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Over the last two decades, the world has experienced a boom in the number of hydropower projects. Considered an important part of sustainable development, particularly in post-socialist transition and developing countries, it is claimed that hydropower plants will make substantial contributions to environmentally friendly economic growth and poverty eradication. However, the so-called 'hydropower boom' has not resulted in a global mass construction of plants. In general, over-ambitious planning, a lack of funding opportunities and corruption are often put forward as explanations for the discrepancy between the number of plans and actual construction of hydropower plants. In this paper, it is added to these three reasons, illustrating with a case study from Bosnia and Herzegovina, where the planning of hydropower projects very rarely results in their construction. The results are based on secondary data and primary data, i.e. semi-structured interviews and informal talks, collected during fieldwork in Bosnia and Herzegovina. The data was analyzed using the analytical induction method. The results highlight how administrative complexity, over-estimations of exploitable capacity, an unattractive sociopolitical and socioeconomic situation and how these factors in combination create the conditions for various practices of corruption hinder the construction of plants. Comparing the results with other findings from around the world, the paper suggests approaching the so-called global hydropower boom with caution. • Over-ambitious planning results in an unrealistic number of planned project. • Lack of funding opportunities hinders the actual construction of the projects. • Prevalent corruption result in projects being revoked or remaining on paper. [ABSTRACT FROM AUTHOR]

Abstract Blue Growth is the creation of economic activity and jobs at sea, while multiple use of space makes efficient use of the available sea area by combining industries. Clearly there are many combinations and many value propositions. However, most technologies to date are considered blue sky concepts, with little robust techno-economic analysis demonstrating profitability. The paper begins by providing a comprehensive review of Blue Growth and multi-use in Blue Growth; both in policy as well as the wide range of current technologies, including ocean energy, offshore wind energy, offshore aquaculture and desalination. The Maribe H2020 project provides the vehicle for the research element of the paper. The major contribution is a new methodology for selecting, filtering, developing and ranking business propositions for multiple-use of space (MUS) and multi-use platforms (MUP). Application of the method for the first time identified three case studies where Blue Growth combination projects can be economically viable, with attractive internal rate of return (IRRs). Results presented for the case studies report standard investment metrics and show the relative contribution of each product (energy, food, water) to the system profitability, as well as socio-economic impact. Existing companies were fully engaged in the process. Co-creation between sector experts and industry led to both improved business value propositions and robust assessment of investment readiness. In contrast to the presumption that large scale platforms are commercially attractive, the highest ranking case study companies required smaller capital expenditure (CAPEX) and operated in niche subsectors. In conclusion, the positive economic performance of the case studies should provide confidence for the EC as well as investors that MUS and MUP have viable economic futures leading towards commercialisation. The macro and micro assessment methods will be particularly useful in other Blue Economy contexts and in other multiple product contexts. Highlights • A comprehensive history of multiple use of space blue growth. • New metrics for comparing salmon to megawatts are presented. • Method and criteria for ranking potential investments in blue growth business models. • Profitable case studies described involving electricity, water, mussels and fish. [ABSTRACT FROM AUTHOR]

Abstract: The paper focuses on the impact of the electricity market regulation on generating technologies, including renewable in Lithuanian and Poland. The paper aims to identify how the regulatory and non-regulatory factors have influenced investors′ choices. A country case studies approach were applied to analyse and address define the main factors that have influenced investors′ choice of technology mix in electricity market in transition. The major findings of the analysis entail: the main driving forces behind the rationale for reform; electricity reform characteristics; the impact of electricity market reform on electricity prices and electricity market reform and non-reform related factors that have influenced investor′s choice for a specific generation technology or a technology mix. [Copyright &y& Elsevier]

Rapid urbanization trends claim long-term urban planning and management strategies towards a more sustainable urban growth. In this context, neighborhoods show as fundamental units in large-scale sustainable approaches of socio-economic indicators to be replicated in urban development models. However, the number of evaluated districts is still too low compared to the number of buildings evaluated so far. To lay the potential weaknesses and strengths behind the use of sustainable certification tools at district level, the present study aims to examine all realized neighborhoods aligned with sustainability goals. To this end, a systematic review (SR) on neighborhood case studies that directly or indirectly employed neighborhood sustainable assessment (NSA) tools – in particular, amongst LEED-ND, BREEAM-C, CASBEE-UD, and Green Star- Community, DGNB-NSQ, – or that denied the applicability of NSA tools to develop tailored ones is provided. Case studies found in academic papers and NSA-tool official websites are examined through five research questions (RQs): i) number and level of certifications; ii) geographical and temporal distribution; iii) availability of data related to physical characteristics (i.e., size, density, number of dwellings, etcetera); iv) variety of key performance indicators (KPIs) addressed; v) authors outcomes. Evaluation of these realized case studies testified the practicality of NSA for achieving carbon neutrality target. However, the lack of data consistency and the significance given to the contextual features hindered the replication of the previous experiences and nudged the development of custom-fitted NSA tools. A more flexible framework adaptable to different contextual priorities and integrative of neighborhood projects worldwide is recommended. [Display omitted] • Realized districts analyzed by five candidate NSA tools are examined. • Case studies are selected from academic papers and official website of NSA tools. • Certification levels, characteristics, and key performance indicators are discussed. • The drivers behind the shortages of NSA tools applications are assessed. • Outcomes recommend more integrative and flexible district-scale frameworks. [ABSTRACT FROM AUTHOR]

Rapid urbanization trends claim long-term urban planning and management strategies towards a more sustainable urban growth. In this context, neighborhoods show as fundamental units in large-scale sustainable approaches of socio-economic indicators to be replicated in urban development models. However, the number of evaluated districts is still too low compared to the number of buildings evaluated so far. To lay the potential weaknesses and strengths behind the use of sustainable certification tools at district level, the present study aims to examine all realized neighborhoods aligned with sustainability goals. To this end, a systematic review (SR) on neighborhood case studies that directly or indirectly employed neighborhood sustainable assessment (NSA) tools – in particular, amongst LEED-ND, BREEAM-C, CASBEE-UD, and Green Star- Community, DGNB-NSQ, – or that denied the applicability of NSA tools to develop tailored ones is provided. Case studies found in academic papers and NSA-tool official websites are examined through five research questions (RQs): i) number and level of certifications; ii) geographical and temporal distribution; iii) availability of data related to physical characteristics (i.e., size, density, number of dwellings, etcetera); iv) variety of key performance indicators (KPIs) addressed; v) authors outcomes. Evaluation of these realized case studies testified the practicality of NSA for achieving carbon neutrality target. However, the lack of data consistency and the significance given to the contextual features hindered the replication of the previous experiences and nudged the development of custom-fitted NSA tools. A more flexible framework adaptable to different contextual priorities and integrative of neighborhood projects worldwide is recommended. [Display omitted] • Realized districts analyzed by five candidate NSA tools are examined. • Case studies are selected from academic papers and official website of NSA tools. • Certification levels, characteristics, and key performance indicators are discussed. • The drivers behind the shortages of NSA tools applications are assessed. • Outcomes recommend more integrative and flexible district-scale frameworks. [ABSTRACT FROM AUTHOR]

