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

Element per unit of energy

  • Coal: 1.12 pounds/kWh
  • Natural gas: 7.36 cubic feet/kWh
  • Petroleum liquids: 0.08 gallons/kWh
  • Petroleum coke: 0.82 pounds/kWh

Energy per unit of element

  • Coal: 0.89 kWh/pound
  • Natural gas: 0.14 kWh/cubic foot
  • Petroleum liquids: 12.69 kWh/gallon
  • Petroleum coke: 1.21 kWh/pound

These values are averages based on data from the Electric Power Annual, November 2022. These values are great for quick calculations or doing some broad comparisons. If you are looking for exact measurements, it is important to understand a few things. The averages are calculated from most of the electricity generated in the United States. These are the few exclusions:


  • Commercial Sectors
  • Industrial Sectors
  • Heat Used in Combined Heat & Power Plants

Actual Amounts

The EIA provides equations and data to calculate more precise values. However, they use terms that aren't as well known. We want to provide you the equations and explanations. 

To calculate electricity generation from a fuel you'll need two things. You will need to know the Heat Content of the fuel and the Heat Rate of the system.

Heat Content is similar to Energy Density. It is the measurement of energy per unit volume of a substance with different units. Where Energy Density typically has units of J/kg or J/m^3. Heat Density is measured in British Thermal Units per the volumetric unit of the substance. The volumetric units used for Natural Gas are Cubic Feet, Petroleum is measured in barrels, and coal is Short Ton.

Heat Rate is the term used for the efficiency of the system. Units for Heat Rate are Btu per kWh. 

Electric Power Annual is an annual publication by the Energy Information Administration that includes data on electric power data in the United States. It includes generating capabilities for the grid, fuel consumptions, costs of fuels, retail sales, revenue, and other values.

This long document can be overwhelming. For ease of use, check out these specific data sets below. Here is where you can find the Heat Contents of specific fuel types.