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[en] Highlights: ► Analyze mutual interactions and restrictions within energy management systems. ► Tackle uncertainties expressed as fuzzy sets, and regular and radial intervals. ► Obtain optimal solutions under preferred satisfaction degrees and system benefits. ► Use protection level to reflect tradeoffs between constraint-violation and system reliability. ► Provide decision makers with effective energy management schemes. - Abstract: In this study, a fuzzy radial interval linear programming (FRILP) model was developed for supporting robust planning of energy management systems with environmental and constraint-conservative considerations, facilitating the reflecting of multiple uncertainties that are existing in energy activities and environmental emissions and could be expressed as fuzzy sets, and regular and radial intervals. Particularly, it could ensure the generation of robust solutions that would be feasible with high probability under input data variations, reflecting tradeoffs between the conservatism levels of solutions and probability levels of constraint violation. Specifically, 24 radial intervals associated with the electricity generation efficiency and electricity demands under different protection levels based on the natural and technologic conditions, as well as decision makers’ expectation were determined. Totally, 30 scenarios under the combinations of five protection levels were analyzed. Through solving the developed model, the results showed that decision variables would be rising with the increase of protection levels and higher radii fluctuation levels of radial intervals would cause higher system cost and lower satisfaction degree. The generated solutions could offer detail energy management plans (e.g., energy conversion technology capacity expansions) for decision makers, and thus could guarantee optimal economic and environmental benefits under desirable system reliability.
[en] Energy management is a system of managing energy utilization wisely and it includes issues such as energy efficiency (conservation), use of renewable energy, use of technology and development of energy policy. Its benefits has been well known for cost reduction and increase competitiveness and also other indirect impact such as preserving the natural resources and reduction of green-house gases. Although various strategies have been formulated by the government for the industries to adopt energy management, the result seems to be minimal and stagnant in some ways due to the various barriers which exists. Industries on the other hand, have successfully welcomed two famous management system namely the Environmental Management System ISO 14000 and the Quality Management System ISO 9000 to be implemented at their premises. This paper shows how energy management system can be effectively implemented by comparing similar generic management elements of energy management to ISO 9000/14000 standards. The seven (7) elements of energy management system discussed are top management commitment, policy establishment, energy management team, energy audit, energy efficiency projects, monitoring and training
[en] Transition countries include a group of countries with similar political, economic and social problems that signify the period after the end of the cold war and the fall of Communism. The paper presents the characteristics of the European Communist countries before and after the fall of the iron curtain, which influenced the transition process toward market economy. The centralist (Russian) economy model had enormous advantages at the beginning, particularly in the energy sector, owing to unlimited consumption of blood, sweat and tears during the construction of major power plants. The bureaucratic system executed ruthless expropriation of land and the existing power system, neglecting the environment and human health and even disregarding the feasibility of new power plants. The market creation and particularly the creation of an energy market, under which we understand selling and buying of all forms of energy, fuels, power plants' equipment and capital for energy sector, asks for a series of tasks from the Eastern European countries. They must accept market rules, standards of highly industrialised western countries and achievements in parliamentary democracy as the canon of behaviour in democracy. Setting up a legal infrastructure for the private sector, devising a taxation system, determining ownership rights, stabilising the macro economy in the sense of managing the government budget so as to avoid an excessive fiscal deficit, and stabilising monetary policy are primary tasks of the transition countries. The paper particularly reviews the tasks specifically related to the energy sector and analyses the problems taking into account national strategic interests. (author)
[en] This paper presents the results of 11 after-hours walk-throughs of offices in the San Francisco CA and Washington D.C. areas. The primary purpose of these walk-throughs was to collect data on turn-off rates for various types of office equipment (computers, monitors, printers, fax machines, copiers, and multifunction products). Each piece of equipment observed was recorded and its power status noted (e.g. on, off, low power). Whenever possible, we also recorded whether power management was enabled on the equipment. The floor area audited was recorded as well, which allowed us to calculate equipment densities. We found that only 44 percent of computers, 32 percent of monitors, and 25 percent of printers were turned off at night. Based on our observations we estimate success rates of 56 percent for monitor power management and 96 percent for enabling of power management on printers
[en] The paper analyzes the energy sector in the period from 1990 to 2005. What is shown here through an analysis of political, economic, energy, technological and institutional processes, and based on actual developments and non-developments, the consequences on energy situation to be evolved in the next 15 years, are analyzed. A crucial characteristic of this period is the fact that consumption growth is more distant from the trends in the developed countries and is increasingly approaching ones occurring in developing and undeveloped countries. The other such characteristic is lack of technological progress, which could generate desirable structural changes in energy production and demand. Taking in consideration what has been accomplished so far and what has not been accomplished, we cannot expect in the coming period the changes that could significantly modify the relations in the structure of energy production and demand. Keeping the balance between production and demand will be increasingly difficult, as well as keeping the influence on energy prices which will be growing. In this, it is more than ever indispensable that the state takes up its role.(author)
[en] Highlights: • Improving the utilization of wind power by the demand response of residential hybrid energy system. • An optimal scheduling of home energy management system integrating micro-CHP. • The scattered response capability of consumers is aggregated by demand bidding curve. • A stochastic day-ahead economic dispatch model considering demand response and wind power. - Abstract: As the installed capacity of wind power is growing, the stochastic variability of wind power leads to the mismatch of demand and generated power. Employing the regulating capability of demand to improve the utilization of wind power has become a new research direction. Meanwhile, the micro combined heat and power (micro-CHP) allows residential consumers to choose whether generating electricity by themselves or purchasing from the utility company, which forms a residential hybrid energy system. However, the impact of the demand response with hybrid energy system contained micro-CHP on the large-scale wind power utilization has not been analyzed quantitatively. This paper proposes an operation optimization model of the residential hybrid energy system based on price response, integrating micro-CHP and smart appliances intelligently. Moreover, a novel load aggregation method is adopted to centralize scattered response capability of residential load. At the power grid level, a day-ahead stochastic economic dispatch model considering demand response and wind power is constructed. Furthermore, simulation is conducted respectively on the modified 6-bus system and IEEE 118-bus system. The results show that with the method proposed, the wind power curtailment of the system decreases by 78% in 6-bus system. In the meantime, the energy costs of residential consumers and the operating costs of the power system reduced by 10.7% and 11.7% in 118-bus system, respectively.
