Field study of system efficiency of detached house with solar energy system and fuel cell cogeneration system in Japan

Abstract

In this study, the energy flow in detached houses in Sendai City in the Tohoku region of Japan where photovoltaic power generation system, solar thermal collection system, and fuel cell cogeneration system were installed was analyzed based on measured data. Hot water obtained by solar heat collected in the house is used to supply hot water to the kitchen throughout the year, to supply hot water to floor heating and to preheat the air supply of the HVAC system in winter, and to regenerate the desiccant wheel of the HVAC system in summer. A hybrid hot water supply system using city gas and a heat pump is used as an auxiliary heat source for a solar thermal system. As a result, the monthly energy self-sufficiency rate, energy efficiency and heat loss rate of the house for three years were calculated, and the necessity of the optimization of the operation method of the solar thermal system was found. In addition, daily analyses of solar thermal system in winter and summer suggested the importance of the operation corresponding to the weather.