The largest electric producers in the US continue to reduce emissions of key air pollutants, according to an annual analysis of power plant emissions.
The new report analyzed publicly reported data on carbon dioxide, nitrogen oxides (NOx), sulfur dioxide (SO2), and mercury emissions from the nation’s 100 largest electric power producers, including Duke, Southern, NextEra Energy, Exelon and AEP. These 100 biggest companies account for 85 percent of the nation’s power production.
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. This echoes last year’s benchmarking report.
CO2 emissions 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, the report says.
Despite the overall declines, there is still significant variability among power producers, with some power providers achieving fleet-wide CO2 emissions rates that are 10 times lower than others. Duke, the largest electric power producer in the US, for example, has a CO2 emission rate (determined by dividing emissions by electricity produced) of 1,129 compared to Exelon, the fourth largest producer, with a CO2 emission rate of 80. And no. 93, Big Rivers Electric, has a CO2 emission rate of 2,294.
The report says three primary factors 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 US has more than doubled in the past five years to over 100 gigawatts. Their combined output is now comparable to total hydroelectric generation in the US. Nuclear power continues to be the largest source of zero-carbon generation in the country at 62 percent of total non-emitting output.
The report also ranks states by the amount of each pollutant released. 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.