Environmental Issues: Air
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This report examines and compares the air pollutant emissions of the 100 largest power producers in the United States based on 2008 plant ownership and emissions data. Table ES.1 lists the 100 largest power producers featured in this report ranked by their total electricity generation from fossil fuel, nuclear, and renewable energy facilities. These producers include public and private entities (collectively referred to as "companies" or "producers" in this report) that own roughly 2,200 power plants and account for 85 percent of reported electric generation and 89 percent of the industry's reported emissions.
The report focuses on four power plant pollutants for which public emissions data are available: sulfur dioxide (SO2), oxides of nitrogen (NOx), mercury (Hg), and carbon dioxide (CO2). These pollutants are associated with significant environmental and public health problems, including acid deposition, global warming, fine particle air pollution, mercury deposition, nitrogen deposition, ozone smog, and regional haze. The report benchmarks, or ranks, each company's absolute emissions and its emission rate (determined by dividing emissions by electricity produced) for each pollutant against the emissions of the other companies. In addition, this report calls attention to the opportunities and risks companies may face from potential changes in environmental regulations. Becoming aware of a company's exposure to these business opportunities and risks is the first step in developing effective corporate environmental strategies.
Several issues and trends are influencing investment decisions in the U.S. electric power sector, including trends in fuel prices, technology developments, and environmental regulations. This report discusses trends in natural gas supply and prices, as well as trends in coal- and oil-fired power plant retirements. The report also examines renewable energy developments in the U.S., including wind and solar, and trends in energy efficiency investments and programs. The report also highlights numerous regulations related to air quality and climate change that are facing the electric generating sector. As these regulatory programs evolve, they will have a significant impact on electric generation in the U.S. by driving investment in lower-carbon technologies and forcing inefficient plants into retirement. In addition, the report discusses the basic structure of the U.S. electric power sector and emissions associated with delivered electricity. This analysis is intended to help inform policy and educate investors and companies on the key issues associated with the electric power industry.
Electric Industry Emission Trends
Since 1990, power plant emissions of SO2 and NOx have decreased and CO2 emissions have increased.
Power plants only began to report their mercury emissions in 1998; therefore, longer-term emissions trends are not available.
Overall Emissions from Electricity
The electric industry in the U.S. is a major source of air pollution.
Air Pollution Rankings and Comparisons
The 100 largest power producers generated 85 percent of electric power in the U.S. in 2008. The 100 largest producers generated 97 percent of all nuclear power, 91 percent of all coal-fired power, 83 percent of all hydroelectric power, 73 percent of all natural gas-fired power, and 52 percent of all non-hydroelectric renewable power.
Air pollution emissions from power plants are highly concentrated among a small number of producers. For example, almost a quarter of the electric power industry's SO2 and CO2 emissions are emitted by just two and five top 100 producers, respectively. Figure ES.1 summarizes the distribution of emissions among electric power producers.
Electric power producers' emission levels and emission rates vary significantly due to the amount of power produced, the efficiency of the technology used in producing the power, the fuel used to generate the power, and installed pollution controls. In 2008, total generation among the 100 largest power producers varied from 6.4 million megawatt hours to 200 million megawatt hours and:
Electric power producers' mercury emissions from coal plants ranged from 0 to 8,719 pounds, and mercury emission rates ranged from 0.0 lbs/GWh to 0.105 lbs/GWh.
Using this Report
The information in this report supports informed decision-making in several areas:
1 U.S. Energy Information Administration (EIA). "Emissions of Greenhouse Gases in the United States 2008." December 2009. p.16.
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