Table 8.2. Average Tested Heat Rates by Prime Mover and Energy Source, 2007 - 2012
(Btu per Kilowatthour)

Prime Mover Coal Petroluem Natural Gas Nuclear
2007
Steam Generator 10,158 10,398 10,440 10,489
Gas Turbine -- 13,217 11,632 --
Internal Combustion -- 10,447 10,175 --
Combined Cycle W 10,970 7,577 --
2008
Steam Generator 10,138 10,356 10,377 10,452
Gas Turbine -- 13,311 11,576 --
Internal Combustion -- 10,427 9,975 --
Combined Cycle W 10,985 7,642 --
2009
Steam Generator 10,150 10,349 10,427 10,459
Gas Turbine -- 13,326 11,560 --
Internal Combustion -- 10,428 9,958 --
Combined Cycle W 10,715 7,605 --
2010
Steam Generator 10,142 10,249 10,416 10,452
Gas Turbine -- 13,386 11,590 --
Internal Combustion -- 10,429 9,917 --
Combined Cycle W 10,474 7,619 --
2011
Steam Generator 10,128 10,414 10,414 10,464
Gas Turbine -- 13,637 11,569 --
Internal Combustion -- 10,428 9,923 --
Combined Cycle W 10,650 7,603 --
2012
Steam Generator 10,107 10,359 10,385 10,479
Gas Turbine -- 13,622 11,499 --
Internal Combustion -- 10,416 9,991 --
Combined Cycle W 10,195 7,615 --

Notes: W = Withheld to avoid disclosure of individual company data.

Heat rate is reported at full load conditions for electric utilities and independent power producers.
The average heat rates above are weighted by Net Summer Capacity.
Coal Combined Cycle represents integrated gasification units.

Source: U.S. Energy Information Administration, Form EIA-860, 'Annual Electric Generator Report.'