J-POWER’s wholly-owned subsidiary J-Wind completed the environmental impact assessment for the 17.2MW New Aso Nishihara onshore wind project expected to replace the 17.5MW original power plant in Nishihara Village, Kumamoto Prefecture. It submitted the final assessment on August 1 and received METI approval on August 21, 2025.
According to the document released for public viewing on September 9, 2025, J-Wind plans to build four 4.3MW turbines across a 70ha site, replacing the 10 1.75MW turbines comprising the original project commissioned in 2005. Construction was set to begin in August 2025 and the repowered asset is expected to start commercial operation in October 2027.
J-Wind launched the environmental impact assessment process in May 2020, advancing it to the methodology stage in November of the same year and to the draft report stage in October 2023. The company shut down the original asset, which operated under a 22 yen per kWh feed-in-tariff (FIT) contract valid until May 2025, in January 2023 due to aging.
The repowering project was FIT-certified in FY2020 when replacement onshore wind assets were offered 16 yen per kWh, two yen lower than the 18 yen per kWh available to greenfield projects at the time. It is unclear whether J-POWER plans to operate New Aso Nishihara under the fixed payment scheme or convert it to the feed-in-premium (FIP) scheme and sell its output via a PPA.
J-POWER’s domestic wind portfolio includes over 20 operational power plants totaling over 550MW. It also has multiple projects under construction, including the 51.6MW Kaminokuni No. 3 Wind Farm, the 19.5MW New Minami Osumi Wind Farm, and the 40.8MW Minami Ehime No. 2 Wind Power Plant. Additionally, it holds a 40% stake in the 220MW Kitakyushu Hibikinada Offshore Wind Farm expected to begin operation within FY2025.
