The U.S. Environmental Protection Agency (EPA) has adopted a rule that shifts to states much of the responsibility for regulating carbon dioxide (CO2) emissions from power plants, potentially opening a door to the increased burning of coal, while simultaneously rescinding the Obama-era Clean Power Plan (CPP).

“The Affordable Clean Energy rule (ACE) gives states the regulatory certainty they need to continue to reduce emissions and provide affordable and reliable energy for all Americans,” said EPA Administrator Andrew Wheeler at a ceremony in Washington, DC, Wednesday attended by Trump administration officials, members of congress representing coal states including Pennsylvania and West Virginia, labor union heads and coal miners, some wearing mining gear, including hard hats.

“Unlike the CPP, the ACE rule adheres to the four corners of the Clean Air Act. EPA sets the best system of emission reductions, and then states set the standards of performance. This is how the Clean Air Act says the process should work. ACE specifically identifies heat-rate improvements as the best system of emission reduction for coal-fire power plants, and these improvements can be made at individual facilities.”

“Also contained within the rule are new implementing regulations for ACE and future existing source rules under Clean Air Act section 111(d). These guidelines will inform states as they set unit-specific standards of performance.”

ACE was first proposed by EPA in August 2018. EPA said the rule would put in place a "reasonable program focused on potential upgrades to coal plants...[and] leaves the market alone and doesn’t pick winners and losers.” As proposed, the regulation:

  • Defines the "best system of emission reduction" for greenhouse gas (GHG) emissions from existing plants as on-site, heat-rate efficiency improvements;
  • Provides states with a list of "candidate technologies" that can be used to establish standards of performance and incorporated into their state plans;
  • Updates EPA’s New Source Review Permitting program to incentivize efficiency improvements at existing power plants; and
  • Aligns Clean Air Act section 111(d) general implementing regulations to give states adequate time and flexibility to develop their state plans.

“Because of what you’ve done with the Affordable Clean Energy Plan, we’re going to see continuous reductions in nitrous oxides, continuous reductions in fine particulate matter, [and] continuous reductions in mercury and CO2,” White House chief of staff Mick Mulvaney told Wheeler Wednesday.

EPA issued a notice of proposed rulemaking announcing it would repeal CPP in October 2017, nearly two years after a final version of the plan had been unveiled by the Obama administration. The CPP, which embraced renewables, solar and wind power, but not so much natural gas, called for states to reduce emissions by 32% below 2005 levels by 2030.

Under the CPP, states were to develop and implement plans that ensured power plants achieved goals for reducing CO2 emissions between 2022 and 2029, and final CO2 emission performance rates by 2030. The CPP would have given states the option of choosing between either an emissions standards plan or a state measures plan to reduce emissions. They would also have had the option of trading emissions rate credits with other states.

The CPP faced repeated legal challenges. Twenty-seven states sued over the plan, arguing that it was an overreach by EPA. In February 2016, the U.S. Supreme Court temporarily blocked implementation of the rule until all legal challenges are resolved.

CPP had to be rescinded, according to Bill Wehrum, assistant administrator of EPA’s Office of Air and Radiation, because it had “fundamental legal flaws that just cannot be reconciled under what the Clean Air Act clearly directs us to do and the clear limits on the authority that are provided in the Clean Air Act.” The most important piece of ACE is EPA’s “determination of what best technology is, and as the administrator said, best technology is efficiency improvements that exist in coal-fired plants.”

But CPP had its defenders. A coalition of 236 mayors of U.S. cities urged EPA to halt its plans for a complete repeal of the CPP, and a trio of former commissioners at FERC said EPA erred when it suggested that the CPP interfered with the authority of the Federal Energy Regulatory Commission and threatened the affordability and reliability of the nation’s electricity supply.

ACE could be an important step by the Trump administration to work with states and the private sector to lower greenhouse gas emissions, according to Christopher Guith, acting president of the U.S. Chamber’s Global Energy Institute.

“While we will thoroughly review the final text, we are particularly pleased that the final ACE rule establishes guidelines emphasizing cooperation with states and encouraging the deployment of innovative technologies and practices to reduce greenhouse gas emissions from existing power plants in a manner that is practical, achievable, and consistent with the Clean Air Act,” Guith said.

Trump’s opponents on the Hill weren’t impressed with ACE.

“‪The Trump Administration’s so-called ‘Affordable Clean Energy’ rule is neither affordable nor clean,” said Sen. Chuck Schumer (D-NY). “It is a huge step backward in the decades-long effort to protect our planet and Earth’s precious resources. The president’s plan is just another giveaway to big polluters and does nothing to reduce carbon pollution.”

Environmental groups had harsher words for the administration’s plan.

“Trump and Wheeler are pushing a plan that will lead to thousands of deaths while ignoring the public’s demands for aggressive climate action, just so a handful of wealthy coal executives can make a little more money,” said Michael Brune, executive director of the Sierra Club.