"A large Southern utility said Tuesday that it would close 30 percent of its North Carolina coal-fired power plants by 2017, a step that represents a bet that natural gas prices will stay acceptably low and that stricter rules are coming on sulfur dioxide emissions, which cause acid rain.
The utility, Progress Energy, based in Raleigh, said it would close 11 coal-fired power plants built between the 1950s and 1970s.
"Some of these plants are quite old," said Bill Johnson, the chief executive of the company. But, he added, "They have a lot of useful life left in them, absent the need to put emissions control units on them."
Mr. Johnson also said the company was taking a risk by reducing its output of carbon dioxide, which is not yet regulated, in the near term. He and others expect that Congress will eventually impose a limit on carbon dioxide emissions, possibly in the form of percentage reductions based on a baseline year. By closing the plants now, Progress is effectively cutting its baseline, meaning it may have to reduce emissions even further in the future."