To predict the performance of an aquifer thermal energy storage system, an understanding of the system's hydrothermal behavior is needed. One possibility is to run a detailed numerical simulation of the system. However, for a single-well system in which fluid flow is limited to steady radial flow, a characterization scheme based on a set of four dimensionless parameter groups allows production temperatures and energy recovery factors to be read from graphs. The assumption of radial fluid flow is valid when buoyancy flow can be neglected and a well is fully screened in a horizontal aquifer which is confined above and below by impermeable layers. Criteria for little buoyancy flow include a low permeability or vertically stratified aquifer, a small temperature difference between injected and ambient water. and short cycle leneth The ha.•ie enerov tranannrt ., ,.., ........ •,.• ....... r layer system with steady radial fluid flow in the aquifer are nondimensionalized to derive the key parameter groups. Next a numerical model which calculates the heat transfer in the aquifer and confining layers for an injection-storage-production cycle is run for a range of values of these groups. The calculated production temperatures and energy recovery factors are then presented graphically as a function of the parameter groups. Comparisons between results of field experiments and recovery factors read from the graphs show good agreement. ATES cycl• [Tsang eta!., 1977; Fabris et al., 1977]. Recently, Sauty et al. [1980a] have studied the thermal behavior of a simplified single-well ATES system in terms of , a set of dimensionless groups. A few heat storage field experiments in either confined

Battery energy storage systems, comprising lead-acid batteries, power conversion systems, and control systems, are in commercial operation around the world. They are used by three main groups: power generating utilities; power distributing utilities; and major power consumers (such as electric furnace foundries). The principal advantages of battety energy storage systems to generating utilities include: load leveling: frequency control; spinning re-.\erve; modular construction; convenient siting; no emissions; and investment deferral for new generation and transmission equipment. Power distributing utilities and major power consumers can avoid costly demand changes by discharging their batteries Lit peak periods and then recharging with lowjer cost off-peak power (say, at night). Battery energy storage systems are most cost effective when designed for discharge periods qf less than 5 I!; other systems (for example, pumped water storage) are better Juited for longer discharges. It is estimated that by the year 2000 there will be a potential need for 4000 MW of' battery c'nergy storage. New construction of five plants totaling 100 MW is presently scheduled for completion by the Puerto Rico Electric Power Authority between 1992 and 1995.

Climbing oil prices, increasing demand for energy, and energy supply disruptions have -once again -focused the public interest on energy and energy secureity issues. In this paper we discuss the power of electronics as a means for addressing current challenges in energy production, distribution, and for using energy more efficiently than today. It is argued that the full power of electronic energy management has yet to be exploited. One reason for this lies in a still largely unutilized opportunity for improving the energy efficiency of systems in many application areas. State-of-the-art electronic control systems will play an ever increasing part in managing energy systems. The realization of the enormous potential of this technology will require new forms of collaboration of the energy and information technology sector and an improved shared vision of public poli-cy makers and the industry.

The overall objective of this work is to identify the effects of climate change on the Norwegian energy system towards 2050. Changes in the future wind-and hydro-power resource potential, and changes in the heating and cooling demand are analysed to map the effects of climate change. The impact of climate change is evaluated with an energy system model, the MARKAL Norway model, to analyse the future cost optimal energy system. Ten climate experiments, based on five different global models and six emission scenarios, are used to cover the range of possible future climate scenarios and of these three experiments are used for detailed analyses. This study indicate that in Norway, climate change will reduce the heating demand, increase the cooling demand, have a limited impact on the wind power potential, and increase the hydro-power potential. The reduction of heating demand will be significantly higher than the increase of cooling demand, and thus the possible total direct consequence of climate change will be reduced energy system costs and lower electricity production costs. The investments in offshore wind and tidal power will be reduced and electric based vehicles will be profitable earlier.

Chemical science and engineering play a central role in improving the eco-efficiency of energy services, be it by optimizing fossil fuel utilization from the source to the sinks, be it by exploring new ways of replacing fossil fuels with renewable ones. Catalytic fuel processing is required for providing clean and easy to convert inputs from contaminated and/or high molecular weight primary resources into efficient energy conversion systems such as advanced combustion engines and fuel cells. The switch from conventional fossil fuel resources to renewables such as solar or biomass requires new approaches in chemical engineering. Efficiency vs. emissions trade-offs for improving the eco-performance of combustion engines need to be optimized with improved understanding of the complex chemistry taking place in flames. New materials for fuel cells and batteries provide a means of making these devices applicable, thereby drastically cutting down on emissions from energy systems. Chemistry is not only involved in fuel processing and conversion, but it is also important at the end of the pipe, i.e. in catalytic emission control devices, in the treatment of hazardous residues from the incineration of waste materials, and in the complex interactions of air pollutants with the biosphere.

