A number of Japanese power companies plan to introduce new pumped-storage hydroelectric plants that enable them to fine-tune their power output and consumption.
In pumped-storage hydroelectricity systems electricity is generated when water stored at a higher elevation flows to a lower elevation, spinning a turbine. The water is then pumped back up to the upper reservoir, often at night, using excees baseload (ie cheap rate) electricity, often from nuclear or coal fired plants. The electricity generated from the storage plant is used to meet peak demand during the daytime.
Conventional pumped-storage hydroelectric plants cannot change the speed at which water is pumped but variable-speed pumps can, allowing the utility to vary its power flow from the storage depending on the load.
Kansai Electric Power Co. plans to convert two of its 320 MW pumped-storage plants to variable-speed plants, one in fiscal 2013 and the other in fiscal 2014. The company hopes to fine-tune its power generation, to meet the growing contribution of wind power. In addition the company aims to reduce carbon dioxide emissions by replacing thermal power plants with hydroelectric ones. Chubu Electric Power is also considering upgrading a facility in Gifu Prefecture.
Tokyo Electric Power Co. (Tepco) plans to build more variable-speed hydroelectric plants in fiscal 2020 or after. With solar power generation estimated to rise by roughly 300% over the period, Tepco believes it will need more regulated power sources.
Kyushu Electric Power Co. and Hokkaido Electric Power Co. are also building new hydropower plants.
Plans to adopt advanced pumped-storage hydroelectric plants are also moving ahead overseas. Projects are under way in several U. states including California, as well as in European countries such as Switzerland and Portugal.
