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Integrating renewable energies into district heating systems has a large potential to reduce CO 2 -emissions in the heating sector. As district heating systems offer the possibility of incorporating renewable energies into the heat supply, new systems have to be built and the existing networks must be maintained. This study investigates ways to optimize existing district heating systems in order to ensure economic sustainability in the long-term. Previous case studies have elaborated on a variety of optimization measures. However, to date, these measures have neither been collected nor consistently assessed for a wider application range. Therefore, in the study presented here a system for assessing the ecological and economic benefits of optimization measures was developed and applied. The assessment method utilized showed that optimization of district heating consumer substations and adding of a central buffer storage tank has a high optimization potential in comparison to intermittent operation strategy, which has a significantly lower optimization potential. From this information and the transferability data, a district heating operator can determine which optimization measure should be prioritized, which is shown at the end of the paper on an example case. • A method was developed to assess benefits of optimizing district heating systems. • A survey was conducted to assess the ecological and economic value. • Optimization measures for DH systems were compared using the new method. • A guideline is provided to offer operators a suggested approach to take. [ABSTRACT FROM AUTHOR]

Integrating electric vehicles (EVs) into the electric power system poses significant challenges to grid operation and planning due to the potential constraints on the power system. To minimize grid congestion, the best option is to increase the production of photovoltaic (PV) energy for domestic use and EV charging stations. This paper addresses the nexus of technical, financial, and environmental effects of customer involvement in economic development and load management. In this paper, a new model design of solar-powered EV charging stations is proposed and implemented in HOMER Grid, and a case study has explored how economic, technical, and energy management benefits can be achieved through customer energy involvement and the integration of PV-based charging stations. The proposed PV-based charging stations contribute toward the energy management of the region, and the study observes the real-time optimal charging and discharging strategy of PV-based grid-connected charging stations. The case study results show that the investigated area can produce 1,070,804.096 MWh/year of energy through maximum customer involvement, consequently reducing overall energy costs. Moreover, the study demonstrates that the selected region can produce 86,961,688 kWh/year through the PV system, achieving 363,899 charging sessions per year, offering maximum advantages and facilitation for EV charging. The proposed model applicability shows that large-scale customer involvement can bring significant techno-economic benefits and attract regional investments. • This paper proposes a new design of a grid-tied renewable energy system. • It investigates the energy economics and environmental effects for a practical location. • The research examines energy management including PV systems and electric vehicles. • The results of proposed model are compared with other models. [ABSTRACT FROM AUTHOR]

The production of electrical energy is always a substantial contributor to a country's economy; in particular, integrating renewable energy sources into the existing power system has tremendous techno-economic implications. However, the optimal penetration of renewables and dynamic loads management is highly complex while considering the multiple variables, time-varying characteristics, and operational uncertainties. This paper proposes a new model design of a grid-tied renewable system. It investigates energy economics and forecasts for the practical locality of the Muzaffarabad area in Azad Jammu and Kashmir. The proposed research examines the annualized energy estimation concerning varied customer PV system participation. The impact of consumer feedback on energy production is briefly examined. Various aspects, such as energy economics, including annual revenue generation, energy prices, and energy sell-back, are demonstrated in detail. The proposed study also looks at the connection between the rising usage of renewable energy and falling greenhouse gas emissions and energy prices. Moreover, it shows how customer input has altered energy economics via each district taking part in energy sharing. Also, it illustrates the relationship between energy bought and sold and how the grid and PV's share of energy interact. Based on the research study findings, PV systems can provide 61% of the total region's energy needs with maximum consumer involvement. The study found that when PV is integrated at a maximum level, grid energy purchases fall to 52%. Polluting gas emissions were reduced by 64% courtesy of the recommended approach, and energy cost was cut from $0.20 per kWh to $0.09 per kWh. The recommended system produces 81,635,608 dollars in revenue yearly and achieves a renewable part of 46.17% with the highest level of customer interaction. [Display omitted] • This paper proposes a new model design of a grid-tied renewable system. • It investigates the energy economics and forecasts for a practical location. • The research examines annualized energy estimation concerning PV systems. • The results of proposed model are compared with other models. [ABSTRACT FROM AUTHOR]

