Idemitsu Kosan and partners commissioned the 15MW/48MWh Himeji Power Storage Station, which is the petroleum company’s first grid-scale battery storage project, on October 10, 2025.
Construction of the facility, located on the former Idemitsu Kosan Hyogo Refinery site and owned by the special purpose company (SPC) Himeji Chikudensho LLC, began in August 2023 and was handled by JGC Holdings. It was supported by a 1.6 billion yen subsidy awarded under METI’s FY2022 supplementary budget program for grid-scale storage projects.
The oil company holds a 51% interest in the project and will handle the asset’s participation in the wholesale, balancing, and capacity markets, as well as maintenance. Nagase & Co., which owns 22%, will provide battery-related engineering support. Renova also has a 22% stake. It handled engineering and is in charge of managing the SPC. SMFL Mirai Partners arranged project finance and holds the remaining 5%.
“We aim to build a battery storage revenue model by utilizing the know-how and human resources cultivated to date through power and renewable energy businesses,” said Idemitsu Kosan. The company holds stakes in over 100MW of solar power plants, as well as several onshore wind, biomass, and thermal projects. It has no other known battery storage projects under development.
