Abstract
In this paper, evaluation methodology for cogeneration district energy system, which provides not only electricity, but also heat energy is discussed. First, evaluation scope and argument point for evaluation of cogeneration system is identified. Second, to find out how system scope and framework affect evaluation result, efficiency of virtual district energy system, which contains high electric efficiency gas engine cogeneration system, has calculated. Through this model analysis, influence of scope and framework for evaluation result has clarified so that means optimization in subsystem doesn't assure optimization of whole system. Finally, based on the model analysis results, this paper proposed hypothesis that city planning may play important role to realize energy consumption reduction with the use of district energy system, by creating development plan of district energy system.
