TESS Engineering will build a 4.47MWh battery system at a 1.99MWAC/2.52MWDC solar power plant in Fukuoka Prefecture acquired by Fuyo General Lease, its parent company TESS Holdings announced on January 16, 2026.
According to the statement, the equipment will be supplied by Huawei. Completion of the project in Kama City is scheduled for June 2026. Alongside the retrofit, Fuyo General Lease plans to switch the power plant’s operations from the feed-in-tariff (FIT) to the feed-in-premium (FIP) scheme. METI data shows the power plant was FIT-certified in FY2013 when 10kWAC or larger solar projects were offered 36 yen per kWh. It was previously owned by Shiga-based Itoyu.
The Fukuoka power plant is one of three solar assets operated under FIT that Fuyo General Lease said in October 2025 it acquired to retrofit with storage and convert to FIP. The other two include a 1.6MWDC facility in Kagoshima Prefecture, where the company plans to install an 8.1MWh BESS in the second half of FY2025, and a 1.3MWDC project in Kumamoto Prefecture, which it plans to expand with a 2MWh battery system within the first half of FY2026.
The three projects mark Fuyo General Lease’s entry into FIT-to-FIP conversions. The company plans to use the experience gained through their execution for rolling out the business model to its other power plants, as well as supporting third-party customers with implementing the scheme.
Fuyo General Lease has been developing solar power plants since 2012 and today holds stakes in over 1,000 facilities. The company also began investing in onshore wind farms from FY2020 and, more recently, expanded into grid-scale storage. It follows a growing list of companies exploring battery retrofits of existing solar assets to improve project economics amid increasing curtailment, particularly in Kyushu.