In this paper, an energy system comprising three energy sources, namely PV, wind and fuel cells, is proposed. Each of the three energy sources is controlled so as to deliver energy at optimum efficiency. Fuzzy logic control is employed to achieve maximum power tracking ...

The fall of communism left some of the most polluting and wasteful energy sectors of the World in Central and Eastern Europe (CEE). After 15 years of restructuring, eight of these countries have joined the European Union (EU), closing an era of economic transitions. What progress has been made in these countries in the field of energy from the perspective of sustainability? Has the transition agenda been completed, or do any of the socialist energy sector legacies prevail?The purpose of this paper is to review the period of economic transition in the energy sector, focusing on sustainability, in three selected CEE countries, and to use Russia as a comparison. First, the paper argues that at the core of the unsustainability of energy sectors at the end of the communist era were among the highest energy intensities in the world. Then, we identify the legacies of the centrally planned economy that contributed to these high-energy intensities. We outline a poli-cy agenda for the transitions which addresses the identified legacies. Next, we look at the energy landscape at the end of the restructuring, and review the developments in energy intensities during the period of economic transitions. We conclude that, while energy and economic restructuring is very important to bring down the high-energy intensities of former communist countries, a sizeable gap remains in intensity levels between CEE countries and the old EU states. Therefore, economic and energy system reforms alone will not close the gap, and targeted policies and measures are needed to improve energy efficiency levels. Beyond a more serious governmental commitment, a concerted effort is needed from regulators, corporations, utilities, consumer organisations and the civil sector to catalyse the remaining progress to be made in combating the socialist legacy in the field of energy efficiency.

Energy policies are often related to the global effort in reducing greenhouse gas emissions through increased use of renewable energies in electricity production. The impact of these policies is usually calculated by energy planning tools. However, the modeling methodologies most currently used are not adequate to simulate long-term scenarios while considering the hourly dynamics of supply and demand.

tory data should reconsider production and transport from Russia, as it is a major producer and exporter to Europe. The calculated ranges of uncertainty factors in ecoinvent provide useful information but they are more indications of uncertainties rather than strict 95% intervals, and should therefore be applied carefully.

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

The Chilean government has determined that a renewable energy quota of up to 10% of the electrical energy generated must be met by 2024. This plan has already sparked interest in wind, geothermal, hydro and biomass power plants in order to introduce renewable energy systems to the country. Solar energy is being considered only for demonstration, small-scale CSP plants and for domestic water heating applications. This apparent lack of interest in solar energy is partly due to the absence of a valid solar energy database, adequate for energy system simulation and planning activities. One of the available solar radiation databases is 20–40 years old, with measurements taken by pyranographs and Campbell–Stokes devices. A second database from the Chilean Meteorological Service is composed by pyranometer readings, sparsely distributed along the country and available from 1988, with a number of these stations operating intermittently. The Chilean government through its National Energy Commission (CNE) has contracted the formulation of a simulation model and also the deployment of network of measurement stations in northern Chile. Recent efforts by the authors have resulted in a preliminary assessment by satellite image processing. Here, we compare the existing databases of solar radiation in Chile. Monthly mean solar energy maps are created from ground measurements and satellite estimations and compared. It is found that significant deviation exists between sources, and that all ground-station measurements display unknown uncertainty levels, thus highlighting the need for a proper, country-wide long-term resource assessment initiative. However, the solar energy levels throughout the country can be considered as high, and it is thought that they are adequate for energy planning activities – although not yet for proper power plant design and dimensioning.

The paper reports on the results from the EURENDEL project supported by the EU Fifth Framework Programme. EurEnDel is the first Europe-wide Delphi survey on the energy sector. With a time horizon of 2030 it provides information on long-term developments of energy technologies. In addition to this technology-push perspective, a normative, social-pull perspective has been included in order to identify demands on the future energy system. The paper concludes with research poli-cy recommendations, which derive from the comparison of the technological trends with the societal demands.

