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Solar heating and cooling systems are a promising technology which may significantly contribute to the reduction of greenhouse gas emissions, the enhancement of energy efficiency, and the increase of renewables share in the building sector. The available literature show a high number of papers aiming at investigating solar heating and cooling systems based on heat driven and solar technologies, configurations, operating strategies, and financing issues. Nevertheless, none of the papers available in literature investigates the possibility to replace conventional solar thermal collectors by flat plat and concentrating photovoltaic/thermal systems, also producing renewable electricity. To cover this lack of knowledge, in this paper a dynamic simulation model of novel solar polygeneration heating and cooling systems is presented. Such dynamic simulation model is developed and implemented in a computer code, written in MatLab, and allows investigating the energy, economic and environmental performance of such novel solar polygeneration systems, based on both adsorption and absorption chiller technologies fed by dish-shaped concentrating and flat photovoltaic/thermal collectors. In order to show the potentiality of the presented tool, a comprehensive parametric case study is carried out to find out the optimal system configurations, as a function of crucial design and operating parameters and of weather conditions. The presented case study analysis refers to a small cluster of four buildings, including office and residential spaces, located in different European weather zones. The modelled solar polygeneration systems simultaneously produce electricity, space heating and cooling, and domestic hot water; electricity is self-consumed or delivered to the electrical grid. For comparative purposes, two different back-up system configurations, based on an electric chiller and a condensing gas-fired heater are also taken into account as conventional reference building-plant systems. By means of this systematic parametric analysis, comprehensive guidelines for system designers, practitioners and/or researchers focused on the development and use of solar heating and cooling systems are provided. [ABSTRACT FROM AUTHOR]

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

Carbon emissions trading (CET) is a market mechanism, aims to promote the control of globe greenhouse-gas emissions. It is an important part of international environmental cooperation and it is also the important application research filed of environmental economics and institutional economics. There is a very obvious phenomenon that the publications about CET increasing year by year. This paper adopts the scientometric analysis method to assess the current state and explore the development trends of carbon emission trading domain based on the literature data retrieved from Web of Science. The research results of this paper could answer the following questions clearly. 1) Which subject category is the most popular in CET research area? Which journal published the most number of articles in this area? Which institution and country is the most productive in CET domain? 2) What are the major research areas and what documents are the most cited? Which journal are the most representative in CET research domain? 3) What are the new emerging trends and development in CET research area? On the whole, the research method in this paper provided a fresh research approach to assess the performance of CET research. The findings may help for the new researchers to pick out the most relevant articles, journals, institutions and seize the research frontier in CET field. [ABSTRACT FROM AUTHOR]

Abstract Increasing flexibility in electricity systems with high-shares of volatile renewable generation is on top of the European policy making agenda. Large-scale pumped hydro storages are appropriate technology candidates to accomplish this. Therefore, they are one of the focus technologies of the European Commission in the Projects of Common Interest discussion. In order to get listed a thorough system benefit analysis has to be conducted. This paper investigates a comprehensive socio-economic benefit analysis of storage technologies according to the indicators expected by the European Commission. The dispatch model EDisOn + Balancing is applied, which includes the functionalities depicting balancing mechanisms. Additionally, the profitability analysis tries to sort out the most convincing business cases where storage technologies contributing to more flexibility in the electricity system can sustain in the long-run. A simulation tool has been developed to model and quantify flexibility options, and to evaluate the profitability from the owner's point-of-view. The results show that in Central Europe with increasing storage capacities the necessity of reserve capacity and investments in peaking units decreases while maintaining a high security of supply level. In addition to electricity generation and balancing cost reductions, shedding of renewables and significant amounts of environmental damage costs of up to 1300 MEuro/a can be avoided. The profitability study shows that a reduction of minimum load or retrofitting hydro reservoir storages with pump mode increase the hours of participation in balancing markets and machine utilisation, e.g. operating hours and frequency of machine starts. With the latter also wear of machines increases. Therefore, it is important to find the optimum in terms of machine starts and market benefits. Several benefits are presented per installed capacity to provide scalability and transferability of outcomes for other applications. Furthermore, the analyses make an important contribution to the European Projects of Common Interest discussion. Highlights • Planned hydro projects in AT till 2030 avoid environmental damage costs of 1300 MEuro/a in CE. • 3.5 GW turbine capacity in addition replaces 1 GW of thermal power capacity. • Reducing minimum load of PHS by 50. [ABSTRACT FROM AUTHOR]

