Tokyo Gas and Okaya launch 75 MWh BESS project in Hokkaido

Tokyo Gas Co., Ltd. and Okaya & Co., Ltd. announced plans to begin construction in December 2025 of a 25 MW/75 MWh battery energy storage system (BESS) in Tomakomai, Hokkaido Prefecture. The site for the facility is owned by Okaya, a trading company historically focused on steel products.

State-backed project under Japan’s subsidy programme

The project will be developed by a special purpose company, Tomakomai Power Storage LLC, established specifically for this initiative. The high-voltage storage station will operate under a 20-year tolling agreement with Tokyo Gas. It will participate in the wholesale, balancing and capacity markets, according to the joint statement from both companies.

The project is one of 27 selected by Japan’s Ministry of Economy, Trade and Industry (METI) to receive financial support under its fiscal year 2024 subsidy programme for large-scale BESS. The awarded subsidy totals approximately JPY2.3bn ($15.3mn), according to available data.

Technical and strategic involvement of Tokyo Gas

Tokyo Gas Energy Solutions Co., Ltd., a wholly owned subsidiary of Tokyo Gas, will provide owner’s engineering services and deploy a chief electrical engineer for the project. This involvement reflects the group’s growing strategic interest in storage infrastructure, following a similar project launched in April 2024 in Oita Prefecture.

That earlier project, a 25 MW/50 MWh BESS, is being developed by Nijio Co., Ltd., another Tokyo Gas subsidiary. In parallel, Tokyo Gas has signed tolling agreements with Eku Energy, Renova and Equis, reinforcing its presence across electricity flexibility markets.

First BESS initiative for Okaya

For Okaya & Co., Ltd., this initiative marks its first known move into stationary battery storage. Traditionally active in industrial trading, particularly in metallurgical products, the company is leveraging its land assets to partner with a major energy player on a high-value energy and logistics project.

According to the announced schedule, commercial operations at the Tomakomai station are expected to begin in 2028 or later, depending on construction and grid connection timelines.