energy production showed that Bishah was the best site for PV based power plant development and Tabuk the worst. From environmental point of view, it was found that on an average an approximate quantity of 8182ton of green house gases can be avoided entering into the local atmosphere each year. [Copyright &y& Elsevier]

Abstract: Proton exchange membrane fuel cells (PEMFCs) have recently passed the test or demonstration phase and have partially reached the commercialization stage due to the impressive worldwide research effort. Despite the currently promising achievements and the plausible prospects of PEMFCs, there are many challenges remaining that need to be overcome before PEMFCs can successfully and economically substitute for the various traditional energy systems. With the many promising research efforts in overcoming these challenges, the most important tools for the commercialization of PEMFCs will be the technical data and information from a real PEMFC application test. For these reasons, this paper introduces and discusses the remaining challenges and some of the latest research on the application test of PEMFC to real systems such as transportation, residential power generation and portable computers. In addition, this paper describes and summarizes the relative prospects and the competitive force of PEMFCs in these fields. These prospects primarily depend on stable and economical high-purity hydrogen supplies, the scale of application, the existence of more efficient competitive power sources and the social viewpoints such as the health and environment benefits as well as infrastructural aspects associated with traditional power supply and demand. The review shows that PEMFC have the most promising applications to buses, recreation vehicles, and lightweight vehicles. Without doubt, the technology for a stable supply of high-purity hydrogen along with the corresponding infrastructure is essential for the success of PEMFC in various application fields. [Copyright &y& Elsevier]

Abstract: Water available in small watersheds primarily serves household and irrigation needs of the local population. For economical use of water, correct understanding of water availability is necessary mainly because the consequences of such plans are immediate and they could impact the livelihood of people around the watershed. In this paper, a post project case is presented to highlight the opportunities and conflicts on water use in a small watershed. Simulation study is done to show the impact of water regulation for irrigation and power generation. Based on the case study, a few recommendations have been made on water regulation policy to avoid water use conflicts in the study area. [Copyright &y& Elsevier]

Abstract: Power production from biomass derived pyrolysis liquids has been under development for the past few years. If technically successful, it would make decentralized bio-energy production possible. Several technologies and system components have been developed by academia, R&D organizations, and industrial companies in many countries. Much experience has been gained and many useful results published. The present work aims at reviewing the most significant experience in power generation from biomass liquids produced by fast pyrolysis processes. Power plant technologies addressed are diesel engines, gas turbines, and natural gas/steam power plants. Main results are reviewed and R&D needs identified for each technology. The analysis shows that even for the most promising solutions long-term demonstration has not yet been achieved. Pyrolysis liquid use in gas turbine plants and in co-firing mode in large power stations are technically most advanced. Recent work with diesel engines also appears quite promising. [Copyright &y& Elsevier]

Abstract: In this paper a survey of solar-based driven thermoelectric technologies and their applications is presented. Initially, a brief analysis of the environmental problems related to the use of conventional technologies and energy sources is presented and the benefits offered by thermoelectric technologies and renewable energy systems are outlined. The development history of solar-based thermoelectric technologies is introduced together with the discussion of the existing drawbacks of current systems. Typical applications of the solar-driven thermoelectric refrigeration and the solar-driven thermoelectric power generation are presented in order to show to the reader the extent of their applicability. The application areas described in this paper show that solar-driven thermoelectric technologies could be used in a wide variety of fields. They are attractive technologies that not only can serve the needs for refrigeration, air-conditioning applications and power generation, but also can meet demand for energy conservation and environment protection. [Copyright &y& Elsevier]

Abstract: This paper examines four mutually exclusive scenarios for the expansion of the Greek electricity system developed by official authorities and representing alternative views on meeting electricity demand. The aim is to encompass all positive and negative side-effects characterizing the electricity generation technologies assumed to participate in each scenario and emphasis is given to the particular role of renewable energy sources which represent a major differentiating factor between them. The calculation of economic, technical and environmental performances of the examined scenarios for the year 2010 shows that electricity planning is a complicated task since improvements in one policy target are accompanied by losses in others. In order to resolve this conflict, the scenarios are comparatively evaluated with two decision support techniques, multicriteria decision analysis and cost–benefit analysis, which are capable of broadening the strict boundaries of a financial analysis while avoiding intuitive solutions that are often applied in practice. Following the two completely different evaluation approaches, it is confirmed that the scenario assuming the highest penetration of renewable energy sources is the best compromise configuration for the Greek power generation sector. [Copyright &y& Elsevier]

