Shin-Idemitsu plans is developing a 1.99MW/8MWh grid-scale storage facility in Nagasu Town, Kumamoto Prefecture, which it aims to commission in November 2026, the company said on March 11, 2025.
The “Nagasu Power Storage Station,” which received an approximately 322 million yen subsidy through METI’s FY2024 program for supporting BESS, will use redox flow batteries supplied by Sumitomo Electric. It will be the first project financed through the program to use that technology. Shin-Idemitsu’s wholly-owned subsidiary Shin-Idemitsu Facilities will be in charge of the asset’s construction and maintenance.
Shin-Idemitsu tasked J-Power with aggregating the asset and trading its power on the wholesale, balancing, and capacity markets on its behalf.
The project is Shin-Idemitsu’s first foray into the grid-scale storage business.
Sumitomo Electric installed over 50MW/176MWh of redox flow batteries in Japan and overseas to date. Most recently, in December 2024, it disclosed having installed a 1MW/8MWh system for Kashiwazaki IR Energy and secured an order for another one from the local retailer serving Kashiwazaki City in Niigata Prefecture.