The building construction has a significant impact on sustainability worldwide. However, industrialised building systems (IBS) might reduce these impacts compared to traditional building systems (TBS). Previous literature reviews have analysed IBS's sustainability, based primarily on environmental aspects and through qualitative indicators, disregarding a detailed quantitative comparison between both technologies and nor considering economic and social sustainability indicators. To fill this gap, this paper aims to evaluate vis-à-vis IBS's sustainability in relation to TBS, based on the quantitative and qualitative indicators studied in the literature. Thus, an exhaustive bibliographic review of IBS and TBS case studies was conducted. In total, 67 scientific papers were selected (papers, book chapters and reports), containing 86 case studies. Major findings indicated that IBS are more sustainable in almost all studied values – except construction costs. Nevertheless, this advantage depends on material design, prefabrication levels, transportation, work management and each author's methodological approaches. These factors are discussed to explain the reasons for IBS′ sustainability. Furthermore, main conclusions indicate that sustainability assessments have been unbalanced in literature, with few analyses of economic and social performance, and some indicators have been poorly studied (e.g., water and acidification potential), so their results are not yet representative. Similarly, reusability, prefabrication levels and the social indicators of IBS were insufficiently analysed in the reviewed case studies. Finally, the current review highlights IBS sustainability indicators that have been less studied in order to motivate new investigations in the broader field, exposing the IBS sustainability outlook and other research gaps. • Comparison of IBS and SCT sustainability based on 86 case studies worldwide. • IBS prove to be more sustainable than SCT based on sustainability indicators. • The energy consumption and GHG emissions of IBS are widely studied, lacking other relevant indicators. • Less-studied IBS sustainability indicators are revealed to motivate new investigations in the broader field. • Reusability, as well as timber and steel construction materials, are less studied. [ABSTRACT FROM AUTHOR]

Abstract: Mini-Hydro power generation could be planned on small-scale on existing small rivers, canals etc. as it could be beneficial in utilization of all existing water reservoirs and streams so as to generate hydro power which is renewable in nature. By this, they do not encounter the problems of rehabilitation of people and environmental problems associated with the large hydro power plants. This paper presents the case study of two potential sites namely Shahnoor and Purna in Vidarbha region of Maharashtra State in India. Here, the hydrological data of a potential site for nearly sixty years is obtained and is thoroughly studied for possible development of mini hydro power plant. The basic parameters those are to be included in feasibility report which is to be prepared for every proposed hydroelectric project are also mentioned. This paper could be well utilized for planning and irrigating land in and around rural areas. [Copyright &y& Elsevier]

Abstract: The impacts of recurrent droughts have increased vulnerability and reduced the adaptive capacity of the people living in arid and semi-arid lands (ASALS) of Kenya. Current interventions are short-term and curative in nature, hence unsustainable. Some of the most arid and semi-arid lands are located within the Kenyan Rift system, which has an estimated geothermal potential of about 7000 to 10,000MWe, out of which only 200MWe has been developed, and about 5000MWe planned by 2030. Recent power sector reforms have built institutional structures that will accelerate development of geothermal energy. The paper analyses the potential use of geothermal energy resources in eastern Baringo lowlands between Lake Bogoria and Silali prospects, which has an estimated potential of >2700MWe, in creating the necessary adjustments needed to adapt to the impacts of recurrent droughts by locals. Opportunities for direct and indirect uses of geothermal energy exist in climate vulnerable sectors, such as, agriculture, fisheries, water, livestock production as well as alternative income generating activities such as, tourism, micro enterprises, aloe, honey and beeswax production, fabric dyeing and others using resources sourced from within a 50km radius. The possibility of accelerated geothermal development and proposed utilisation schemes in causing maladaptation if unsustainably implemented is also discussed. The paper draws a Lindal diagram adapted to the study area showing potential utilisation in the above sectors, and new flow diagram showing potential for cascaded use of geothermal hot water through the different processes. An estimated capacity of 100MWt and 100MWe can be used in the potential utilisation schemes discussed in this article to meet local adaptation and lighting needs and much less in a cascaded process. Potential barriers and possible solutions are also discussed. The study concludes that geothermal energy is a vital option for adaptation in the study area if sustainably used. [Copyright &y& Elsevier]

Abstract: Construction and operation of plants that produce energy from renewable energy sources is the subject for discussion in all the countries that have accepted the sustainable development concept and Kyoto protocol as their own development direction. Enlargement of the renewable energy production is clearly an imperative, but only economically viable construction and operation can result in long-term sustainability, which is initially the goal when deciding upon such investments. In line with this goal, this paper presents the estimation of the economic viability of constructing and operating biogas electricity plant on the farm Vizelj in Serbia. The timeframe for this estimation is from 2011 until 2020. This paper also presents all parameters which are necessary for performing this estimation, respectively, analysis of revenues and expenditures, projection of economic and financial flow, ratio analysis, dynamic and static analysis, and analysis of sensitivity of the project, i.e. impact of the changes in prices and raw material on the overall performance of the project. The observed investment is predicted to be financed from the EBRD''s credit line for renewable energy in Western Balkans, while the total investment is estimated at Euro 958,000.00. After the performed economic assessment, the conclusion is that the observed investment in biogas electricity plant is very acceptable and it can serve as a role model for similar investments in the region. [Copyright &y& Elsevier]

