April 3, 2025: Sumitomo Electric Industries’ redox flow battery tech has been selected to support a pioneering grid-scale power stabilization system under construction in Japan.

Sumitomo said on March 28 the project for renewables developer Shin-Idemitsu on the island of Kyushu, marks the first redox flow battery to be approved under a grid-scale batteries subsidy program set up by Japan’s Ministry of Economy, Trade and Industry and the Agency for Natural Resources and Energy.

The battery will be installed at the Nagasu Energy Storage Facility in Kyushu, the southernmost of the four major Japanese islands, with a capacity of 8,000kWh (2,000kW × 4 hours). Construction has already started and completion is scheduled for October 2026, 

The subsidy program boost for BESS follows a major expansion of solar power in the region. As a result, solar power supply has exceeded the surrounding areas’ electricity demand during the daytime, becoming a challenge. 

Financial details of the project were not disclosed, but Sumitomo said its redox flow battery was chosen for its long lifespan, durability and reduced risk of fire.