Minamiaiki Dam

The Minamiaiki Dam is a rock-fill embankment dam on the Minamiaiki River in Minamiaiki, Nagano Prefecture, Japan. Together with the Ueno Dam, it provides water for the Kannagawa Hydropower Plant owned by the Tokyo [Electric Power Company]. The Minamiaiki dam is the higher of the two dams. When completed, the station will have the largest power output of any pump-storage power plant in the world at around 2.82 GW. Since 2005, Unit 1, with an installed capacity of 470 MW, is in commercial operation. Commercial operation of Unit 2 is planned in 2012, commercial operation of all six units as late as 2020.