Slovakia’s Slovenské elektrárne achieved a historic nuclear production record in 2025, it generated 21,013 gigawatt-hours (GWh) of carbon-free electricity, the company announced. Slovenské elektrárne, Slovakia’s largest power producer, generated 95 percent of this amount of electricity from nuclear energy.
The utility delivered 18,804 GWh to the grid after internal consumption. Nuclear power remained the portfolio’s backbone, with five operating units delivering a record 17,930 GWh. Officials attributed the success to high plant availability, a cooler summer, and the shortest-ever maintenance outage at the Mochovce plant. It is worth noting that construction on the first two VVER-440 units at the Mochovce plant began in 1982. While work on units 3 and 4 followed in 1986, the project stalled in 1992. Ultimately, the first two reactors were completed and entered service in 1998 and 1999, respectively.
The hydroelectric production suffered from a prolonged drought, hydroelectric plants produced 1,691 GWh last year. Run-of-river plants saw their lowest delivery in history, forcing the company to rely heavily on pumped-storage facilities. These plants were deployed at their highest levels in 20 years, pumping water during midday solar surpluses when prices turned negative and generating power during high-demand morning and evening peaks.
“From an operational standpoint, 2025 was a success for our nuclear plants,” said Ján Mazánik, Manager of Ancillary Services Trading and Resource Optimisation. “Units were kept at slightly higher outputs than planned, helped by a cooler summer which reduced the need to lower power levels.”