Erex will invest in its first co-located battery storage project, a 1.98MW/8.15MWh system that will be installed at a Nishinippon Plant Engineering and Construction-affiliated 1.98MWAC/2.25MWDC solar power plant in Munakata City, Fukuoka Prefecture, the company announced on April 1, 2026.
According to the statement, the battery system, which is expected to come online in the first half of FY2027, will be owned by a special purpose company (SPC) wholly owned by Erex. The power plant will be converted from the feed-in-tariff (FIT) to the feed-in-premium (FIP) scheme and continue to be owned by Nishinippon Plant Engineering and Construction’s unit Munakata Asty Solar Generation.
The SPC will purchase the solar asset’s output at the equivalent of its FIT price. Erex, which will aggregate the project, said that it will consider ways to maximize the battery system’s value beyond arbitrage, through use for frequency regulation and promotion of local consumption of renewable energy. The companies did not disclose further details about the contractual arrangements or grid connection setup.
METI data suggests the power plant operates under a 40 yen per kWh FIT contract valid until July 2033.
Nishinippon Plant Engineering and Construction will be in charge of the battery system’s engineering, procurement, and construction (EPC). It will also handle its operation and maintenance (O&M) alongside that of the existing solar power plant. The Kyushu Electric Power Group company said it will use TMEIC equipment.
Unlike traditional co-located assets with shared ownership of generation and storage, the project allows the solar plant owner to switch to FIP to limit lost output due to changes that will see FIT assets curtailed first, while benefiting from storage-driven value optimization without incurring battery-related capital expenditures. The battery owner, meanwhile, can capture solar time-shift value without taking on generation asset ownership risk.
