Sunpin Japan launches large-scale 45 MW energy storage system in Shiga Prefecture

Japanese company Sunpin Japan has announced the successful grid connection of a large-scale energy storage system located in Otsu, Shiga Prefecture. The lithium-ion battery installation has a power output of 45 MW and an energy storage capacity of 180 MWh, providing four hours of discharge at full power. Commercial operations are scheduled to begin in December 2026.

A new player in Japan’s energy market and advanced market optimization

For Sunpin Japan, the project in Shiga Prefecture marks its official full-scale debut in Japan’s electricity market. The energy storage facility was developed in an area served by the local grid operator, Kansai Transmission and Distribution Inc.

E-Flow is responsible for the day-to-day management of charging and discharging cycles, based on real-time market prices and electricity supply and demand forecasts. The entire development process, including land acquisition, complex administrative procedures, and grid connection arrangements, was handled in-house by Sunpin Japan. Meanwhile, another company within the group, Blue Point Power Solution, was responsible for general contracting as well as subsequent operation and maintenance.

Sunpin Japan’s further expansion plans

Commissioning such a large facility in the Kansai region represents a testing ground for the Japanese developer. Company representatives have announced that the expertise gained from this project will be used to rapidly scale up the development of additional large-scale energy storage facilities across the country.