Rational planning for remote integrated energy systems is of great importance for demand guarantee and sustainable development of remote areas. A critical challenge is that comprehensive factors, e.g., technical, economic, environmental, and social, which are inherently intertwined, should be properly evaluated and balanced in terms of social benefits. In addition, the feasibility of each planning scheme can only be verified based on their local electrical conditions by employing multi-energy flow calculations. Thus, this paper develops a comprehensive methodology for the optimal planning of remote integrated energy systems taking into account the uncertainty of renewable energy, where a multi-criteria decision-making procedure is designed, including the candidate set construction, remote integrated energy systems modeling, multi-energy flow calculation of the candidates, index definition and selection, and the optimal scheme determination. The methodology is applied to a case study in Lankao County, China. The optimal scheme, selected by the proposed multi-criteria decision-making procedure from 432 candidates, shows the best comprehensive performance, which is verified by different ranking methods. The optimal scheme can rank in the top 13% of each aspect on average, with economic and environmental aspects ranking in the top 2%. The methodology can help decision-makers find reasonable solutions for energy system planning in remote areas. • A comprehensive methodology for planning remote integrated energy systems is proposed. • Refined multi-energy flow calculation fitting with remote area characteristics is presented. • Multi-criteria decision-making procedure realizes high social benefits. • A real case in Lankao is performed to verify the rationality of the proposed method. [ABSTRACT FROM AUTHOR]

Solar-generated energy supply has been applied as a solution to address the increasing global population, global warming challenges, and the search for alternative sources of renewable and clean energy supply. Regions such as Latin America and the Caribbean have a significant rural population that lacks access to electricity, impeding their development, and increasing unemployment rates. This paper presents a system dynamics model (SD) for assessing the implementation of a solar energy supply chain (SESC), combining the analysis with the national industry's development for the manufacture of solar modules used in the implementation of solar farms and individual solution projects, especially in the non-interconnected zones of Colombia. This case study examines three scenarios in Colombia: national government-implemented solar farm projects; development of national supply chain implementation; and development of the solar energy market. These scenarios are evaluated using performance indicators for supply chain variables, including coverage, diversification, emissions, and job creation. The results indicate that implementing a supply chain and developing solar module production in Colombia can positively impact the proposed indicators, resulting in improvements of 5.9% in coverage, 6.3% in diversification, 6.7% in emission reductions, and 13% in job creation. • A novel model is developed for the solar energy supply chain. • The solar energy supply chain modeled prospectively and sustainably. • Analysis of energy, economic, environmental and social sustainability performance indicators. [ABSTRACT FROM AUTHOR]

Climate change and fossil fuel reserve depletion both pose challenges for energy security and for wellbeing in general. The top ten among them include: Decarbonising the world economy; Enhancing the energy efficiency and energy savings in buildings; Advancing the energy technologies; Moving towards energy systems based on variable renewables; Electrifying the transport and some industrial processes; Liberalizing and extending the energy markets; Integrating energy sectors to Smart Energy Systems; Making the cities and communities smart; Diversifying the energy sources; and Building more biorefineries. Presenting the contributions of selected conference papers published in the special issues of leading scientific journals (including all the papers from the current Energy special issue), this review demonstrates the capacity of the Conferences on Sustainable Development of Energy, Water and Environment Systems for generation of knowledge which could serve as the centrepiece of a pertinent response to those challenges. [ABSTRACT FROM AUTHOR]

