Pumped storage data Project name Project size (MW) Maximum discharge (m3/sec) Effective head (m) Tokyo Electric Power Company Shin Tagasegawa PSP (1981) 1280 644 229m Tamahara PSP (1986) 1200 276 518 Imaichi PSP (1991) 1050 240 524 Electric Power Development Corporation Shin Toyone PSP (1973) 1125 645 203 Okukiyotsu PSP (1982) 1000 260 470 Shimogo PSP (1991) 1000 314 387 Kansai Electric Okutataragi PSP (1998) 1932 376 383 Okawachi PSP (1995) 1280 382 395 Okuyoshino PSP (1980) 1206 288 505 Key: (date in brackets) = year commissioned