Abstract: Singapore is one of the most industrialised and urbanised economies in South-East Asia. Power supply is an important sub-system in its economy and heavily reliant on imported oil and natural gas. Due to its geographical area, clean/renewable energy sources for power generation are limited. At the same time, in its deregulated electricity market, the adoption of clean/renewable based power generation technology may be hindered by a market pricing mechanism that does not reflect externality costs. For a sustainable power supply, there is a need to change the conventional appraisal techniques. Life cycle assessment (LCA) and life cycle cost analysis (LCCA) are good tools to quantify environmental impacts and economic implications. LCA and LCCA are performed for centralised and distributed power generation technologies in Singapore, namely, oil and Orimulsion-fired steam turbines, natural gas-fired combined cycle plant, solar PV and fuel cell systems. A life cycle energy, emission and cost inventory is established. The results are discussed from the perspectives of fuel security, environmental protection and cost effectiveness of future power generation strategies for Singapore. [Copyright &y& Elsevier]

Abstract: The increase in the use of natural gas in Brazil has stimulated public and private sectors to analyse the possibility of using combined cycle systems for generation of electrical energy. Gas turbine combined cycle power plants are becoming increasingly common due to their high efficiency, short lead times, and ability to meet environmental standards. Power is produced in a generator linked directly to the gas turbine. The gas turbine exhaust gases are sent to a heat recovery steam generator to produce superheated steam that can be used in a steam turbine to produce additional power. In this paper a comparative study between a 1000 MW combined cycle power plant and 1000kW diesel power plant is presented. In first step, the energetic situation in Brazil, the needs of the electric sector modification and the needs of demand management and integrated means planning are clarified. In another step the characteristics of large and small thermoelectric power plants that use natural gas and diesel fuel, respectively, are presented. The ecological efficiency levels of each type of power plant is considered in the discussion, presenting the emissions of particulate material, sulphur dioxide (SO2), carbon dioxide (CO2) and nitrogen oxides (NO x ). [Copyright &y& Elsevier]

Abstract: Geothermal energy and the other renewable energy sources are becoming attractive solutions for clean and sustainable energy needs of Turkey. Geothermal energy is being used for electricity production and it has direct usage in Turkey, which is among the first five countries in the world for the geothermal direct usage applications. Although, Turkey is the second country to have the highest geothermal energy potential in Europe, the electricity production from geothermal energy is quite low. The main purpose of this study is to investigate the status of the geothermal energy for the electricity generation in Turkey. Currently, there is one geothermal power plant with an installed capacity of 20.4MWe already operating in the Denizli–Kizildere geothermal field and another is under the construction in the Aydin–Germencik field. This study examines the potential and utilization of the existing geothermal energy resources in Kutahya–Simav region. The temperature of the geothermal fluid in the Simav–Eynal field is too high for the district heating system. Therefore, the possibility of electrical energy generation by a binary-cycle has been researched and the preliminary feasibility studies have been conducted in the field. For the environmental reasons, the working fluid used in this binary power plant has been chosen as HCFC-124. It has been concluded that the Kutahya–Simav geothermal power plant has the potential to produce an installed capacity of 2.9MWe energy, and a minimum of 17,020MWh/year electrical energy can be produced from this plant. As a conclusion, the pre-feasibility study indicates that the project is economically feasible and applicable. [Copyright &y& Elsevier]