Abstract Recent electricity management systems such as Smart Grids and Virtual Power Plants help to better integrate distributed generation renewable resources (RDG), such as photovoltaic, small hydro or micro wind in electricity markets. In this context, an important increase of small-scale power generation technologies is expected in Spain by 2020, according to the Spanish Action Plan for Renewable Energy. This paper analyses the environmental and economic impacts of the massive integration of RDG in Spain for 2020 by using an Input-Output approach. The induced production and employment effects in every sector due to new RDG project investments as well as the CO 2 reductions attributed to a decline in conventional electricity consumption are estimated. The results indicate that investments in RDG based on photovoltaic and small-hydro have the greatest impact on employment generation. The RDG investments will lead to a decrease in emissions of 21.67% in 2020 compared with 2013. The RDG technologies become an alternative to reach a sustainable economic growth in Spain. In future research, a multi-regional input-output model and the study of the links between energy consumption, standard of living and consumption patterns will aid to delve deeper into the relationship between economic growth and the environmental impacts of small-scale renewable technologies. Highlights • RDG will be over half of total installed electricity generation capacity in 2020. • The impact of RDG deployment is quantified on Spanish economy in 2020. • The IO methodology is used to study the environmental and economic impacts. • Photovoltaic and small-hydro have the highest impact on employment generation. • RDG becomes an alternative to reach a sustainable economic growth in Spain. [ABSTRACT FROM AUTHOR]

Abstract This paper aims to analyze Iran's long-term power sector development from economic, environmental, social, and sustainable perspectives. For this purpose, a linear programming model is developed, which includes three objective functions: minimization of costs, minimization of CO 2 emissions, and maximization of created jobs. To provide a sustainable plan, analytical hierarchy process is employed to allocate expert-based weights to the objective functions. Moreover, to support the decision-makers, Pareto-optimal alternatives are explored by varying the weights of objectives. The multi-objective model is solved by applying a weighted method based on fuzzy membership functions. The results show that a sustainable scenario leads to high technology diversification. Furthermore, the combined cycle would be the dominant option in Iran's long-term generation mix. In addition, power generation from non-hydro renewables, solar PV in particular, should grow faster than the total electricity demand. The findings indicate that the economic scenario fulfills Iran's commitment to 4% reduction of emissions compared to the current trend; however, the sustainable and environmental scenarios would cause achievement of the superior 12% reduction goal. Multi-objective analysis shows that moving away from one's objective optimum value leads to significant improvements in other objective values. Highlights • A multi-objective model is developed to explore the sustainable power plan of Iran. • Optimal power development plans based on economic, environmental, and social objectives are surveyed. • Moving away from one's objective optimum value leads to significant improvements in other objective values. • The international emissions mitigating targets are met by the sustainable plan. • The sustainable plan leads to high diversification in the generation mix. [ABSTRACT FROM AUTHOR]

Geothermal energy is a constant and independent form of renewable energy and plays a key role towards the world's future energy balance. In particular, deep geothermal resources are largely available across continents and can help countries become less dependent on energy imports and build a broader base in their future energy mix. However, despite its significant potential, the total contribution of the geothermal sector to global power generation remains relatively small. The International Energy Agency has recommended devising plans to address technology-specific challenges to achieve faster growth and improving policies tackling pre-development risks for geothermal energy. Reaching considerable depths is a requirement to exploit deep geothermal resources, but experience gained to date from the implementation of complex, engineered deep geothermal projects has unveiled technical and economic challenges, lower-than-expected performance and poor public image. There is therefore an urgent need for alternative, more sustainable well designs. This paper critically assesses conventional and unconventional deep geothermal well concepts, focusing on the basic Borehole Heat Exchanger (BHE) concept. The discussions are supported by numerical simulations of a BHE design that includes heat conductive fillers to enhance the heat exchange with the surrounding formation, while avoiding direct fluid interaction with the latter. [ABSTRACT FROM AUTHOR]

