This study aims to verify the effectiveness of optimum utilization of residential combined heat and power systems in cold regions for energy conservation. The numerical simulations concerning optimum utilization of residential combined heat and power systems including fuel cells and gas engines were carried out, their optimum operation conditions and the effects of the primary energy reduction were evinced. In order to verify the availability of power and heat supply system that uses the CHP, we carried out analyses on characteristics of energy demand and the ratio of heat to power.
