MIRARTH Holdings, via its wholly-owned subsidiary MIRARTH Asset Management, commissioned the group’s first grid-scale battery storage project on September 1, 2025, the company announced on September 8, 2025. The 2MW/7.4MWh MSB Kanagawa Aikawa Power Storage Station is also the first standalone BESS aggregated by PowerX, operating under a fixed-price tolling contract.
“This scheme will enable MSB Kanagawa Aikawa Power Storage Station to receive fixed income, making it easier to forecast the cash flow of the battery storage business,” said the statement. PowerX will use the asset for balancing supply under PPAs and retail contracts, as well as for trading in the wholesale, capacity, and balancing markets.
The project in Aikawa Town, Kanagawa Prefecture, was first announced by the companies in June 2024 and uses three Mega Power 2700A units.
The companies said they plan to continue jointly developing grid-scale BESS projects. PowerX’s Power Business Executive Officer Yusuke Kojima noted in a LinkedIn post that the company plans to launch additional similar projects within this fiscal year, without specifying their counterparties.
Separately from MSB Kanagawa Aikawa, MIRARTH is also developing its first extra high-voltage project jointly with Tokyo Century, also in Kanagawa. The 12MW/65.8MWh grid-scale facility in Yokohama City is expected to be commissioned in FY2029.
PowerX joins a limited number of early movers offering capped-downside structures to grid-scale BESS owners in Japan, including Tokyo Gas, which signed 20-year tolling contracts for multiple extra high-voltage projects, and Engelhart CTP, which inked a Heads of Terms agreement for 10-year revenue floor arrangements with Bison Energy.
