The Ilava hydroelectric power plant was a second hydroelectric power plant on the Váh river and built on the same diversion channel – the first built on the Váh river (the third in geographic order) made up of the Dolné Kočkovce reservoir and the Ladce, Ilava, Dubnica nad Váhom and Trenčín HPP´s. It was built 10 years after the Ladce HPP and, based on the experience in its operation, it was already designed to a higher flow rate of 2 x 75 m3.sec-1, even though also this is little in the light of today´s needs.
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.