The agency proposal, announced in May, would mandate under the U.S. Clean Air Act new carbon dioxide emission cuts from those plants based on what it says are cost-effective and available control technologies—specifically carbon capture and sequestration, hydrogen and natural gas co-firing. 

New and existing gas-powered plants operating full-time must capture 90% of emissions by 2035. Existing coal-fired power plants must do the same by 2030 to stay online in 2040

EPA has said it aims to finalize the rule next year, but that could be a challenge.

The proposal would tighten emissions reduction requirements closer to those in the Obama Administration Clean Power Plan, which was only briefly enacted in 2015 because of lawsuits that challenged EPA regulatory authority. The issues were addressed last year in the U.S. Supreme Court's West Virginia v. EPA ruling. 

In a joint comment August 9, a coalition of 20 largely Democratic-led states and six cities said the proposed emissions-reduction rule is “within the four corners of the Supreme Court’s decision last year ... and consistent with Congress's ambitious actions to curb power plant GHG emissions.” 

But a group of 21 Republican-led states strongly contrasted that view in comments they submitted on Aug. 8, with a legal showdown ahead likely.  "If finalized, EPA’s impossible proposal will leave coal- and natural-gas plants with no other option but to close. Yet EPA has no more authority to mandate this result indirectly than it did when it tried to do so directly." said the states. "The proposed rule exceeds EPA’s authority by forcing the kinds of major shifts that West Virginia already said can’t be imposed."

EPA estimates that between 2028 and 2042, the rule would cut 617 million metric tons of CO2 from the air in the U.S.

Techs Could Limit Power Delivery

But trade groups such as the Edison Electric Institute, which represents investor-owned utilities and even the nonprofit, independent Electric Power Research Institute, note current shortfalls in the technologies to enable sufficient reliable power delivery. In its comments, the institute said the technologies  “have seen little to no deployment at scale so far and depend on new infrastructure” that affect their feasibility and costs beyond the scope of the agency analysis.

The new supporting infrastructure required—including production space, pipelines and storage for hydrogen, and pipelines and storage for carbon capture—“should be considered in their entirety to fully understand the potential benefits, costs and deployment challenges and opportunities,” said the institute.

It said provisions in the EPA rule use optimistic assumptions about cost, schedule and operating flexibility for carbon capture and storage, adding that while hydrogen power could play an important role in a net-zero economy, it has not been demonstrated at the scale “envisioned.”

The Federal Energy Regulatory Commission said it will hold a technical conference in November on the proposed rule.

Four large regional power transmission operators—the 13-state PJM Interconnection, 15-state Midcontinent Independent System Operator, Southwest Power Pool serving 14 states abd Electric Reliability Council of Texas—said the proposed rule has the potential to “materially and adversely” affect grid reliability. 

Southwest Power Pool noted its progress in being an early renewable energy integrator and large user of onshore wind to supplement fossil-fuel power when feasible, but it said proposed technologies will not be available to replace reductions in that generation.

They said that when combined with other EPA rules and policies, the CO2 emission-cut proposal “could well exacerbate” the growing risk of generation retirements. New clean energy resources seeking connection “do not, at present, provide the same level of essential reliability services as their thermal counterparts,” the grid operators said.

While they support new technologies, the grid systems said EPA’s proposed “best system” of emissions reduction “overstates” current co-firing viability for carbon-capture and hydrogen “and ignores the cost and practicalities of developing new supporting infrastructure” within the agency's planned timeline. 

“Hope is not an acceptable strategy,” they said. 

Utility members of the American Public Power Association said they have reduced GHG emissions 31% from 2005 to 2022 but noted the proposed rule's expected impact on providing affordable power reliably. 

The Iowa Utilities Board slammed EPA as “entirely unconcerned with the negative impacts of a lack of electricity in the bulk power system” under the rule, with its hard focus on air quality impacts from coal and natural gas power plants. The agency is “meddling in reliability determinations that are outside its expertise," the state board said, stressing that it needs to listen to concerns by key stakeholders “to avoid introducing further instability” into the U.S. power system.

A group of unions, including the International Brotherhood of Electrical Workers, ironworkers' union, Transportation Communications union, International Association of Machinists and Aerospace Workers and United Mine Workers, said the proposed rule could eliminate nearly 274,000 direct jobs in the industry and 1.1 million indirect jobs. The group supports its mandate for routine maintenance and a unit-specific emissions rate for facilities set to retire before 2032, but the unions suggested adding flexibility for states to develop in-state emission trading programs.

Stakeholders Look at Solutions

The Natural Resources Defense Council said the rule will reduce atmospheric CO2 and sulfur dioxide but could increase nitrogen oxide and fine particle emissions through more CCS and hydrogen. “While the fundamental structure of the proposal is strong, key improvements can and should be made,” said David Doniger, its senior strategic director.

Other Edison Electric Institute members said they are installing the technologies, including Entergy in Texas, with a $1.5-billion new power plant under construction set to use a fuel blend of at least 30% hydrogen. NextEra Energy said it plans to convert over the decade most gas-powered plants of its subsidiary Florida Power & Light to run on hydrogen, while California-based Pacific Gas & Electric said it will have hydrogen fuel-blending operational by the end of 2024.

“Far from being too restrictive, the guidelines offer flexibility and build on technology and processes that the industry is already putting in use to great effect today,” said comments by Joe Dominguez, CEO of energy firm Constellation Energy Corp., which has been developing nuclear power. He said he was "disappointed" by responses "from many of my peers represented by the Edison Electric Institute and others working to block these very practical measures."

Xcel Energy said the proposed rule is largely workable but it recommended more compliance flexibility 

“Carbon capture and storage and co-firing with clean hydrogen are approaches individual plants can use to meet the required emission limits,” said Michael Myers, New York assistant attorney general, in the state comment submission, adding that states can use emissions averaging and trading to comply. 

“This is the way cooperative federalism is supposed to work,” he said.