Frequently Asked Questions

What is the efficiency of different types of power plants?

One measure of the efficiency of a power plant that converts a fuel into heat and into electricity is the heat rate. The heat rate is the amount of energy used by an electrical generator or power plant to generate one kilowatthour (kWh) of electricity. EIA expresses heat rates in British thermal units (Btu) per net kWh generated. Net generation is the amount of electricity a power plant (or generator) supplies to the power transmission line connected to the power plant. It accounts for all the electricity that the plant itself consumes to operate the generator(s) and other equipment, such as fuel feeding systems, boiler water pumps, cooling equipment, and pollution control devices.

To express the efficiency of a generator or power plant as a percentage, divide the equivalent Btu content of a kWh of electricity (which is 3,412 Btu) by the heat rate. For example, if the heat rate is 10,140 Btu, the efficiency is 34%. If the heat rate is 7,500 Btu, the efficiency is 45%.

EIA only publishes heat rates for fossil fuel-fired generators and nuclear power plants. EIA does not publish estimates for the efficiency of generators using biomass, geothermal, hydro, solar, and wind energy.

Learn more:

Historical average annual heat rates for fossil fuel and nuclear power plants.

Average annual heat rates for specific types of fossil-fuel generators and nuclear power plants for most recent year available.

Last updated: May 13, 2014

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