Serbia and Montenegro has abundant hydroelectric potential, but there are frequent electrical blackouts and brownouts during the peak winter months. Serbia alone accounted for 40% of the electricity production before Yugoslavia broke apart into five separate republics. Since 1992 energy supplies have been interrupted by UN and US sanctions. Hydroelectric projects are located on the Danube, Drina, Vlasina, and Lim rivers. Thermal plants are located at Kostolac and Kosovo. Total electrical capacity in 2001 was 9.6 million kW. Generation of electricity in 2000 amounted to 40 billion kWh, of which 59% was thermal and 41% hydroelectric. Consumption of electricity in 2000 was 31.5% billion kWh.
Serbia and Montenegro is the only Balkan country with substantial coal deposits. Proven reserves as of 1999 totaled 18.2 billion tons, 95% of which was lignite. The country's largest lignite mine is operated by Kolubara Povrsinski Kopovi near Vreoci, Serbia, and has an annual capacity of 14,000 tons. Natural gas production totaled 850 million cu m (30 billion cu ft) in 1997. Crude oil production was reported at 18,000 barrels per day.