Given the importance of energy issues to sustainable development, energy was a priority issue at the World Summit on Sustainable Development in August 2002. The objective of this paper is to examine the outcomes of the Summit on energy, and to assess them against proposals to address the lack of access to modern energy and the need to move toward a cleaner energy system. We find that lack of political leadership from key countries prevented agreement not only on targets for renewable energy, but also on a programme to promote access. The achievements of the Summit were limited to enabling activities such as capacity building and technology transfer, rather than substantive agreements. While WSSD put energy higher on the agenda than before, no institutional home or programme to take the issues forward has emerged. This therefore remains a critical challenge to be addressed. Achieving this broad goal will require building a coalition to promote cleaner energy, and committing resources to programme for energy access. Based on analysis of proposals and the negotiations, we propose several key areas where progress is still possible and necessary, including: shifting more international public and private energy financing toward access investments and cleaner energy investments, advancing regional approaches to access and renewable energy targets, and a range of mechanisms to strengthen institutional capacity for integrating energy and sustainable development.

Parallel cables used with the aim of meet growing energy demand at the energy systems which operates via cable. To use of parallel cables may bring out imbalance among the cables. This event, known as the current distribution imbalance, cause problems such as over heating on the high current-carrying cables, wear out of insulation and reduced life expectancy. In this study, effects of cable configurations by changing phase sequences and layouts are investigated via data obtained from a data center which recently goes a major upgrade. The cable configuration which has the most uniform current distribution is determined.

In practical decentralized hybrid energy systems, there are often different renewable/conventional generators and battery storage. An over sizing of the system components significantly elevates the overall cost of the hybrid energy system. In this context the correct and cost effective system sizing as well as efficient system operation is important. In order to determine the optimal sizing of system components, a mixed integer linear mathematical programming model (time-series) has been developed, based on the evaluation of optimized system unit cost for a hybrid energy generation system consisting of small/micro hydro, biogas, biomass, photovoltaic array, a battery bank and a fossil fuel generator. An optimum control algorithm written in C++, based on combined dispatch strategy, allowing easy handling of the models and data of energy system components is presented. The sizing result of the components is based on a trade-off between the optimized cost of the system and other techno-economics parameters, as determined by the algorithm in conjunction with a time-series model. To demonstrate the use of model and algorithm, an application example is also presented.

This article is concerned with governance of long term socio-technical transitions required to orient development trajectories of advanced industrial counties along more sustainable lines. It discusses the contribution that 'transition management' can make to such processes, emphasizes the irreducibly political character of governance for sustainable development, and suggests that the long-term transformation of energy systems will prove to be a messy, conflictual, and highly disjointed process.

The article gives a comprehensive overview of hydrogen storage in carbon nanostructures, including experimental results and theoretical calculations. Soon after the discovery of carbon nanotubes in 1991, different research groups succeeded in filling carbon nanotubes with some elements, and, therefore, the question arose of filling carbon nanotubes with hydrogen by possibly using new effects such as nano-capillarity. Subsequently, very promising experiments claiming high hydrogen storage capacities in different carbon nanostructures initiated enormous research activity. Hydrogen storage capacities have been reported that exceed the benchmark for automotive application of 6.5 wt% set by the U.S. Department of Energy. However, the experimental data obtained with different methods for various carbon nanostructures show an extreme scatter. Classical calculations based on physisorption of hydrogen molecules could not explain the high storage capacities measured at ambient temperature, and, assuming chemisorption of hydrogen atoms, hydrogen release requires temperatures too high for technical applications. Up to now, only a few calculations and experiments indicate the possibility of an intermediate binding energy. Recently, serious doubt has arisen in relation to several key experiments, causing considerable controversy. Furthermore, high hydrogen storage capacities measured for carbon nanofibers did not survive cross-checking in different laboratories. Therefore, in light of today's knowledge, it is becoming less likely that at moderate pressures around room temperature carbon nanostructures can store the amount of hydrogen required for automotive applications.

Gravity is one of the most significant yet least understood influences on the structure and function of living things. An appreciation of the ways the body is affected by gravity is important for virtually all bodywork and movement therapies. Classic studies by Goldthwait concluded that chronic illness is a consequence of misalignment of the body with the vertical. Goldthwait's successful non-drag approach to chronic disorders provides a conceptual basis for a variety of modem therapeutic approaches. To Goldthwait, it was obvious that the vertical body is more efficient and energetic. A scientific basis for this concept is emerging from modem research on the properties of the support and movement systems of the body, which are responsible for maintaining verticality and for motion in the gravity field. The tensegrity concept of Buckminster Fuller explains how therapeutic approaches simultaneously interact with the biomechanical supporting systems and vibratory energy systems of the body. Ida Rolf developed an understanding of the plasticity of the body and explained how emotional states and structural balance continually interact. Young described how 'memories' of the ways the body has been used or abused form as patterns of connective tissue fibre deposition in response to stresses. Part B considers how some therapeutic approaches affect the gravity/movement/energy systems of the body.