Abstract: The choice of electricity generation technologies not only directly affects the amount of CO2 emission from the power sector, but also indirectly affects the economy-wide CO2 emission. It is because electricity is the basic requirement of economic sectors and final consumptions within the economy. In Thailand, although the power development plan (PDP) has been planned for the committed capacity to meet the future electricity demand, there are some undecided electricity generation technologies that will be studied for technological options. The economy-wide CO2 mitigations between selecting cleaner power generation options instead of pulverized coal-thermal technology of the undecided capacity are assessed by energy input–output analysis (IOA). The decomposition of IOA presents the fuel-mix effect, input structural effect, and final demand effect by the change in technology of the undecided capacity. The cleaner technologies include biomass power generation, hydroelectricity and integrated gasification combined cycle (IGCC). Results of the analyses show that if the conventional pulverized coal technology is selected in the undecided capacity, the economy-wide CO2 emission would be increased from 223millionton in 2006 to 406millionton in 2016. Renewable technology presents better mitigation option for replacement of conventional pulverized coal technology than the cleaner coal technology. The major contributor of CO2 mitigation in cleaner coal technology is the fuel mix effect due to higher conversion efficiency. The demand effect is the major contributor of CO2 mitigation in the biomass and hydro cases. The embedded emission in construction of power plant contributes to higher CO2 emission. [Copyright &y& Elsevier]

Abstract: Utilization of non-renewable energy sources not only results in environmental deterioration but also confronts us with the dilemma of a rapid rate of depletion of such resources, while renewable energy sources can serve us indefinitely with minimal environmental impacts as compared with fossil and nuclear fuels. This article deals with the extent of harnessing renewable energy sources for power generation in Iran, a Middle Eastern Asian nation. [Copyright &y& Elsevier]

Abstract: Conventionally, power plants have been large, centralized units. A new trend is developing toward distributed energy generation, which means that energy conversion units are situated close to energy consumers, and large units are substituted by smaller ones. A distributed energy system is an efficient, reliable and environmentally friendly alternative to the traditional energy system. In this article, we will first discuss the definitions of a distributed energy system. Then we will evaluate political, economic, social, and technological dimensions associated with regional energy systems on the basis of the degree of decentralization. Finally, we will deal with the characteristics of a distributed energy system in the context of sustainability. This article concludes that a distributed energy system is a good option with respect to sustainable development. [Copyright &y& Elsevier]

Abstract: Fossil fuel reserves are diminishing rapidly across the world, intensifying the stress on existing reserves day-by-day due to increased demand. Not only that, fossil fuels, presently contributing to 80% of world primary energy, are inflicting enormous impacts on environment. Climatic changes driven by human activities, in particular the production of greenhouse gas emissions, directly impact the environment. Energy sector has a key role in this regard since energy during its production, distribution and consumption is responsible for producing environmentally harmful substances. A secure and accessible supply of energy is thus very crucial for the sustainability of modern societies. There is an urgent need for a quicker switch over of energy systems from conventional to renewables that are sustainable and can meet the present and projected world energy demand. Solar power is one of the most promising renewables. It is reliable and less vulnerable to changes in seasonal weather patterns. Hydrogen, in the capacity of energy vector, is expected to be the optimum solution for intermittency and storage of energy produced by renewables. Thus, coupled with hydrogen as an energy carrier, solar energy has a large potential to become the fuel of the future. The present study is aimed to explore such potential for India in 2025. India is expected to have a high growth rate in energy demand over the coming years due to its huge population and rapid economic development. By the year 2020, the country''s demand for commercial energy is expected to increase by a factor of 2.5. Presently, more than 90% of the energy demand is met by fossil fuels, in spite of the fact that India has limited fossil fuel resources as compared to global reserves. By the year 2020, India, presently the world''s sixth largest energy consumer, is expected to meet 75% of its oil and gas needs by imports. Being an energy deficient country, it has not been able to keep up with demand, leading to power shortages and supply interruptions. The growing gap between the demand and supply of energy, and environmental externalities associated with fossil fuel require immediate and substantial increases in electric power generation and transmission capacities, and exploitation of new avenues of energy supply that are more stable and environment friendly. The geographic location of India makes it a strong candidate for harnessing solar energy. Thus, solar PV is a potential technology to meet India''s future energy demand and its associated environmental challenges. The present work proposes solar hydrogen based energy network to meet the future energy demand for the major cities of India in a sustainable way. In the proposed energy network, solar PV produced electricity is to be utilized to meet the energy demand during day hours. The solar generated electricity that is excessive of demand is to be stored in the form of hydrogen to be utilized during nocturnal hours and prolonged overcast conditions. A modular approach has been adopted for the purposed energy network to meet the year 2025 demand of six major cities of India: Chennai, Delhi, Jodhpur, Kolkata, Mumbai and Trivandrum. Present as well as projected cost scenarios for 2025 have been provided for all the proposed technologies to evaluate the economical viability of the energy network under study. Based on the futuristic trends, it is foreseen that by the year 2025, the PV electricity would be more economical than the fossil fuel electricity. [Copyright &y& Elsevier]

