Battery Station Kyushu LLC (Executive Officers: Yoichiro Yamazaki and Keita Kojima; hereinafter “Battery Station”), jointly established by Kyushu Railway Company (Head Office: Fukuoka City, Fukuoka Prefecture; President & Chief Executive Officer: Yoji Furumiya; hereinafter “JR Kyushu”), Sumitomo Corporation (Head Office: Chiyoda-ku, Tokyo; Representative Director, President & Chief Executive Officer: Shingo Ueno), and Sumitomo Corporation Kyushu Co., Ltd. (Head Office: Fukuoka City, Fukuoka Prefecture; President & Chief Executive Officer: Tadao Saida; hereinafter “Sumitomo Corporation Kyushu”), began preparatory work in October 2026 for the construction of its third project, the grid-scale battery energy storage facility “Battery Station Isahaya,” in Isahaya City, Nagasaki Prefecture, with operations scheduled to commence in December 2028.
“Battery Station Isahaya” will utilize the site of a former JR Kyushu railway substation and adjacent land to construct a grid-connected energy storage facility with a rated output of 16 MW and a storage capacity of 70 MWh, making it the largest project Battery Station has undertaken to date.
1. Overview of the Battery Station Business
Battery Station provides energy services centered on stabilizing electricity supply and demand and expanding the use of renewable energy (“renewables”) by utilizing railway-adjacent land and idle property managed by JR Kyushu, leveraging JR Kyushu’s expertise in maintenance and management and the Sumitomo Corporation Group’s knowledge of energy storage businesses. In 2024, Battery Station completed its first project, “Battery Station Kawasiri,” followed by its second project, “Battery Station Tomiai,” in 2026, both in Kumamoto City, Kumamoto Prefecture. “Battery Station Kawasiri” and “Battery Station Tomiai” have begun operating as grid-connected energy storage systems through the supply-demand balancing market.
2. About Battery Station Isahaya
The third project, “Battery Station Isahaya,” is a grid-scale battery energy storage facility being developed on the site of a former JR Kyushu railway substation and adjacent land. While the first project, “Battery Station Kawasiri,” and the second project, “Battery Station Tomiai,” each have a rated output of 1.5 MW, “Battery Station Isahaya” will have a rated output of approximately 16 MW and a storage capacity of approximately 70 MWh, making it the largest project undertaken by Battery Station to date and its first extra-high-voltage battery energy storage facility.
In the Kyushu region, renewable energy deployment, particularly solar power, has been expanding. However, renewable energy output curtailment is implemented during periods when electricity supply exceeds demand, highlighting the need for additional storage to improve balancing. “Battery Station Isahaya” will help stabilize electricity supply and demand through battery charging and discharging, while contributing to the further expansion of renewable energy use.
3. Future Outlook
Since its establishment in 2023, Battery Station has been developing grid-scale battery energy storage in the Kyushu region by combining JR Kyushu’s railway network land and community-rooted business foundation with the expertise the Sumitomo Corporation Group has cultivated through its energy storage operations both in Japan and overseas.
Battery Station and its investing partners will continue to leverage the expertise they have accumulated in the development, construction, and operation of energy storage projects to promote the expansion of such projects in the Kyushu region, utilizing land along railway lines and other underutilized land. Through the stabilization of electricity supply and demand and the further expansion of renewable energy use, Battery Station and its partner companies will contribute to the realization of a sustainable society.
Battery Station Kyushu Company Profile
| Investors | Kyushu Railway Company BS Holdings Co., Ltd.* Sumitomo Corporation Kyushu Co., Ltd. |
|---|---|
| Date of Establishment | April 12, 2023 |
| Location | Fukuoka City, Fukuoka Prefecture |
| Business Activities | Battery storage projects on railway-adjacent land and idle property managed by JR Kyushu (Project development, battery asset construction, maintenance, and operation as a battery storage business) |
* BS Holdings: A wholly owned subsidiary of Sumitomo Corporation that holds and manages energy storage assets
Battery Station Isahaya Facility Overview
| Location | : | Isahaya City, Nagasaki Prefecture (Site of the Former JR Kyushu Railway Substation and Adjacent Land) |
| Operator | : | Battery Station Kyushu LLC |
| Construction Start Day | : | October 2026 |
| Commercial Operation | : | December 2028 (tentative) |
| Rated Output | : | 16 MW |
| Storage Capacity | : | 70MWh |
| System Features | : | Installation of 14 stationary battery energy storage systems Effective Use of the Site of a Former JR Kyushu Railway Substation (Land and System Capacity) |