EPA trying again on power-plant rules; here are four big questions about them. Some answers will be up to states.

Photo by Brendan O'Donnell, Unsplash

The third time maybe the charm for the Environmental Protection Agency to put controls on greenhouse gases from power plants that burn coal and gas. "It's something EPA has tried and failed to do twice before," reports Jean Chemnic of Energy & Environment News. "Both times, the courts threw the rules out . . . . . once for trying to replace fossil fuels with renewable energy and once for not doing enough to confront climate change." Given the topsy-turvy landscape, Chemnic outlines four questions and some answers about what the EPA rules can do and what they may mean for energy companies.

Will coal-fired plants be forced to close? "Maybe. But only incidentally. There's a consensus among legal experts that the Clean Air Act doesn't allow EPA to set a date certain by which U.S. coal generation will cease to exist. . . . The Supreme Court made it plain in its decision last year in West Virginia v. EPA that the agency can only require power plants to use emissions controls that they can employ themselves. In other words, a coal plant must be able to comply with the rules while remaining a coal plant. EPA can't regulate by cutting coal's market share in favor of cleaner fuels — like gas, nuclear or renewables."

Will the rules require gas plants to capture their carbon emissions, too? "Yes — if they're big and run most of the time. The question is what EPA will propose for gas plants that run part-time and ramp up and down to provide the grid with power at times of peak demand. . . . Utilities have argued that these so-called peaker plants play a vital role in maintaining grid reliability. . . . EPA has signaled that it will treat those units 'differently' to keep more of them online. . . . Some environmental justice advocates have expressed dismay that EPA may let dirty plants comply with its rules more easily. But some clean energy experts say peaker units remain useful."

Can power companies and state regulators skip carbon capturing? "Yes. . . . It falls to states to decide how to implement the standards for existing power plants. And the Supreme Court's prohibition against federally mandated fuel switching doesn't necessarily apply to the states, environmentalists say. Julie McNamara, a deputy policy director at the Union of Concerned Scientists, told Chemic, "There's a much wider array of options available to states, and one of those is clean energy resources." Chemnic notes, "States may be able to use existing cap-and-trade programs to meet the rules' requirements. Utilities could then comply with the rule by purchasing credits from another plant that exceeded its required carbon reductions."

Since the EPA already requires new coal plants to use carbon capture, what impact will the new rules have? "A 2015 standard requires new coal plants to capture approximately 40 percent of their carbon. . . . Environmental groups have urged EPA to require new gas plants and existing coal and gas plants to capture and store most of their emissions. . . . Environmental attorneys say there isn't a statutory requirement that prevents EPA from setting stricter rules for existing plants than for new ones." Jay Duffy, litigation director for Clean Air Task Force, told Chemnic, "EPA is required to consider costs, and the costs of retrofitting a plant can be more expensive than for building the pollution control into the new plant — so sometimes the dynamic is such that limits for new plants are tighter than for existing."