LCS has proposed small-scale, distributed, and inexpensive new pumped storage power generation utilizing existing multipurpose dams as lower ponds. In the 2020 proposal, in order to improve the accuracy of the potential storage capacity and cost figures for the new pumped storage power generation plant, the nationwide potential storage capacity that can be developed and the power generation cost were calculated for various conditions based on the actual topography, etc. As a result, the annual potential storage capacity that can be practically developed is 180 to 420 TWh/year, and the power generation cost is 19 to 21 JPY/kWh, indicating that the new pumped storage power generation is a promising power storage system for the future.
　In this proposal, the specifications of the new pumped storage power generation plant were reviewed in line with the disaster prevention measures implemented by the government, in light of the prediction that floods and droughts may occur twice as often as they do currently owing to the climate change in the future. As a result, by increasing the water storage capacity of the upper pond for example, a function comparable to the raising of dam bodies, which is one of the government's disaster prevention measures, could be expected, and the construction cost would be 40% less than the construction cost of raising the dam body.
　Through these reviews, the annual potential storage capacity could be increased to 700 TWh/year, which is 1.7 times the 2020 proposal. In addition, as a result of the investigation into the potential and distribution of solar and wind power generation that could be developed in the future as power sources for pumping water for the new pumped storage power generation that is widely distributed throughout the country, the potential is about eight times greater than that of the new pumped storage power generation, the distribution is widely dispersed in each region as the new pumped storage power generation, and it was found that the new pumped storage power generation can be fully utilized if a transmission line network and a distribution system is constructed in the future.