For decades, these power plants ran on coal. Now, they’re converting to clean energy

For six decades, a coal power plant near Peoria, Illinois, belched black soot into the air, polluting nearby neighborhoods and racking up thousands of air quality violations. Like other coal plants, it was also a major contributor to climate change. But the plant will close by the end of this year. By 2025, it will become a battery storage facility for renewable energy.

The same transition to clean energy is happening at coal plants across the country. In Illinois alone, 11 plants will close over the next three years and be converted to solar farms or battery storage. In Louisiana, where a coal plant closed last year, a new solar farm is planned that could power 45,000 homes. In Hawaii, where the last-ever shipment of coal arrived in July, a huge battery storage facility is now being built with Tesla Megapack batteries near a former coal plant. In Virginia, a former coal plant may be replaced by a hydrogen plant. In Massachusetts, coal plants near the coast will soon connect with offshore wind power. In Minnesota, a 3,500-acre solar farm will soon be built next to a coal plant that is being shut down in phases. Other projects are underway in multiple states.

Coal plants have been steadily closing over the last two decades, driven largely by economics (though in Illinois, the Peoria plant closed after a lawsuit over its air pollution). More than 350—more than half of all the plants—have retired since 2010, or have plans to shut down. When plants stop running, reusing them for renewable energy is an obvious choice, says Andy Knott, the central region director for the Sierra Club’s Beyond Coal campaign, which works with grassroots activists to push for the transition. 

“They have the existing electric infrastructure—the power lines, the transformers, all the equipment that’s needed to put electricity on the grid is already there,” he says. “And it helps create jobs in an area where the plant is retired.”

According to the Sierra Club, there are still 172 active coal plants in the U.S. But the Inflation Reduction Act could help accelerate the shift that’s already underway. The new climate law has “definitely improved the economics of the ‘coal to clean’ transition in terms of making renewables cheaper,” says Michelle Solomon, policy analyst for electricity at the energy and climate think tank Energy Innovation, who is currently analyzing how the new law will impact the cost of coal versus renewables. The benefit is especially big, she says, in communities with an existing coal plant, where there’s now an extra 10% tax credit for new renewable projects.

The law extends existing tax credits for wind and solar power, but also adds a new tax credit for batteries, which is a critical way to help renewables compete with fossil power that’s available 24/7. “That means it’s a lot easier to integrate renewables into the utility’s overall portfolio,” she says. “If you’re building solar, you don’t have to use that solar energy during the middle of the day. You can shift it if you couple it with batteries.”

Some projects are beginning to use batteries in new ways. In Oregon, the recently opened Wheatridge Renewable Energy Facility—not far from the state’s last remaining coal plant, which was demolished this year—combines batteries with both solar and wind. By using solar panels and wind turbines, it’s more likely to keep generating power at any given time. And the batteries can store electricity for the times when neither resource is available. Multiple other battery storage projects were underway before the new climate law passed, but it will help bring down their cost. 

Although coal was the cheapest source of electricity for decades, it’s now cheaper to build new renewable energy than to keep running old coal power plants (even though inflation has raised the cost of things like solar panels over the last year, along with everything else). But because coal plants can run for 60 years, and utilities can pass the costs along to consumers, some utilities keep them running while they pay off the initial cost of building the plant. The Inflation Reduction Act also has a provision to help with the issue of that unpaid debt, offering loans to help utilities refinance debt for old infrastructure. 

There are other reasons that some utilities are moving slower than others, including the fact that utilities and regulators like to stick with technology they’re already familiar with. Many utilities have made changes only after intense pressure from grassroots activists, says Sierra Club’s Knott; others are making changes based on state laws, as in Hawaii, where a law says that coal generation had to stop by the end of this year.

The Inflation Reduction Act also offers loans to reinvest in communities with old infrastructure, including support for the shift to clean energy. “That has the potential to be a lifeline because in a lot of these coal communities that are really rural, the coal plant can make up a really significant portion of the jobs and can make up a significant portion of the tax base that provides things like funding for schools and emergency services,” Solomon says. “So making sure that there’s a community transition plan in place is the next really big barrier to retiring a lot of these coal plants.”

Renewable energy can’t necessarily replace old coal jobs on its own. Constructing a new project can create hundreds of temporary jobs; but running a solar farm, for example, requires far less ongoing work than a coal plant. “Diversification of these economies is really critical,” she says. In Colorado, for example, the Office of Just Transition is focused on creating new jobs that go beyond energy, including in tourism and manufacturing. In Minnesota, part of the land adjacent to the coal plant will become a data center. “It’s really important to plan before the coal plant closes, from the community perspective,” Solomon says. 

Reusing old coal plants is one way to help with the challenge of red tape in building new renewable energy infrastructure. Right now, there are so many proposals to build new wind and solar projects that the approval process can take nearly four years. If it’s possible to use existing transmission lines, it removes one hurdle. Also, communities often object to new wind or solar farms on undeveloped land; using an existing industrial site can be easier. (Some former coal mines are also being reused for renewable energy, including a massive project in Kentucky.)

Renewables aren’t a one-for-one replacement for a coal power plant, since they take up more space. The new solar farm in Minnesota, sprawling over 3,500 acres, will only replace a fifth of the power of the coal plant being retired there. New technology could help address that problem. Quaise Energy, for example, plans to dig deep underground at former fossil power plants to access geothermal energy, something that can happen on the existing footprint of an old coal plant and fully replace the old fossil-fueled power. “A geothermal well can be built close to the existing power plants, requiring minimal or no additional land use, while solar requires a significant amount of land to match the same amount of energy a power plant produces,” says Kevin Bonebrake, CFO of Quaise Energy. The technology can provide constant energy without the use of batteries. 

Others are advocating to build nuclear energy at old coal plants—like TerraPraxis, which recently partnered with Microsoft to build software aimed at helping utilities switch—but geothermal is far cheaper and faster to build (and doesn’t have the challenges like, say, radioactive waste). 

Quaise plans to begin pilot tests next year, but doesn’t plan to open its first commercial plant until 2028. For now, it makes sense to stay focused on scaling up existing tech like wind and solar, says Solomon. To meet the U.S. climate targets, 80% to 90% of the electricity sector will have to decarbonize by the end of the decade. While new tech will have a role to play as it becomes available, “we don’t really have time to wait as far as deploying the technologies that we have right now, as quickly as possible,” she says.