Benchmarking Air Emissions of the 100 Largest Electric Power Producers in the United States 2023

After a post-pandemic rebound in emissions in 2021, last year the U.S. electric system resumed its long-term trend of decreasing emissions because of growth in zero-emitting generation and coal’s decline. However, natural gas was responsible for more generation in 2022 than any preceding year and fossil sources continue to be responsible for nearly 60% of electricity generation. Overall, energy production from zero-carbon power sources held steady at 40%. 

The report shows that the power sector is not on track to cut carbon emissions enough to achieve national and international climate goals.  

The report examines data from the U.S. Energy Information Administration and the U.S. Environmental Protection Agency (EPA) regarding four power plant pollutants: sulfur dioxide (SO2), nitrogen oxides (NOx), mercury, and CO2. For the electric sector overall, in 2022, power plant SO2 and NOx emissions were 94% and 87% lower, respectively, than in 1990 when Congress passed major amendments to the Clean Air Act.

With major technological improvements across the electric power sector and new investment spurred by the historic Inflation Reduction Act—including $350 billion for clean energy projects—the time is ripe for utilities to achieve a cleaner, more efficient, and equitable energy future. 

Additional findings: 

• Despite the changes between 2021 and 2022, the current generation mix still represents a significant shift from a decade ago. In 2012, coal accounted for 37% of power production, while natural gas generated only 30%. In 2022, coal accounted for 19%, while natural gas has risen to 39%. 

• Ninety of the top 100 power producers generated power from zero-carbon resources in 2021, which accounted for more than 85% of the national total generated from resources including nuclear, hydro, and renewables. 

• In 2022, power plant SO2 and NOx emissions were 8% and 3% lower, respectively, than they were in 2021.  

• Mercury air emissions from power plants continue to decrease—93% since 2000. The first-ever federal limits on mercury and other hazardous air pollutants from coal-fired power plants went into effect in 2015. 

The benchmarking analysis is a collaborative effort between Ceres, Constellation Energy and NRDC. It is authored by ERM.