Achieving sustainable development is a target that is now widely seen as important to worldwide public opinion. In this regard, the utilization of renewable energy resources, such as solar, geothermal, and wind energy, appears to be one of the most efficient and effective ways in achieving this target. Recently, wind power as a potential energy has grown at an impressive rate in Turkey.This paper reviews the development of wind energy in the country as of the end of October 2003, including its history, studies conducted on wind energy, restructuring of the Turkish electricity market and wind energy applications.Turkey’s total theoretically available potential for wind power may be around 88,000 MW annually, with particularly attractive areas for wind located along Turkey’s west coast and in southeastern Anatolia. Electricity generation through wind energy for general use was first realized in Izmir, Turkey in 1986 with a 55 kW nominal wind energy capacity. However, the utilization of wind energy in Turkey has increased since 1998 when the first wind power plant with a total capacity of 1.5 MW was installed. Up to date, three wind power plants were installed with a total capacity of 18.9 MW, while a wind power plant with a total capacity of 1.2 MW will be commissioned in November 2003.Present applications have shown that wind energy in Turkey is a promising alternative and the strong development of wind energy is expected to continue in the coming years following restructuring of the Turkish electricity market. [Copyright &y& Elsevier]

The future economic development trajectory for India is likely to result in rapid and accelerated growth in energy demand, with attendant shortages and problems. Due to the predominance of fossil fuels in the generation mix, there are large negative environmental externalities caused by electricity generation. The power sector alone has a 40 percent contribution to the total carbon emissions. In this context, it is imperative to develop and promote alternative energy sources that can lead to sustainability of the energy–environment system. There are opportunities for renewable energy technologies under the new climate change regime as they meet the two basic conditions to be eligible for assistance under UNFCCC mechanisms: they contribute to global sustainability through GHG mitigation; and, they conform to national priorities by leading to the development of local capacities and infrastructure. This increases the importance of electricity generation from renewables. Considerable experience and capabilities exist in the country on renewable electricity technologies. But a number of techno–economic, market-related, and institutional barriers impede technology development and penetration. Although at present the contribution of renewable electricity is small, the capabilities promise the flexibility for responding to emerging economic, socio–environmental and sustainable development needs. This paper discusses the renewable and carbon market linkages and assesses mitigation potential of power sector renewable energy technologies under global environmental intervention scenarios for GHG emissions reduction. An overall energy system framework is used for assessing the future role of renewable energy in the power sector under baseline and different mitigation scenarios over a time frame of 35 years, between 2000 to 2035. The methodology uses an integrated bottom-up modelling framework. Looking into past performance trends and likely future developments, analysis results are compared with officially set targets for renewable energy. The paper also assesses the CDM investment potential for power sector renewables. It outlines specific policy interventions for overcoming the barriers and enhancing deployment of renewables for the future. [Copyright &y& Elsevier]

The generation of energy by clean, efficient and environmental-friendly means is now one of the major challenges for engineers and scientists. Fuel cells convert chemical energy of a fuel gas directly into electrical work, and are efficient and environmentally clean, since no combustion is required. Moreover, fuel cells have the potential for development to a sufficient size for applications for commercial electricity generation. This paper outlines the acute global population growth and the growing need and use of energy and its consequent environmental impacts. The existing or emerging fuel cells’ technologies are comprehensively discussed in this paper. In particular, attention is given to the design and operation of Solid Oxide Fuel Cells (SOFCs), noting the restrictions based on materials’ requirements and fuel specifications. Moreover, advantages of SOFCs with respect to the other fuel cell technologies are identified. This paper also reviews the limitations and the benefits of SOFCs in relationship with energy, environment and sustainable development. Few potential applications, as long-term potential actions for sustainable development, and the future of such devices are discussed. [Copyright &y& Elsevier]

