Itochu and Kyudenko partnered on adding co-located battery storage to existing solar projects, the companies announced on July 28, 2025. To begin with, they will add a 12MW/49.4MWh system to their 50:50 joint venture Saga Ochi Solar’s 16.5MWAC/21MWDC power plant in Karatsu City, Saga Prefecture.
According to the statement, Itochu will supply batteries and support financing via leasing and investment. It will also aggregate the assets after their conversion from the feed-in-tariff (FIT) to the feed-in-premium (FIP) scheme and be in charge of BESS operation and maintenance (O&M). Kyudenko will handle engineering, procurement, and construction (EPC) and solar system O&M.
The first plant to be upgraded was commissioned in April 2018. It was FIT-certified in FY2013 when 10kWAC and larger solar projects were offered 36 yen per kWh and is under a contract valid until March 2038.
The BESS is expected to be commissioned in FY2026. A rendering provided with the press release suggests the system will use PowerX Mega Power lithium-ion units delivered under Itochu’s Bluestorage brand.
Construction will be supported by METI’s FY2024 subsidy for solar-plus-storage projects.
Itochu and Kyudenko are the latest among a growing list of companies, such as Kyocera TCL Solar and SMFL Mirai Partners, converting existing early-FIT solar power plants in Kyushu to FIP and adding BESS. The switch minimizes economic curtailment due to an upcoming regulatory change that will limit the output of FIT assets before their FIP counterparts. The storage further maximizes value by shifting delivery from peak solar production hours to high-demand hours.
