Consortium breaks ground on 230 MWh battery project in Japan

A consortium of Itochu Corp., Mitsubishi Estate, and Tokyo Century has begun construction of a 67 MW/230.1 MWh battery energy storage system in Chikuzen, Fukuoka prefecture, targeting commercial operation in fiscal 2027 and participation across Japan’s capacity, wholesale, and balancing markets.

The facility will deploy 102 units of PowerX’s Mega Power 2500 containerized system, each housed in a 10-foot ISO container using lithium iron phosphate chemistry. PowerX lists nominal capacity at 2,507 kWh and rated capacity at 2,256 kWh per unit – 102 units at rated capacity reconciles to the project’s 230.1 MWh total. The product is supplied under PowerX’s partnership with Itochu, branded as the PowerX × Bluestorage package. PowerX manufactures the Mega Power 2500 at its facility in Tamano, Japan.

The project was selected for Japan’s Ministry of Economy, Trade and Industry (METI) fiscal 2025 subsidy program for utility-scale storage. The three sponsors will split financing and operational responsibilities, though the exact capital structure has not been disclosed. An AI-based optimization system will manage dispatch across the three market participation categories.

Kyushu has experienced acute solar curtailment and interconnection constraints as the region’s rapid solar buildout has outpaced the grid’s ability to absorb variable generation, making it one of Japan’s most active markets for storage deployment. The sponsors said the facility is designed to participate in regional balancing as well as national capacity and wholesale markets, combining regulated subsidy support with multi-market revenue exposure.

Japan’s grid-scale storage pipeline has expanded sharply, with companies seeking connections for 113 GW of storage capacity, according to Reuters reporting in 2025. METI’s auction framework and subsidy programs are shaping which projects advance to construction. The 120 MWh Eku Energy project in Miyazaki prefecture, which broke ground in 2024 with a Tokyo Gas offtake agreement, illustrates the range of commercial structures emerging across the country as developers combine contracted and merchant revenue to underpin project finance.