The Calpine Los Medanos Energy Center natural gas-fired power plant in Pittsburg, California, in February.
CNN  — 

The Environmental Protection Agency on Thursday proposed one of its most highly anticipated climate rules to date, compelling nearly all US power plants that generate the nation’s electricity to capture or otherwise slash their planet-warming fossil fuel emissions.

The rules would apply to the nation’s fleet of existing and new power plants that run on coal and natural gas – two major fossil fuels, which are the root cause of the climate crisis. The Biden administration’s proposal would push utilities to outfit many power plants with costly carbon capture technology or add clean hydrogen fuel to reduce their emissions.

Unlike the Obama-era Clean Power Plan, which faced fierce opposition that rose to the Supreme Court, the proposed rules will leave it to individual utilities to choose how to meet the emissions standards – which will ultimately be implemented and enforced by individual states, EPA officials said. Some power plants that are slated to close in the next few years may not have to meet the new requirements.

Between 2028 and 2042, the EPA estimated the rules would cut about 617 million metric tons of carbon pollution from existing coal and new gas plants. In addition, the agency estimates the rules will cut between 214 and 407 million metric tons of carbon dioxide from existing gas plants.

EPA and White House officials said the proposed rules would help meet President Joe Biden’s goal of 100% clean electricity by 2035, while only marginally raising costs for the nation’s ratepayers. EPA Administrator Michael Regan said his agency estimated that while baseline electricity costs would go up 2% by 2030, they would rise just 0.08% further by 2040.

“We believe that where we will end up will be squarely in line with the president’s goal,” Regan told reporters. “We’re looking at a negligible impact on electricity prices, while yielding climate and public health benefits that far exceed those costs.”

Speaking at the White House on Thursday, Biden said the new EPA rules proposal “kicks off a public commitment to engage with labor and industry and environmentalists and other experts to make sure we make a major step forward in the climate crisis, protecting public health.”

Combined with a larger suite of regulations aimed at cutting pollution from oil and gas, vehicles, refrigerants, the new rules that the EPA has put forth in the past few years could save up to 15 billion metric tons of plant-warming pollution, Regan said.

Much of that comes from the administration’s recent proposals to cut vehicle emissions, but the clean power plant rules are critical. The power sector makes up a quarter of overall US emissions, but it holds outsized importance since it will provide power for electric vehicles and help decarbonize heavy industry.

“Getting carbon pollution out of the power sector is the lynchpin by which we tackle carbon pollution throughout the rest of the economy,” Sam Ricketts, a former adviser to Washington state Gov. Jay Inslee who now works with Evergreen Action and the Center for American Progress, told CNN.

The rule will likely face new legal challenges and political headaches. But Regan said the new power plant rules “would bring us one step closer in our mission to safeguard the air our children breathe.”

How the new power plant rules would work

The Obama-era Clean Power Plan focused on getting power plants to change how they generated electricity, and ultimately was blocked by Supreme Court. But the Biden EPA’s proposal focuses on outfitting existing plants with technology to capture pollution before it escapes into the air, and it gives utilities the ability to choose how they meet the new standard.

The agency is betting that much if this can be done through carbon capture and sequestration: catching carbon pollution at its source, after which it can be stored or reused. According to the EPA rules, carbon capture would be used for baseload power plants that generate a lot of electricity and expect to have a long life – operating after the year 2040.

For plants that generate less electricity, or ones that are shutting down earlier, the rules would be different. For instance, some categories of plants could add clean hydrogen to the mix – starting at 30% clean hydrogen early in the 2030s and ramping up to over 90% clean hydrogen by the end of the decade.

“Each power plant is going to have its own individual set of circumstances,” Jay Duffy, an attorney and expert on power plant emissions at nonpartisan group Clean Air Task Force, told CNN. “Some of them may already be old and marginal, and it might make more sense for them to not make some big pollution control investment later in their life.”

Many of the proposed rules would go into effect years from now – a recognition from the EPA that much of this technology isn’t in wide use yet.

Carbon capture has traditionally been quite expensive to add to power plants, causing some utilities to choose to shut plants down and replace them with cheaper, renewable energy like solar or wind. However, the Inflation Reduction Act came with significant subsidies for carbon capture to make the technology cheaper and on par with other technologies that can cut emissions.

“Essentially, the costs of (carbon capture) are minimal” and comparable to other technologies given the tax credits in the IRA, Duffy said.

Still, a utility industry source said that even if IRA subsidies bring the costs down, there’s no escaping the fact that there’s little existing pipeline and storage infrastructure for captured carbon in the US. Clean hydrogen projects are similarly nascent, the source said.

But others said the long timelines and some flexibility for industry in EPA’s proposed rule is a recognition of that.

“They’re trying to phase it in over time,” Carrie Jenks, the executive director of Harvard Law School’s Environmental & Energy Law Program, told CNN. “I’m sure they’re considering the infrastructure that’s needed.”

Regan told reporters that some plants would shut down, though didn’t offer a precise number.

“The short answer is yes, we will see some retirements within the system,” Regan said. “But this is really a decision that will be made state by state, company by company.”

The rules could face challenges

The new EPA rules landed with immediate criticism from lawmakers and officials in a coal-heavy state.

Democratic Sen. Joe Manchin of West Virginia has already vowed to oppose any future EPA nominee in the Senate over the rule. Meanwhile, Manchin’s Republican colleague Sen. Shelley Moore Capito of West Virginia called it an attempt to “kill American energy jobs” and vowed to introduce a Congressional Review Act bill to attempt to overturn it.

And though the EPA’s regulatory ability survived one Supreme Court challenge last year, it could face new attempts to squash it. West Virginia Attorney General Patrick Morrisey suggested the rules were headed for a court battle.

“Based upon what we currently know about this proposal, it is not going to be upheld, and it just seems designed to scare more coal-fired power plants into retirement — the goal of the Biden administration,” Morrisey, a Republican, said in a statement. “That tactic is unacceptable, and this rule appears to utterly fly in the face of the rule of law. The U.S. Supreme Court has placed significant limits on what the EPA can do — we plan on ensuring that those limits are upheld, and we expect that we would once again prevail in court against this out-of-control agency.”

Still, administration officials and advocates underscored they believed the rule comports with the Supreme Court’s recent decision in West Virginia v. EPA and is one that will survive future legal challenges.

“I have confidence in its durability,” Ricketts said. “The EPA has learned the lessons. … I think they’re operating tightly in the bounds of what the Clean Air Act and Supreme Court allow.”

While Duffy said it would be no surprise if the new rules were challenged in the courts, he added that he “wouldn’t expect this rule to present the same sort of big legal questions that the Supreme Court usually takes up.”

Regan announced the new proposed rules on Thursday at the University of Maryland where he spoke directly to young voters about the Biden administration’s climate goals.

The slate of EPA rules combating pollution, Regan said, made him “optimistic about what’s possible for the future of our nation.”

This story has been updated with more information.