A polluting, coal-fired power plant has found the key to solving America's biggest clean energy challenge. CNN

Baker, Minnesota
CNN
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Smoke plumes from the old Sherco coal power plant tower over illuminated solar panels spread over thousands of acres of farmland.

The polluting coal plant is nearing completion, scheduled to retire in the next five years. It's generated billions of dollars worth of electricity over its 50-year life, but its most valuable part is the plug — how it connects to the grid that powers our homes.

Rather than let fossil fuel plants go to waste as they shut down, Xcel Energy is keeping it plugged in to connect the largest solar project in the upper Midwest, and one of the largest in the entire country, directly to the grid.

Re-implementation of the so-called interconnection system short-circuits seven years of bureaucracy and red tape to deliver this electricity to consumers.

Experts say this is the secret to solving America's clean energy problem: There is more electricity waiting to be added to the grid from clean energy than the grid currently has. Year-long delays are an existential threat to the construction prospects of many projects.

“It allows us to move much faster,” said Ryan Long, president of Xcel Energy in Minnesota, who called plant infrastructure reuse “a real key to our strategy here.”

By plugging renewable projects into old fossil fuel power plants, be they coal, gas or oil, the US could double the capacity of its electric grid overnight, University of California Berkeley researchers have found. And projects can be plugged into existing plants, not just retired.

“That should be a major strategy that we pursue, because we already have so many existing assets, so much grid infrastructure, and we don't want to throw them away,” said Umed Paliwal, a senior scientist at UC Berkeley. and lead author of the study.

Right now building a project like Sherco Solar is much faster than connecting that project to the electrical grid. That's because adding new energy sources requires making room in the grid, which requires lengthy engineering studies and uncertain project timelines. A cheap, clean energy boom is underway against this complex, regional bureaucracy.

Rob Gramlich, CEO of consulting firm Grid Strategy LLC, compared plugging renewable projects into existing interconnection sites to using a fast pass to skip the long lines at Disney.

“There's a line where everybody wants to go, and then somebody has this Disney pass to skip the line,” Gramlich said. “It's talking about a sensitive topic, jumping around the interconnection row. But the fact is, it is.”

Supercharging could be the answer to clean energy among the most polluting power plants in the United States.

Sherco has been Minnesota's largest coal-fired power plant — and its biggest polluter — since it was built in the 1970s and '80s. In 2022 alone its smokestacks will emit about 10.5 million tons of planet-warming pollution, equivalent to the emissions of more than 2 million cars in a year.

But as the Berkeley researchers found, plants like Sherco that are either slowly retiring or even still operating are good candidates for renewables to plug into their infrastructure.

“No fossil fuel power plant operates every hour of the day,” said Sonia Aggarwal, CEO of clean energy think tank Energy Innovation and a former White House climate official. “The other hours — that big plug, that really valuable resource that everyone's been waiting years to get access to — it's just sitting there, not being used.”

Agarwal and Paliwal argue that this approach allows utilities to have the best of both worlds; They can build wind and solar farms nearby, putting that clean energy into the grid when a coal or gas plant isn't producing electricity, and a plant doesn't have to shut down completely.

Doing so brings many benefits. This helps save jobs at a plant that would otherwise be threatened with closure and helps increase the local tax base around the plant. In Minnesota, Xcel is promising to lay off workers at a Sherco coal plant.

“We really need to stay in those coal plants for the rest of their (plant) lives because they provide critical reliability and power to our community,” Long said. “When the time is right, we will find them a job at Xcel Energy and we will retrain them and position them for success in that role.”

It could also result in savings for electric customers, as plants ditch coal and switch to wind and solar, which are much cheaper sources of energy.

The Berkeley study considered several factors to determine good candidates for interconnection: whether there was land near a thermal center suitable for wind and solar power; How much energy can be generated by the sun or wind; And how much renewable energy can be fed into the plant's interconnection system.

The answer to that last question? a lot

Paliwal and his colleagues found that by 2032, utilities could install close to 1,000 gigawatts of new clean energy with power plants that checked all three boxes. And they need America in large numbers; Energy analysts believe data centers, AI and the electrification of people's homes and cars will drive demand.

Several power plants in Illinois are trying something similar, and in Virginia, a new solar array is plugging into the interconnection at a nearby gas plant.

For Pete Wyckoff, who serves as the Minnesota Department of Commerce's deputy commissioner of energy resources, the Sherco solar farm represents an opportunity to produce energy locally.

“We're a good wind and solar state,” Wyckoff said. “Whatever fossil fuel we burn, we are importing. We are generating wind and solar power here.”

It's also a huge step forward for Minnesota's climate and clean energy goals. Under its Democratic governor and 2024 vice-presidential candidate Tim Walz, the state is aggressively trying to decarbonize its power sector – reaching 100% clean electricity by 2040.

“It's a key driver of how we're going to decarbonize the rest of the economy,” Wyckoff said. “We're aiming to be a clean economy by 2050. And I think we'll get there.”