Hydropower Generation

Abstract

There are two main types of hydropower, conventional and pumped storage. The former dates back more than a century. It developed with the growth of Japanese industries, although its share subsequently declined with the rise of fossil fuel-based thermal power plants. Several decades later, as a global warming countermeasure, hydropower has reemerged as an important solution, together with an increase in the use of renewable energy sources. R&D of pumped-storage hydropower has progressed with the growth of nuclear energy, and Japan came into possession of world-class advanced technology. However, despite being an essential power source to stabilize power systems (particularly with the coming full electricity deregulation), the importance of pumped-storage hydropower has yet to be affirmed, because of a lack of methods to assess its value. Nevertheless, the increased use of renewable energies, which are also unstable power sources, has underlined the importance of power system stabilization measures. This explains the significant expectations of pumped-storage hydropower features, such as its storage function and its ability to swiftly absorb supply and demand imbalances. Both types of hydropower are power sources that suit the culture and geography of Japan and will certainly contribute to the energy society on the basis of an energy storage system.