Table A6.  Approximate Heat Rates for Electricity, and Heat Content of Electricity, 1949-2007                       (Btu per Kilowatthour)
Year	Approximate Heat Rates 1 for Electricity Net                                                         Generation						Heat Content 6 of Electricity 7
	Fossil-Fueled Plants 2,3		Nuclear Plants 4		Geothermal Energy Plants 5
1949	15,033		– –		– –		3,412
1950	14,030		– –		– –		3,412
1951	13,641		– –		– –		3,412
1952	13,361		– –		– –		3,412
1953	12,889		– –		– –		3,412
1954	12,180		– –		– –		3,412
1955	11,699		– –		– –		3,412
1956	11,456		– –		– –		3,412
1957	11,365		11,629		– –		3,412
1958	11,085		11,629		– –		3,412
1959	10,970		11,629		– –		3,412
1960	10,760		11,629		23,200		3,412
1961	10,650		11,629		23,200		3,412
1962	10,558		11,629		23,200		3,412
1963	10,482		11,877		22,182		3,412
1964	10,462		11,912		22,182		3,412
1965	10,453		11,804		22,182		3,412
1966	10,415		11,623		22,182		3,412
1967	10,432		11,555		21,770		3,412
1968	10,398		11,297		21,606		3,412
1969	10,447		11,037		21,606		3,412
1970	10,494		10,977		21,606		3,412
1971	10,478		10,837		21,655		3,412
1972	10,379		10,792		21,668		3,412
1973	10,389		10,903		21,674		3,412
1974	10,442		11,161		21,674		3,412
1975	10,406		11,013		21,611		3,412
1976	10,373		11,047		21,611		3,412
1977	10,435		10,769		21,611		3,412
1978	10,361		10,941		21,611		3,412
1979	10,353		10,879		21,545		3,412
1980	10,388		10,908		21,639		3,412
1981	10,453		11,030		21,639		3,412
1982	10,454		11,073		21,629		3,412
1983	10,520		10,905		21,290		3,412
1984	10,440		10,843		21,303		3,412
1985	10,447		10,622		21,263		3,412
1986	10,446		10,579		21,263		3,412
1987	10,419		10,442		21,263		3,412
1988	10,324		10,602		21,096		3,412
1989	10,432		10,583		21,096		3,412
1990	10,402		10,582		21,096		3,412
1991	10,436		10,484		20,997		3,412
1992	10,342		10,471		20,914		3,412
1993	10,309		10,504		20,914		3,412
1994	10,316		10,452		20,914		3,412
1995	10,312		10,507		20,914		3,412
1996	10,340		10,503		20,960		3,412
1997	10,213		10,494		20,960		3,412
1998	10,197		10,491		21,017		3,412
1999	10,226		10,450		21,017		3,412
2000	10,201		10,429		21,017		3,412
2001	10,333	[2]	10,448		21,017		3,412
2002	10,173		10,439		21,017		3,412
2003	10,241		10,421		21,017		3,412
2004	10,022		10,427		21,017		3,412
2005	9,999		10,435		21,017		3,412
2006	9,919	[R]	10,434	[R]	21,017		3,412
2007	9,919	[E]	10,434	[E]	21,017	[E]	3,412
1The values in columns 1-3 of this table are for net heat rates.  See "Heat Rate" in Glossary.  6See "Heat Content" in Glossary.  2Used as the thermal conversion factor for hydro, solar/photovoltaic, and wind electricity net generation to approximate the quantity of fossil fuels replaced by these sources.  Through 2000, also used as the thermal conversion factor for wood and waste electricity net generation at electric utilities; beginning in 2001, Btu data for wood and waste at electric utilities are available from surveys. 7The value of 3,412 Btu per kilowatthour is a constant.  It is used as the thermal conversion factor for electricity retail sales, and electricity imports and exports. 3Through 2000, heat rates are for fossil-fueled steam-electric plants at electric utilities.  Beginning in 2001, heat rates are for all fossil-fueled plants at electric utilities and independent power producers. R=Revised.  E=Estimate.  – – = Not applicable.   4Used as the thermal conversion factor for nuclear electricity net generation. Sources:  See "Thermal Conversion Factor Source Documentation," which follows this table. 5Used as the thermal conversion factor for geothermal electricity net generation.