Total generation in 2000 amounted to 26.4 billion kWh, of which 35.3% was from fossil fuels, 17.1% from hydropower, and 47.6% from nuclear power. By 2001 nuclear power accounted for 54% of production, thanks to two new reactors that had come on line between 1998 and 2000, reducing Slovakia's dependence on fossil fuels and allowing it to become a net exporter of electricity. Consumption of electricity in 2000 was 25.2 billion kWh. As of 2001, total installed capacity was 7,454,000 kW. The Bohunice nuclear power plant has four 408 MW reactors that became operational in the early 1980s. Slovensky Energeticky Podnik (SEP) is a state-owned enterprise that is the dominant producer and provider of electricity; its transmission system includes 1,519 km (943 mi) of high voltage lines with 14 substations, and 964 km (196 mi) of standard voltage lines with 11 substations.
In November 1993, the Gabcikovo Project began operating. Originally begun as a joint project with Hungary in 1977, it was delayed when all construction stopped in October 1989, because Hungary perceived it as environmentally hazardous to the Danube basin. By May 1992, Hungary agreed to a compromise that allowed the project's completion. The power station has eight Kaplan turbines and generators with an installed capacity of 720,000 kW, enough to satisfy peak demands.
Coal mining produced some 2.5 million tons of lignite in 2001, from reserves of 190 million tons. In early 2003 Slovakia had oil reserves of 9 million barrels. Production in 2002 was 1,000 barrels per day. In the same year the refinery at Slovnaft had a capacity of 115,000 barrels per day. Slovakia's gas consumption is the highest in north-central Europe. In 2002 natural gas was used by 80% of all Slovak households.