photo coal pile
Photo by jpmueller99/CC

Old coal is the dirtiest kind, and it still keeps the lights burning in large swaths of the U.S.

A new report from the Government Accountability Office says the U.S. is getting much of its electricity from power plants that are more than 30 years old – the biggest polluters.

The GAO found that coal-fired units in operation since 1978 or earlier provided 45 percent of the electricity from fossil fuel in 2010, but produced more than their share of emissions compared to newer units: 75 percent of sulfur dioxide emissions (3.6 times), 64 percent of nitrogen oxide emissions (2.1 times), and 54 percent of carbon dioxide emissions (1.3 times) – pollutants linked to respiratory health effects, smog, and climate change.

The report was requested by U.S. Sen. Sheldon Whitehouse, D-Rhode Island, who has praised proposed mercury standards for power plants, and educated some fellow lawmakers about the realities of climate change.

A total of 93 percent of the juice produced by older fossil fuel units came from coal, the report says. The old coal plants, compared to newer natural gas units, emitted more than 90 times as much sulfur dioxide, twice as much carbon dioxide, and five times as much nitrogen oxides.

About 45 percent of electricity in the U.S. comes from coal, followed by natural gas at 24 percent.

A map here, from page 24 of the report (pdf), shows fossil fuel generation by location, with a cluster of dots in the Midwest.

photo graphic distribution of electricity generation fossil fuel units 2010
from the GAO report

Old coal units in the Great Lakes region were among those that produced the most emissions, along with the South Central and Southeast regions of the U.S.

These three regions bore the brunt of the generation burden, at 62 percent, and accounted for 69 percent of the sulfur dioxide, 59 percent of the nitrogen oxides, and 63 percent of the carbon dioxide emitted from older coal units nationwide.

For the Midwest, here are fossil-fueled units per state, and carbon dioxide emissions in tons, as one example:

  • Illinois: 196 units; 107,058,198 tons
  • Indiana: 126; 124,321,920
  • Iowa: 48; 45,296,689
  • Kansas: 48; 39,757,268
  • Michigan: 96; 74,272,141
  • Minnesota: 45; 32,900,506
  • Missouri: 102; 83,182,289
  • Nebraska: 29; 26,402,103
  • North Dakota: 11; 33,609,781
  • Ohio: 135; 125,054,961
  • South Dakota: 8; 3,765,854
  • Wisconsin: 84; 49,753,419

“Nonetheless, older (coal) units remain an important part of the electricity generating sector, particularly in certain regions of the United States,” the report says.

By the way, the U.S. Environmental Protection Agency just announced it will be holding hearings on May 24 in Chicago and Washington, D.C., on a proposed new carbon pollution standard for new power plants. Currently, power plants can emit CO2 at will.

However, the proposed rule would only apply to new power plants, not the ones analyzed in the GAO report.