The plant, operated by the Fukuoka District Waterworks Agency, marks Japan as only the second country in the world to deploy this technology after a Danish company pioneered it in 2023, according to Kyodo News. Local officials and experts present the project as a breakthrough for renewable energy that can run around the clock, unaffected by weather or sunlight, and without emitting carbon dioxide. “I feel overwhelmed that we have been able to put this into practical use. I hope it spreads not just in Japan, but across the world,” said Akihiko Tanioka, professor emeritus at the Institute of Science Tokyo, in comments to Kyodo News.