Highlights: June 2022

• Electricity Reliability Council of Texas broke its previous all-time high for electricity demand 10 times in 15 days between June 12 and 26.

• The highest 12-month average electricity prices were set in the Midwest (Midcontinent Independent System Operator), the Mid-Atlantic (PJM), and in Louisiana (into Entergy) during June 2022.

• Total U.S. coal stockpiles decreased month over month by 6.1%, reaching 87 million tons in June 2022.

Key indicators

Carbon intensity of U.S. power generation continues to fall but varies widely by state

Data source: U.S. Energy Information Administration, Form EIA-923, Power Plant Operations Report
Note: Net generation is from Form EIA-923. Emissions include total emissions from both electricity generation and the production of useful thermal output. See Electric Power Annual, Appendix A, Technical Notes, for a description of the sources and methodology used to develop the emissions estimates. This graph is based on final 2016 through 2020 data. Preliminary 2021 data indicate aggregate electric power sector emissions may have increased by about 7% in 2021, but final state data are not yet available to calculate state carbon intensity metrics for 2021.

The carbon intensity of U.S. power generation (measured as pounds [lbs.] of carbon dioxide [CO₂] emissions per megawatthour [MWh] of net generation) continued to trend downward in 2020. This decline is being driven by two market developments: the displacement of coal by natural gas and the increased market share of non-emitting renewable generation. Looking over the last five years of data, natural gas (980 lbs. CO₂/MWh in 2020) has increased from 34% of total net generation in 2016 to 41% in 2020, while coal (2,274 lbs. CO₂/MWh in 2020) has decreased from 30% of total net generation in 2016 to 19% in 2020. Meanwhile, non-emitting renewable generation (primarily wind, hydroelectric, and solar generation) has expanded from 15% of total net generation in 2016 to 20% in 2020. These two developments have pushed total CO₂ emissions from U.S. power generation down by 18% between 2016 (1,928 million metric tons) and 2020 (1,553 million metric tons).

Data source: U.S. Energy Information Administration, Form EIA-923, Power Plant Operations Report
Note: Net generation is from Form EIA-923. Emissions include total emissions from both electricity generation and the production of useful thermal output. See Electric Power Annual, Appendix A, Technical Notes, for a description of the sources and methodology used to develop the emissions estimates.

These national trends, however, only tell part of the story because the carbon intensity of power generation varies significantly by state and region. In 2020, the carbon intensity of power generation at the state level ranged from a low of 8.4 lbs. CO₂/MWh in Vermont to 1,970.8 lbs. CO₂/MWh in Wyoming. The states with the lowest carbon intensities (less than 500 lbs. CO₂/MWh) are clustered in northern New England and the Pacific Coast; these states also include New York, Idaho, and South Dakota. The common denominator for these states is a high percentage of generation from renewable sources or a combination of high renewable and nuclear sources. Eight of these states—Vermont (99.9%), Washington (83.1%), Idaho (76.1%), Oregon (67.5%), South Dakota (80.5%), Maine (76.7%), New York (58.2%), and California (51%)—get over 50% of their generation from renewable resources. New Hampshire, meanwhile, gets 76.4% of its net generation from nuclear (60.3%) and renewables (16%) combined. It is important to point out, however, that these are generation carbon intensities and end-use consumption intensities will differ depending on the import/export profile of generation sources used to serve a state.

States with the second-lowest carbon intensities (500 lbs. CO₂/MWh–1,000 lbs. CO₂/MWh) tend to have a mix of renewable, natural gas-fired, and nuclear generation that keeps their carbon intensities low relative to the national average. Twenty-six states fall into this broad category, ranging from South Carolina (516.4 lbs. CO₂/MWh), which generates 87.9% of its power from nuclear (55.6%), natural gas (24.6%), and renewables (7.8%), to Montana (983.3 lbs. CO₂/MWh), which generates 60.6% of its power from renewables (59.4%) and natural gas (1.2%).

States with the highest carbon intensities (1,000 lbs. CO₂/MWh–1,500 lbs. CO₂/MWh and more than 1,500 lbs. CO₂/MWh) tend to have higher percentages of generation coming from coal or petroleum than the national average. These states are clustered in the Midwest, upper Plain states, Rocky Mountains, and the non-contiguous United States. Seventeen states fall into these two tiers, ranging from Michigan (1,099.6 lbs. CO₂/MWh), which generates 26.2% of its power from coal, to Wyoming (1,970.8 lbs. CO₂/MWh), which generates 79.4% of its power from coal.

Data source: U.S. Energy Information Administration, Form EIA-923, Power Plant Operations Report
Note: Net generation is from Form EIA-923. Emissions include total emissions from both electricity generation and the production of useful thermal output. See Electric Power Annual, Appendix A, Technical Notes, for a description of the sources and methodology used to develop the emissions estimates.

Despite the large statewide variance in carbon intensity levels, most states are reducing the carbon intensity of their power generation. Just as carbon intensity has been dropping at the national level, it is also dropping at the state level; 43 states and the District of Columbia reduced the carbon intensity of their power generation in 2020 relative to 2016. Eight states reduced their carbon intensities by more than 300 lbs. CO₂/MWh, 16 states and the District of Columbia reduced their carbon intensities between 150 lbs. CO₂/MWh and 300 lbs. CO₂/MWh, and 19 states reduced their carbon intensities by up to 150 lbs. CO₂/MWh. Seven states, meanwhile, increased the power intensity of their power generation during the same period.

Data source: U.S. Energy Information Administration, Form EIA-923, Power Plant Operations Report
Note: Net generation is from Form EIA-923. Emissions include total emissions from both electricity generation and the production of useful thermal output. See Electric Power Annual, Appendix A, Technical Notes, for a description of the sources and methodology used to develop the emissions estimates.

The states that reduced the carbon intensity of their power generation between 2016 and 2020 the most were Tennessee (by 486 lbs. CO₂/MWh), Maryland (by 477 lbs. CO₂/MWh), Iowa (by 443 lbs. CO₂/MWh), Kansas (by 371 lbs. CO₂/MWh), and Oklahoma (by 348 lbs. CO₂/MWh). Interestingly, these states followed somewhat different paths in reducing the carbon intensity of power generation. Tennessee increased its share of nuclear (up 8.3%) and natural gas-fired (up 5.2%) generation in place of coal-fired (down 21.6%) generation. Iowa, Kanas, and Oklahoma, located in the central wind belt, similarly reduced carbon intensity by increasing wind generation and retiring coal-fired generation. In Maryland, natural gas’s share of generation increased 24.5% (from 14.6% in 2016 to 39.1% in 2020) while coal’s share decreased by 27.9% (from 37.2% in 2016 to 9.3% in 2020).

• Principal Contributor:

• Name: Paul McArdle
  Email: Paul.McArdle@eia.gov