The present study provides firstly a comprehensive review of studies on measuring the impacts of different biodiesel blends on exhaust emissions characteristics of urban busses under real-world operating conditions. Secondly, this paper discusses the errors that can be made in conducting case studies. Thirdly and finally, it shows lessons learned and provides guidelines to setup case studies, conduct the measurements, perform the statistical analysis and report the results to policy makers and the wider audience. To achieve climate change mitigation targets, using alternative fuels, e.g., biodiesel, hydrogen or electricty (EVs) for the urban fleets requires an in-depth analysis of the impacts under real-world operating conditions. Such experiments are generally very complex as numerous factors could directly or indirectly interfere with the results produced and potentially jeopardize the integrity of the research and the conclusions drawn. Results of the present research show that some vital parameters were ignored by many of the studies performed including the statistical uncertainties, driving cycle uncertainties and fuel uncertainties. Lack of appropriate experimental designs or clear assertions about the level of significance for differences in emissions/fuel consumption between alternative fuels (i.e. biodiesel) and the reference fuel used (i.e., diesel) could be regarded as the main weaknesses. Moreover, many other overarching and very influential factors (e.g., covariates/confounders) can interfere with the research outcomes as these were mostly overlooked by the reviewed studies. A careful and complete experimental design for assessments of alternative fueled vehicles (are critical when conducting real-world operating condition tests. The study findings help to formulate the guidelines for assessing real-world operating condition experiments to achieve the most feasibly and meaningful research outcomes that will have significant implication for local and global policy makers. The guidelines are of use for all types of research studies that want to evaluate the effects of alternative fuels for any transportation fleet. Image 1 • Real-world driving tests on urban buses were examined and discussed. • Key issues were uncertainties related to statistical design, driving cycle, and fuel. • Lack of appropriate experimental design was the main weakness in most studies. • Covariate/confounder factors were mostly overlooked. • Guidelines to perform more complete real-world diving test studies were presented. [ABSTRACT FROM AUTHOR]

The paper presents an in-depth analysis of a novel scheme for the sustainable mobility, based on electric vehicles, photovoltaic energy and electric energy storage systems. The work aims to analyse such innovative system, putting in evidence its advantages in comparison to a conventional one, based on the grid-to-vehicle technology. The study also provides interesting guidelines for potential users and system designers. Two case studies are presented: i) the taxi fleet of the city centre of Naples and ii) the cargo vans of the city of Salerno; both towns are in Southern Italy. For each case, the hourly power consumption of the vehicles was evaluated, as a function of the daily trip length. An accurate procedure was implemented to select the sites suitable for the installation of the charging stations, including a photovoltaic field and an electric storage system. A comparison was also performed between two different electric storage technologies: lead-acid and lithium-ion battery. The case studies were analysed by means of a detailed dynamic simulation model, developed in TRNSYS. A sensitivity analysis was also performed, to evaluate how different values of the most important design and operating parameters affect the system overall performance. It was found that the results are mostly affected by solar field area, capacity of the energy storage system and investment cost. The comparison between the two selected storage technologies did not exhibit significant differences. For both the cases investigated, it was found that, during the summer, solar energy covers an important amount of the total energy demand. On the contrary, in winter the amount of energy provided by the public electric grid was high. From an economic point of view, assuming a lithium-ion battery capital cost equal to 90 €/kWh, acceptable pay-back periods (about 6 years) were obtained, for both the applications considered. • Dynamic analysis of electric vehicle solar parking focused on sustainable mobility concept. • Transport/statistical model development for both private/public transport sector. • Environmental, energy and economic comparison between lead-acid and lithium-ion battery. • Interesting pay-back periods in case of lithium-ion battery capital cost expected reduction. [ABSTRACT FROM AUTHOR]

Abstract Global concerns for pressing fossil fuel demand with concurrent emissions deliberated India to direct policies for rapid adoption of clean energy methods as sustainable solutions. Responsiveness for affordable electricity access to its residents induced implementation of off-grid and consumer driven energy models like Community Energy (CE), playing significant role in meeting national energy demand in developed countries. It is evident from energy secured nations that centralized planning and electrification is not alone sufficient for meeting energy security. Renewable CE model is predicted to emerge as an effective system of clean energy access to off-grid communities while reducing emissions vividly. In past few years, cases of renewable CE system have been reported in India as well. Hence, it becomes pertinent to assess the extent of CE projects in Indian context, however a comprehensive landscape of such projects is currently lacking. This paper attempts to profile the status of CE projects with their scope and relevance to ensure national energy security. Six diversified case studies of CE projects are analysed by applying actor network theory. Role of community participation in implementation of these projects and its socio-economic impact on localized growth is represented by reviewing detailed case-studies. Qualitative analysis reveals parameters across diversified CE projects in India leading to an assessment framework for sustainable replication in other regions. Insights provide basis to identify associated challenges and incentives with CE projects, policy implications in interest of developers, end users, beneficiaries, promoters and towards emission reduction. Highlights • ANT critically analyses diversified CE projects and builds grounded concept for actor interactions in different capacity. • Analytical parameters derived define replicability of CE projects in Indian context. • Cross-case comparison highlights socio-techno-economic markers responsible for operational sustainability of CE projects. [ABSTRACT FROM AUTHOR]

Abstract: The paper discusses the need of renewable energy sources. A case study has been carried out to study the technical state of art, reasons for the plant becoming non-operative, revival opportunities with justification and finally comes out with recommendations to revive on the basis of comprehensive survey conducted in the village. The case study is carried out at Nayakana Hulikatti village in Dharwad district that was developed by IEI (International Energy Initiative) in 1995–96 in co-ordination with rotary club and the plant was functional for few years. The paper also highlights the need of educating consumers to involve in power generation using locally available renewable resources for their power requirement. [Copyright &y& Elsevier]

Abstract: The probability density function (PDF) of wind speed is important in numerous wind energy applications. A large number of studies have been published in scientific literature related to renewable energies that propose the use of a variety of PDFs to describe wind speed frequency distributions. In this paper a review of these PDFs is carried out. The flexibility and usefulness of the PDFs in the description of different wind regimes (high frequencies of null winds, unimodal, bimodal, bitangential regimes, etc.) is analysed for a wide collection of models. Likewise, the methods that have been used to estimate the parameters on which these models depend are reviewed and the degree of complexity of the estimation is analysed in function of the model selected: these are the method of moments (MM), the maximum likelihood method (MLM) and the least squares method (LSM). In addition, a review is conducted of the statistical tests employed to see whether a sample of wind data comes from a population with a particular probability distribution. With the purpose of cataloguing the various PDFs, a comparison is made between them and the two parameter Weibull distribution (W.pdf), which has been the most widely used and accepted distribution in the specialised literature on wind energy and other renewable energy sources. This comparison is based on: (a) an analysis of the degree of fit of the continuous cumulative distribution functions (CDFs) for wind speed to the cumulative relative frequency histograms of hourly mean wind speeds recorded at weather stations located in the Canarian Archipelago; (b) an analysis of the degree of fit of the CDFs for wind power density to the cumulative relative frequency histograms of the cube of hourly mean wind speeds recorded at the aforementioned weather stations. The suitability of the distributions is judged from the coefficient of determination R 2. Amongst the various conclusions obtained, it can be stated that the W.pdf presents a series of advantages with respect to the other PDFs analysed. However, the W.pdf cannot represent all the wind regimes encountered in nature such as, for example, those with high percentages of null wind speeds, bimodal distributions, etc. Therefore, its generalised use is not justified and it will be necessary to select the appropriate PDF for each wind regime in order to minimise errors in the estimation of the energy produced by a WECS (wind energy conversion system). In this sense, the extensive collection of PDFs proposed in this paper comprises a valuable catalogue. [Copyright &y& Elsevier]