Abstract: Several measures in the environment and energy realms are currently being implemented in the EU and its Member States. Three of these instruments, with an impact on the electricity market, are demand side management activities, promotion of electricity from renewable energy sources and measures aimed at the mitigation of Greenhouse Gas (GHG) emissions. The objective of this paper is to analyse the impact of these energy efficiency and environmental goals and instruments on electricity demand and costs to electricity consumers when electricity markets are either national or international and when those policies are implemented by a national or an international institution. The paper shows that the effectiveness and impact of those measures largely depends on the demand response in the electricity market. An additional conclusion is that, when either the electricity markets or the support policies are national, distortions may occur, i.e. the reductions in electricity demand in one country may be subsidised by consumers or taxpayers in another country. [Copyright &y& Elsevier]

The excessive combustion of fossil fuels for energy provision have altered natural planetary functions, resulting in adverse biophysical and societal implications. Such implications have prompted many governments globally to advocate for the adoption of renewable energy systems in order to reduce GHG emissions. While renewable energy technologies such as solar and biogases have been thoroughly researched and deployed, tidal current turbines (TCTs) that harness kinetic energy from the lateral movement of the tides are a comparatively emerging renewable energy technology, and thus has received relatively less attention with respect to their potential to supplement the renewable energy transition. This paper examines the physics behind tidal movements and cycles, and the technological operation of TCTs. Environmental impacts and economic barriers are analyzed. Best practices of MSP from world leading nations are examined, along with current deploy-andmonitor-consenting regimes of TCT test facilities. An optimal TCT design is suggested based on a synthesis of information from proceeding sections. Finally, an analysis of the implementation of TCTs in Canada, China, and Norway is presented, the results of which demonstrate that harnessing the accessible and sustainably extractable resource of each nation can result in an aggregate installed capacity of 9076 MW through the deployment of 7564 TCTs at a cost of $5,740,964,430, thereby creating 14,467 jobs. This would produce 29,829,711 MW h/yr of electricity sold at approximately 22 cents/kWh, eliminating a total of 14,914,855,258 kg of CO2e, approximately 0.1%. of the projected global electricity demand for 2016. [ABSTRACT FROM AUTHOR]

This paper examines the convergence of per capita carbon dioxide (CO 2 ) emissions for 162 countries across the globe covering all income groups (high-income OECD, high-income non-OECD, middle-income and low-income countries) as categorized by the World Bank. The incidence of stochastic convergence is analysed by making use of recently developed wavelet based unit root tests. The existing studies on this subject make use of conventional unit root tests using time series and/or panel data. A serious drawback of these tests is that they analyse the stochastic behaviour of any series in time domain only whereas the stochastic process may behave differently across different frequencies as well. Thus, wavelet methods are an obvious solution as they consider frequency dimension as well in addition to time dimension when analyzing the stochastic behaviour of any data series and hence these methods encompass the conventional unit root testing methodologies by providing a clear and complete picture of the stochastic process. Our empirical findings, based on latest available time series annual data from 1960 to 2010, lend support in favor of convergence among 38 countries including 18 high income OECD countries, 2 high income non-OECD countries, 13 middle income countries and 5 low income countries while for the rest of 124 countries, the CO 2 emission series is found to be non-stationary suggesting the divergence in these countries. These findings are in contrast with the most of the existing studies, which may be due to the use of wavelet based unit root tests, that are of course better alternatives. Some policy implications evolve from the empirical findings. [ABSTRACT FROM AUTHOR]

Despite the very positive – as measured by market surveys – attitude towards eco-innovations and sustainability in general, the actual market penetration of green products and practices generally falls behind the expectations. In this paper we argue that considering difficulty of engagement , as used in the Campbell Paradigm, is of critical importance when modeling diffusion of eco-innovations. Such a notion of difficulty possesses three desired properties: (i) parsimony – it is represented by a single value, (ii) interpretability – it can be regarded as an estimator of the otherwise complex notion of behavioral cost , and (iii) applicability – it can be easily measured through market surveys. In an extensive simulation and analytical study involving empirically measured difficulty and an agent-based model spanned on different social network structures, we show that innovation adoption may exhibit abrupt changes in market penetration as a result of even small changes in difficulty. The latter may be of particular interest to policy makers who have to make strategic decisions when introducing socially – but not necessarily individually – desired products and practices, like dynamic or green electricity tariffs. [ABSTRACT FROM AUTHOR]

