The Okinawa Yanbaru Seawater Pumped Storage Power Station (沖縄やんばる海水揚水発電所 Okinawa Yanbaru Kaisui Yōsui Hatsudensho) is a hydroelectric power station located in Kunigami Okinawa Japan and operated by the Electric Power Development Company. It is the world’s first pumped-storage to use seawater for storing energy. Its maximum output is 30 MW.