This paper presents a generalized framework to construct composite indicator, which can be used in static and dynamic analysis. By grouping DMUs (decision making units) first, the proposed approach is more flexible to derive weights for entities featuring diverse characteristics. A more neutral set of weights can be obtained through investigating the lower and upper bound of possible weights. Subsequently, we introduce a slack-based composite indicator from the perspective of distance function, which facilitates studying entities' improvement potential in sub-indicators. Furthermore, the slacks-based composite indicator is combined with the Malmquist index to conduct dynamic assessment, aiming to quantify the evolvement of composite indicator over time and the underlying driving forces. To illustrate the usefulness of the proposed approach, it is applied to construct the Sustainable Energy Index for 109 countries worldwide in 2005–2010. Our results show that the high-income country group has the best sustainable energy performance among all the three country groups in 2010. The dynamic assessment indicates the worldwide sustainable energy development level declined during 2005–2010, and the efficiency change was the main negative driving force. More discussions and implications are presented in the paper. [ABSTRACT FROM AUTHOR]

In recent years, the terms “Smart Energy” and “Smart Energy Systems” have been used to express an approach that reaches broader than the term “Smart grid”. Where Smart Grids focus primarily on the electricity sector, Smart Energy Systems take an integrated holistic focus on the inclusion of more sectors (electricity, heating, cooling, industry, buildings and transportation) and allows for the identification of more achievable and affordable solutions to the transformation into future renewable and sustainable energy solutions. This paper first makes a review of the scientific literature within the field. Thereafter it discusses the term Smart Energy Systems with regard to the issues of definition, identification of solutions, modelling, and integration of storage. The conclusion is that the Smart Energy System concept represents a scientific shift in paradigms away from single-sector thinking to a coherent energy systems understanding on how to benefit from the integration of all sectors and infrastructures. [ABSTRACT FROM AUTHOR]

Following the 2015 Paris Agreement and other agreements which have been signed after, sustainable energy development is becoming the major goal in many countries. EU have set the targets to reduce the annual greenhouse gas emission by 40% in 2030 and 80% for 2050 compared with 1990 levels. For achieving this ambitious energy policy, three major technological changes are available: energy savings on the demand side, efficiency improvements in the energy production, and replacement of fossil fuels by various sources of renewable energy. Also, for realization cited three major technological changes the support of the multi-disciplinary scientific knowledge is needed. Therefore, from the beginning of the 21st century, since 2002, a series of Sustainable Development of Energy, Water and Environment Systems (SDEWES) Conferences were founded. This paper presents an overview of published researches in special issues of leading journals dedicated to the series SDEWES Conferences, including also the papers in current special issue. The focus is on five main fields: (1) energy policy and analysis of smart energy systems; (2) energy savings in the building sector; (3) co/polygeneration - integrated heating, cooling and electricity systems and district heating; (4) biomass for energy; and (5) measurement of energo-environmental sustainability of processes and systems. Researchers are focused on the development of methods, policies and technologies for both efficient production of energy, mainly from renewable sources, and consumption in industry, buildings and transport. Undoubtedly, the researches presented in the papers in this special issue as well as in previous ones, dedicated to SDEWES conferences, will contribute to the promotion of sustainable development and thus to the achievement of the goals of the Paris Agreement. [ABSTRACT FROM AUTHOR]

