Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock (LockA locked padlock) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

    • Environmental Topics
    • Air
    • Bed Bugs
    • Cancer
    • Chemicals, Toxics, and Pesticide
    • Emergency Response
    • Environmental Information by Location
    • Health
    • Land, Waste, and Cleanup
    • Lead
    • Mold
    • Radon
    • Research
    • Science Topics
    • Water Topics
    • A-Z Topic Index
    • Laws & Regulations
    • By Business Sector
    • By Topic
    • Compliance
    • Enforcement
    • Laws and Executive Orders
    • Regulations
    • Report a Violation
    • Environmental Violations
    • Fraud, Waste or Abuse
    • About EPA
    • Our Mission and What We Do
    • Headquarters Offices
    • Regional Offices
    • Labs and Research Centers
    • Planning, Budget, and Results
    • Organization Chart
    • EPA History

Breadcrumb

  1. Home
  2. Stationary Sources of Air Pollution

Proposal: Affordable Clean Energy (ACE) Rule

Related Actions

Affordable Clean Energy Rule and Repeal of the Clean Power Plan
In June 2019, EPA issued the final Affordable Clean Energy rule (ACE) and repealed the Clean Power Plan. 

Advance Notice of Proposed Rulemaking
In December 2017, EPA issued an Advance Notice of Proposed Rulemaking (ANPRM) to solicit information from the public about a future rulemaking to limit greenhouse gas emissions from existing electric utility generating units (EGUs).

On August 21, 2018, the U.S. Environmental Protection Agency proposed the Affordable Clean Energy rule (ACE) which would establish emission guidelines for states to develop plans to address greenhouse gas emissions from existing coal-fired power plants. ACE would replace the 2015 Clean Power Plan, which EPA has proposed to repeal because it exceeded EPA's authority. The Clean Power Plan was stayed by the U.S. Supreme Court and has never gone into effect.

ACE has several components: a determination of the best system of emission reduction for greenhouse gas emissions from coal-fired power plants, a list of “candidate technologies” states can use when developing their plans, a new preliminary applicability test for determining whether a physical or operational change made to a power plant may be a “major modification” triggering New Source Review, and new implementing regulations for emission guidelines under Clean Air Act section 111(d). 

  • Press Release: EPA Proposes Affordable Clean Energy (ACE) Rule
  • Fact Sheets
    • Fact Sheet: Proposed Affordable Clean Energy Rule - Overview (pdf) (163.45 KB)
    • Fact Sheet: Proposed ACE Rule - CO2 Emissions Trends (pdf) (184.06 KB)
    • Fact Sheet: Proposed ACE Rule - Costs and Benefits (pdf) (144.86 KB)
    • Fact Sheet: Proposed ACE Rule - Legal Overview (pdf) (157.65 KB)
    • Fact Sheet: Proposed ACE Rule - Permitting Improvements Under New Source Review Program (pdf) (152.92 KB)
    • Fact Sheet: Proposed Affordable Clean Energy Rule - Comparison of ACE and CPP (pdf) (111.55 KB)
  • Federal Register Notice: Affordable Clean Energy rule proposal (pdf) (886 KB)
  • Regulatory Impact Analysis:  Regulatory Impact Analysis: Affordable Clean Energy rule proposal (pdf) (5.27 MB)
    • Power Sector Analysis of the proposed ACE rule
  • Public Hearing
    • EPA held a public hearing on the Affordable Clean Energy (ACE) rule proposal on Monday October 1, 2018, from 9:00 a.m.-8:00 p.m. at the Ralph H. Metcalfe Federal Building, 77 West Jackson Boulevard, Chicago, Illinois.​ 
    • Read the Federal Register Notice for more details. The preliminary speaker list is posted below.  

      • Public Hearing on the Proposed ACE Rule: Preliminary Speakers List (pdf) (102.81 KB)

Stationary Sources of Air Pollution

  • Regulations
    • Industry Sector Groups
    • National Emission Standards for Hazardous Air Pollutants (NESHAP)
      • Area Source Standards
      • Risk and Technology Review Status
    • New Source Performance Standards
    • Good Neighbor Plan for the 2015 Ozone National Ambient Air Quality Standards
  • Small Business Assistance Program
Contact Us About Stationary Sources of Air Pollution
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on May 8, 2025
  • Assistance
  • Spanish
  • Arabic
  • Chinese (simplified)
  • Chinese (traditional)
  • French
  • Haitian Creole
  • Korean
  • Portuguese
  • Russian
  • Tagalog
  • Vietnamese
United States Environmental Protection Agency

Discover.

  • Accessibility Statement
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshot
  • Grants
  • No FEAR Act Data
  • Plain Writing
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data
  • Inspector General
  • Jobs
  • Newsroom
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions
  • Site Feedback

Follow.