This paper presents an assessment of the technical and economic performance of thermal processes to generate electricity from a wood chip feedstock by combustion, gasification and fast pyrolysis. The scope of the work begins with the delivery of a wood chip feedstock at a conversion plant and ends with the supply of electricity to the grid, incorporating wood chip preparation, thermal conversion, and electricity generation in dual fuel diesel engines. Net generating capacities of 1–20 MWe are evaluated.The techno-economic assessment is achieved through the development of a suite of models that are combined to give cost and performance data for the integrated system. The models include feed pretreatment, combustion, atmospheric and pressure gasification, fast pyrolysis with pyrolysis liquid storage and transport (an optional step in de-coupled systems) and diesel engine or turbine power generation. The models calculate system efficiencies, capital costs and production costs. An identical methodology is applied in the development of all the models so that all of the results are directly comparable.The electricity production costs have been calculated for 10th plant systems, indicating the costs that are achievable in the medium term after the high initial costs associated with novel technologies have reduced. The costs converge at the larger scale with the mean electricity price paid in the EU by a large consumer, and there is therefore potential for fast pyrolysis and diesel engine systems to sell electricity directly to large consumers or for on-site generation. However, competition will be fierce at all capacities since electricity production costs vary only slightly between the four biomass to electricity systems that are evaluated.Systems de-coupling is one way that the fast pyrolysis and diesel engine system can distinguish itself from the other conversion technologies. Evaluations in this work show that situations requiring several remote generators are much better served by a large fast pyrolysis plant that supplies fuel to de-coupled diesel engines than by constructing an entire close-coupled system at each generating site. Another advantage of de-coupling is that the fast pyrolysis conversion step and the diesel engine generation step can operate independently, with intermediate storage of the fast pyrolysis liquid fuel, increasing overall reliability. Peak load or seasonal power requirements would also benefit from de-coupling since a small fast pyrolysis plant could operate continuously to produce fuel that is stored for use in the engine on demand.Current electricity production costs for a fast pyrolysis and diesel engine system are 0.091 /kWh at 20 MWe and 0.199 /kWh at 1 MWe in the base case studied here reducing to 0.073 /kWh at 20 MWe and to 0.146 /kWh at 1 MWe when learning effects are included. These systems are handicapped by the typical characteristics of a novel technology: high capital cost, high labour, and low reliability. As such the more established combustion and steam cycle produces lower cost electricity under current conditions.The fast pyrolysis and diesel engine system is a low capital cost option but it also suffers from relatively low system efficiency particularly at high capacities. This low efficiency is the result of a low conversion efficiency of feed energy into the pyrolysis liquid, because of the energy in the char by-product. A sensitivity analysis has highlighted the high impact on electricity production costs of the fast pyrolysis liquids yield. The liquids yield should be set realistically during design, and it should be maintained in practice by careful attention to plant operation and feed quality. Another problem is the high power consumption during feedstock grinding. Efficiencies may be enhanced in ablative fast pyrolysis which can tolerate a chipped feedstock. This has yet to be demonstrated at commercial scale.In summary, the fast pyrolysis and diesel engine system has great potential to generate electricity at a profit in the long term, and at a lower cost than any other biomass to electricity system at small scale. This future viability can only be achieved through the construction of early plant that could, in the short term, be more expensive than the combustion alternative. Profitability in the short term can best be achieved by exploiting niches in the market place and specific features of fast pyrolysis. These include:

