Maeda Corporation and RS Asset Advisors began commercial operation of two jointly developed 2MW/8MWh grid-scale battery storage projects, the companies announced on August 17, 2026.
According to the statement, their Saitama Nishisayama Power Storage Station in Tokorozawa City, Saitama Prefecture, started participating in the wholesale market in May 2026, followed by Gifu Tajimi Power Storage Station in Tajimi City, Gifu Prefecture, in July 2026. Both assets also joined the balancing market. The companies did not disclose the assets’ aggregators.
The partners are developing four additional 2MW/8MWh facilities, with Aomori Sannohe Power Storage Station in Gonohe Town, Aomori Prefecture, scheduled to begin commercial operation in December 2026. Projects in Higashiomi City, Shiga Prefecture; Kani City, Gifu Prefecture; and Iizuka City, Fukuoka Prefecture, are expected to follow in January, July, and October 2027, respectively.
Engineering, procurement, and construction (EPC) of Saitama Nishisayama Power Storage Station was handled by Eitai Japan. Broad Links was the contractor for Gifu Tajimi Power Storage Station and will also build the projects in Gonohe Town, Higashiomi City, and Kani City. Uni Root was selected for the planned facility in Iizuka City.
The projects are being developed under a tie-up signed by the two companies’ parents Infroneer Holdings and RS Holdings in September 2024. In addition to both investing in the assets, Maeda Corporation is responsible for technical strategy including EPC contractor, battery supplier, and aggregator selection. RS Asset Advisors handles site selection and acquisition, grid connection, business planning, and other development work.
Outside the partnership, Maeda commissioned a 2MW/8MWh asset in Kakamigahara City, Gifu Prefecture, in January 2026, and is developing a pair of same-scale projects in Nagano Prefecture.
RS Asset Advisors has formed similar tie-ups with Mitsubishi HC Capital Energy and Fuyo General Lease. It also launched a grid-scale battery storage asset management joint venture with Sumitomo Mitsui Trust Bank and was selected as the developer and asset manager for a 40MWh, five-project portfolio held by Hulic, Fuyo General Lease, and Itochu.