The development of renewable energy is of paramount importance towards the energy security and environment integrity of Malaysia. The Malaysia government has been implementing various policies that could facilitate the advancement of renewable energy technology and increase its contribution to the national energy mix to reduce the country dependency on fossil fuels. On the other hand, due to rapid urbanization and population growth, there is also increasing concern over the high production rate of organic waste. Among the renewable energy available, biogas is of great interest due to its ability to treat organic waste and generate power addressing both concerns simultaneously. This paper aims to review some of the important policies on renewable energy followed by the emphasis on solid waste management policies towards effective implementation of biogas generation from municipal solid waste. The biogas network is divided into three phases on a life cycle basis, namely MSW as feedstock, biogas production and biogas utilization. Under each phase, several important stages were identified. Analysis was performed to identify the role of currently implemented policies as well as the lacking support and challenges. It was envisioned that with proper SWM policies, in terms of waste collection, waste segregation and allocation of resources, which can be further complemented with more financial initiatives and technical support under the RE policies, the biogas development in Malaysia can progress more efficiently. Several supportive actions needed were derived from the analysis and presented in three figures, representing each of the phase, which could constitute a solid biogas framework. [ABSTRACT FROM AUTHOR]

Abstract: Two diverse energy storage technologies, namely the compressed-air and hydrogen energy storage systems, are examined. In particular, a steady state analysis (IPSEpro simulation software) of four configurations of micro-CAES systems is conducted from the energetic and exergetic point of view. The hydrogen energy storage system is dynamically simulated using the HOMER energy software. Load and wind profiles for the island of Karpathos are used as input data to the program. The two-stage micro-CAES system without air preheating is selected to be investigated dynamically as it is proven to have high efficiency and zero emissions. The last part of the paper compares the two systems in terms of energy storage efficiency, includes an approximation of the costs and highlights the technological advantages and disadvantages of these technologies. [Copyright &y& Elsevier]

This paper provides detailed information on the developed hardware and software for sun tracking mechanism and shows the effectiveness of utilizing time and date-based sun positioning solar collector system in tropical climate. The sun positioning system is based on the calculated azimuth and altitude at location E100°11′, N6°26′ in Northern Peninsular Malaysia where the climate is categorized as tropical climate. The system has two axes tracking with accuracy of 1° controlled by a programmable logic controller (PLC). The field test has been done during a sunny and clear day, cloudy day and, heavy overcast and rainy day in which the results show that the improvement in the generated power of 91.97%, 122.71% and 90.42%, respectively, as compared with the fixed horizontal system. [ABSTRACT FROM AUTHOR]

Abstract: Nowadays, due to incentive policies, the PhotoVoltaic (PV) installations become an economically attractive investment. The different policies aim to reduce the PV installation costs, consequently to the deployment of the market. In recent years, a progressive price decrease of components for PV installations has occurred, according their learning curve: every doubling of the volume implies approximately a cost reduction of −20%. In order to reduce the burden of the incentive rate on the national budget, maintaining the economic margin of the investment attractive for investors, a progressive tariff decline has also taken place. This paper provides a technical-economic analysis of investments in PV systems installed on the rooftop, considering incentive policies, and applies it to some significant case studies in the Countries, in which PV market is the most prosperous (Germany and Italy). The analysis puts into evidence the past and current economic margins of the PV investments since 2006 to 2012. Four case studies from 3kWp to 1MWp are examined in detail. The profitability indexes in terms of net present value and internal rate of return, evaluated throughout incentive duration of 20 years, become very interesting above all in Italy (higher than 100% of the installation cost and higher than 10%, respectively) since 2009, when an abrupt decrement in installation cost occurred. In Italy the best profit margins occur for large-size PV plants and are poorly counterbalanced by the decline of the feed-in tariff up to 2012, when a new framework has given a knock to the investments, whereas in Germany the best margins happen for medium-size PV plants and are well adjusted by the feed-in tariff. However, it is predictable that a cut in German feed-in tariff will take place, because the profit margins have been higher in last year than in the previous years. [Copyright &y& Elsevier]

Abstract: In recent years, the demand for natural gas has shown strong growth in China. However, the relative lack of domestic natural gas resources and dependence on gas imports have resulted in rising natural gas prices. In order to ensure market order, the natural gas pricing mechanism must be closely linked to customer affordability. The objective of this paper is to analyse natural gas prices’ economic and psychological affordability for Beijing's residents by the income-expenditure elasticity model and the equivalent heating value method, and further to evaluate the comprehensive affordability of the natural gas price by the small-taking and interval-number methods. Finally, it provides some suggestions for the formulation of Beijing's residential natural gas prices. [Copyright &y& Elsevier]

Abstract: Hydropower development has significant impacts on the society and community economically, environmentally and socially. These impacts may go beyond the regional level, even across the nation. As one of the largest scale hydropower developments in the world, the Three Gorges Project has attracted attentions right from the conception stage. This paper adopted a case study approach to investigate the sustainable development practice in the Three Gorges Project. The case study shows that under the guidance of the State Council, the China Three Gorges Corporation has devoted to manage environmental, economic and social sustainability issues of the Three Gorges Project across various project stages (e.g. conception, design, construction and operation). The sustainability practice adopted in the Three Gorges Project generally follows the Hydropower Sustainability Assessment Protocol developed by the International Hydropower Association. As a result, the environmental auditing is satisfactory to the national standards and the project has achieved numerous social and economic benefits. However, resettlement, coordinated development and ecological impacts on the local ecosystem present significant challenges to future hydropower developments. This study highlighted a number of factors contributing towards better sustainability performance of hydropower developments in China, e.g. international collaboration, system approach, ongoing monitoring and strategic human resource management. The experiences gained from the Three Gorges Project have been applied into other hydropower developments in China. This study provides a useful reference to the sustainable energy development practice over the world. [Copyright &y& Elsevier]

