The nation’s largest electric producers continue to substantially reduce emissions of key air pollutants, the latest comprehensive analysis of U.S. power plant emissions shows.
The new report analyzed publicly reported data on carbon dioxide, nitrogen oxides, sulfur dioxide (SO2), and mercury emissions from the nation’s 100 largest electric power producers, which account for 85 percent of the nation’s power production.
Notably, the report, “Benchmarking Air Emissions of the 100 Largest Electric Power Producers in the United States,” concludes that since 2000 emissions of all four major pollutants have dropped while total electricity generation and the American economy have grown.
“The nation’s electric power providers are in the midst of an unprecedented shift toward cleaner sources of energy,” said Dan Bakal, director of electric power at Ceres. “Yet progress is uneven, which highlights the need for many of the nation’s power providers to accelerate their transition to cleaner resources and lower carbon emissions.”
The report, which ranks emissions by producer and state, finds that CO2 emissions—a key driver of climate change—totaled 1.96 billion tons in 2014. But they dropped 15 percent between 2005 and 2014, and with preliminary data suggesting another 6 percent decline in 2015, CO2 emissions are almost back down to 1990 levels. This will help the U.S. continue to make progress towards the goals agreed upon in the Paris Climate Agreement. Despite the overall declines, there is still variability among power producers, with some power providers achieving fleet-wide CO2 emissions rates that are 10 times lower than others.
“Power plants are pouring out less and less of the carbon pollution driving climate change. And America is embracing the benefits of clean energy,” said Starla Yeh, senior policy analyst in the Climate and Clean Air Program at the Natural Resources Defense Council. “Renewable energy is widely expected to continue its strong growth, which will put the electricity sector in an excellent position to help the U.S. meet its international commitments. We must reach this milestone to avoid the worst impacts of climate change.”
The report identifies three primary factors that are driving the drop in CO2 emissions: energy efficiency improvements, coal plant retirements driven by market conditions and new air pollution standards, and an increase in generation from low- and zero-emitting resources, including natural gas, wind, and solar. Installed wind and solar capacity in the U.S. has more than doubled in the past five years to over 100 GW. Their combined output is now comparable to total hydroelectric generation in the U.S. Nuclear power continues to be the largest source of zero-carbon generation in the country at 62 percent of total non-emitting output.
Together with CO2, SO2, NOx, and mercury are associated with environmental and public health problems, including climate change, mercury deposition, acid rain, smog, regional haze and fine particle air pollution, which can lead to asthma and other respiratory illnesses.
Other key findings in the benchmarking report include:
In 2014, power plant SO2 and NOx emissions were 80 percent and 75 percent lower, respectively, than in 1990, when Congress passed major amendments to the Clean Air Act.
Mercury air emissions from power plants have decreased 55 percent since 2000. Mercury emissions will continue to decline as the first federal limits on mercury and other hazardous pollutants from coal-fired power plants went into effect in 2015 and 2016.
In 2014, power plants were responsible for 62 percent of SO2 emissions, 14 percent of NOx emissions, 58 percent of mercury air emissions (among sources reporting to EPA’s Toxic Release Inventory), and 37 percent of all CO2 emissions in the U.S.
Air pollution is highly concentrated among just a few electricity producers: Ten producers were responsible for 56 percent of SO2 emissions; 43 percent of NOx; 49 percent of mercury; and 40 percent of CO2 emissions.
Coal accounted for 40 percent of the power produced by the top 100 power producers, followed by natural gas at 26 percent, nuclear at 22 percent, and renewable power, including large hydroelectric, and other sources at 12 percent.
“The Benchmarking Air Emissions report is an important resource for tracking changes in the environmental performance of the U.S. electric power sector and making this information available to our stakeholders – owners, customers, employees and communities,” said Chuck Barlow, vice president of environmental strategy and policy for Entergy Corp.. “Since 2001, Entergy has operated under voluntary commitments to stabilize our CO2 emissions through 2020 at 20 percent below year 2000 levels. Through 2015, our cumulative emissions are more than 9 percent below our 2001–2015 target. Our fleet emission intensity is well below that of a new combined-cycle gas unit.”
The Benchmarking report is the 12th in a series since 1997 highlighting environmental improvements and progress in the nation’s electric sector. The 100 power producers evaluated in the report represent 85 percent of the electric power generated in the U.S. and 87 percent of the industry’s air emissions. The report ranks each power company’s emissions and its emission rate (determined by dividing emissions by electricity produced) for each pollutant against the emissions and rates of the other companies.
In addition, states are ranked by the amount of each pollutant released. For example, the 10 states with the highest CO2 pollution are: Texas, 263.3 million tons; Florida, 119 million tons; Indiana, 114.1 million tons; Pennsylvania, 109.3 million tons; Ohio, 106 million tons; Illinois, 101 million tons; Kentucky, 94.1 million tons; Missouri, 82.8 million tons; West Virginia, 79.5 million tons; and Alabama, 73.4 million tons.
When ranked by CO2 emissions rate (lb CO2/MWh), the top 10 states in descending order are Kentucky, Wyoming, West Virginia, Indiana and Missouri, North Dakota, Utah, New Mexico, Ohio, and Colorado.
Based on 2014 generation and emissions data from the U.S. Energy Information Administration (EIA) and EPA, the benchmarking report is a collaborative effort between Ceres; Bank of America; power producers including Calpine, Entergy, and Exelon; and the Natural Resources Defense Council. It is authored by M.J. Bradley & Associates.