TESS Holdings has completed retrofitting four solar power plants owned by its subsidiaries with battery storage and switched the operation of three of them to the feed-in-premium (FIP) scheme, the company announced on October 20, 2025. The fourth is expected to follow in December 2025.
According to the statement, the company installed 5.8MWh of storage using Huawei-supplied BESS at each facility. The assets, which were originally operating under the feed-in-tariff (FIT) scheme, will be aggregated in-house, likely by subsidiary TESS Engineering, when operating under FIP.
All four power plants, including a 1.5MWAC/2.3MWDC project in Kagoshima City owned by Prime Solar 3 LLC, and a 1.5MWAC/2.1MWDC asset in Kanoya City, and 1.5MWAC/1.8MWDC and 1.5MWAC/2.1MWDC facilities in Yusui Town owned by T&M Solar LLC, are located in Kagoshima Prefecture in the Kyushu TSO area. They were certified under FIT in FY2013 and operated under 36 yen per kWh contracts valid until 2036-2040.
The company previously said it began operating one of the Yusui Town assets under FIP in partnership with Kansai Electric Power’s aggregation unit E-Flow. The same project is the only one of the four that has not begun operation under the new scheme and is scheduled to do so in December according to the latest announcement. Japan Energy Hub has reached out to confirm if the new date represents the timing of a shift to in-house aggregation or otherwise.
TESS Holdings is among a growing group of solar power plant owners that are adding battery storage to their Kyushu assets to counter declining returns amid increasing generation curtailment in the area. The company plans to add BESS and switch to FIP 113MW of its solar capacity by FY2030.
