The proposed New Source Performance Standards (NSPS) are based on the application of combustion controls and selective catalytic reduction (SCR).

EPA said the proposed standards would ensure that new turbines built at natural gas-fired plants or industrial facilities — especially large ones that could operate for decades — would be among the lowest-emitting turbines ever built.

To strengthen the NOx performance standards for new stationary combustion turbines, EPA is specifically proposing:

• To determine that combustion controls with the addition of post-combustion SCR is the best system of emission reduction (BSER) for most combustion turbines. Post-combustion SCR is already widely used in the power sector.
• To lower the NOx standards of performance for affected sources based on the application of the BSER.
• To establish more protective NOx standards for affected new sources that plan to fire or co-fire hydrogen, ensuring that these units have the same level of control for NOx emissions as sources firing natural gas or non-natural gas fuels. 

The proposed standards would establish size-based categories based on base load heat input. The proposed size-based categories include:

• Large combustion turbines — facilities with a base load heat input rating of > 850 MMBtu/h (> ~ 85 MW).
• Medium combustion turbines — facilities with a base load heat input rating of > 250 and ≤ 850 MMBtu/h (> ~ 25 MW and ≤ ~ 85 MW). 
• Small combustion turbines — facilities with a base load heat input rating of ≤ 250 MMBtu/h (≤ ~ 25 MW).

EPA is proposing to further subcategorize sources based on whether they operate at high, intermediate or low loads, as well as whether they burn natural gas or non-natural gas fuels. When classifying low, intermediate or base load units, EPA will consider the 12-calendar-month capacity factor of these combustion turbines.

• High load — capacity factor greater than 40% (i.e., base load).
• Intermediate load — capacity factor greater than 20% and less than or equal to 40%.
• Low load — capacity factor of less than or equal to 20%.

For non-EGU stationary combustion turbines, the capacity factor would be determined based on the prior 12 calendar months of data on a rolling basis updated each month.

EPA acknowledged that SCR technology becomes less cost-effective and efficient at smaller scales or variable operating levels. Therefore, the agency is proposing standards for certain combustion turbines relying on combustion controls instead of SCR. This applies to small turbines at low or intermediate loads, and medium and large turbines at low loads.

The agency estimated the proposal would reduce NOx emissions by 198 tons in 2027 and 2,659 tons in 2032. The present value of net benefits to society is estimated at up to $340 million, with an equivalent value of up to $46.4 million per year. 

NOx contributes to harmful health effects, such as asthma and respiratory infections. Children, the elderly, and people with chronic heart, lung or other cardiopulmonary diseases are most at risk. 

EPA is also proposing to maintain the current limits for sulfur dioxide, which is well-controlled in the sector based on the long-term required use of low-sulfur natural gas and distillate fuels.

The agency last established New Source Performance Standards (NSPS) for stationary combustion turbines in 2006. The future of the proposal, as with other EPA power plant rules finalized in the last year, is unclear under the incoming Trump presidency.

EPA will accept comments for 90 days after the proposal is published in the Federal Register.

WASHINGTON (AP) — The Supreme Court left in place Friday two Biden administration environmental regulations aimed at reducing industry emissions of planet-warming methane and toxic mercury from power plants.

The justices did not detail their reasoning in the orders, which came after a flurry of emergency applications to block the rules from industry groups and Republican-leaning states. There were no noted dissents.

The high court is still considering challenges to a third Environmental Protection Agency rule aimed at curbing planet-warming pollution from coal-fired power plants.

The regulations are part of a broader effort by the Biden administration aimed at curbing climate change that includes financial incentives to buy electric vehicles and upgrade infrastructure, and rules tightening tailpipe pollution standards for cars and trucks.

The industry groups and states had argued the EPA overstepped its authority and set unattainable standards with the new regulations. The EPA, though, said the rules are squarely within its legal responsibilities and would protect the public.

An EPA spokesperson said Friday the agency is pleased that the Supreme Court denied applications to stay the final methane and mercury rules. EPA believes the rule tightening methane emissions from oil and gas drilling will deliver major climate and health benefits for all Americans, while the mercury rule will limit hazardous pollution from coal-fired power plants, spokesperson Remmington Belford said.

The methane rule will build on innovative technologies and solutions that many oil- and gas-producing states and companies are already using or have committed to use, while the mercury and air toxics rule “will ensure that the nation’s coal-fired power plants meet up-to-date standards for hazardous air pollutants,” Belford said.

Both rules are firmly grounded in the EPA’s authority under the Clean Air Act, he said.

The Supreme Court has shot down other environmental regulations in recent years, including a landmark decision that limited the EPA’s authority to regulate carbon dioxide emissions from power plants in 2022, and another that halted the agency’s air-pollution-fighting “good neighbor” rule.