The paper provides an overview of the historical development of wind energy technology and discusses the current world-wide status of grid-connected as well as stand-alone wind power generation. During the last decade of the twentieth century, grid-connected world-wide wind capacity has doubled approximately every three years. Due to the fast market development, wind turbine technology has experienced an important evolution over time. An overview of the different design approaches is given and issues like power grid integration, economics, environmental impact and special system applications, such as offshore wind energy, are discussed. Due to the complexity of the wind energy technology, however, this paper mainly aims at presenting a brief overview of the relevant wind turbine and wind project issues. Therefore, detailed information to further readings and related organisations is provided. This paper is an updated version of the article ‘Wind Energy Technology and Current Status: A Review’, published in Renewable and Sustainable Energy Reviews, 4/2000, pp. 315–374. This update was requested by Elsevier due to the large interest in wind power. [Copyright &y& Elsevier]

The automotive industry is experiencing a revolutionary moment in search of reducing the carbon footprint from its activities. Despite the demand for lower pollutant vehicles, there is no need for a complete disruption of the current industrial production processes. Notably, electric vehicles have been promoted by some parties as the only and best solution for the sustainable future of mobility, to the detriment of the internal combustion engine. This tendentious point of view, although controversial and potentially dangerous, has been gaining strength especially after the pandemic started in 2019, when a considerable reduction in the circulation of the fleet worldwide was observed. Therefore, this work aims to demonstrate the importance of a diversity of solutions for the sustainable future of the transport sector. The risks of a technology ban were examined, as well as the reasons why the development of internal combustion engines, alongside biofuels, is still and will continue to be necessary for cleaner mobility. Moreover, an investigation towards the real responsible for global emissions showed that electricity generation, not automobiles, is the major cause of atmospheric pollution. • The exclusive adoption of BEVs to reduce pollution is a questionable action. • Electricity generation emits more GHG than automobiles. • In the near future, emission reduction is linked to clean energy and biofuels. • The potential of biofuels to generate clean energy is addressed. [ABSTRACT FROM AUTHOR]

Olive sector residues could contribute to increased use of renewable energies, especially in those areas where the olive crop is produced. This paper determines the maximum amount of electrical and thermal energy which could be obtained in Andalusia from olive sector residues, and the economic value that could be obtained from these energy uses. For this, the current data on installed power and electrical and thermal generation are compared with the calculated potential data which would be obtained at full capacity. The results show there is a 69.23% wastage of olive sector residues for energy purposes. Thus, using the resources at full capacity, 3.9 million tons of biomass per year could be obtained for energy purposes. Currently, only 2 million tons of biomass are used for energy purposes. This wastage translates into a below potential generation of electrical and thermal energy. The full use of these residues would allow 83.9% and 64.9% higher generation of electrical and thermal energy, respectively. The results obtained also show that the economic value of olive sector biomass is higher than the market price value, with the average values for each use being 248.20 €/t for domestic thermal use, 165.04 €/t for electrical use and 139.50 €/t for industrial thermal use. Thus, it is considered feasible that the olive sector biomass could be used to a greater degree than at present. In this sense, it is recommended that more electricity generation plants and thermal-generating systems be put into operation. • There is a 69.2% wastage of olive sector residues that could be used for energy purposes. • The full use of olive by-products would account for 6.2% of renewable electricity. • The full use of olive by-products would account for 26.7% of thermal generation. • Better use of residues would promote the start-up of 55 and 1762 electricity and thermal plants, respectively. • The economic value of olive sector biomass allows the value chain to be covered. [ABSTRACT FROM AUTHOR]

Concomitant with decarbonising the global economy, the water industry is increasingly subject to ambitious renewable electricity targets. This will be a significant transition, requiring major investments in new technology, new business models, and unprecedented rates of technology rollout. In this work, we seek to elucidate the key barriers and enablers required to facilitate a rapid switch to a future water sector comprising high levels of renewable electricity generation. Specifically, this research investigates i) the evolution of renewable electricity generation in Australian water utilities since 1998, ii) the effect of the grid electricity price and national climate change policies, and iii) the challenges that utilities are facing in achieving renewable energy targets. The study shows that the water industry has increased its on-site renewable electricity generation capacity from 26 MW in 1998 to 90 MW in 2018. Until 2010, the industry focused on recovering the embedded energy in water and wastewater as hydropower and biogas. After exploiting the economically viable embedded energy, the industry subsequently turned to solar PV as an additional source of renewable electricity. Consequently, solar PV has been the main new source of renewable electricity since 2013. The main drivers for this shift were a solar PV-centred feed-in tariff, increases in grid-sourced electricity prices, and falling technology costs. In regard to renewable electricity targets, if the industry relies solely on solar PV to achieve target electricity generation, utilities will have to install 182 MW of solar PV systems across the whole Australian industry to achieve the set targets in time. [Display omitted] • Renewable electricity evolution in Australian water industry between 1998 and 2018. • Economically viable biogas recovery and hydropower have already been exploited. • The Australian water industry currently relies on solar PV to meet its RET. • 182 MW of additional solar capacity is needed to meet renewable electricity targets. • Renewable energy transition will be more challenging for small utilities. [ABSTRACT FROM AUTHOR]

