Japanese solar project developer Sun Village has connected a solar-plus-storage facility with a DC/AC oversizing ratio of 327% at an undisclosed location in Japan. The plant has 163.2 kW of installed solar capacity, a 253.3 kWh battery system and a 49.9 kW power conversion system (PCS).
The company describes the facility as a low-voltage, super-oversized solar plant. In Japan, low-voltage projects typically have an AC output below 50 kW. Super-oversizing means installing substantially more PV capacity than the PCS’s rated output, allowing a project to increase generation without expanding its grid connection capacity.
Sun Village expects the plant to sell approximately 222,000 kWh of electricity annually. Its DC-coupled configuration is designed to store surplus daytime solar generation that might otherwise be curtailed, then export that electricity in the evening and at night. Company simulations indicate the system could maintain an output of 49.9 kW for about 14 hours.
Under Japan’s feed-in premium scheme, Sun Village will act as an aggregator, managing generation forecasts, power planning and battery operations, and selling electricity on the wholesale market.
For comparison, the average oversizing ratio for Japanese solar installations between 10 kW and 50 kW commissioned in 2024 was about 180.5%, according to the Ministry of Economy, Trade and Industry. The new plant’s 327% ratio is therefore substantially higher.
Sources: pv magazine.