The United States has over twice the generating capacity of any other country. By the end of 2006, 986,000 megawatts of capacity supply the nation’s demand for electricity. Capacity measures the steady hourly output that a generating system can supply.

At EIA we catagorize the electrical system into two segments—the Electric Power Sector and the Combined Heat and Power Sector. The Electric Power Sector is further divided into Electric Utilities and Independent Power Producers. An Independent Power Producer owns or operates facilities that generate electricity primarily for the public, but is not a Utility. Combined Heat and Power plants produce both heat and electricity.

Capacity additions in 2006 were less than half the amount of the previous two years. The industry added only about 8,000 megawatts of new capacity (new generators) in 2006. About 65% of the new capacity was fueled by natural gas.

Since the late 1990s, natural gas has been the fuel of choice for the majority of new generating units. In 2006, natural gas capacity accounted for nearly 40% of the total generating capacity. Coal-fired capacity dropped only slightly.

What is the outlook through 2030?¹

	With growing electricity demand and the retirement of older generating capacity, EIA projects that 292,000 megawatts of new capacity (including combined heat and power) will be needed by 2030.
	Coal-fired (54%) and natural-gas-fired (36%) plants are expected to account for the majority of the new capacity.
	Generally, coal-fired capacity is more economical to operate than natural gas-fired capacity because coal prices are considerably lower than natural gas prices. On the other hand, natural gas-fired plants can be started and stopped relatively quickly. They are only needed for a comparatively few hours daily and ensure reliability for the system in times of high demand.
	Of the expected capacity expansion through 2030, 6% is projected to be renewable and 4% nuclear.
	1  From Annual Energy Outlook 2007.  For the recently released 2008 forecast, follow the link below to Annual Energy Outlook.

More information on this subject can be found in the following EIA publications:
    Electricity projections from the Annual Energy Outlook
    Electricity capacity from the Electric Power Annual
    Additional basic electricity information