Energy Information Administration FAQs:

"In 2017, emissions of carbon dioxide (CO₂) by the U.S. electric power sector were 1,744 million metric tons, or about 34% of the total U.S. energy-related CO₂ emissions of 5,140 million metric tons.¹

CO₂ emissions from U.S. electric power sector by source, 2017

Source	Million Metric Tons	Share of Total
Coal	1,207	69%
Natural gas	506	29%
Petroleum	19	1%
Other3	12	<1%
Total	1,744

¹ Preliminary data for 2017. 

² Includes CO₂ emissions from the combustion of miscellaneous waste materials made from fossil fuels and by some types of geothermal power generation."
 

Learn More:

• Historical and most recent available U.S. energy-related CO₂ emissions by source and sector (Data), Energy Information Administration
  Statistics from the Monthly Energy Review on carbon dioxide emissions by source (coal, natural gas, petroleum) and sector; includes biomass and biofuel emissions

• Electricity Sector Emissions (Webpage), Environmental Protection Agency
  Introductory information for electricity-related emissions, electricity emission trends, and how emissions can be reduced

• Life Cycle Assessment Harmonization (Website), National Renewable Energy Laboratory
  Report on the total greenhouse gas emissions involved in generating electricity from a wide range of sources, including coal, oil, natural gas, nuclear, wind, hydropower, geothermal, biofuels, and different types of solar power