The U.S. Environmental Protection Agency (EPA) proposed a new rule to reduce greenhouse gas (GHG) emissions from existing coal-fired electric utility generating units and power plants across the country.

This proposal, called the Affordable Clean Energy (ACE) Rule, establishes emission guidelines for states to use when developing plans to limit GHGs at their power plants. The ACE Rule replaces the Obama administration's Clean Power Plan, which the EPA called "overly prescriptive and burdensome." The Clean Power Plan was never put into effect, but remained a lightning rod for the Trump administration's EPA.

The ACE proposal says it will work to reduce GHG emissions through four main actions:

  • It would define the “best system of emission reduction” (BSER) for existing power plants as on-site, heat-rate efficiency improvements.
  • It would provide states with a list of “candidate technologies” that can be used to establish standards of performance and be incorporated into their state plans.
  • It would update the New Source Review (NSR) permitting program to "further encourage efficiency improvements at existing power plants."
  • It would modify regulations under CAA section 111(d) to give states adequate time and flexibility to develop their state plans.

Decades of Rules

Most of the air and water emission rules affecting power plants stem from the Clean Air Act and the Clean Water Act. Both were passed by Congress decades ago. Both have been subjected to litigation over the years with rulings handed down from as high up as the Supreme Court.

In short, many of the rules have been written, debated, modified, litigated, revised again and set in place so that they are firmly entrenched pieces of regulation. What's more, billions of dollars worth of emission control equipment has already been installed at power plants to comply with the rules.

And even with a more favorable political climate for coal in the present administration, utilities are still not investing in new coal-fired power plants. For example, just as the EPA was rolling out its proposed rule, DTE Energy said it had broken ground on a $1 billion, 1,100 MW, gas-fired power plant that will replace three existing coal-fired units in Michigan.

Some presidential administrations have been more aggressive than others in writing rules and enforcing regulations.

The George W. Bush EPA was seen by some as taking a less active role in writing rules. Environmental groups were only too happy to sue. In some instances, court orders that stemmed from Bush-era lawsuits compelled the Obama EPA to write rules.

The EPA, first under Lisa Jackson and later under Gina McCarthy, may have been aggressive in what they proposed and ultimately put in place. But in many instances, court orders compelled the agency to get out its paper and pen and write some rules.

For many, the Obama administration's "war on coal" was the fruit (rotten or otherwise) of lawsuits brought during the Bush years. And if anything is true about the EPA, it is a lightning rod for lawsuits. If an environmental group isn't suing, then an industry group is in court.

Because most environmental rules stem from the Clean Air Act and the Clean Water Act, an act of Congress might be the only way to make deep and lasting changes. It would be quite tough to amend or rewrite either Act.

Not only that, but citizen lawsuits are likely to meet every proposed change. Groups like the Environmental Defense Fund are not going away. These groups already are frequent litigants against EPA and likely will remain so.

The Natural Gas Factor

Not only has fracking made low-cost natural gas widely available in the U.S., but it also has made huge reserves of domestic U.S. natural gas economically viable. Natural gas presents a smaller environmental footprint compared to coal (although it still is a fossil fuel and a source of carbon emissions). And technology advances mean that gas-fired generation is a reliable and competitive fuel for power generation.

What's more, most utilities long ago committed to the idea of championing clean air and water. Most embrace energy efficiency (e.g., light bulbs, insulation) as a fifth generating fuel in addition to coal, nuclear, natural gas and renewables.

The rapid adoption of solar rooftop technology and energy storage enables non-traditional players to challenge the utility business model. Few, if any, utilities have any intention of willfully shutting off their emission control equipment and returning to the days of billowing black smoke.

Finally, technology advances have made it possible to run gas-fired power plants with a fraction of the employees required by either a coal-fired or a nuclear power unit. For example, the new DTE gas-fired power plant can be run with as few as 35 people across all shifts.

(Read "Automation Is Engineering the Jobs Out of Power Plants.")

The Clean Power Plan ended up as little more than an academic exercise. Decades of well-established rules, the availability of low-cost natural gas and the economics of advanced combined cycle technology are already proving to be significant forces. That means the current EPA's proposed ACE rulemaking may already have been trumped.