Sustainable development and environmental protection are key concepts in the European energy policy. The Europe 2020 Strategy establishes the necessity of reducing environmental pressure and resource consumption to increase sustainable development in the EU. In this context, the aim of this paper is to develop an Environmental and Resource Pressure Aggregated Index that considers these two dimensions. This index provides information about the achievement of the targets in the member states as well as the achieved effects of the environmental policies on energy policy and sustainable development. Therefore, it would help policy-makers to plan future policy actions. The results show that, among EU countries, Portugal, Latvia, Italy, Austria and France have low environmental and resource pressure. Recommendations are made for member states with the worst results (Estonia, Poland, Cyprus, Czech Republic and Luxembourg) in order to improve their actions in climate change and energy policy. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to assess the status and progress of rural household energy sustainable development in China. A new composite indicator, rural energy sustainable development index (RESDI), is developed based on the improved grouped principal component analysis method (GPCA) which is the combination utilization of principal component analysis (PCA), factor analysis (FA), and entropy weight method. The improved grouped principal component analysis method keeps the advantages of principal component analysis and factor analysis. To capture the characters of rural energy sustainable development, ten indicators selected based on the criteria presented by OECD are designed to construct the RESDI. The main results are as follows. The RESDI increased from 0.185 in 1991 to 3.189 in 2012. However, the curve of RESDI can be divided into three phases: a slow increase stage between 1991 and 1996, a rapid decrease stage from 1997 to 1998, and a rapid increase stage between 1999 and 2012. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents Concrete Institutional Economics as an economic paradigm to understand how the wish for sustainable energy in times of economic crisis can be used to generate jobs as well as economic growth. In most countries, including European countries, the USA and China, the implementation of sustainable energy solutions involves the replacement of imported fossil fuels by substantial investments in energy conservation and renewable energy (RE). In such situation, it becomes increasingly essential to develop economic thinking and economic models that can analyse the concrete institutions in which the market is embedded. This paper presents such tools and methodologies and applies them to the case of the Danish heating sector. The case shows how investments in decreasing fossil fuels and CO2 emissions can be made in a way in which they have a positive influence on job creation and economic development as well as public expenditures. [Copyright &y& Elsevier]

Abstract: Energy procurement is a necessity which needs a deep study of both the demand and the generation sources, referred to consumers territorial localization. The study presented in this paper extends and consolidate the Shimon Awerbuch’s study on portfolio theory applied to the energy planning, in order to define a broad generating mix which optimizes one or more objective functions defined for a determined contest. For this purpose the computation model was specialized in energy generation problem and extended with the addition of new cost-risk settings, like renewable energy availability, and Black–Litterman model, which extends Markowitz theory. Energy planning was then contextualized to the territory: the introduction of geographic and climatic features allows to plan energy infrastructures on both global and local (regional, provincial, municipal) scale. The result is an efficient decision making tool to drive the investment on typical energy policy assets. In general the tool allows to analyze several scenarios in support of renewable energy sources, environmental sustainability, costs and risks reduction. In this paper the model was applied to the energy generation in Italy, and the analysis was done: on the actual energy mix; assuming the use of nuclear technology; assuming the verisimilar improvement of several technologies in the future. [Copyright &y& Elsevier]

Abstract: It has been widely accepted worldwide that global warming is by far the greatest threat and challenge in the new millennium. In order to stop global warming and to promote sustainable development, renewable energy is a perfect solution to achieve both targets. Presently million hectares of land in Malaysia is occupied with oil palm plantation generating huge quantities of biomass. In this context, biomass from oil palm industries appears to be a very promising alternative as a source of raw materials including renewable energy in Malaysia. Thus, this paper aims to present current scenario of biomass in Malaysia covering issues on availability and sustainability of feedstock as well as current and possible utilization of oil palm biomass. This paper will also discuss feasibility of some biomass conversion technologies and some ongoing projects in Malaysia related to utilization of oil palm biomass as a source of renewable energy. Based on the findings presented, it is definitely clear that Malaysia has position herself in the right path to utilize biomass as a source of renewable energy and this can act as an example to other countries in the world that has huge biomass feedstock. [Copyright &y& Elsevier]

