The White House has identified more than 60 fossil fuel-fired power plants that will have two extra years to comply with the more stringent mercury and air toxics standards (MATS) finalized in 2024.
Under a proclamation signed by US president Donald Trump last week, the plants on the list will be able to operate under whatever existing mercury and air toxics standards they currently are subject to until 8 July 2029. That is two years after the compliance deadline put in place in May 2024.
The Environmental Protection Agency (EPA) rules finalized last year tightened mercury and air toxics standards for coal- and oil-fired units by 67pc, included new emissions-monitoring requirements and added standards for lignite-fired coal plants that put them in line with those for other coal plants.
EPA in March said it was reviewing the new standards and said companies could seek exemptions to the mercury rule and other emissions rules. Trump followed that up last week with a proclamation that certain generating facilities would be given a two-year exemption in complying with the 2024 rule. The White House released the list of exempt power plants late on 14 April.
Most of the plants on the list are coal-fired generators, some of which were scheduled for retirement by the end of 2027. These include Tennessee Valley Authority's Kingston plant and one unit of its Cumberland plant, as well as Vistra Energy's Kincaid, Baldwin and Newton plants and two coal units of Vistra's Miami Fort plant.
The two coal units at Southern Company's Victor J Daniel plant in Mississippi also have been exempted from the new mercury and air toxics rules for two years. Southern had planned on retiring those units by the end of 2027, but in February, the Mississippi Public Service Commission approved two special contracts that were expected to need unit 2 of the Daniel plant and possibly a unit of a natural gas plant to run into the 2030s.
Some other coal plant units owned by Southern, TVA and Vistra also are now exempt from the July 2027 mercury and air toxics compliance deadline. So are some plant units owned by East Kentucky Power Cooperative (EKPC), NRG, Ameren and Entergy.
At least two natural gas plant units — unit 5 of Southern's Plant Barry and City Utilities of Springfield's John Twitty Energy Center, which has coal and natural gas generation — are exempt from the July 2027 deadline. So is unit 5 of Entergy's RS Nelson plant, which runs on petroleum coke.
Essentially all of the other units in the White House's list are coal units, including Otter Tail Power's Big Stone and Coyote Station plants in North Dakota. Otter Tail said it had requested the exemptions "to avoid making unnecessary expenditures" if EPA decides to roll back the 2024 rule.
EKPC said it was "grateful" its request to exempt the Spurlock and Cooper coal-fired power plants in Kentucky was granted and that the company "will continue to operate the plants in accordance with all market and environmental rules."
NRG said it was still reviewing the order, but did not expect it to have any effect on its plans.
TVA, Southern, Vistra and owners of other power plants given compliance extensions did not respond to requests for comment.
