In West Virginia, the largest of the two new lists included the relatively small Morgantown Energy Facility and the Grant Town power plant, but contained a surprise: American Electric Power's John E. Amos plant in Putnam County.
Jeff Deyette, a UCS energy analyst and report co-author, said his group believes the largest of the plant's three units -- a 1,300-megawatt generator opened in 1973 -- would have trouble competing with natural gas if it were forced to add a bag-house to control particulate matter pollution and activated carbon injection, or ACI, to reduce mercury emissions.
But Melissa McHenry, a spokeswoman for AEP, said her company is confident that the John Amos facility can meet the latest federal mercury and air toxics limits with its existing pollution controls, which include $1 billion sulfur dioxide scrubbers that serve all three of the plant's units.
"We are fully committed to continuing to operate the Amos units long term," McHenry said.
McHenry said that while natural-gas prices are low now, its costs have historically been volatile. Many coal-fired plants are going to close, she said, but AEP plans to maintain use of a diversity of fuels, including coal.
"The real challenge that has happened is the very low price of natural gas," McHenry said. "But natural-gas prices have been very volatile, and it's not clear that shale gas has ended that volatility."
Deyette acknowledged that if John Amos can meet the latest U.S. Environmental Protection Agency limits with its existing pollution equipment that could help keep it economical going forward. Even assuming AEP were to invest money for bag-houses and additional mercury controls, John Amos was close to not making the UCS list, Deyette said.
"It's sort of a yellow-flag situation," Deyette said. "There is a risk that the Amos plant faces going forward."
The Union of Concerned Scientists said that shuttering the 59 gigawatts of coal-fired generators the new study identified, along with the 41 gigawatts already slated for retirement would reduce the electric power sector's annual carbon dioxide emissions up to 16.4 percent, or 410 million tons.
"This is an historic opportunity to accelerate the transition to a clean energy economy," the report said. "Decisions we will make in the next three to five years can improve public health, reduce global warming, and create a more resilient energy system."
Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.