Abstract: India''s energy challenges are multi-pronged. They are manifested through growing demand for modern energy carriers, a fossil fuel dominated energy system facing a severe resource crunch, the need for creating access to quality energy for the large section of deprived population, vulnerable energy security, local and global pollution regimes and the need for sustaining economic development. Renewable energy is considered as one of the most promising alternatives. Recognizing this potential, India has been implementing one of the largest renewable energy programmes in the world. Among the renewable energy technologies, bioenergy has a large diverse portfolio including efficient biomass stoves, biogas, biomass combustion and gasification and process heat and liquid fuels. India has also formulated and implemented a number of innovative policies and programmes to promote bioenergy technologies. However, according to some preliminary studies, the success rate is marginal compared to the potential available. This limited success is a clear indicator of the need for a serious reassessment of the bioenergy programme. Further, a realization of the need for adopting a sustainable energy path to address the above challenges will be the guiding force in this reassessment. In this paper an attempt is made to consider the potential of bioenergy to meet the rural energy needs: (1) biomass combustion and gasification for electricity; (2) biomethanation for cooking energy (gas) and electricity; and (3) efficient wood-burning devices for cooking. The paper focuses on analysing the effectiveness of bioenergy in creating this rural energy access and its sustainability in the long run through assessing: the demand for bioenergy and potential that could be created; technologies, status of commercialization and technology transfer and dissemination in India; economic and environmental performance and impacts; bioenergy policies, regulatory measures and barrier analysis. The whole assessment aims at presenting bioenergy as an integral part of a sustainable energy strategy for India. The results show that bioenergy technology (BET) alternatives compare favourably with the conventional ones. The cost comparisons show that the unit costs of BET alternatives are in the range of 15–187% of the conventional alternatives. The climate change benefits in terms of carbon emission reductions are to the tune of 110T C per year provided the available potential of BETs are utilized. [Copyright &y& Elsevier]

Abstract: This paper discusses the perspective of renewable energy (wind, solar, wave and biomass) in the making of strategies for a sustainable development. Such strategies typically involve three major technological changes: energy savings on the demand side, efficiency improvements in the energy production, and replacement of fossil fuels by various sources of renewable energy. Consequently, large-scale renewable energy implementation plans must include strategies for integrating renewable sources in coherent energy systems influenced by energy savings and efficiency measures. Based on the case of Denmark, this paper discusses the problems and perspectives of converting present energy systems into a 100% renewable energy system. The conclusion is that such development is possible. The necessary renewable energy sources are present, and if further technological improvements of the energy system are achieved the renewable energy system can be created. Especially technologies of converting the transportation sector and the introduction of flexible energy system technologies are crucial. [Copyright &y& Elsevier]

The viability of energy storage systems is evaluated from technical, cost and emission reduction perspective in this paper. With the rising penetration rate of renewable energy sources, ESS (energy storage systems) are widely researched on the ability to overcome the mismatch of generation and load profiles. This research develops a methodology to assess the financial benefits of ESS connected to conventional power systems in reducing the load variability. These include reduced network losses, increased plant factor, reduced system costs, deferment of network upgrade, improved power system stability and improved power quality. These factors are weighted against the additional cost of ESS. The methodology is applied in a case study based on the electrical load collected from a building, with a peak load of 736 kW and load factor of 0.371. From the results, ESS is found to be effective to reduce the overall cost of the system. A large portion of the saving is obtained by the power operator when ESS is installed by the customer. In order to incentivize the building owner to install ESS, these savings need to be shared with the building owner. [ABSTRACT FROM AUTHOR]

One of the key issues in adopting a sustainable and renewable energy system is gaining social acceptance for technological change. Many technological changes can adversely affect residents and lead to opposition. Extensive development of electricity infrastructure has been met with especially strong resistance from local stakeholders. An abundance of research has been conducted to study the process and driving factors of social acceptance in the context of these infrastructural developments. This paper develops a conceptual definition of social acceptance that is both explicit and allows for quantitative assessment. This definition will aid future literature by clearly defining the goal of social acceptance research from the outset. As examples of the problems faced in electricity system change, factors of discontent surrounding the social acceptance of wind farms, transmission lines, and pump hydro-storage facilities are identified and synthesized. Policy relevant conclusions from previous research are summarized for these three infrastructure types. It is concluded that while research has done well in understanding the causes of opposition, more work is needed to grasp the efficacy and implementation of acceptance improving strategies. Future research should be focused on devising procedures to facilitate quick and efficient negotiations between infrastructure developers and local groups. [ABSTRACT FROM AUTHOR]