Large-scale hydro-photovoltaic-wind hybrid systems have the potential to improve flexibility with multiple renewable energy sources. However, few studies have investigated the optimal configuration of hybrid systems, especially on a global scale. This paper examines the regulation capacity of global reservoirs and the characteristics of wind and solar resources, thereby configuring hybrid energy systems at 3080 selected sites around the world. The operation schemes of each hybrid system are simulated, and the optimal sizes of wind and PV power plants are determined considering the risks and benefits of systems. The results show that the total potential installed capacity is 1699 GW with an electricity generation of 4348 TW-hours per year. Hydropower, PV and wind power account for 67%, 20% and 13% of the total electricity generation, respectively, and the largest potential is found in the Asia-Pacific region (40%). The fluctuation ratios of hybrid systems are 78–99% lower than those of independent systems, and integration of wind and PV power into hydropower results in an increase in the average utilization efficiency of transmission networks from 50% to 72%. It is expected that 3900 GW of additional PV and wind power will be produced by 2040, 26% of which could be provided by hybrid systems. The results indicate that large-scale hydro-PV-wind hybrid systems could make important contributions to the global transition to low-carbon energy systems. [Display omitted] • Global potential assessment of large-scale hydro-PV-wind hybrid systems is provided. • Size optimization considering the risks and benefits is performed on 3080 selected sites across the globe. • The total potential installed capacity is 1699 GW and annual yield is 4348 TW-hours worldwide. • Such hybrid systems have the potential to provide 26% of future wind and PV installed capacity additions by 2040. [ABSTRACT FROM AUTHOR]

Stand-alone electrification systems based on renewable energies are suitable for electrifying isolated rural communities. After some years of operation, their impact on the development of beneficiaries must be evaluated; in order to understand the strengths and weaknesses of each design option and to learn useful lessons for future projects. The literature lacks a unified study that compares the long-term impact on population of several projects combining different options for electricity generation (solar PV, wind and hydro) and distribution (microgrids and individual systems). In this context, this work performs a two-phase assessment of 9 electrification projects combining different systems and located in 6 rural Peruvian communities. First, a qualitative analysis is performed to monitor the progress experienced by the communities, considering previous evaluations carried out shortly after the projects' implementation. Second, an in-depth analysis of the systems and the development of the communities is quantitatively performed through 28 indicators, evaluating 9 sustainability objectives organised into 4 dimensions: technical, social, economic and environmental. The results show that microgrid projects require and encourage community involvement to promote effective maintenance of the shared equipment. Conversely, individual systems can work for longer periods without as much regular maintenance, but still need an efficient management model to raise funds for repairs. Also, hydro is confirmed as providing continuous and high-quality supply, while solar and wind options allow more flexible designs. In all cases, a well-planned management model is essential for reducing the default rate, organizing effective maintenance and allowing the sustainable development of the community. • An assessment is made of different stand-alone electrification systems in Peru. • Various technologies for electricity generation and distribution are compared. • Former evaluations and a field visit are used to assess sustainability objectives. • An effective management model is highlighted as key to push community development. • Recommendations for future rural electrification plans are given. [ABSTRACT FROM AUTHOR]

