On Wednesday, June 19, the U.S. Environmental Protection Agency (EPA) issued the final Affordable Clean Energy (ACE) rule, which will replace former President Barack Obama administration’s Clean Power Plan (CPP). The new rule “restores the rule of law and empowers states to continue to reduce emissions while providing affordable and reliable energy for all Americans,” the EPA said.

A review of the CPP was done in response to President Donald Trump’s Executive Order 13873 – Promoting Energy Independence and Economic Growth issued in March 2017. In 2016, the Supreme Court issued a stay of the CPP.

“Today, we are delivering on one of President Trump’s core priorities: ensuring the American public has access to affordable, reliable energy in a manner that continues our nation’s environmental progress,” said EPA Administrator Andrew Wheeler. “Unlike the CPP, ACE adheres to the Clean Air Act and gives states the regulatory certainty they need to continue to reduce emissions and provide a dependable, diverse supply of electricity that all Americans can afford.”

Wheeler said the EPA anticipates a decrease of 35% below 2005 levels by 2030.

The EPA said the ACE rule identifies heat rate improvements as the best system of emission reduction (BSER) for CO2 from coal-fired power plants, and these improvements can be made at individual facilities. States will have three years to submit plans.

There are also new regulations for ACE and future existing-source rules under the Clean Air Act. There will be unit-specific standards of performance. States can take remaining useful life and other factors into account when establishing a standard of performance for that source, the EPA said. The EPA’s role will be to determine nationally applicable BSER and the states will have the power to determine standards and implement them.

In 2030, the ACE rule is projected to reduce CO2 emissions by 11 million short tons; SO2 emissions by 5,700 tons; NOX emissions by 7,100 tons; PM2.5 emissions by 400 tons; and mercury emissions by 59 pounds.

EPA projects that ACE will result in annual net benefits of $120 million to $730 million, including costs, domestic climate benefits, and health co-benefits.

“In this rule, the EPA has accomplished what eluded the prior administration: providing a clear, legal pathway to reduce emissions while preserving states’ authority over their own grids,” said National Mining Association (NMA) President and CEO Hal Quinn. “ACE replaces a proposal that was so extreme that the Supreme Court issued an unprecedented stay of the proposal, having recognized the economic havoc the mere suggestion of such overreach was causing in the nation’s power grid.”