Application multi-objective genetic algorithm for optimal design method of distributed energy system

Distributed energy system based on cogeneration system has high potential of energy saving due to utilizing waste heat from power generator effectively. However, unless the appropriate combination of machinery and operation are conducted, the expected performance is not achieved, it is quite difficult to determine the optimal combination of machinery and operation. Authors had already developed and proposed new optimal design method for building energy systems or distributed energy systems using Genetic Algorithm (GA) in some previous studies (e.g. Ooka R et al, 2008). GA could deal with nonlinear optimization problems. The proposed method designs the most efficient energy system by optimizing operation of available systems in consideration of optimal machinery capacity in the systems. However, it can intend just only optimization of primary energy consumption. For practical use, it is necessary that the method is able to search optimal energy systems with various kinds of objectives, such as environmental impact factors, economical factors, building structural factors, and so on. Therefore, the method was improved to be able to exam the energy systems with various kinds of objectives using Multi-Objective Genetic Algorithm (MOGA) in this study. This study has developed the optimal design method for energy system of single building for the first step aiming at establishing optimal design method for distributed energy system. A case study of hospital building was carried out to examine application possibility of the method as an optimal design tool.