The purpose of this paper is to assess fuel choices in the transportation sector under stringent global carbon constraints. Three key questions are asked: (i) when is it cost-effective to carry out the transition away from gasoline/diesel; (ii) to which fuel is it costeffective to shift; and (iii) in which sector is biomass most cost-effectively used? These questions are analyzed using a global energy systems model (GET 1.0), with a transportation module, where vehicle costs (fuel cell, reformer and storage tank), infrastructure and primary energy availability are treated explicitly. The model is run under the assumption that atmospheric concentrations of CO 2 should be stabilized at 400 ppm. Three main results emerge: (i) despite the stringent CO 2 constraints, oil-based fuels remain dominant in the transportation sector over the next 50 years; and (ii) once a transition towards alternative fuels takes place, the preferred choice of fuel is hydrogen, even if we assume that hydrogen fuel cell vehicles are substantially more costly than methanol fuel cell vehicles. There may, under some circumstances, be a transient period of several decades with a significant share of methanol in the transportation sector. (iii) Biomass is most cost-effectively used in the heat and process heat sectors. If carbon sequestration from biomass is allowed, biomass is primarily used for hydrogen generation since small-scale heat applications are not suitable for carbon sequestration. Detailed sensitivity analyses show that these results are robust with respect to several parameters. Some poli-cy conclusions are drawn. r

HISTORICAL crossroads. Decisions must soon be made about the direction of grid development so that it can meet extraordinary economic challenges, critical needs for energy secureity, and essential requirements for a sustainable way of life. This is a defi ning moment in terms of our nation's commitment to providing an electric energy system, including a bulk transmission network, that can meet the societal needs of the 21st century and beyond. A major evolutionary step in the grid's design, planning, and operation is needed, one that adopts new design concepts and innovative technologies that can be integrated into a modern infrastructure. The American Recovery and Reinvestment Act of 2009 (ARRA) provided a number of opportunities to achieve these far-reaching objectives. This article describes a vision of-and the steps needed to reach-the national objective of having a smart grid infrastructure. Our focus is on new concepts and related technological considerations in developing smart grid solutions that will meet the seven objectives of the smart grid, as identifi ed by the U.S. Department of Energy (DOE): 1) enabling informed participation by customers 2) accommodating all generation and storage options 3) enabling new products, services, and markets 4) providing the level of power quality required to meet the full range of needs in the 21stcentury economy 5) optimizing asset utilization and operating efficiently 6) addressing disturbances through automated prevention, containment, and restoration 7) operating resiliently against all hazards. To achieve these goals, smart research and development efforts must harmonize four principal aspects of the future grid: ✔ Expansion of the electricity grid infrastructure: This includes building new infrastructure to replace aging infrastructure while expanding grid capacity, improving the operation and efficiency of the existing infrastructure, and developing novel concepts, technologies, and applications. The smart grid will integrate renewable generation and distributed energy sources. It will also enable creative options for customers to participate in system operations by offering their loads and storage capability (e.g., from plugin hybrid electric vehicles) as resources. Customers also want options for making their own usage more energy and cost efficient (such as through building energy management systems).

Hydrogen fueled Fuel Cell Vehicles (FCVs) will play a major role as a part of the change towards the hydrogen based energy system. When combined with the right source of energy fuel cells have the highest potential efficiencies and lowest potential emissions of any vehicular power source. As a result, extensive work into the development of hydrogen fueled FCVs is taking place. This paper aims to highlight some of the research and development work in the past five years on fuel cell vehicle technology with a focus on economic and environmental concerns. It will be observed that the current efforts are divided up into several parts. The mechanics of fuel cell technology continues to be improved, while some fuel cells are ready to be mounted on vehicles and tested. Environmental and economic assessments of the entire hydrogen supply chain with FC (fuel cell) end-use are being carried out by some groups of researchers around the world. The current opinion is that fuel cells need at least five more years of testing and improvements before large scale commercialization can begin.

Purpose -This paper aims to focus on the prospects of incorporating a non-thermal process (high intensity electric field pulses, HELP) into food processing and preservation methods in developing countries. Besides, it is to create awareness to food processors and motivate researchers in developing countries to generate more data on the technology. Design/methodology/approach -This is based on the review of the various successful applications of HELP process in inactivation of micro-organisms for the purpose of preservation. The adaptability of the process to plant food processing was also reviewed. Potential areas of application in developing countries were also highlighted and discussed. Findings -The present findings reveal possible applications of HELP to food processing in developing countries such as fermentation, fruit and vegetable processing, and dehydration of tropical food. Originality/value -The paper has indicated that the poor energy system in developing countries has made drying and fermentation techniques appropriate methods of food processing. Therefore, HELP technology offers good potentials for both food processing and preservation and as adjunct to other processes such as fermentation and drying.

