The Fukuoka Osmotic Power Plant is a salinity gradient power facility located in Fukuoka Prefecture, Japan, and operated by the Fukuoka District Waterworks Agency. [1] [2] [3] Situated at the Uminonakamichi Nata Seawater Desalination Center, it began operation on 5 August 2025. [4] [5] The installation is the first in the country to be built for salinity gradient power generation and the second in the world to achieve continuous operation, following an earlier project in Denmark. [6] The estimated annual generation capacity is 880,000 kilowatt-hours, equivalent to the average electricity consumption of approximately 220 households. [7] [8] [9] The project's construction cost was approximately ¥700 million. [10] [11]