Study for Merit of Battery Combined Photovoltaic Generation System for Residential House.

In this paper we examine the merits that a practical photovoltaic system combining photovoltaic generation with storage batteries would provide if used in ordinary residences. Various configurations and operation methods could be envisaged for such a system. In this research we examined the optimal battery capacity, operation methods, and economic effects for a system emphasizing economical merits for the user. We first calculated the hourly amount of photovoltaic generated electricity each month, and used data on average load patterns from actual measurements to calculate battery capacity. Next, taking battery capacity and photovoltaic module capacity/price as parameters, we calculated and evaluated the economic merits for ordinary residences. The results showed that the optimal battery capacity for combination with 3 or 5 kW photovoltaic generation is around 10 kWh, and that a combined system provides merits even though it entails higher photovoltaic module costs than the use of photovoltaic generation alone.