Effective from today, we hereby announce the start of commercial operations of the Kannagawa Hydroelectric Power Station (HPS) located at Ueno Village, Tano District, Gunma Prefecture.

As a pumped storage power plant generating a maximum output of 2,820 MW (470 MW x 6 Units), the construction of Kannagawa HPS has been in operation since May 1997, utilizing the effective 653 m head between the Upper and Lower dams. Following Unit 1, which has been in operation since December 2005, the start of Unit 2 (470 MW, equivalent to 150,000 households electricity demand) was achieved one month ahead of schedule.

Kannagawa HPS is the ninth pumped storage power plant owned by TEPCO. At Unit 2 (second unit), we again employed the "splitter runner" ^(*1) co-developed with TOSHIBA and for the first time in the world incorporated into Unit 1 allowing for the simultaneous operations of both the pump and turbine blade. This has improved the generating efficiency by 4%, increasing the output by 20 MW per unit.

We will not only continue to maintain the safety and stable operation of Units 1 & 2 already in commercial operations, but will continue to make our utmost efforts to secure a stable electricity supply while always keeping the importance of safety at the forefront of our minds.

(*1) A turbine blade used at the pumped storage hydro generation plant. Via its turning in a rotating direction, generating and pumping operations are realized.

Appendix: Kannagawa Hydroelectric Power Station (PDF 312KB)