HEXA Energy Services began construction of a 50MW/200MWh grid-scale storage battery facility in Shiraoi Town and a 30MW/120MWh system in Eniwa City, Hokkaido, the company announced on September 10, 2025. It plans to commission both in 2027.
According to the statement, Sungrow will supply BESS units and Shirokuma Power will handle balance-of-plant engineering, procurement, and construction (EPC). Both projects were awarded capacity contracts in Japan’s first long-term decarbonization auction (LTDA) held in FY2023.
The Shiraoi and Eniwa projects’ groundbreaking follows that of the 30MW/130MWh Tagawa Power Storage Station in Fukuoka Prefecture, which the company expects to bring online in the fall of 2025. MUFG Bank and Societe Generale provided project finance for the inaugural facility, which will also use Sungrow equipment. HEXA did not disclose the two Hokkaido assets’ financing details.
In addition to the three under-construction assets, HEXA is developing eight other extra high-voltage battery storage facilities, also four hours in duration and backed by the LTDA. Those include a 30MW/120MWh and a 50MW/200MWh project in Hokkaido, as well as similarly-sized projects in Mie, Kumamoto, Toyama, Kyoto, and Akita prefectures. All but one are being supported by Shirokuma Power and expected to be commissioned by the end of FY2028.