Several environmental rating methodologies are available worldwide to evaluate and compare the environmental performance of vehicles, which can be useful for consumers decisions and for organizations in the promotion of less pollutant technologies and fuels. This paper presents an overview of vehicle environmental rating methodologies available worldwide. Four of them adopt a life-cycle perspective: Green Score (US), Ecoscore (Belgium), Green Car Rating (UK) and EcoTest (Europe), while VCD (Germany), Eco vehicles rating (Mexico) and Green Vehicle (Australia) only consider the fuel in-use stage. Fuel in-use stages methodologies are good indicators of air quality rankings but would rank a fuel cell hydrogen vehicle on top along with the electric vehicles which does not reflect the carbon footprint of the overall fuel pathways and side effect pollutants. Therefore life cycle based methodologies are worth being further explored. Between the more complete life cycle based methodologies, Green Score and Ecoscore differ in terms of the impact categories considered, stages of the life cycle taken into account, weighting system and geographical application, but both use environmental economics and translate the results into a single indicator 0–100 (best). For this relevant variability of aspects they were selected to be applied to a set of seven real vehicles, comprising internal combustions engines and alternative vehicles, including the alternative fuels hydrogen and biodiesel. The application of methodologies shows that the position of the commercial vehicles obtained in the ranking for both methodologies differs. Internal combustion engine (ICE) has the higher impact in the environment and electric vehicle (EV) scores between the best positions; the position of the fuel cell hybrid electric vehicle (FCHEV) and the biodiesel ICE vary significantly. A sensitivity analysis shows that the US rating has high sensitivity to variations, namely in damage costs and fuel pathway. [ABSTRACT FROM AUTHOR]

This paper reviews existing vehicle environmental rating methodologies worldwide and focuses on how these methodologies deal with alternative vehicle technologies (plug-in vehicles, hybrid vehicles, and fuel cell vehicles) and emissions of greenhouse gases (CO2, N2O, and CH4) and pollutants (NOx, VOC, CO, SOx, PM10 and PM2.5) derived from embodied materials life cycle. United States, Mexico, Europe and Australia have public access data and websites with top 10 rankings. The ways the scores are calculated for each vehicle have differences in what regards the considered boundaries for the emissions analysis. In Europe, there is still not a unique rating methodology or ranking system, e.g., Belgium, Germany and United Kingdom have their specific scoring schemes. Multilinear regression models were developed as an attempt to estimate the vehicle embodied emissions as a function of vehicle lifecycle mileage, electricity mix, vehicle mass, battery mass and fuel cell power to cope with different production regions and different alternative vehicle technologies. The regression models were validated against Volkswagen life cycle assessments (LCAs), and compared against American Council for an Energy Efficient Economy (ACEEE) - Green Book linear functions for material assessment and UK 12 material dataset for materials assessment. The developed models proved to be useful in applications related to rating methodologies using life-cycle concepts, with good reliability for comparisons considering the complexity of processes involved in vehicle materials life-cycle assessment. [ABSTRACT FROM AUTHOR]

The uncontrolled discharge of large amounts of food waste (FW) causes severe environmental pollution in many countries. Within different possible treatment routes, anaerobic digestion (AD) of FW into biogas, is a proven and effective solution for FW treatment and valorization. The present paper reviews the characteristics of FW, the principles of AD, the process parameters, and two approaches (pretreatment and co-digestion) for enhancing AD of food waste. Among the successive digestion reactions, hydrolysis is considered to be the rate-limiting step. To enhance the performance of AD, several physical, thermo-chemical, biological or combined pretreatments are reviewed. Moreover, a promising way for improving the performance of AD is the co-digestion of FW with other organic substrates, as confirmed by numerous studies, where a higher buffer capacity and an optimum nutrient balance enhance the biogas/methane yields of the co-digestion system. [ABSTRACT FROM AUTHOR]

