Abstract
The objective of this study is to investigate the contribution of distributed energy system when electricity and gas utilities stop operation due to disasters. The distributed energy system consists of gas engine, solar energy technologies and energy storage, which is installed in apartment building. Optimal combination of the technologies was derived by minimizing total system cost under the constraint of energy sustained days for which the distributed energy system keeps electricity and hot water supplies independently. The results indicate that gas engine has priority to be selected and gas storage tank for emergency has an important role. It was found that initial cost increases to keep energy supply in winter due to fuel shortage. The way of reducing fuel consumption is to enhance thermal insulation of building. It was found that enhancing thermal insulation has effect to reduce energy storage as battery which is required for long energy sustained days more than six days.
