Evaluation of energy systems for selecting the optimal energy system

Recently, due to extensive use of fossil fuels, the problem of global warming has been raised. For solving this problem new energy sources have been growing extensively. In this paper the selection of the optimal energy supply system is considered. Due to energy policies in recent years this selection is not only based on financial aspects but also environmental and social aspects, this problem considers as a multi criteria problem. In this paper, several alternatives including renewable energy sources, micro CHP systems and conventional system has been compared by means of an integrated model of linear programming and multi criteria approach with respect to the end user requirement. New factors like availability of sources, fuels' price volatility, besides traditional factors are considered beside financial, environmental and social parameters. For each parameter a mathematical index is obtained for systems using a mathematical programming model and based on these indexes using a multi criteria decision making method different systems are evaluated. Three multi criteria decision making methods tools are discussed in this paper. The results from each approach have been compared in order to see the sensitivity of the results to each aspect of evaluation, several scenarios have been defined and the results have been compared. The results show that renewable sources and micro CHP systems are good alternatives for conventional systems when a strong attention is paid to environmental issues, without considering environmental issues renewable energy sources cannot compete with conventional systems.