Frequently Asked Questions

How much coal, natural gas, or petroleum is used to generate a kilowatthour of electricity?

The amount of fuel used to generate electricity depends on the efficiency or heat rate of the generator (or power plant) and the heat content of the fuel. Power plant efficiencies (heat rates) vary by types of generators, power plant emission controls, and other factors. Fuel heat contents also vary.

Two formulas can be used to calculate the amount of fuel used to generate a kilowatthour (kWh) of electricity:

Amount of fuel used per kWh = Heat rate (in Btu per kWh) / Fuel heat content (in Btu per physical unit)
Kilowatthour generated per unit of fuel used = Fuel heat content (in Btu per physical unit) / Heat rate (in Btu per kWh)

Calculation examples using these two formulas and the assumptions below:

Amount of fuel used to generate 1 kWh:
- Coal = 0.00052 short tons or 1.04 pounds
- Natural gas = 0.01011 Mcf (an Mcf equals 1,000 cubic feet)
- Petroleum = 0.00173 barrels (or 0.07 gallons)
Kilowatthour generated per unit of fuel used:
- 1,927 kWh per ton, or 0.96 kWh per pound, of coal
- 99 kWh per Mcf (1,000 cubic feet) of natural gas
- 578 kWh per barrel, or 13.76 kWh per gallon, of petroleum

Assumptions:

Power plant heat rates (for steam electric generators in 2014)
Coal = 10,080 Btu/kWh
Natural gas = 10,408 Btu/kWh
Petroleum = 10,156 Btu/kWh

Fuel heat contents (for fuels received by electric power industry in 2014)
Coal = 19,420,000 Btu per short ton (2,000 pounds) Note: Heat contents of coal vary widely by types of coal.
Natural gas = 1,029,000 Btu per 1,000 cubic feet (Mcf)
Petroleum = 5,867,946 Btu per Barrel (42 gallons) Note: Heat contents vary by type of petroleum product.

Last updated: February 29, 2016