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
 2 10,333 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
 R 9,919 R 10,434 21,017 3,412
2007
 E 9,919 E 10,434 E 21,017 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.