Erex to build 2MW/8MWh grid-scale BESS facility in Tokyo TSO area, targets Q3 FY2026 COD

Erex will build a 2MW/8MWh grid-scale battery storage facility in an undisclosed location in the Tokyo TSO area, the company announced on January 9, 2026.

According to the statement, the asset will be aggregated in-house and participate in the wholesale, balancing, and capacity markets. Erex signed an engineering, procurement, and construction (EPC) contract for the project with GreenEnergy Plus on December 26, 2025, and plans to commission the facility in the third quarter of FY2026.

The project is being developed as part of the company’s efforts to expand from biomass generation and power trading into aggregation. It follows another 2MW/8MWh asset that Erex plans to commission in FY2026’s second quarter in Kushima City, Miyazaki Prefecture.

Erex signed a memorandum of understanding with Samsung C&T to cooperate on developing grid-scale BESS projects in October 2025. The two companies plan to build assets nationwide through a 50:50 joint venture, with the Korean company also expected to invest in the Kushima facility. It is unclear whether the Tokyo project will also be part of the partnership.