Electric Company Actions
| Federal Regulations | Resources
Ground-level ozone is created by chemical reactions between emissions of nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of sunlight. Emissions from motor vehicles, industrial facilities, electric utilities, construction equipment, locomotives, ships, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOCs. Currently, electric utilities emit only about 10 percent of the nation’s combined emissions of NOx and VOCs.
The Clean Air Act (CAA) requires the U.S. Environmental Protection Agency (EPA) to establish national ambient air quality standards (NAAQS) – at levels that are protective of public health with an adequate margin of safety – for six pollutants, including ozone. Breathing elevated ozone concentrations can trigger adverse health effects, such as respiratory inflammation, particularly for sensitive groups like asthmatics. Ground-level ozone also can reduce crop yields and tree growth.
EPA reviewed its ozone standards in 1997 and set a tighter limit of 0.08 parts per million (ppm) for a new measuring time period, the 8-hour average (with rounding, the standard actually is 0.084). The CAA requires EPA to complete a review of each national ambient air quality standard (NAAQS), including ozone, at five-year intervals and make any necessary revisions. EPA in March 2008 again tightened the standard, to 0.075 ppm.
What are electric utilities doing to help reduce ozone?
The electric power industry nationally has reduced its national total NOx emissions by 54 percent over the period of 1980 to 2007. Electric generators emit virtually no VOCs, the other primary ingredient in the formation of ozone. Since 1980, NOx reductions from electric utilities have been required to meet the CAA’s Acid Rain Program requirements and the “NOx SIP Call.”1
Under the Acid Rain Program, coal-fired boilers were required to reduce annual NOx emissions in the United States by over 2 million tons per year beginning in 2000. In addition, EPA’s NOx SIP Call to address long range transport of ozone across 22 eastern states and the District of Columbia, reduced summer season NOx emissions by approximately 1 million tons per year beginning in 2004. To comply with the NOx SIP Call, electric utilities invested approximately $10 billion to install emission control technology and hundreds of millions of dollars each year to operate the equipment. As a result, the electric power sector will reduce emissions of NOx by 80-90 percent throughout most of the eastern U.S. during the summer ozone season (May-September).
In fact, during the 2004 ozone season, power industry NOx emissions in the eastern U.S. were about 70 percent lower than in 1990, before implementation of the Acid Rain Program. 2 EPA, in its November 2008 National Air Quality Status and Trends Report, says that "Ozone levels did not improve in much of the East until 2002, after which there was a significant decline. This decline is largely due to reductions in oxides of nitrogen (NOx) emissions required by EPA's rule to reduce ozone in the East, the NOx SIP Call."
The electric power sector has done all of this despite a steady climb in electricity demand, and without sacrificing the reliability and affordability of the electricity that we produce. Between 1980 and 2007 national electric generation increased 75 percent.
Despite all of the progress that has been made, EPA recognizes that some areas of the country do not consistently meet the ozone standard and recently finalized several regulations, such as the Clean Air Interstate Rule (CAIR) and the Clean Air Diesel Rule, to reduce interstate transport of NOx emissions that contribute to the formation of ozone (and particulate matter).
CAIR has been struck down by a federal appeals court, although the court is considering appeals and whether to allow EPA to fix the rule. If the court rejects the appeals and vacates the rule, then EPA and states will work on a replacement program that is certain to be more stringent. At a minimum, states and EPA will implement the NOx SIP Call discussed above to deliver similar emission reductions to those that would take place under CAIR.
The CAIR NOx program covers 25 States and the District of Columbia. In 2009, CAIR would reduce NOx emissions from electric utilities by 1.7 million tons or 53% from 2003 levels. By 2015, CAIR would reduce power plant NOx emissions by 2 million tons, achieving a regional emissions level of 1.3 million tons, a 61% reduction from 2003 levels. EPA estimated the cost for the electric power sector to comply with CAIR (as well as the Clean Air Mercury Rule and Clean Air Visibility Rule) at $41 billion, and a portion of that cost will be for additional NOx emission controls. 3
3 The majority of costs associated with CAIR are not ozone-related. In addition to NOx emission reductions, CAIR requires a significant reduction in electric power sector emissions of sulfur dioxide (SO2) across 28 states and the District of Columbia. At full implementation, CAIR will reduce power plant SO2 emissions in affected states to 73% below 2003 emissions levels.