Across the country, aging and decommissioned coal-fired power plants are getting a new lease of life as solar, battery, and other renewable energy projects, in part because they share a decades-old trait that’s becoming increasingly valuable: They’re already wired to the grid.
The miles of high-voltage cables and towers that are often needed to connect power plants to customers far and wide can be costly, time-consuming and controversial when built from scratch. In this way, solar and other projects avoid regulatory problems and potentially accelerate the transition to renewable energy by plugging into the unused ports left over when it becomes uneconomical to continue burning coal.
In Illinois alone, at least nine coal-fired power plants are set to convert to solar farms and battery storage over the next three years. Similar projects are taking shape in Nevada, New Mexico, Colorado, North Dakota, Nebraska, Minnesota and Maryland. In Massachusetts and New Jersey, two disused coal-fired power plants along the coast are being repurposed to connect offshore wind turbines to the regional power grid.
“One silver lining after we had all these dirty power plants is that we now have pretty robust transmission lines in those places,” said Jack Darin, director of the Illinois chapter of the Sierra Club, an environmental advocacy group. “It’s a tremendous asset.”
According to the US Energy Information Administration, more than 600 coal-fired generators with a total generation capacity of about 85 gigawatts have been retired over the past two decades. (Individual power plants may have more than one generator.) A majority of the 266 remaining coal-fired power plants in the country were built in the 1970s and 1980s and are nearing the end of their approximately 50-year operational life.
Most of this idle capacity will not be replaced by coal as the industry is crowded out by cheaper renewable energy and stricter emissions regulations. At the same time, renewable energy producers face obstacles to bringing their projects online. Building new power lines is costly and controversial, as neighbors often object to transmission lines, which can disrupt scenic views or potentially reduce the value of nearby property. Additionally, it can be time-consuming to get power line projects approved by regulators.
Renewable energy projects have long been cheaper to build and operate than fossil fuel power plants. The barrier “is no longer economics,” said Joseph Rand, a research scientist at Lawrence Berkeley National Laboratory, which conducts research on behalf of the US Department of Energy. “The hardest part is securing connection and transmission access.”
This makes old coal-fired power plants an attractive option as a location for renewable energy projects. Not only are the legacy plants already connected to the transmission grid, but they also have substations that help convert the electricity into a supply suitable for household and business use.
That was a key factor in choosing the Brayton Point power plant as the grid connection point for a 1,200-megawatt wind farm 37 miles off the coast of Massachusetts, said Michael Brown, chief executive officer of offshore wind developer Mayflower Wind.
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At 1,600 megawatts, the coal-fired power plant was the largest in New England when it retired in 2017. The facility itself, in the coastal town of Somerset, will be replaced by an undersea cable factory owned by Italian company Prysmian Group. And the offshore wind project will connect to the grid at Brayton Point, using the existing substation there.
In one of the most ambitious efforts, Vistra Corp., a Texas-based power generation company that also owns a variety of power plants in California and Illinois, said it would spend $550 million to bring at least nine of its coal-burning plants online in Illinois locations for solar panels and battery storage.
The largest, a Baldwin, Illinois facility due to retire by 2025, will have 190,000 solar panels on 500 acres of land. Together, the panels will generate 68 megawatts of power, enough to power between 13,600 and 34,000 homes, depending on the season. It will also get a battery that can store up to 9 megawatts, which will help distribute power when demand peaks or the sun isn’t shining.
Vistra CEO Curtis Morgan said it’s become clear that the energy company needs to “leave coal behind” and is keen to build new zero-emissions projects to replace some of the electricity from those plants. However, he said the slow approval process from the grid operators, who coordinate and monitor the power supply, has been an obstacle to a number of Vistra’s proposed projects.
According to an analysis by the Lawrence Berkeley National Laboratory, which overlooks the campus of the University of California at Berkeley, a spate of proposals for wind, solar and battery storage projects has overwhelmed regulators in recent years. In 2021, wait times had nearly doubled to nearly four years from a decade earlier, and that doesn’t include the increasing number of projects pulling out of the process entirely.
If every project currently awaiting approval is built, “we could reach 80 percent clean energy by 2030,” said Mr. Rand, the report’s lead author. “But we would be lucky if even a quarter of the proposal actually gets completed.”
Three of Vistra’s battery storage projects in Illinois — at the Havana, Joppa, and Edwards coal-fired power plants — also benefited from grants from a state law, the Climate and Equitable Jobs Act, which aims to support a “just transition” for coal-dependent communities toward renewables energies. Signed by Gov. JB Pritzker last fall, it also required all fossil-fuel-burning power plants to reduce their emissions to zero by 2045, which could lead to their closure, though most of Illinois’ coal-fired power plants were already close to closure down within a decade.
The Coal-to-Solar Energy Storage Grant Program resulting from the legislation also supports two other NRG Energy battery projects being built at the Waukegan and Will County coal-fired power plants.
Building renewable energy projects on old coal plants has two advantages, said Sylvia Garcia, the director of the Illinois Department of Commerce and Economic Opportunity, which oversees the coal-to-solar program. First, projects benefit from the ease of reusing an existing connection to the network. Second, it’s an attempt to primarily “try to invest in the communities that lost those coal plants,” she said.
While the new projects will create temporary construction jobs, running a solar array or battery array doesn’t typically require as many employees. The Baldwin plant previously employed approximately 105 full-time employees. And while Vistra hasn’t finalized final numbers for individual sites, the nine Illinois projects combined will create 29 full-time jobs annually, the company’s communications director, Meranda Cohn, said in an email.
Coal-fired power plants are also typically located on sizable property, and redeveloping these sites into renewable energy projects is a way of putting something productive on a property that would otherwise go unused.
“It really shifts a very negative resource into a more positive one for the community,” said Jeff Bishop, chief executive of Key Capture Energy, which plans to build a 20-megawatt battery storage project at a disused coal-fired power plant near Baltimore, Maryland .
Elsewhere in Holyoke, Mass., the decommissioning of Mount Tom Station, a coal-fired power plant that has operated for more than five decades, presents a number of opportunities, said Julie Vitek, vice president of government and regulatory affairs for power producer ENGIE North america . After meetings with government officials, environmental groups and local residents, a solar farm emerged as the best way “to breathe new life into industrial land on Mount Tom,” she said.
Today, the property is home to around 17,000 solar panels and a small battery facility that make up a community solar project managed by Holyoke Gas & Electric, a city-owned utility that allows customers to choose to purchase solar power from the project. The panels produce around 6 megawatts of power, enough to power around 1,800 homes.
It’s not just solar, battery and wind developers eyeing legacy coal plants for their infrastructure. TerraPower, a nuclear company founded by Bill Gates, is constructing a modern 345-megawatt nuclear reactor next to a disused coal-fired power plant in Kemmerer, Wyo, which will not only allow the reactor to use the existing grid connection, but also utilize the coal-fired plant’s cooling system, said Chris Levesque, President and CEO of TerraPower.
“In a way, it would be a real shame not to use these coal plants,” said Mr. Levesque.