In May, the EPA announced a proposal for new rules for power plants that it expects would cut carbon dioxide emissions from existing coal plants and new natural gas plants by 617 million metric tons from 2028-42. That would be equivalent to taking half of today’s cars off the road for a year. As power generation accounts for 25% of U.S. greenhouse gas emissions, second to transportation, the rules have the potential to make a big impact on how we power the country. Even if fully enacted, though, the rules would fall short of 100% clean electricity by 2035, one of President Joe Biden’s stated goals. But they would be significant nonetheless, especially considering that clean energy initiatives like electric cars still rely on the same old power grid to function. The devil is in the details, so let’s dive in.
The intent of the new rules for power plants certainly seems to be the phasing out of coal-fired plants over the next couple of decades. Under the proposal, existing coal plants would have to cut their carbon emissions by 90% or set a retirement date before 2040. The last coal-fired plant of more than 100 megawatts in the U.S. came online a decade ago, and there are no plans for any new ones. In the 2010s, 290 coal plants closed. Coal still generates around 20% of U.S. electricity, but a combination of clear, cheaper natural gas and the rapidly increasing affordability of renewables has rendered the idea of opening new coal plants a nonstarter. Renewables first surpassed coal in terms of percentage of energy in the U.S. grid in 2020, and there’s been no looking back. To stay in business into the 2040s, coal plants could install carbon capture and storage systems, which we’ll discuss more below.
Natural Gas Plants
The new rules for power plants would be much more lenient on natural gas. Firstly, they would only apply to 300 MW plants that run at least half the time. Since many natural gas plants fall below that capacity threshold and some only run during peak energy demand periods in summer and winter, the rules as proposed would affect only about 23% of existing plants. For the gas plants that would be affected, they might be in a better position than coal plants to take such emissions-cutting measures as firing hydrogen or doing carbon capture. Because natural gas is so much cheaper than coal, it might make financial sense for large gas plants to invest in new technologies to meet the requirements of cutting carbon emissions by 90% by 2035. With the fracking boom behind them, though, plant owners might decide the expense is not worth keeping plants open.
The EPA’s proposal specifically mentions “low-GHG hydrogen” as a co-firing option in plants. Being the most abundant element in the universe, hydrogen is about as renewable as it gets. But there are a lot of tradeoffs in extracting it. The most common method uses electrolysis to separate the hydrogen from the oxygen in water molecules. This process requires energy itself, and using renewable energy to do it (producing what’s known as “green hydrogen”) is about twice as expensive as producing “gray hydrogen” through a process of steam-methane reforming. The gray hydrogen process uses super-heated steam and methane and yields not only hydrogen but carbon monoxide and dioxide as well. Gray hydrogen is by far the most common form used in the U.S. Many of the proposed new rules for power plants would not take effect for years, giving cleaner technologies like green hydrogen the chance to catch up.
Carbon Capture & Storage
CCS technology removes carbon dioxide (through a variety of methods) from a plant before it enters the atmosphere. The captured carbon is then buried, usually in deep geological formations (sometimes exhausted oil fields or saline aquifers). There are only 12 operational CCS projects in the U.S. right now, though 51 new projects were announced in 2021 alone. CCS has proven to be expensive and difficult to scale, but the EPA hopes federal subsidies provided by the Inflation Reduction Act will help in those regards. “This is the crucial demonstration and deployment decade for these technologies to fulfill their emissions reduction and economic benefits,” Carbon Capture Coalition executive director Jessie Stolark said. “By 2030, we need to be on track to sufficiently deploy carbon management technologies economywide, to keep midcentury global temperature targets within reach.”
Last year, the Supreme Court struck down the 2015 Clean Power Plan, and the court has continued to take a narrow view of the EPA’s authority in its attempts at environmental regulation since then. When legal challenges to the new rules for power plants come, EPA administrator Michael Regan said, “We feel really good that we are within those bounds.” Evergreen Action co-founder Sam Ricketts agrees. “I have confidence in its durability,” Ricketts said. “The EPA has learned the lessons. … I think they’re operating tightly in the bounds of what the Clean Air Act and Supreme Court allow.” West Virginia Sen. Joe Manchin, whose family owns a coal brokerage, said he would block all EPA nominees in the Senate. EPA officials believe the challenges are worth it. They estimate the net climate and health benefits of the new rules for power plants will be up to $85 billion. “By proposing new standards for fossil fuel-fired power plants, EPA is delivering on its mission to reduce harmful pollution that threatens people’s health and wellbeing,” EPA administrator Michael Regan said.