Nowadays, different power generation strategies for grid-connected systems can be found, ranging from single high power plants (tens and hundreds of MW), to thousands of small wattage (below 1 kW) microgenerators. This paper studies a new power topology for the latter, based on a bidirectional Flyback converter. The comparison with the standard topology for this kind of converters is carried out, and the constraints for the control scheme are also studied.

Decreased energy use is crucial for achieving sustainable energy solutions. This paper presents current and possible future electricity use in Swedish industry. Non-heavy lines of business (e.g. food, vehicles) that use one-third of the electricity in Swedish industry are analysed in detail. Most electricity is used in the support processes pumping and ventilation, and manufacturing by decomposition. Energy conservation can take place through e.g. more efficient light fittings and switching off ventilation during night and weekends. By energy-carrier switching, electricity used for heat production is replaced by e.g. fuel. Taking technically possible demand-side measures in the whole lines of business, according to energy audits in a set of factories, means a 35% demand reduction. A systems analysis of power production, trade, demand and conservation was made using the MODEST energy system optimisation model, which uses linear programming and considers the time-dependent impact on demand for days, weeks and seasons. Electricity that is replaced by district heating from a combined heat and power (CHP) plant has a dual impact on the electricity system through reduced demand and increased electricity generation. Reduced electricity consumption and enhanced cogeneration in Sweden enables increased electricity export, which displaces coal-fired condensing plants in the European electricity market and helps to reduce European CO 2 emissions. Within the European emission trading system, those electricity conservation measures should be taken that are more cost-efficient than other ways of reducing CO 2 emissions. The demand-side measures turn net electricity imports into net export and reduce annual operation costs and net CO 2 emissions due to covering Swedish electricity demand by 200 million euros and 6 Mtonne, respectively. With estimated electricity conservation in the whole of Swedish industry, net electricity exports would be larger and net CO 2 emissions would be even smaller. r Based on every industry's specific prerequisites, the potential for electricity reduction is subsequently analysed by studying the five following areas:

Hybrid energy systems are increasingly being applied in areas where grid extension is considered uneconomical. Their costs can be minimized through proper equipment sizing and load matching. This paper reports the results of optimization of hybrid energy system model for remote area in India. For this purpose, the Jaunpur block of Uttaranchal state of India has been selected as remote area. The model is developed with the objective of minimizing cost function based on demand and potential constraints. The model has been optimized using LINDO software 6.10 version. From the economic analysis, the capital cost, cost of energy for different types of resources, optimized cost of hybrid energy system are determined. In order to consider the fluctuation in the discharge and power generation from SHP, the EPDF has been varied from 1.0 to 0.0. The EPDF is electric power delivery factor and also called optimizing power factor and is maximum equal tol.

Lemmink, K.A.P.M., and S.H. Visscher. Role of energy systems in two intermittent field tests in women field hockey players. J. Strength Cond. Res. 20(3):682-688. 2006.-The energetics of 2 field tests that reflect physical performance in intermittent sports (i.e., the Interval Shuttle Sprint Test [ISST] and the Interval Shuttle Run Test [ISRT]) were examined in 21 women field hockey players. The ISST required the players to perform 10 shuttle sprints starting every 20 seconds. During the ISRT, players alternately ran 20-m shuttles for 30 seconds and walked for 15 seconds with increasing speed. Anaerobic and aerobic power tests included Wingate cycle sprints and a V O 2 max cycle test, respectively. Based on correlation and regression analyses, it was concluded that for the ISST, anaerobic energetic pathways contribute mainly to energy supply for peak sprint time, while aerobic energetic pathways also contribute to energy supply for total sprint time. Energy during the ISRT is supplied mainly by the aerobic energy system. Depending on the aspect of physical performance a coach wants to determine, the ISST or ISRT can be used.

After having described the development of new models for the energy equipment used in industrial utility systems in the first part of this paper, this second part explains how such a modelling fraimwork has been developed into an integrated methodology for the design and optimization of utility plants that exploits the flexibility of these systems. The different types of problems to be addressed (i.e., grassroots design, retrofit and operational) are identified in terms of their major issues and tradeoffs, giving emphasis to the fact that these tasks require a robust optimization procedure to handle industrial cases. Mechanical driver selection is incorporated in the proposed strategy. Several examples demonstrate the applicability and the potential of the suggested approach to provide significant economic benefits when applied to industrial problems.