This data analysis — the 15th in a series going back to 1997 and highlighting environmental performance in the United States’ power sector — examines and compares air pollutant emissions of the 100 largest power producers in the U.S. based on their 2017 generation, plant ownership and air emissions data. This 2019 benchmarking analysis is once again a collaborative effort, based on publicly reported data. The analysis shows that in 2017, for the first year ever, zero-carbon sources took the lead in power generation.
The 2019 air benchmarking analysis is the 15th collaborative effort of its kind, based on publicly reported data.
In 2017, the U.S. electric system continued its general shift away from coal toward lower-and zero-emitting sources. In fact, this year’s analysis shows that in 2017, for the first time ever, zero-carbon sources took the lead in power generation.
This report is intended to facilitate the comparison of emissions performance by combining generation and fuel consumption data compiled by the U.S. Energy Information Administration (EIA) with air emissions data on sulfur dioxide (SO2), nitrogen oxides (NOx), carbon dioxide (CO2) and mercury (Hg) compiled by the U.S. Environmental Protection Agency (EPA), error checking the data, and presenting emissions information for the nation’s 100 largest power producers in a graphic format that aids in understanding and evaluating the data.
Some other key findings from this year’s benchmarking report:
Also for the first time, natural gas (at 35 percent) overtook coal (at 27 percent) as the largest source of electricity in the U.S. This marks a shift away from higher-emitting power sources compared to a decade ago (2006), when coal and natural gas accounted for 49 percent and 20 percent of power production, respectively.
For the electric sector overall, in 2018, power plant SO2 and nitrogen NOx emissions were 92 percent and 84 percent lower, respectively, than they were in 1990 when Congress passed major amendments to the Clean Air Act to help combat air pollution. These power plant SO2 and NOx emissions were 5.5 percent and 3.7 percent lower than they were in 2017.
Power sector CO2 emissions increased about 1 percent between 2017 and 2018, in a reversal of the annual declines that had occurred each year since 2014. Nevertheless, 2018 power plant CO2 emissions were 4 percent lower than 1990 levels, and 25 percent percent lower than their peak in 2007. Some of the factors driving this longer-term trend include energy efficiency improvements and the displacement of coal by natural gas and renewable energy resources.
Mercury air emissions from power plants have decreased 90 percent since 2000. The first-ever federal limits on mercury and other hazardous air pollutants from coal-fired power plants went into effect in 2015 to help improve air quality.
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This report is intended for a wide audience, including electric industry executives, environmental advocates, financial analysts, investors, journalists, power plant managers, and public policymakers. Plant and company-level data used in this analysis, along with interactive charts, are available at https://www.mjbradley.com/content/emissions-benchmarking-maps.
The organizations that fund this analysis believe maintaining public access to this information is essential to tracking the industry’s performance and making accurate and informed analyses and policy decisions.