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Report: Power Plant Emissions Down Substantially

According to a report released on May 28, NOX and SO2 emissions in 2012 were 74% and 79% lower, respectively, than they were in 1990 when Congress passed major amendments to the Clean Air Act.

Although power plant CO2 emissions have actually increased 13% from 1990 levels, the trend has been down in recent years, declining 13% between 2008 and 2012. In addition, mercury emissions have decreased 51% since 2000.

The report, “Benchmarking Air Emissions of the 100 Largest Electric Power Producers in the United States,” was produced through a collaborative effort between Ceres, Bank of America, four power producers—Calpine, Entergy, Exelon, and Public Service Enterprise Group—and the Natural Resources Defense Council; it was authored by M.J. Bradley and Associates. The report is the 10th in a series, which began in 1997, using publicly reported data to compare the emissions performance of the 100 largest power producers in the U.S. The current report is based on 2012 generation and emissions data.

It was noted that the electric power industry is in a period of transition. Demand has been flat and natural gas prices have remained low, spurring increased use of gas in the electric generation sector.

Since 2010, plant owners have announced the retirement of about 60 GW of coal-fired capacity (roughly 18% of the fleet). Coal plant utilization has also declined. The average annual capacity factor for coal-fired power plants in 2008 was 73%, but that declined to 60% in 2013.

In contrast, natural gas consumption by the electric sector has increased by nearly 60% over the past 10 years. Natural gas combined cycle power plants’ average capacity factors have increased from 40% to 47% between 2008 and 2013.

While total electricity generation has decreased slightly since 2010, renewable generation (excluding large hydroelectric projects) increased 31% between 2010 and 2012. Wind led the way with over 13 GW of capacity added in 2012.

A small number of companies account for the majority of emissions. Nearly a quarter of the electric power industry’s SO2 and NOX emissions come from just three and four top producers, respectively. American Electric Power (AEP), Southern Co., and Duke Energy generated the most SO2, while AEP, Duke, FirstEnergy, and MidAmerican Energy emitted the most NOX. Of course, the sizes of these companies contribute to their positions within the rankings, as all are among the top 12 electric power producers in the U.S.

More telling is the state-by-state data. CO2 emissions per megawatt-hour of power produced were found to vary almost twenty-fold among the states, with Kentucky, Wyoming, West Virginia, Indiana, and North Dakota having the highest CO2 emissions rates, while Idaho, Vermont, Washington, Oregon, and Maine had the lowest.

“One objective of this report is to help illuminate the complex emissions landscape in this country—the struggle to balance environmental priorities with economic sustainability,” said Chuck Barlow, Entergy’s vice president of environmental strategy and policy.

“The electric power industry is firmly on the path toward a low carbon energy future, and history shows that it is not only capable of meeting new pollution limits, but that it can do so while keeping our lights on and our economy growing,” said Mindy Lubber, president of Ceres, a nonprofit sustainability group that helped produce the report.

Aaron Larson, associate editor (@AaronL_Power, @POWERmagazine)

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