The methane rule puts new requirements on the oil and gas industry, which is the largest emitter of the gas that’s a key contributor to climate change. A lower court previously refused to halt the regulation.
Methane is the main component in natural gas and is far more potent than carbon dioxide in the short term. Sharp cuts in methane emissions are a global priority — including the United States — to slow the rate of climate change.

The methane rule targets emissions from existing oil and gas wells nationwide, rather than focusing only on new wells. It also regulates smaller wells that will be required to find and plug methane leaks.

Studies have found that smaller wells produce just 6% of the nation’s oil and gas but account for up to half the methane emissions from well sites. The plan also calls for a phased-in requirement for energy companies to eliminate routine flaring, or burning of natural gas that is produced by new oil wells.

The states challenging the rule called the new standards “impossible to meet” and said they amounted to an “attack” on the industry.

The mercury rule, meanwhile, came after a reversal of a move by the Trump administration. It updated regulations that were more than a decade old for emissions of mercury and other harmful pollutants that can affect the nervous system, kidneys and fetal development.

Industry groups and conservative-leaning states argued emissions were already low enough, and the new standards could force the shuttering coal-fired power plants.

The EPA said the updates are needed to protect public health.

David Doniger, senior attorney at Natural Resources Defense Council, called the two rules critical safeguards and applauded the court order leaving them in place. He also looked ahead to the still-undecided challenges to the power plant rule.

“The court should do the same with the effort to block EPA’s power plant carbon pollution standards, which comply with the very directions the court gave it in 2022,” Doniger said.

This comes a day after the trade association, which represents nearly 900 U.S. local electric cooperatives, filed a motion to stay the rule in the U.S. Court of Appeals for the D.C. Circuit.

As we’ve reported, coal and new gas plants would have to capture their emissions using carbon capture and sequestration (CCS) or retire by various compliance dates in the 2030s.

Jim Matheson, CEO of NRECA, said carbon capture technologies are promising but not ready for prime time, especially under the compliance deadlines EPA set in the final rule. This is one of the chief arguments from opponents of the rule.

“This is a flawed rule,” said Matheson. “We have multiple members across the country that face not only massive costs if they could implement this, but also requirements to use a technology that’s simply not ready,” he added, referring to CCS.

Plant owners are expected to file their implementation plans by May of 2026. Yet of the more than 75 coal-fired units owned or operated by members of NRECA, the association knows of only 3 units that could plausibly attempt to demonstrate CCS at any notable level by the 2030s compliance dates — yet even they would not come close to meeting the rule’s 90% capture rate, according to one exhibit in court filings.

Two of those units are at the coal-fired Milton R. Young Station near Center, North Dakota. Minnkota Power Cooperative and TC Energy are hosting a large-scale carbon capture demonstration project there, known as Project Tundra. NRECA noted in court filings that the project sits atop ideal geology for storage, has been in planning for nearly a decade, has used government funding for two-thirds of the costs so far, yet still would not meet the 90% capture rate.

“I have great confidence that we’re going to capture substantial amounts of CO2 from [Project Tundra],” said Mac McLennan, CEO of Minnkota Power Cooperative, which operates primarily in the states of North Dakota and Minnesota. “But for us to have a reference point called a 90% removal from EPA when it’s yet to be demonstrated or verified, it causes me pause.”

90% capture or otherwise, McLennan said the soonest Project Tundra could be commercially online would be 2028 and 2029, but other variable factors that could further delay the project include labor and supply chain constraints.

Matheson said matter-of-factly: “The short answer is there is not some silver bullet technology that is going to achieve the Biden administration’s stated goal of zero emissions from the electric sector by 2035.”

Opponents argue the EPA rule would be a death blow to the coal industry. Under the rule, coal plants which plan to stay open beyond 2039 would have to reduce or capture 90% of their CO2 emissions by 2032. Coal plants that are scheduled to close by 2039 would have to cut their emissions 16% by 2030, while those that are set to retire by 2032 would be exempted from the new rule.

Tony Campbell, President and CEO of East Kentucky Power Cooperative, said coal-fired power has proved necessary during extreme cold snaps. He said retiring coal units too early would jeopardize reliability.

He said natural gas is not the solution or “stepping stone” everyone thinks it is. He said the co-op couldn’t get natural gas during Winter Storm Elliott during frozen infrastructure. While a lot of those units are dual fuel, Campbell said onsite diesel reserves might last a few days, where coal plants would have 40 to 60 days of reserves.

We’re not misguided by a belief that we have to have coal forever,” he said, “But we do believe that coal right now is supporting the system.”

Campbell added the reliability challenge will be compounded by significant projected load growth in the U.S., largely driven by artificial intelligence.

