Even analysts who agree that the country needs more power plants that can run at all hours say that forcing aging coal units to stay online can be counterproductive, because they can distort energy markets and make it harder for states and companies to plan to bring new power plants online.

“Using a blunt instrument like this to keep the legacy coal fleet online could backfire,” said Devin Hartman, director of energy and environmental policy at the R Street Institute. “There are a ton of risks.”