In a twist, old coal-fired power plants help provide renewable energy. Here’s how.

Across the country, aging and defunct coal-fired power plants are being given a new lease of life as solar, battery and other renewable energy projects, in part because they serve a decades-old function that has become increasingly valuable: they are already connected to the grid.

The miles of power lines and towers often needed to connect power plants to customers around the world can be costly, time consuming and controversial to build from scratch. So solar and other projects avoid regulatory hassles and potentially accelerate the transition to renewable energy, by plugging in the unused connections left behind as coal becomes uneconomical to keep burning.

In Illinois alone, at least nine coal-fired power plants are on track to become solar farms and battery storage facilities in 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 retired coastal coal plants will be repurposed to connect offshore wind turbines to regional power grids.

“A silver lining of having all these dirty power plants is that we now have pretty robust transmission lines in those places,” said Jack Darin, director of the Illinois branch of the Sierra Club, an environmental advocacy group. “That’s a huge asset.”

Over the past two decades, more than 600 coal-fired generators totaling about 85 gigawatts of generation capacity have been retired, according to the US Energy Information Administration. (Individual power plants can have more than one generator.) A majority of the 266 remaining coal plants in the country were built in the 1970s and 1980s and are nearing the end of their operational life of about 50 years.

Most of that waste capacity will not be replaced by coal, as the industry is being squeezed out by cheaper renewable energy and stricter emissions regulations. At the same time, renewable energy producers face obstacles to connect their projects to the grid. Building new high-voltage lines is expensive and controversial because neighbors often resist transmission lines that can disrupt scenic vistas or potentially reduce the value of nearby real estate. In addition, getting powerline projects approved by regulators can be time consuming.

Build and operate sustainable energy projects has long been cheaper than fossil fuel plants. The barrier “isn’t economics anymore,” said Joseph Rand, a scientist at Lawrence Berkeley National Laboratory, who conducts research for the U.S. Department of Energy. “The hardest part is securing the interconnection and transmission access.”

This makes old coal-fired power stations an attractive option as locations for renewable energy projects. Not only are the old plants already connected to the transmission system, they also have substations, which help convert electricity into a power supply suitable for use in homes and businesses.

That was a key factor in choosing Brayton Point Power Station as the grid connection point for a 1,200-megawatt wind farm 60 kilometers off the coast of Massachusetts, said Michael Brown, chief executive officer of offshore wind developer Mayflower Wind.

At 1,600 megawatts, the coal-fired power plant was the largest in New England when it retired in 2017. The facility itself, located in Somerset’s waterfront, will be replaced by a submarine cable factory owned by Italian company Prysmian Group. And the offshore wind project will be connected to the grid at the Brayton Point interconnection point, using the existing substation there.

In one of its 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 upgrade at least nine of its coal-burning plants in Illinois to sites for solar panels and battery storage.

The largest, a factory in Baldwin, Illinois, which will be retiring 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 anywhere from 13,600 to 34,000 households, depending on the time of year. It will also get a battery that can store up to 9 megawatts, which will help distribute electricity when demand peaks or the sun isn’t shining.

Vistra chief executive, Curtis Morgan, said it was becoming clear that the power company needed to “get out of coal” and that it was eager to build new zero-emission projects to replace some of the power from those plants. However, he said the slow process of getting approval from the grid operators, who coordinate and control the electricity supply, has been a roadblock for a number of projects proposed by Vistra.

A wave of proposals for wind, solar and battery storage projects has overwhelmed regulators in recent years, according to an analysis from the Lawrence Berkeley National Laboratory, which overlooks the Berkeley campus of the University of California. By 2021, wait times had nearly doubled from a decade earlier to nearly four years, and that doesn’t include the increasing number of projects that are completely pulling out of the process.

If every project currently awaiting approval is built, “we could achieve 80 percent clean energy by 2030,” said Mr. Rand, the report’s lead author. “But we’d be lucky if even a quarter of what’s proposed actually get completed.”

Three of Vistra’s battery storage projects in Illinois — at the Havana, Joppa and Edwards coal plants — also benefited from an infusion of grants from a state law called the Climate and Equitable Jobs Act, aimed at supporting a “just transition” for coal-dependent communities in the United States. towards renewable energy. It was signed last fall by Governor JB Pritzker and also required all fossil fuel plants to cut their emissions to zero by 2045, which could lead to their closure, although most Illinois coal plants were already set to close within a year. decade down.

The Coal-to-solar energy storage subsidy program that stemmed from the legislation also supports two other battery projects, owned by NRG Energy, which will be built at the Waukegan and Will County coal-fired power plants.

The benefit of building renewable energy projects on old coal plants is twofold, 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 grid. Second, it is primarily an effort to “try to reinvest in the communities that have lost those coal plants,” she said.

While the new projects will create temporary construction jobs, operating a solar plant or battery facility will usually doesn’t need that many employees. The Baldwin plant previously employed approximately 105 full-time employees. And while Vistra hasn’t finalized the numbers by site yet, the nine Illinois projects combined will create 29 full-time jobs a year, company communications director Meranda Cohn said in an email.

Coal plants are also usually on a large tract of land, and redeveloping those sites into renewable energy projects is one way to put something productive on a piece of land that would otherwise go unused.

“It really shifts a very negative source to one that is more positive for the community,” said Jeff Bishop, chief executive of Key Capture Energy, which plans to locate a 20-megawatt battery storage project at a retired coal-fired power plant near Baltimore. , Maryland. .

Elsewhere in Holyoke, Massachusetts, the retirement of Mount Tom Station, a coal-fired power station that had been in operation for more than five decades, presented 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 residents, a solar park emerged as the best way to “revitalize industrial land on Mount Tom,” she said.

Today, the property houses some 17,000 solar panels and a small battery installation forming a community solar project operated by Holyoke Gas & Electric, a city-owned utility that gives customers the choice of receiving solar power from the project. . The panels produce about 6 megawatts of electricity, enough to power about 1,800 households.

It’s not just developers of solar, battery and wind energy that keep an eye on old coal-fired power plants for their infrastructure. TerraPower, a nuclear power company founded by Bill Gates, will locate an advanced 345 megawatt nuclear reactor next to a declining coal-fired power station in Kemmerer, Wyo. cooling system at the coal-fired power plant, said Chris Levesque, TerraPower’s president and chief executive.

“In a way it would be a real shame not to use those coal plants,” said Mr. Levesque.