For more than three centuries, Maine has been exploiting its enormous waterpower potential. In recent decades, however, waterpower has been surpassed in importance by oil-fired steam plants and, most recently, by nuclear power. In referendums in 1980 and 1982, voters decided that the Maine Yankee Atomic Power Company station in Wiscasset, Maine's only nuclear power plant, should remain open and that future nuclear power development should be allowed. For 25 years, the plant was the state's most important producer of electricity; in 1994 it accounted for 74% of power generation. However, due to economic and regulatory concerns, its owners closed the plant in 1997. As of 2003 the plant was being dismantled and the site restored for other uses.
Installed generating capacity (utility and nonutility) in 1999 totaled 2,956,000 kW. Power production in 1999 totaled 13 billion kWh. Oil-fired steam units accounted for 37% of electric power generation in 1999, and hydroelectric units for 29%.
All fuel oil and coal must be imported; natural gas, piped into the southwest corner of the state, is available in Portland and the Lewiston-Auburn area. In 2000 Maine's total per capita energy consumption was 440 million Btu (110.9 million kcal), ranking it 10th among the 50 states.