Abstract: Investment in transmission for renewable power penetration to the remote grid essentially faces a set of inherent, regulatory, economic and technical challenges. This work investigates these challenges to enhance renewable power integration into the remote grid. This study aims to enhance regulatory policies and associated planning frameworks to be more efficient and justifiable for renewable power integration paradigm. First, a set of leading transmission schemes practiced, or investigated, in different countries are evaluated against the challenges which are obvious for long distance renewable power transmission. Second, a net benefit framework is presented to address the challenging issues of location constrained renewable power penetration into the Queensland network of the Australian grid. The proposed framework incorporates the carbon emission price as an environmental benefit which significantly influences the cost–benefit analysis. This paper discusses the ‘hub approach’ of network integration. The transmission investment cost allocation is addressed here as well. The concepts are verified through the implementation of the proposed framework in four prospective projects of the Queensland network in the Australian national electricity market (NEM). [Copyright &y& Elsevier]

Abstract: This paper deals with finding the optimum tilt angle of solar panels for solar energy applications. The optimization of tilt angles was performed using solar radiation data measured for eight big provinces in Turkey. The optimum angle for tilted surfaces varying from 0° to 90° in steps of 1° was calculated by searching for the values of which the daily total solar radiation was at a maximum for a specific period. It was found that the optimum tilt angle changed between 0° and 65° throughout the year in Turkey. It was seen that the optimum tilt angle reached a minimum of 0° in June and July and, the monthly average daily total radiation at this angle was generally at a maximum. In addition, the optimum tilt angle increased during the winter months and reached a maximum in December in all provinces. Likewise, general correlations were developed to estimate the optimum tilt angle of solar collectors used in Turkey and their accuracies were compared on the basis of statistical error tests of Mean Bias Error (MBE), Root Mean Square Error (RMSE), t-statistic (t-stat) and correlation coefficient (r). [Copyright &y& Elsevier]

Abstract: In this paper, relative life cycle economic analysis (LCEA) of stand-alone solar PV modules is performed with respect to portable fossil fuel driven power sources to test their commercial prospects in remote regions of Bangladesh which do not have a direct access to grid supply. Overall life time expenditures related to the power projects are analyzed and compared with the help of net present worth (NPW) theory. The influence of market controlling factors like government subsidies, excess inflation over the general trend, and price hike are established with case study of medium-scale petrol–diesel generators (0.8–10kW) and solar photovoltaic modules (100Wp). It is found that the cost effectiveness of conventional or ‘green’ power driven sources depends on kW rating of generators and daily demand on customer-end in the context of a developing country like Bangladesh. The demand coverage which would determine the commercial viability of renewable and non-renewable sources is calculated considering pragmatic power rating of generators available in the local market. This study is intended to assist planning of financial matters with regard to installing small to medium scale renewable projects in remote localities of Bangladesh. [Copyright &y& Elsevier]

Abstract: The rapid development of technologies, their increasing complexity and variety, long lead times of R&D and market dynamics have made the task of technology selection difficult. Considering high level of competitiveness, organizations need to strategically allocate their limited resources to the best subset of possible projects. Today, the increased consumption of energy in modern industrial societies, in addition to the risk of quick exhaustion of fossil resources, has brought about irreversible and threatening environmental changes faced by the world. Dealing with these challenges, decision makers focus on the development of renewable energy technology viewed both as a process of diversification of energy sources and as a creation of an alternative energy option that will help curb down global climate change. To successfully tackle investment projects in renewable energy, it is essential to use models facilitating decision making process and guarantying the greatest possible value for organizations. Technology portfolio managers have traditionally used consensus-based tools, such as Analytical Hierarchy Process (AHP), Delphi but these tools are limited in their ability to fully quantify the impact of technology portfolio selection on the overall aspects of the system. This paper presents the results of developing a mathematical model for renewable technology portfolio selection at an oil industry R&D center maximizing support of the organization''s strategy and values. The model balances the cost and benefit of the entire portfolio. It is also flexible and changes can be applied very easily. [Copyright &y& Elsevier]

Abstract: The Scottish Executive has set ambitious targets of achieving 100% of electricity from renewable sources by 2020. As Scotland has the best offshore wind resources in Europe, the development of this energy source is crucial for reaching these targets. However, the development of offshore wind raises a number of issues related to economic viability, grid connection and public acceptability. This paper investigates these areas in greater depth, using a case study of the Firth of Forth offshore wind farm, in order to determine if these barriers can be overcome in time to make a valuable contribution to 2020 targets. Through interviews with relevant stakeholders, it emerged that there are various obstacles which are impeding progress in offshore wind development in Scotland. It became evident that stakeholder opposition, an inadequate renewable energy support mechanism, and the insufficient grid infrastructure off the Scottish coast are posing barriers, and hindering development. It became apparent that in order to overcome these barriers, a number of changes need to take place. A more inclusive approach to stakeholder engagement is required, which facilitates the sharing of knowledge. In order to improve the economic viability of offshore wind in Scotland, adopting a new mechanism which reduces risk and provides developers and investors with more certainty, would be more effective in encouraging offshore wind development. Finally, in order to overcome the most significant barrier, the grid, a more integrated and collaborative approach is required, which will share the burden of responsibility between the developer, Ofgem, and the National Grid. [Copyright &y& Elsevier]

Abstract: A review of the wind parks’ environmental and human impacts, based on extended research on the most recent relevant bibliography, is carried out in the present paper. The results of former studies are presented on: [•] the impact on the aesthetic of the landscape [•] the noise emissions [•] the impact on birds and wildlife [•] the shadow flicker from wind turbines [•] the occupation of land [•] the wind turbines electromagnetic interference. In addition, the results of case studies for selected wind parks installed in the Prefecture of Lasithi in Crete, concerning their visual impacts and their noise emissions are presented. A statistical survey implemented in Crete concerning the public opinion on wind parks and wind energy is also presented. The accomplished tasks indicated: [•] There are no serious impacts caused by the installation or operation of wind parks. The wind parks’ impacts may be eliminated with the optimum selection of the installation sites and the appropriate siting of the wind turbines. [•] People in Crete exhibit a strongly positive attitude towards wind energy and wind parks, although they are not willing to pay a higher price for the electricity produced from wind parks. A map with the optimum sites for wind parks installation in the Prefecture of Lasithi was constructed, taking into account all possible restrictions concerning the use of land, the environmental conservation and the impacts on human life. This map can constitute a flexible tool for the optimum site selection for a wind park installation, contributing to the elimination of environmental and human impacts of new wind parks, to the minimization of the required project''s licensing time and to the limitation of possible negative public reactions. [Copyright &y& Elsevier]