Latest developments in thermoacoustic devices have demonstrated comparable power output and efficiency, but higher reliability and lower cost when compared to conventional low-grade heat recovery technologies. A good coupling between multiple physical fields plays a pivotal role in realizing these potentials. This article provides a comprehensive review of the multi-physics coupling effects, namely, thermal-acoustic coupling, acoustic-mechanical coupling and mechanical-electric coupling, inside thermoacoustic devices including thermoacoustic engines, thermoacoustic electric generators, thermoacoustically-driven refrigerators, etc. The basic principles, operating characteristics, design strategies and future prospects are discussed individually for each coupling effect. System-level design techniques and synthetic optimization methodologies in consideration of the multi-physics coupling effects are presented. This review work gives insights into the underlying mechanisms of various coupling effects in thermoacoustic devices and provides guidelines for improvements of modern thermoacoustic technologies for low-grade thermal energy recovery, refrigeration and electric power generation purposes. • The multi-physics coupling effects in thermoacoustic systems are reviewed. • Basic principles and operating characteristics are discussed for each coupling effect. • System design techniques and synthetic optimization methodologies are presented. • The design strategies and future prospects of thermoacoustic devices are provided. [ABSTRACT FROM AUTHOR]

Solar power plants transform the existing landscape. This landscape change raises concerns about visual impact , land use competition and the end-of-life stage of solar power plants. Existing research stresses the need to address these concerns, arguing for a combined spatial arrangement of solar power plant and landscape: solar landscape. Solar landscapes share the aim to achieve other benefits (e.g. reducing visibility, habitat creation) in addition to electricity generation, yet empirical evidence on solar landscapes is scarce. This comparative analysis of 11 frontrunner cases aims to contribute to the understanding of solar landscapes, by studying the spatial properties visibility , multifunctionality and temporality. Visibility is reduced in all cases. In five cases, however, visibility is partly enhanced in combination with recreational amenities. Between 6 and 14 provisioning, regulating and cultural functions were found in the cases. Functions were located beneath arrays, between arrays and adjacent to photovoltaic patches. Temporal considerations were identified in most cases, yet only two cases introduced new landscape features to enhance future use of the sites after decomissioning. Across cases, this case study shows how contemporary concerns about solar power plants, such as visual impact, land use competition and the end-of-life stage are addressed. Although the cases altogether present a portfolio of measures responding to societal concerns, the full potential of the three key properties is yet to be explored. Furthermore, this comparative analysis highlights the need to address emerging trade-offs between spatial properties and to discern between different types of solar landscapes. The used analytical framework may supplement the assessment of solar power plants to examine not only negative , but also positive impacts. • Innovative designs of solar power plants respond to societal concerns. • A novel analytical framework was developed to compare 11 frontrunner cases. • Cases address concerns about visual impact, land use impact and end-of-life stage. • Solar landscapes combine energy provision with ecological and cultural functions. • Despite visibility and multifunctionality strategies, trade-offs may still emerge. [ABSTRACT FROM AUTHOR]

The energy sector provides fuel for much of everyday life, particularly economically and socially. Fighting against the COVID-19 pandemic, a well-functioning and resilient energy sector is vital for maintaining the operation of critical infrastructures, including, most importantly, the health sector, and timely economic recovery. Notwithstanding its importance in everyday life and crises, the energy sector itself is currently in a complex and far-reaching transformation to combat climate change whilst supporting the transition to a low-carbon economy and society, mainly through the development of variable renewable energy sources (RES) such as wind and solar photovoltaics. This paper highlights the need for energy resilience as countries face the triple challenge of the COVID-19 health crisis, the consequent economic crisis, and the climate crisis. Focusing on Europe, it is advanced here that with the ability to balance fluctuating electricity generation and demand, flexibility allows the energy sector to utilise low-carbon RES reliably, ensuring a more resilient and sustainable energy future. This paper derives five urgent policy recommendations for Europe that address possible impacts of COVID-19 on the economic and societal prerequisites for flexibility in energy systems. • Considers the COVID-19 pandemic as an instigator for change. • Highlights the importance of flexibility for resilient energy systems. • Derives five policy recommendations concerning flexibility in energy systems. [ABSTRACT FROM AUTHOR]