“Our responsibility is to deliver reliable, affordable and safe power to the end consumer,” he said. “Electricity is no longer a luxury in our country, it’s a necessity.”

NRECA’s motion to stay the EPA rule comes nearly a week after the association filed a lawsuit challenging the rule. A coalition of 23 states also challenged the rule in court.

The rules targets coal-fired plants and new natural gas-fired plants, which would have to capture their emissions or retire by various compliance dates in the 2030s.

Both lawsuits were filed in the U.S. Court of Appeals for the District of Columbia Circuit.

Major coal producing states are leading the multistate challenge, saying the EPA rules would be a death blow to the coal industry while jeopardizing grid reliability.

“This green new deal agenda the Biden administration continues to force onto the people is setting up the plants to fail and therefore shutter, altering the nation’s already stretched grid,” said West Virginia Attorney General Patrick Morrisey in a statement.

BREAKING: The WV AG is co-leading a multistate coalition challenging the EPA's recently-released new rule on existing coal-, natural gas- and oil-fired power plants.

READ ALL ABOUT IT: https://t.co/CQBhw1W2br pic.twitter.com/LQpEr7NXOI

— WV Attorney General (@WestVirginiaAG) May 9, 2024

“Make no mistake, this rule intentionally sets impossible standards to destroy the coal industry,” North Dakota Attorney General Drew Wrigley said. “Federal agencies cannot decide on a whim to destroy entire industries.”

EPA’s final rules heavily rely on on carbon capture and sequestration/storage (CCS) as the best system of emission reduction (BSER) for the longest-running existing coal-fired units and most heavily utilized new gas turbines.

Under the rules, coal plants which plan to stay open beyond 2039 would have to reduce or capture 90% of their carbon dioxide emissions by 2032. Coal plants that are scheduled to close by 2039 would have to cut their emissions 16% by 2030, while those that are set to retire by 2032 would be exempted from the new rule.

New natural gas-fired plants that run more than 40% of the time, considered “baseload” by the agency, would also have to eliminate 90% of their carbon dioxide emissions using CCS by 2032. 

Read our full recap of EPA’s rules here

“This rule strips the states of important discretion while using technologies that don’t work in the real world—this administration packaged this rule with several other rules aimed at destroying traditional energy providers,” Morrisey said. “We are confident we will once again prevail in court against this rogue agency.”

The other states joining West Virginia and North Dakota are Alabama, Alaska, Arkansas, Florida, Georgia, Idaho, Indiana, Iowa, Kentucky, Louisiana, Mississippi, Missouri, Montana, Nebraska, New Hampshire, Oklahoma, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia and Wyoming.

The National Rural Electric Cooperative Association (NRECA) also filed a lawsuit challenging the rules.

“EPA’s power plant rule is unlawful, unreasonable and unachievable. It exceeds EPA’s authority and poses an immediate threat to the American electric grid,” NRECA CEO Jim Matheson said. “Under the rule, EPA illegally attempts to transform the U.S. energy economy by forcing a shift in electricity generation to the agency’s favored sources.”

“Reliable electricity is the foundation of the American economy,” he added. “EPA’s rule recklessly undermines that foundation by forcing the premature closure of power plants that are critical to keeping the lights on – especially as America increasingly relies on electricity to power the economy.”

The highly-anticipated announcement outlined a suite of measures aimed at reducing air, water and land pollution from the power sector. As the sector makes long-term investments in the transition to clean energy, EPA said the rules are designed to work with power companies’ planning processes. Regulators say they project the rules will result in reductions of 1.38 billion metric tons of carbon pollution overall through 2047.

Notably, EPA’s final rule heavily relies on on carbon capture and sequestration/storage (CCS) as the best system of emission reduction (BSER) for the longest-running existing coal-fired units and most heavily utilized new gas turbines. Unlike the original proposal from nearly a year ago, decarbonizing these plants through clean hydrogen co-firing is not a factor in the new rule.

As we’ve reported, rules for existing natural gas-fired plants aren’t expected to come out until after the November election.

What are the changes from the original proposal?

Under EPA’s final rule, coal plants which plan to stay open beyond 2039 (a year earlier than previously proposed) would have to reduce or capture 90% of their carbon dioxide emissions by 2032.

Initially, the compliance date to implement CCS for this subcategory of coal plants was January 1, 2030, but the agency said it heard from stakeholders that this deadline did not provide adequate lead time.

Under the final rule, coal plants that are scheduled to close by 2039 would have to cut their emissions 16% by 2030. In this case, EPA said the BSER for this subcategory is co-firing with natural gas, at a level of 40 percent of the unit’s annual heat input. For reference, EPA said more than half (100 GW) of still-operating coal-fired units have already announced retirement dates or conversion to gas-fired units before 2039.

