¹Excludes 0.6 quadrillion Btu of ethanol, which is included in "Renewable Energy.”
²Excludes supplemental gaseous fuels.
³Includes 0.1 quadrillion Btu of coal coke net imports.
⁴Conventional hydroelectric power, geothermal, solar/PV, wind, and biomass.
⁵Includes industrial combined-heat-and-power (CHP) and industrial electricity-only plants.
⁶Includes commercial combined-heat-and-power (CHP) and commercial electricity-only plants.
⁷Electricity-only and combined-heat-and-power (CHP) plants whose primary business is to sell electricity, or electricity and heat, to the public.

Note:  Sum of components may not equal 100 percent due to independent rounding.
Source:  Energy Information Administration, Annual Energy Review 2007, Tables 1.3 and 2.1b-2.1f, and 10.3.