America’s Biggest Polluters:

Carbon Dioxide Emissions from Power Plants in 2007

Carbon Dioxide Emissions from Power Plants in 2007

Environment Maryland Research and Policy Center

Executive Summary

The United States relies heavily on outdated technology and limited resources for most of its electricity needs. While the production of clean, renewable energy such as wind and solar power is growing, the vast majority of American electricity comes from burning fossil fuels—coal, oil, and natural gas—and from nuclear power.  Our long-time dependence on fossil fuels is a threat to our future. It wreaks havoc on our environment by polluting our air, land, and water; and it puts our entire economy at risk due to our reliance on imports from unfriendly parts of the world. Most importantly, it fuels global warming—the most profound environmental problem of our time, with ever growing impacts that will impose threats to our safety and immense financial cost on our society. Power plants are the single largest source of U.S. carbon dioxide (CO2) emissions, the main pollutant that fuels global warming.
Coal is the biggest culprit. Coal supplies just under half of America’s electricity – more than any other source – and is the dirtiest of all fuels. Coal has the highest carbon content of any fossil fuel per unit of energy, meaning that burning coal for electricity produces more carbon per kilowatt-hour generated than does burning oil or natural gas. America’s fleet of coal-fired power plants emitted more than 80 percent of CO2 pollution from U.S. power plants in 2007 and 36 percent of the total U.S. CO2 pollution, as well as disproportionate amounts of smog- and soot-forming pollutants, toxic mercury, and other toxic air pollutants.

This report examines CO2 emissions of America’s power plants. We analyze 2007 plant-by-plant data from the Environmental Protection Agency’s Acid Rain Program; 2007 is the most recent year for which final data is available. The report finds that America’s power is dirty – and also very old – and that these two qualities tend to go hand-in-hand.

Key findings include the following for 2007:

America’s power is old:

  • Two-thirds of fossil-fuel electricity was generated by plants built before 1980. We are reliant on plants more than 30 years old for the majority of our electricity. See ES Figure 1.
  • The oldest plants in the nation – which have been in operation for as long as 70 years – are located in Indiana, Wisconsin, New York, Iowa, and North Carolina. These dinosaur plants were built in the same decade that the television first became commercially available.

America’s power is dirty:

  • In 2007, power plants released 2.56 billion tons of CO2, equivalent to the amount produced by 449 million of today’s cars. This represents 42 percent of the total U.S. CO2 emissions in 2007
  • Georgia, Alabama, and Indiana are home to the dirtiest power plants. Along with Texas, Michigan, and Arizona, these states are home to power plants that each emitted more than 20 million tons of carbon dioxide pollution – equivalent to the pollution from 3.5 million of today’s cars – in 2007. Georgia and Texas both have two plants that belong to this elite dirty club.
  • Texas, Ohio, Florida, Indiana, and Pennsylvania emitted the most CO2 pollution from power plants. Texas power plants emitted nearly twice the amount of CO2 emitted by power plants in Ohio and Florida, the next highest polluting states.

The oldest and dirtiest often go hand-in hand:

  • The oldest power plants are dirty. Plants built before 1980 produced 73 percent of U.S. CO2 emissions from power plants. These represent just less than half of all plants, indicating that the older half of plants pollute a disproportionate amount. See ES Figure 2.
  • The dirtiest power plants are old. Of plants that produced more than five million tons of CO2 pollution in 2007, 83 percent were built before 1980. This subset of 129 plants, just 10 percent of plants—the oldest of the dirtiest—generated almost half of our electricity and produced half of the CO2 emissions from power plants in 2007. See ES Figure 3.
  • Older means dirtier on average. For each year older a coal generator is on average, it created 0.001 more tons of CO2 for each Megawatt-hour of electricity it produced in 2007. The relationship is slightly stronger for natural gas.

Cleaning up America’s fleet of aging, inefficient power plants is critical to stopping global warming. We cannot achieve the real and sustained reductions in global warming pollution that science shows are urgently needed to stop the worst effects of global warming unless we begin now to reduce carbon pollution from the utility sector.

The most recent report by the United Nations’ Intergovernmental Panel on Climate Change, released in 2007, found that in order to have a 50-50 chance of avoiding dangerous global warming, developed nations as a whole must reduce global warming emissions by 25-40 percent below 1990 levels by 2020 and by 80-95 below 1990 levels by 2050. Cutting pollution from the oldest and dirtiest power plants is a key to being able to achieve these reductions.

Moving to clean energy means leaving old, inefficient, and dirty technology behind. The U.S. Department of Energy projects that electricity demand will remain relatively flat over the next two decades, growing at an annual average rate of less than 1 percent – and that’s without factoring in the enormous efficiency gains that we can and should make. These projections make it clear that allowing polluting fossil fuels to maintain the monopoly over America’s electricity will result in a much smaller market for renewables. Making the move to clean, renewable energy will cut pollution as well as jump-start our economy and create millions of clean energy jobs.

In order to build a clean energy economy and stop global warming, lawmakers should adopt the following recommendations:

  1. The Environmental Protection Agency should finalize its proposal to require coal plants and other big smokestack industries to meet modern standards for global warming pollution when new plants are built or existing plants are upgraded.
  2. Congress should pass strong clean energy and global warming legislation that caps global warming pollution at science-based levels, establishes strong mandates for clean energy production, and does not repeal the sections of the Clean Air Act that require coal-fired power plants to meet modern standards for global warming pollution.
  3. Congress should eliminate subsidies that help keep our nation dependent on fossil fuels for its electricity.


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