Updated March 11, 2025, 6:10 p.m.: This article has been updated to include ownership shares, construction start date, and information about power trader.
Kamigumi and Banpu Japan ordered Power X equipment for the 1.999MW/8.226MWh “Tokyo Metropolis Umi no Mori Power Storage Station” they are jointly developing in Koto City, Tokyo, the battery system manufacturer said on March 11, 2025.
According to the statement, the project will use three 2.742MWh Mega Power containers, which are expected to be installed by April 2028. Construction is expected to begin in January 2027. The facility will be located on the premises of Kamigumi’s Tokyo Multipurpose Logistics Center.
Banpu Power Trading will trade the asset’s power in the wholesale market.
The project, being developed by Tokyo-to Umi-no-Mori Battery Project LLC, a 51:49 joint venture between Kamigumi and Banpu Japan, was awarded a 290 million yen subsidy in Tokyo Metropolitan Government’s FY2024 subsidy for the introduction of grid-scale storage. It is the first such project to be located within the metropolis rather than in its surrounding prefectures.
Both Banpu Japan and Kamigumi are concurrently working on other BESS projects. The former was awarded subsidies for two facilities in a nationwide METI program similar to Tokyo’s and, according to its website, is also developing a 14.5MW BESS facility in Iwate Prefecture. The latter is developing a 13MW/54.84MWh asset in Hyogo Prefecture, which it aims to commission in February 2026.