Coal plants that are set to retire by 2032 would be exempted from the new rule.

New natural gas-fired plants that run more than 40% of the time, considered “baseload” by the agency, would also have to eliminate 90% of their carbon dioxide emissions using CCS by 2032. Previously, the proposed rule required large turbines with at least a 50% capacity factor to capture 90% of their carbon by 2035 or co-fire with 30% hydrogen starting in 2032.

EPA has also removed hydrogen co-firing as a BSER in the final rule, prompted by cost uncertainties and concerns shared during the public comment process.

“While the EPA believes that hydrogen co-firing is technically feasible based on combustion turbine technology, information about how the low-GHG hydrogen production industry will develop in the future is not sufficiently certain for the EPA to be able to determine that adequate quantities will be available,” the agency said in its explanation.

EPA did say “certain sources may elect to co-fire hydrogen for compliance with the final standards of performance, even absent the technology being a BSER pathway.”

Read EPA’s full explanation for the final rules here.

EPA pivots to CCS

EPA called carbon capture and sequestration an “available and cost-reasonable emission control technology” that can be applied directly to coal and gas-fired plants.

The agency cited lower costs and continued improvements in CCS technology as a reason for it being a BSE. EPA said process improvements learned from earlier deployments of CCS, the availability of better solvent. and other advances have decreased the costs of CCS in recent years.

EPA also said tax incentives from the Inflation Reduction Act would allow companies to help offset the cost of CCS. The Infrastructure Investment and Jobs Act (IIJA) additionally includes billions of dollars to advance and deploy CCS technology and infrastructure.

The power industry has been fractured over EPA’s emissions-slashing proposal since the initial version was released last May. Opposition to the rule has mainly come with concerns that its implementation would jeopardize grid reliability and that the emission reduction technologies proposed by EPA aren’t ready for prime time.

Those concerns continued after EPA released its final rule. The Edison Electric Institute (EEI), the association that represents U.S. investor-owned utilities, reiterated that its members are not confident in CCS as a compliance technology based on the proposed implementation timelines.

“While we appreciate and support EPA’s work to develop a clear, continued path for the transition to cleaner resources, we are disappointed that the agency did not address the concerns we raised about carbon capture and storage (CCS),” said Dan Brouillette, who is EEI’s President and CEO. “CCS is not yet ready for full-scale, economy-wide deployment, nor is there sufficient time to permit, finance, and build the CCS infrastructure needed for compliance by 2032.”

Brouillette added: “While CCS and other 24/7 clean energy technologies could be important tools for reducing emissions in the future, EPA’s record does not support a finding that CCS is demonstrated today.”

MORE: Power industry “at an inflection point” regarding EPA rules

In response to the rule’s release, Electric Power Supply Association (EPSA) President and CEO Todd Snitchler said the final rule is a “painful example of aspirational policy outpacing physical and operational realities.”

Despite the skepticism, some companies have thrown their support behind EPA’s rule.

Constellation Energy issued a statement which reads in part: “EPA’s power plant rules offer a sensible roadmap for phasing in greenhouse gas emissions reductions from the power sector, while meeting rising demand from onshoring manufacturing, the electrification of transportation and heavy industry and the growth of emerging technologies.”

Constellation also added: “This rule enables the U.S. to utilize its abundant, domestic natural gas resources to provide reliable and affordable power to American families and businesses while helping the U.S. achieve its emissions goals.”

Other final rules

Additionally, EPA updated regulations on mercury and air toxics emissions from coal-fired power plants, foreseeing reductions in harmful pollutants like mercury and fine particulate matter.

The final [Mercury and Air Toxics Standards] rule reduces the mercury emissions limit by 70 percent for lignite-fired units and reduces the emissions limit that controls for toxic metals by 67 percent for all coal plants. EPA said this final rule under the Clean Air Act is the most significant update since MATS was first issued in February 2012.

EPA is also strengthening wastewater discharge standards for coal-fired power plants to minimize water pollution. EPA’s final rule establishes technology-based discharge standards for flue gas desulfurization wastewater, bottom ash transport water, combustion residual leachate, and “legacy wastewater” that is stored in coal ash ponds. The standards include flexibilities for compliance. EPA said the standards are projected to have minimal impact on electricity prices while providing significant health and environmental benefits.

Finally, the agency moved to finalize rules to manage coal combustion residuals (coal ash) to mitigate public health risks associated with its disposal. These regulations aim to protect communities from contamination by requiring safe management practices for coal ash storage and disposal, especially focusing on legacy sites prone to leaks and structural issues. This rule is not expected to affect the current operations of power plants.