Krpeľany hydroelectric power plant is part of the Krpeľaly reservoir constructed just downstream the Orava and Váh river confluence. Its first control stage of the highest-laying diversion cascade of HPP´s built on the Váh river, even if this plant only followed the Dubnica and Nové Mesto cascades in building the Váh water works. As the HPP capacity requirements, and in particular for peak-load electricity supply, have increased over time, its maximum useful flow is substantially higher than that of the lower-laying cascades – 3 x 70 = 210 m3.sec-1.
Slovenské elektrárne operates 31 hydroelectric plants. Their combined output is 1,652.7 MW, representing approximately 38.4% of the Company’s total installed capacity. Majority of the installations is located on the Váh River cascade, or the longest river in Slovakia. On average, the hydroelectric sources generate 2,070 MW annually (consumption of pumped storage power stations excluded), or some 11% of the electricity produced by Slovenské elektrárne.
Because of their very variable power output and operational flexibility, hydroelectric plants are capable to satisfy the swiftly changing demands in the daily-load diagram, pairing nicely with the base load supply covered by nuclear power plants. Slovenské elektrárne has 736.6 MW installed in river hydropower plants and 916.4 MW in pumped storage power stations.