Recently, photovoltaic (PV) system has attracted attention because of serious environmental and energy problems. However, if PV systems are intensively connected to the grid in a specific area, it is predicted that the voltage of the distribution feeder in power system increases due to the reversal power flow. Such degradation of electric power quality leads to the depression of PV output by power conditioners. In our previous research, we have overcome the problem by introducing the storage batteries and optimally charging and discharging them . On the other hand, the residential fuel cell (FC) system has been a focus of attention because FC has achieved a primary energy efficiency of 80% by making the best use of generator waste heat. When the FC system is operated according to the residential thermal demand as a general operation, its electric output doesn't always follow the residential electric load. Therefore, it is also indispensable to introduce the storage battery to the hybrid system with a combination of PV subject to weather condition and FC giving the priority to heat supply. In this paper, we investigate the optimal operation of the storage battery for the hybrid PV and FC system.