Carbon dioxide produced per Kilowatt Hour

Using the US as an example total annual electricity net generation by utility-scale electric power plants ( plants with at least one megawatt of electric generation capacity) of about 4.23 trillion kilowatthours (kWh) from all energy sources resulted in the emission of about 1.65 billion metric tons of carbon dioxide (CO₂).

Emissions from electricity generation vary by type of energy source and by type and efficiency of electric power plants. The amount of CO₂ produced per kWh during any period of time will vary according to the sources of electricity supplied to the electric power grid during that time. Therefore, electricity-related CO₂ emissions and CO₂ emission factors will vary hourly, daily, monthly, and annually.

The table below presents data on total annual electricity net generation and CO₂ emissions at utility-scale electric power plants and a CO₂ emission factor (pounds of CO₂/kWh) for coal, natural gas, and petroleum, and the average of all energy sources. Actual CO₂ emissions per KWh from specific power plants may vary considerably from the factors in the table.