[en] The biological conversion of the Urban Solid Residuals (USR) for energy purposes comes winning importance every day, once the urban residuals became considered a source of alternative energy. To foresee the generation of resulting biogas of the process of biological decomposition of the solid residuals of organic origin in the sanitary fillers is fundamental to estimate the energy and economic balance of facilities of recovery of gas. For the appropriate determination of the potential of generation of gases you employment the calculation methodology presented by the Agency of Environmental Protection of United States. In this context, the objective of this article is to quantify the potential of electric power generation coming from the gas methane originating of the Urban Solid Residuals of the municipalities Belas, Cacuaco and Viana of the County of Luanda in Angola. The available energy power was determined annually of the three municipalities. The instinct demonstrates that the biogas flow arrives at the maximum level and it possesses the maximum available Power in the year 2037, obtaining stops the municipalities Belas, Cacuaco and Viana 3330 · 103, 1206.13 · 103 and 2809.23 · 103m"3/year of profitable methane respectively whose calculated energy potential was respectively of 2316.52, 1358.88 and 3165,02 kW. The carried out calculations not allow alone to evaluate the energy potential of the filler, but also to evaluate, in certain way, the environmental impact for the mitigation of emissions of gases of effect hothouse. (author)
[en] Energy is a very important component of most manufacturing activities. Its level of importance depends on whether or not the manufacturing processes employed are energy intensive. For less energy intensive manufacturing activities, energy costs contribute only a small portion of total cost of production. Even in this case, it has been shown that considerable scope for cost savings through more efficient utilization of energy exist. Small investments in energy efficiency measures have been known to bring significant savings in production costs, and consequently improved profit margins. The advantages of better and efficient use of energy in an energy - intensive manufacturing outfit have been extensively demonstrated in many nations over the past few decades. For these groups, profitability improvement is usually more apparent, and the scope for achieving a cost savings through improved energy use efficiency, more considerable. Cost savings or profitability improvement is not the only reason for considering energy use efficiency improvement in a manufacturing facility. Energy use efficiency improvement is also the most effective way of reducing environmental pollutant emission such as greenhouse gases. Actual cost savings achievable will depend on factors such as: the production process; the age of the facilities; its design and maintenance; and the extent of pasts efforts in energy use efficiency improvements. Evidence suggests that for facilities where energy management has not been practiced, saving of between 10% to 20% on energy bills are possible, through simple measures, with quick payback period. When a manufacturing facility addresses issues of energy efficiency, through the institution of a viable energy management systems, it also takes a very necessary step towards obtaining international accreditation. Such accreditation include: the Eco-Management and Audit Scheme (EMAS); or the International Standard Organisation's ISO 14001. This is becoming a vital requirement in international competitiveness. The focus of this paper is the review of energy management technologies that can be used to achieve energy efficiency improvement objectives in textile manufacturing. The paper is arranged as follows: in section 2, the characteristics of energy consumption in textile manufacturing are presented; energy efficiency improvement technology options for the textile industry are discussed in section 3, section 4 covers a discussion of process specific technologies for improving energy use efficiency in textile manufacturing; the paper is concluded in section 5 with salient recommendation for promoting rational use of energy in the Nigerian Textile Industrial Sector
[en] Although the meaning of energy efficiency is clear, different definitions exist and important issues relating to its implementation still need to be addressed. It is now recognised that complicating factors – such as complex industrial sites and energy flows, multiple products and fuels, and the influence of production rate on energy efficiency – render it necessary to adopt a structured framework to define and measure energy efficiency more precisely. In this paper, a methodology is proposed to build such a framework. The whole energy system of a site is represented using a single matrix equation, which expresses the relationship between imported energies and energy drivers. The elements of the matrix are the specific energy consumptions of each single process. Mathematical process modelling, through statistical analysis of energy consumption data, is used to quantify the specific energy consumption as a function of the output. The results of this structured approach are relevant for energy benchmarking, budgeting and targeting purposes. Furthermore, this approach is suitable for implementation in an energy management system standard (e.g. EN 16001, ISO 50001) or LCA standard (e.g. ISO 14044). Glass and cast iron melting processes are presented in order to illustrate the application of the method. -- Highlights: ► A structured framework for energy efficiency in industrial processes is proposed. ► Two energy efficiency indicators are revised to take into account a variable output. ► The whole energy system of a factory can be represented by a single matrix equation. ► Mathematical modelling is used to characterise the energy consumption of a process. ► The results are relevant for energy benchmarking, budgeting and energy targeting.