Affordable Clean Energy Rule

Latest News

The ACE rule provides states guidelines to develop plans to reduce greenhouse gas emissions from power plants. Whereas the Clean Power Plan forced states to comply with a single federal standard, the ACE rule gives states flexibility to set their own standards within the boundaries of the federal guideline. The proposed rule gives states three years to develop plans and provides a list of six “candidate technologies” for states to incorporate in their plans.

The ACE rule also defines the “best system of emission reduction” for existing power plants as on-site heat efficiency improvements. The best system of emission reduction is used in setting the standard of performance under the Clean Air Act.

EPA expects CO2 emissions to decrease by as much as 35 percent below 2005 levels, according to the press release. The agency estimates the ACE rule will result in annual benefits of $120 million to $730 million in costs, climate benefits, and health benefits. A previous regulatory impact analysis from EPA estimated that the ACE rule would reduce compliance costs alone by up to $400 million annually compared to the Clean Power Plan.



August 13, 2019 State AGs file lawsuit against ACE rule
Petition for Review
June 19, 2019 Final Affordable Clean Energy Rule issued
Federal Register Notice
EPA Press Release
October 1, 2018 Public hearing
August 21, 2018  Proposed Rule on Affordable Clean Energy
Docket ID No. EPA-HQ-OAR-2017-0355
Federal Register Notice
Regulatory Impact Analysis
Press ReleaseThe proposed rule will:

  1. Replace the Clean Power Plan with revised emission guidelines for state plans to reduce greenhouse gases from power plants. Provide “candidate technologies” for states to incorporate into their plans. States would have three years to develop plans.

2. Define the “best system of emission reduction” for existing power plants as on-site heat efficiency improvements.

3. Revise the New Source Review program with a new, less burdensome preliminary applicability test.

4.Generally, provide new regulations to direct EPA and states on implementing emissions guidelines.

December 2017  Advance Notice of Proposed Rulemaking (ANPR) on limiting greenhouse gas emissions from power plants
Docket ID No. EPA–HQ–OAR–2017–0545
Federal Register NoticeUnder the ANPR, EPA sought comments on the role of states and EPA in regulating power plants’ emissions; application and definition of the “standard of performance” (Clean Air Act § 111(a)(1)) and “best system of emission reduction”; interaction with New Source Review and other federal programs.
October 2017 Proposed Rule on repeal of Clean Power Plan
Docket ID No. EPA–HQ–OAR–2017–0355
Federal Register Notice
Regulatory Impact AnalysisThe proposed rule would repeal the Clean Power Plan and would return the requirements for “best systems of emission reductions” to be based only on measures that can be applied at the existing source. EPA estimates a $33 billion reduction in compliance costs.
March 28, 2017 Executive Order on Promoting Energy Independence and Economic Growth
President Donald Trump Executive Order 13873
February 9, 2016  U.S. Supreme Court stayed Clean Power Plan
October 23, 2015 Clean Power Plan final rule released


Administration Documents

 Overview of the proposed ACE rule

CO2 emissions trends

Costs and benefits

Legal overview

Permitting improvements under the New Source Review Program

Side-by-side comparison of ACE and CPP

Clean Air Act § 111 Standards for performance for new stationary sources


Hamilton Analysis

AG Kaul Joins Lawsuit Against Clean Power Plan Repeal August 22, 2019

EPA Finalizes Affordable Clean Energy Rule June 26, 2019

EPA Proposes Affordable Clean Energy Rule August 23, 2018.


News Clips

Trump EPA rolls back Obama rule on coal-fired power plants; foes pledge court challenges:, June 19, 2019.

White House gets Clean Power Plan replacement: E&E News, April 30, 2019.

EPA’s new carbon plan won’t slow down coal unit shutdowns: utilities: Reuters, October 5, 2018.

Activists, politicians call on EPA to drop Trump plan to relax emissions standards for coal-fired power plants: Chicago Tribune, October 1, 2018.

Trump power plan unlikely to make case for coal, utilities say: S&P Global, September 11, 2018.

Dire climate change warnings cut from Trump power-plant proposal: Bloomberg, September 4, 2018.

Utilities are reluctant to invest in coal plants, even after Trump tries to save them: Washington Examiner, September 4, 2018.

Trump’s rollback of pollution rules will hit coal country hard: Governing, September 4, 2018.

Wheeler rejects premature-death worries from rule redo: E&E News, August 29, 2018.

Utilities recommit to clean energy in wake of Trump administration’s power plant regulatory rollback: Green Tech Media, August 27, 2018.

Climate rule litigation: Here we go again? E&E News, August 22, 2018.

Conservatives warn endangerment finding fight is ‘still alive’: E&E News, August 22, 2018.

Cost of new E.P.A. coal rules: Up to 1,400 more deaths a year: New York Times, August 21, 2018.

With new coal emissions rules, EPA to give states more power: Governing, August 21, 2018.

EPA tucks major permitting change into climate proposal: E&E News, August 21, 2018.

Trump EPA plan would prolong power plants, but Wisconsin utilities are moving away from coal: Milwaukee Journal Sentinel, August 21, 2018.

States greet Trump’s new coal rules with lawsuit threats: CBS, August 22, 2018.

EPA unveils new Trump plan gutting Obama power plant rules: The Hill, August 21, 2018.

Utilities are decarbonizing. Will Trump rule change that? E&E News, August 21, 2018.

Market, consumers could deflate impact of Trump’s proposed carbon emission changes: Wisconsin Public Radio, August 20, 2018.