ACE Rule vacated, new CO2 rule expected under Biden administration

The DC Circuit Court has vacated the Affordable Clean Energy (ACE) Rule, the Environmental Protection Agency’s (EPA) rule regarding carbon dioxide (CO2) emissions under the Trump Administration. Now, for the third time in as many presidential administrations, EPA will write another CO2 rule for power plants.

“In 2016, the Clean Power Plan (CPP) ultimately resulted in the first-ever Supreme Court stay of an administrative rulemaking,” said Tyler Hamman, Basin Electric senior legislative representative. “President Trump was elected before the DC Circuit could rule on that regulation, and his administration began the task of repealing and replacing the Clean Power Plan with the ACE Rule, which also ended up being litigated in the DC Circuit Court of Appeals. In January 2021, the court vacated the ACE rule and sent it back to the EPA for a new rule, clearing the way for the Biden Administration to develop a new rule.”

Hamman said that while the court never weighed in on the merits of the CPP, it’s a fair assumption that with the Supreme Court stay, the court thought it was too broad and would likely be overturned. In the case of the ACE rule, the DC Circuit went the other direction and faulted EPA for being too narrow in its interpretation of the Clean Air Act. “Going forward,” Hamman said, “we can reasonably assume the Biden Administration’s rule will be somewhere between the ACE Rule and Clean Power Plan.”