Abstract: Many islands face problems in regard to sustainable development, both environmentally and economically. Due to geographical isolation energy is often imported from the mainland. Focusing on local energy use may help islands to identify sustainable strategies and solutions. Islands in transition towards using more renewable energy sources are part of the project “Cradle to Cradle Islands”, funded by the EU Interreg IVb North Sea Region Programme. Energy systems on islands are diverse and linked to each specific location. Opportunities for the development of sustainable energy solutions are often inhibited by institutional, organisational or habitual problems. It is therefore essential to examine islands individually in their context; both in regard to energy use and available resources. This can be used to assess possible energy savings and unused renewable energy sources, and visualise their interaction, the consequences for the environment, as well as the effect on insular economy. Even though islands face different problems, they may inspire each other. In this paper a straightforward tool for examining insular energy systems is presented. The tool has been applied to five different islands in the North Sea Region. The application of the model has facilitated the identification of possibilities for each island to improve the regional development in these areas. Furthermore, a learning process can be identified, which helps to develop renewable energy systems on these islands, while addressing insular development. [Copyright &y& Elsevier]

Abstract: We propose in this paper an integrated energy strategy based on a systems approach to address the energy challenges and energy dilemma in China. First, we give a review of existing approaches to energy planning and strategic management, followed by a discussion on the major relationships among energy, economical, environmental and societal systems. Next, we present a conceptual system model with alternative solutions and clarify corresponding concepts. Based on the results, we propose, summarize, and present strategic ideas as policy implications for China’s decision makers. In conclusion, we determine that China should enhance strategic planning and regulation from a life cycle viewpoint of the whole society, prioritize energy saving, continuously improve incumbent energy, and rationally develop alternative energy. [Copyright &y& Elsevier]

Abstract: Ireland with its resource of wind has the potential to use this natural resource and sustain the country’s power needs for the future. However, one of the biggest drawbacks to renewable energy generation, particularly wind-generated electricity is that it is an intermittent and a variable source of power. Even at the “best” sites wind varies dramatically from hour to hour and minute to minute. This leads to two main problems: 1) When the wind drops below a lower limit or goes above a higher limit the turbine can shut down and electricity is not produced. 2) Energy is not stored when there is an excess of electricity generated on site. Because of these problems wind power has a very low capacity credit and backup power is needed to handle the large fluctuation of production. This paper introduces the current energy system in Ireland and the targets that Irish operators are to achieve in the next decade. A review of energy storage options for Ireland is outlined including the use of hydrogen and fuel cell technology. It is concluded that a project similar to the Norwegian Utsira wind/hydrogen project could be piloted in Ireland and a site similar to Dundalk Institute of Technology could be used to demonstrate and test the system. Going forward to achieve high levels of renewable energy generation, similar distributed wind/hydrogen hybrid systems could reduce the need for curtailment of wind farms, save wasted energy, reduce backup power, reduce transmission losses, generate large revenue by selling power at peak times, ensure security of supply and reduce the need for costly interconnects to Europe. [ABSTRACT FROM AUTHOR]

Abstract: This paper identifies the main features of CO2 emission from fossil energy combustion in China. Then it estimates China''s future energy requirements and projects its CO2 emission from 2010 to 2020 based on the scenario analysis approach. China''s rate of carbon productivity growth is estimated to be 5.4% in the period 2005–2020, while the CO2 intensity of GDP will reduce by about 50% but CO2 emission in 2020 will still be about 40% higher than prevailing in 2005 because of rapid growth of GDP. This estimation is based on the assumption that China will implement a sustainable development strategy in consideration of climate change issues. The main objectives of the strategy are to implement an “energy conservation first” strategy, to develop renewable energy and advanced nuclear technology actively, to readjust the country''s economic structure, and to formulate and legislate laws and regulations, and to build institutions for energy conservation and development of renewable energy. It concludes that international measures to mitigate CO2 emission will limit world fossil fuel consumption. China is not placed to replicate the modernization model adopted by developed countries and has to coordinate economic development and carbon dioxide emission control while still in the process of industrialization and modernization. China has to evolve a low carbon industrialization model. This is the key to the success of sustainable development initiatives in China. [Copyright &y& Elsevier]