Abstract: This paper shows a methodology for the assessment of the photovoltaic potential in urban areas using Google Earth™ tool that provides either satellite images of the roofs of buildings or their number of floors by means of the Street View function. The applicability of the methodology has been tested on a selected urban area of the city of Palermo in the South of Italy. After classifying roofs according to the shape, orientation and pitch of buildings with different morphologies, the share of energy generated by the installable PV systems was evaluated with regard to the number of floors. Moreover the coverage of the electricity demand was investigated on the basis of the consumption of electricity of the households. The results of the energy assessment have been screened considering the economic feasibility of grid-connected photovoltaic systems. The proposed methodology permits to select a threshold number of floors of the buildings in correspondence of which the PV system that may be installed, and the consequent production of electricity, may not recover the costs for installation and maintenance of the system. This aspect has also been analyzed by considering the main factors that influence the computation, such as the mismatch between generated and consumed electricity and the shading effects due to the surrounding obstacles. The methodology could also be used to assess the effectiveness of the national incentives to support the diffusion of the PV systems in the short term. [Copyright &y& Elsevier]

Abstract: The results of a Life Cycle Assessment (LCA) study can be affected by several uncertainty sources, mainly due to the methodological choices, the initial assumptions, i.e. allocation rules, system boundaries and impact assessment methods, and the quality of the available data. Then, the experts should estimate the extent of the above-mentioned sources of uncertainty for improving the reliability and the representativeness of the obtained eco-profiles. To estimate the uncertainty is necessary to obtain reliable, transparent and representative LCA results and to correctly support decision-makers in the selection of different product or process options. The following paper starts from a LCA study of the so-called “Sicilian tiles”, which are typical roof tiles employed in restoring old buildings of the Mediterranean area. The authors identify the most relevant sources of uncertainty in the LCA study. Then a sensitivity analysis is performed to estimate the effects on the tile eco-profile of different secondary input data and of the chosen methods for the environmental impact assessment. The results show that, in some cases, significant differences in the energy and environmental indices can be obtained, pointing out the need of developing sensitivity analysis for strengthening the reliability of the obtained eco-profiles. [Copyright &y& Elsevier]

Abstract: In the scientific literature concerning renewable energies there have been proposals for the use of Artificial Neural Networks (ANNs) as a tool to estimate the mean wind speed at a target station for which only incomplete data series are available. In general terms, the wind speeds recorded at neighbouring reference stations are used as signals of the input layer of multilayer perceptron (MLP) architectures. An analysis is undertaken in this paper of the extent to which estimation of the wind speed, the wind power density and the power output of an installed wind turbine at a target site is affected by the number of reference stations, the degree of correlation between the wind speeds of the reference stations and the target station, the wind direction and the manner in which the direction signal is introduced into the input layer. For the purposes of this study mean hourly wind speeds and directions were used which had been recorded at twenty two weather stations located in the Canary Archipelago (Spain) in 2002 and 2006. The power-wind speed characteristic curves of five wind turbines of different rated power were also used. The MLP architectures were trained using the backpropagation algorithm. Amongst other conclusions reached with the tests performed with the set of data not used in the training nor in the validation of the models is that the estimation errors tend to decrease as the number of reference stations used increases, independently of the existing correlation coefficient values between the reference stations and the candidate station. It was also observed that if input signals of angular wind direction and wind speed are used then the number of reference stations required to achieve a certain decrease in the error is lower than the number required if only wind speed input signals are used. By using multiple reference stations with input signals of angular wind direction and speed, error reductions have been achieved for some stations in the estimation of the wind power density and the power output of wind turbines, with respect to the case of a single reference station and identical input signals, of 75% and 62%, respectively. [Copyright &y& Elsevier]

Abstract: Among the technologies of exploitation of renewable energy sources, solar photovoltaic plants and wind power plants are the ones who had the highest growth rate and in the future may contribute substantially to meeting energy demand and requests for production of carbon-free energy. However, it was also shown that even though there is a considerable support for policies promoting renewable energy at a general level, local communities often perceive the installation of systems powered by renewable sources such as limiting the quality of life, or impacting on the natural and built landscape. Consequently, the studies concerning the procedures for assessing the territorial and landscape impacts of this type of systems have recently seen a remarkable development. If an extensive scientific literature is now available regarding the assessment of visual impact of wind turbines, with applications in several countries, there are few studies, theoretical or applied, dealing with the visual impact of photovoltaic plants, which represent, also for their physical size, an important form of transformation of the agricultural and forestry land. As part of studies conducted by the authors regarding the territorial impacts of photovoltaic plant, in this paper, a procedure to evaluate the visual impact of a PV plant based on a quantitative indicator and that was published in the same journal (vol. 13, no. 5, p. 986–99) is adopted and discussed with reference to the application on some case studies. As a result, some modifications to the procedure are presented and a discussion on how this procedure may be used and integrated into the administrative requirements of large and small scale PV plants developments is carried out. From the results, it can be derived that such a procedure can be effectively used provided that a regulatory framework is set by the local authority that carries out the authorizaion procedures. [Copyright &y& Elsevier]

Abstract: As concerns about global warming grow, societies are increasingly turning to the use of intermittent renewable energy resources, where energy storage becomes more and more important. Pumped-hydro energy storage (PHES) is the most established technology for utility-scale electricity storage. Although PHES has continued to be deployed globally, its development in the United States has largely been dormant since the 1990s. In recent years, however, there has been a revival of commercial interests in developing PHES facilities. In this paper we examine the historical development of PHES facilities in the United States, analyze case studies on the controversies of disputed projects, examine the challenges to and conflicting views of future development in the United States, and discuss new development activities and approaches. The main limiting factors for PHES appear to be environmental concerns and financial uncertainties rather than the availability of technically feasible sites. PHES developers are proposing innovative ways of addressing the environmental impacts, including the potential use of waste water in PHES applications. In some cases, a properly designed PHES system can even be used to improve water quality through aeration and other processes. Such new opportunities and the increasing need for greater energy storage may lead policymakers to reassess the potential of PHES in the United States, particularly for coupling with intermittent renewable energy sources such as wind and solar power. [Copyright &y& Elsevier]