The intermittent nature of renewable sources, uncertain demand load, and the location of microgrids cause challenges for the proper energy balance between supply and demand. To overcome the issues caused by such challenges and to be economically efficient while minimizing environmental impacts, microgrid design with renewable energy sources has recently attracted the attention of researchers. However, the sustainable microgrid design involving multiple types of demand areas (residential and industrial areas) and seasonal factors has not been explored by researchers. Therefore, this paper investigates the sustainable microgrid design problem with multiple types of demand areas and peer-to-peer energy trading involving seasonal factors and uncertainties to maximize total profit and to minimize environmental costs while satisfying demand. The problem is to determine optimal decisions on the number, location, and capacity of renewable distributed generation sources, energy flows, and seasonal electricity sales prices for the system that includes peer-to-peer trading. A fuzzy multi-objective programming model is developed to handle the uncertainties of demand load and capacity of renewable distributed generation sources. A genetic algorithm is applied to solve the proposed model. Results of computational experiments to assess its effectiveness and efficiency show that the proposed model increases total profit by over 12% and reduces environmental costs by almost 30% compared to the cases of no peer-to-peer energy trading and seasonal factors. [Display omitted] • Sustainable microgrid design problem with residential and industrial demand areas, peer-to-peer energy trading, and uncertainties is studied. • Seasonal factors and multiple demand areas are considered in the pricing mechanism. • Economic, environmental and social objectives are explicitly considered. • Fuzzy multi-objective programming model is developed to handle the uncertainty and inaccuracy. • Genetic algorithm is used to solve the propose model. [ABSTRACT FROM AUTHOR]

Hybrid polygeneration systems offer a great opportunity to meet growing energy demands with cost efficiency and environmental benefits. The identification of the optimal solution (configuration and operational strategy) is strongly affected by the relationship between the system and its surroundings. Previous studies have analyzed the influence of boundary conditions on the synthesis of polygeneration systems for buildings. However, local regulations are often disregarded or oversimplified in those studies. Therefore, this paper aims to evaluate the influence of legal conditions on the integration of renewable energy technologies in polygeneration systems for buildings. A comprehensive synthesis model is developed, including different types of legal conditions, such as power exchange modalities, subsidies/surcharges on energy prices and investment costs, and total ban on fossil fuels. Then, the model is applied to the case study of a Brazilian hospital. The current Brazilian net metering scheme is implemented. Results show that natural gas cogeneration is an attractive solution to cover the hospital's energy demands with or without the possibility of selling/exporting electricity. Also, the Brazilian net metering scheme, by itself, is not enough to ensure renewable energy deployment. An in-depth discussion about the conditions that would promote renewable energy integration is reported and recommendations are made on how current policies can be improved, including the need to explicitly address renewable technologies, the application of minimum renewable fractions, and the role of renewable heat/cooling. While the case study considers the specific circumstances in Brazil, it provides insights that can be extended to other countries or applications. • Synthesis model of hybrid renewable polygeneration systems for buildings. • Influence of legal constraints on the integration of renewable energy technologies. • Power exchange modalities, subsidies/surcharges, and fossil fuel ban are considered. • Technical, economic, and environmental analysis of a Brazilian hospital case study. • The Brazilian net metering scheme did not promote renewable energy technologies. [ABSTRACT FROM AUTHOR]

The need for the selection of an appropriate insulation is becoming more important as environmental problems continue to grow. This paper investigates insulation performance in terms of heating energy requirement, environmental impact and cost. The thermal performance of insulations (natural, petrochemical, rock/slag based) is modelled, on brick, rammed earth (RE) and cavity walls, in different locations (external, internal and inside the wall), using software. The environmental performance of the insulation is determined using the Life Cycle Assessment-LCA-technique. A new scoring tool is created which allows inputted data, across the three areas of performance (energy, environmental, economic), to be standardized and compared, providing a final score that represents the overall performance. The input data and weightings can be modified easily to investigate new materials and to meet user requirements. Out of all the insulations, cellulose fibre showed the best overall performance. The model results highlight the importance of the hygrothermal properties of the insulation, and their compatibility with the substrate, for best energy performance. The insulated earth buildings require less energy for heating and are responsible for lower carbon emissions than the insulated brick buildings. This is attributed to the lower diffusivity of the earth walls attenuating external temperature fluctuation and economizing energy. The permeable insulations (cork and hemp) tend to perform better with earth than with brick, which is attributed to a more compatible hydric performance. The model results indicate that the best thermal performance is obtained when insulation is placed outside the wall. • A flexible tool that allows to compare the energy performance (modelled with software), environmental impact (assessed with LCA) and economy of an insulation is produced. • The energy performance is based on thermo-hygric properties, heat transfer, room heat gains, air exchanges and weather data, and the insulations are modelled (externally/internally) on brick, cavity and earth walls. • Cellulose fibre was the best performer, and the permeable insulations (cork and hemp) perform better with earth, highlighting the importance of the insulation's hygrothermal properties. • The insulated earth buildings (with lower diffusivity) require less energy for heating and produce lower carbon emissions. • According to the models, thermal performance is best when the insulation is placed outside the wall. [ABSTRACT FROM AUTHOR]