Abstract: Because of the needs of sustainable development of the mankind society and natural environment building a renewable energy system is one of the most critical issues that today''s society must address. In the new energy system there is a requirement for a renewable fuel to replace current energy carrier. Hydrogen is an ideal secondary energy. Using solar energy to produce hydrogen in large scale can solve the problems of sustainability, environmental emissions, and energy security and become the focus of the international society in the area of energy science and technology. It has also been set as an important research direction by many international hydrogen programs. The Ministry of Science and Technology of China supported and launched a project of National Basic Research Program of China (973 Program) – the Basic Research of Mass Hydrogen Production using Solar Energy in 2003 for R&D in the areas of solar hydrogen production. The current status of solar hydrogen production research is reviewed and some significant results achieved in the project are reported in this paper. The trends of development and the future research directions in the field of solar hydrogen production in China are also briefly discussed. [Copyright &y& Elsevier]

Abstract: This paper first provides an overview of the context of renewable energy development in China, including the country''s recent renewable energy legislation. Further, it summarizes the current status of renewable energy development and the role it plays in the national energy supply. Next it introduces the national indicative targets for renewable energies in 2010 and 2020, and conducts a long term scenario of the role of renewable energies in China''s energy system transition till 2050. It discusses the main risks involved in China''s renewable energy development, and proposes some policy measures for risk management. [Copyright &y& Elsevier]

Abstract: The development of a combined cooling, heating, and power (CCHP) system in China is presented in this paper. The key scientific problems of a distributed energy system and the integration principles of a CCHP system are also pointed out. Moreover, two corresponding CCHP systems: one with the complementarities of fossil fuels energy and renewable energy, and the other integrated with desalination technology, are investigated. With special attention to thermal energy utilization, the integrating characteristics of these systems are likewise revealed, and the important role that the principle of cascade utilization of physical energy plays in system integration is identified. We have found that the energy-saving ratio of the integrated CCHP systems can be as high as 30%, and as such, the innovative CCHP systems suitable for China''s sustainable development are also recommended. [Copyright &y& Elsevier]

Abstract: Because of the needs of sustainable development of the mankind society and natural environment building a renewable energy system is one of the most critical issues that today''s society must address. In the new energy system there is a requirement for a renewable fuel to replace current energy carrier. Hydrogen is an ideal secondary energy. Using solar energy to produce hydrogen in large scale can solve the problems of sustainability, environmental emissions, and energy security and become the focus of the international society in the area of energy science and technology. It has also been set as an important research direction by many international hydrogen programs. The Ministry of Science and Technology of China supported and launched a project of National Basic Research Program of China (973 Program) – the Basic Research of Mass Hydrogen Production using Solar Energy in 2003 for R&D in the areas of solar hydrogen production. The current status of solar hydrogen production research is reviewed and some significant results achieved in the project are reported in this paper. The trends of development and the future research directions in the field of solar hydrogen production in China are also briefly discussed. [Copyright &y& Elsevier]

Following a strategic orientation towards sustainable development, the Government of the Republic of Croatia has changed its energy legislation and has put forward a framework for the systematic development and increased use of renewable energy sources and cogeneration. This paper focuses on changes in the regulatory context relevant to the cogeneration sector and also analyses the impact of energy market transition on cogeneration viability in municipal district heating, industry, services and the residential sector. Particular attention has been paid to the expected changes of heat, electricity and gas prices. We present a simple model for quantitative prediction of the cogeneration system profitability at different power levels under given national circumstances. Our findings support a need for a strong institutional support for initial penetration of the micro-cogeneration technologies into the Croatian energy system. [Copyright &y& Elsevier]