Mori Building completed three hybrid solar power plants in the Tokyo TSO area combining 7.2MWDC of generation capacity with 11MWh of storage that it plans to use for an intra-group off-site PPA sleeved by TEPCO Energy Partner, the company announced on November 20, 2025.
According to the statement, one of the plants is located in Tochigi City, Tochigi Prefecture, and two are in Hitachi City, Ibaraki Prefecture. They are expected to be commissioned gradually from January 2026 and generate about 10GWh annually once fully online. TEPCO Energy Partner will supply their output, as well as renewable power from other sources, to Toranomon Hills Mori Tower and other Tokyo real estate operated and managed by Mori Building.
The projects were completed by Ecokaku under an approximately 2 billion yen development and engineering, procurement, and construction (EPC) contract.
Previously, Mori Building also contracted with Ecokaku to build six agrisolar power plants in the Tokyo TSO area totaling 12MWDC for a similarly structured intra-group PPA.
The three power plants are among the first known purpose-built utility-scale off-site hybrid solar plants, with the majority of generation projects co-located with storage continuing to be existing feed-in-tariff (FIT) assets being converted to the feed-in-premium (FIP) scheme and retrofitted with batteries.