Abstract: As Taiwan has a dense population and only limited natural resources, the government began actively establishing a Taiwan''s sustainable development indicators (TSDI) system in 2003, which was developed with reference to the Pressure–State Response (PSR) framework to evaluate the progress towards sustainability. Energy is a very important factor in leading to sustainable development at the national level. However, there are only two indicators concerning the energy sustainability in the TSDI system. This paper summarizes the current status of energy supply, energy consumption, carbon dioxide (CO2) emissions and renewable energy production since the year 2000. The updated information on the TSDI was also addressed and analyzed to imply the progress towards energy sustainability during 2000–2008. Finally, the weighted-sum method was proposed to make an analysis of energy sustainability from Taiwan''s renewable energy production, showing that this country has experienced a significant progress toward energy sustainability in recent years. [Copyright &y& Elsevier]

Abstract: The world has been relying on fossil fuels as its primary source of energy. This unsustainable energy source is not going to last long and thus, gradual shift towards green renewable energy should be practiced. In Malaysia, even though fossil fuel dominates the energy production, renewable energies such as hydropower and biomass are gaining popularity due to the implementation of energy policies and greater understanding on the importance of green energy. Malaysia has been well endowed with natural resources in areas such as agriculture and forestry. Thus, with the availability of feedstock, biomass energy is practical to be conducted and oil palm topped the ranking as biomass source here because of its high production. However, new sources should be sought after as to avoid the over dependency on a single source. Hence, other agriculture biomass should be considered such as banana plant biomass. This paper will discuss on its potential as a new biomass source in Malaysia. Banana plant is chosen as the subject due to its availability, high growth rates, carbon neutrality and the fact that it bears fruit only once a lifetime. Conversion of the biomass to energy can be done via combustion, supercritical water gasification and digestion to produce thermal energy and biogas. The theoretical potential power generation calculated reached maximum of 950MW meeting more than half of the renewable energy requirement in the Fifth Fuel Policy (Eighth Malaysia Plan 2001–2005). Thus, banana biomass is feasible as a source of renewable energy in Malaysia and also other similar tropical countries in the world. [Copyright &y& Elsevier]

Abstract: This paper presents an integrated method that assesses the socio-economic impact of establishing renewable energy on a regional scale, in particular on the creation of jobs. The method proposed is based on the collection, critical analysis and presentation of the results obtained using primary information sources considering the jobs created as the most direct measure of the socio-economic potential of renewable energy sources. Its design includes contributions extracted from a prior analysis of the existing assessment methods, to lessen the uncertainty of the job ratios often used in these types of analysis. The integrated method implemented has been applied to the autonomous community of Aragon (Spain) as a pilot case, through which the method has been tested and the indicators selected to analyse the socio-economic impact of renewable energy sources on the jobs created, the quality of the jobs and other factors related to the socio-economic development of a territory: technological development, per capita income, territorial development and human capital. [Copyright &y& Elsevier]

Abstract: The aim of this paper was to outline a proposed a new brackish water greenhouse desalination unit powered by geothermal energy for the development of arid and relatively cold regions, using Algeria as a case study. Countries which have abundant sea/brackish water resources and good geothermal conditions are ideal candidates for producing fresh water from sea/brackish water. The establishment of human habitats in these arid areas strongly depends on availability of fresh water. The main advantage of using geothermal energy to power brackish water greenhouse desalination units is that this renewable energy source can provide power 24h a day. This resource is generally invariant with less intermittence problems compared to other renewable resources such as solar or wind energy. Geothermal resources can both be used to heat the greenhouses and to provide fresh water needed for irrigation of the crops cultivated inside the greenhouses. A review of the geothermal potential in the case study country is also outlined. [Copyright &y& Elsevier]

Abstract: One of the main challenges faced by mankind in the 21st century is to meet the increasing demand for energy requirements by means of a more sustainable energy supply. In countries that are net fossil fuel importers, expectation about the benefit of using alternative fuels on reducing oil imports is the primary driving force behind efforts to promote its production and use. Spain is scarce in domestic energy sources and more than 50% of the energy used is fossil fuel based. The promotion of renewable energies use is one of the principal vectors in the Spanish energy policy. Selected herbaceous crops such as Brassica carinata are currently under study as potential energy sources. Its biomass can be considered as potential feedstock to ethanol conversion by an enzymatic process due to the characteristics of its composition, rich in cellulose and hemicellulose. This paper aims to analyse the environmental performance of two ethanol-based fuel applications (E10 and E85) in a passenger car (E10 fuel: a mixture of 10% ethanol and 90% gasoline by volume; E85 fuel: a mixture of 85% ethanol and 15% gasoline by volume) as well as their comparison with conventional gasoline as transport fuel. Two types of functional units are applied in this study: ethanol production oriented and travelling distance oriented functional units in order to reflect the availability or not of ethanol supply. E85 seems to be the best alternative when ethanol production based functional unit is considered in terms of greenhouse gas (GHG) emissions and E10 in terms of non-renewable energy resources use. Nevertheless, E85 offers the best environmental performance when travelling distance oriented functional unit is assumed in both impacts. In both functional unit perspectives, the use of ethanol-based fuels reduces the global warming and fossil fuels consumption. However, the contributions to other impact indicators (e.g. acidification, eutrophication and photochemical oxidants formation) were lower for conventional gasoline. Life Cycle Assessment (LCA) procedure helps to identify the key areas in the B. carinata ethanol production life cycle where the researchers and technicians need to work to improve the environmental performance. Technological development could help in lowering both the environmental impact and the prices of the ethanol fuels. [Copyright &y& Elsevier]

Abstract: This paper assesses the macroeconomic impacts in terms of GDP, trade balance and employment of large-scale bioenergy production on surplus agricultural land. An input–output model is developed with which the direct, indirect and induced macroeconomic impacts of bioenergy production and agricultural intensification, which is needed to make agricultural land become available for bioenergy production, are assessed following a scenario approach. The methodology is applied to a case study of Argentina. The results of this study reveal that large-scale pellet production in 2015 would directly increase GDP by 4%, imports by 10% and employment by 6% over the reference situation in 2001. When accounting for indirect and induced impacts, GDP increases by 18%, imports by 20% and employment by 26% compared to 2001. Agricultural intensification reduces but does not negate these positive impacts of bioenergy production. Accounting for agricultural intensification, the increase in GDP as a result of bioenergy production on surplus agricultural land would amount to 16%, 20% in imports and 16% in employment compared to 2001. [Copyright &y& Elsevier]

