Sinanen commissioned its first grid-scale battery storage facility on August 8, 2025, its parent Sinanen Holdings announced on August 12, 2025. The 1MW/5.3MWh asset is located on the premises of its group company Melife’s Asahi Branch in Asahi City, Chiba Prefecture.
The facility is owned and operated by another group company, Taiyoko Support Center. It is expected to participate in the wholesale, balancing, and capacity markets.
Construction of the project, which was first announced in July 2024, began in February 2025. It was completed about one month behind schedule. Mitsubishi Electric System & Service handled engineering, procurement, and construction (EPC). Itochu supplied the battery system.
Taiyoko Support Center, co-applying with Sinanen, received an approximately 271 million yen subsidy to build the facility under Tokyo Metropolitan Government’s FY2023 support scheme for grid-scale storage assets within the TEPCO TSO area.
The Melife Asahi Branch facility’s five-hour duration enables longer shifting than the 3- to 4-hour systems common in Japan, but at lower average spreads. In July 2025, the five-hour day-ahead spread averaged 9.08 yen per kWh, compared with 10.25 yen for three-hour and 9.66 yen for four-hour systems.
Sinanen has no other disclosed BESS projects under development.