Abstract: The overall objective of this paper is to analyze the impact of climate policy and technology learning on future investments in the Swedish power sector. Methodologically we assess the lifetime engineering costs of different power generation technologies in Sweden, and analyze the impact of carbon pricing on the competitive cost position of these technologies under varying rate-of-return requirements. We also argue that technological learning in the Swedish power sector – not the least in the case of wind power – is strongly related to the presence of international learning and R&D spillovers, and for this reason capacity expansions abroad have important influences of the future cost of power generation in Sweden. The results suggest that renewable power will benefit from existing EU climate policy measures, but overall additional policy instruments (e.g., green certificate schemes) are also needed to stimulate the diffusion of renewable power. Moreover, under a recent European Commission scenario and using estimated learning rates for wind power and the combined cycle gas turbine (CCGT), wind power gains considerable competitive ground due to international technology learning impacts. These latter results are, however, very sensitive to the assumed learning-by-doing rates for wind power and CCGT, respectively. [Copyright &y& Elsevier]

Abstract: Bioenergy is the major domestic energy for rural households in developing countries due to its cheap or easy-getting characteristics. Productive use of bioenergy is an important strategy for rural households to improve not only their income, but also their health, living environment and so on. In Tibet of China, which is rich in cattle dung and firewood as the major energy sources for rural households, the efficiency of energy utilization is just about 10%. In order to improve energy utilization efficiency and the living conditions for rural residents, the Tibet Autonomous Region government introduced residential biogas model (RBM) to local households, which was a comprehensive utilization system of energy integrated with residential biogas digester, vegetable greenhouse and livestock shed. This paper aims to show the productive use of the bioenergy by the RBM, which could be depicted as the feasibility and the benefits on economic, eco-environmental and social aspects of biogas utilization, based on household questionnaires in Panam County. In RBM, biogas digester works as the biomass material supplement loop to transform originally biomass flow from single-direction to recycling-direction. The results indicate that the output of unit biogas digester could replace 1.44t of firewood, 1.65t of agricultural residues and 1.75t of cattle dung, respectively. The net incremental benefit of RBM could reach 5550.72 Yuan in 15 years. The reduced amount of CO2 emission when substituted by biogas in other agricultural areas and the areas of semi-agricultural and semi-husbandry in Tibet could be (76.66–79.89)×104 t/year and the capability for nitrogen storage could achieve (0.39–0.99)×104 t/year. The amount of cattle dung replaced by biogas could reach 78.29×104 t/year; this means that the saved cattle dung, 3.51t/hm2, could be reallocated back to cultivated land to improve the soil fertility and to keep the balance of nutrient elements in cultivated land. Biogas utilization reduces the labor opportunity costs of women compared to use of traditional bioenergy sources. It could be concluded that the productive use of bioenergy through RBM in this area has its capability to release the current pressures on biomass sources by adjusting patterns of rural energy consumption, and to improve the conditions of health, environment, economy and energy conservation. [Copyright &y& Elsevier]

Abstract: In this paper, a thorough review of photovoltaic and photovoltaic thermal systems is done on the basis of its performance based on electrical as well as thermal output. Photovoltaic systems are classified according to their use, i.e., electricity production and thermal applications along with the electricity production. The application of various photovoltaic systems is also discussed in detail. The performance analysis including all aspects, e.g., electrical, thermal, energy, and exergy efficiency are also discussed. A case study for PV and PV/T system based on exergetic analysis is presented. [Copyright &y& Elsevier]

Abstract: Energy and electricity in particular, are of unquestionable value for the welfare of all modern societies. The electricity sectors of Eastern European countries have undergone several phases of development between the post-WWII days within the CEMA and USSR frameworks and today''s EU and global energy and environmental regimes. The present paper examines the progress of the Polish electricity sector throughout the last decades, providing useful information regarding not only the technical generation and distribution infrastructure but also the policies that have been and are currently implemented. The results are discussed in the context of indicators such as the electricity intensity and per capita consumption, and show that although the Polish electricity sector has gone a long way, there still are several necessary technology management steps to be taken if Poland is to adequately address the challenges of international competition, electricity supply security and environmental sustainability. [Copyright &y& Elsevier]

Abstract: The implementation of resource management strategies aimed at reducing the impacts of the anthropogenic activities system requires a comprehensive approach to evaluate on the whole the environmental burdens of productive processes and to identify the best recovery strategies from both an environmental and an economic point of view. In this framework, an analytical methodology based on the integration of Life Cycle Assessment (LCA), ExternE and Comprehensive Analysis was developed to perform an in-depth investigation of energy systems. The LCA methodology, largely utilised by the international scientific community for the assessment of the environmental performances of technologies, combined with Comprehensive Analysis allows modelling the overall system of anthropogenic activities, as well as sub-systems, the economic consequences of the whole set of environmental damages. Moreover, internalising external costs into partial equilibrium models, as those utilised by Comprehensive Analysis, can be useful to identify the best paths for implementing technology innovation and strategies aimed to a more sustainable energy supply and use. This paper presents an integrated application of these three methodologies to a local scale case study (the Val D’Agri area in Basilicata, Southern Italy), aimed to better characterise the environmental impacts of the energy system, with particular reference to extraction activities. The innovative methodological approach utilised takes advantage from the strength points of each methodology with an added value coming from their integration as emphasised by the main results obtained by the scenario analysis. [Copyright &y& Elsevier]

The two purposes of this study are to identify factors for the failure of 31% of community anaerobic digesters (CADs) in the United States through a case study of the development, operation, and shutdown of a $4.5 million CAD in Vermont, and to derive policy recommendations for sustainable development of CADs. While many studies have used aggregated data to assess the potentials, obstacles, and policy implications of on-farm biogas production, this paper contributes to the literature with a case study of a large CAD's investment and funding sources, feedstock utilization, energy output, and operating costs and revenues over multiple years. Empirical findings suggest that it is technically feasible to use cow manure and organic wastes from multiple sources to generate electricity, but the economic feasibility and returns depend highly on grants and subsidies for initial investments and on such factors as electricity price, feedstock availability and quality, and market price of renewable energy credits (RECs). Major reasons for the shutdown of this CAD, and likely a large proportion of other CADs in the country, include underestimation of technical problems and operating costs, overestimation of financial returns, and low REC price in the past several years. Future CADs should be invested in and operated by commercial enterprises and government subsidies, and public supports should be based on CADs' outputs such as electricity and utilization of their byproducts like waste heat and recycled nutrients. Also, the educational and research needs of nonprofit organizations could be met via collaboration with privately operated CADs. • Only 29 community digesters have been built in the U.S. and 31% of them have failed. • Factors for the high failure rate are identified via a case study with detailed data. • Limited economic returns are due to low REC price and lack of public support. • Future community digesters should be invested in and operated by private enterprises. • Government support should be linked to energy products and environmental benefits. [ABSTRACT FROM AUTHOR]