On her fingers, Chicago’s Chief Sustainability Officer Angela Tovar counted the city buildings that will soon source all of their power from renewable energy: O’Hare International Airport, Midway International Airport, City Hall.

Chicago’s real estate portfolio is massive. It includes 98 fire stations, 81 library locations, 25 police stations and two of the largest water treatment plants on the planet — in all, more than 400 municipal buildings.

It takes approximately 700,000 megawatt hours per year to keep the wheels turning in the third-largest city in the country. Beginning Jan. 1, every single one of them will come solely from clean, renewable energy, mostly sourced from Illinois’ newest and largest solar farm. The move is projected to cut the Windy City’s carbon footprint by approximately 290,000 metric tons of carbon dioxide each year — equal to taking 62,000 cars off the road, the city said.

Chicago is among several cities across the country that are not only shaking up their energy mix but also taking advantage of their bulk-buying power to spur new clean energy development.

“It’s a plan that gets the city to take action on climate and also leverages our buying power to generate new opportunities for Chicagoans and the state,” said Tovar. “There’s opportunities everywhere, not to mention vast amounts of land.”

Patrick L. Pyszka/City of Chicago

The city — and much of Illinois — already has one of the cleanest energy mixes in the country, with over 50% of the state’s electricity coming from nuclear power. But while nuclear energy is considered “clean,” carbon-free energy, it is not considered renewable.

Chicago’s move toward renewable energy has been years in the making. The goal of sourcing the city’s energy purely from renewable sources was established by Mayor Rahm Emanuel in 2017. In 2022, Mayor Lori Lightfoot struck a deal with electricity supplier Constellation for the city to purchase renewable energy from developer Swift Current Energy, beginning in 2025.

Swift Current began building the 3,800-acre, 593-megawatt solar farm in central Illinois as part of the same five-year, $422 million agreement. Straddling Sangamon and Morgan counties in central Illinois, the Double Black Diamond Solar project is now the largest solar installation east of the Mississippi River. It can produce enough electricity to power more than 100,000 homes, according to Swift Current’s vice president of origination, Caroline Mann.

Chicago alone has agreed to buy about half the installation’s total output, enough to cover about 70% of its municipal electricity needs. City officials plan to cover the rest by buying renewable energy credits.

“That’s really a feature and not a bug of our plan,” said deputy chief sustainability officer Jared Policicchio, adding that he hopes the built-in market will encourage additional clean energy development locally, albeit on a much smaller scale. “Our goal over the next several years is that we reach a point where we’re not buying renewable energy credits.”

Los Angeles, Houston, Seattle, Orlando, Florida, and more than 700 other U.S. cities and towns have signed similar purchasing agreements since 2015, according to a 2022 study from World Resources Institute, but none of their plans mandate nearly as much new renewable energy production as Chicago’s.

“Part of Chicago’s goal was what’s called “additionality” — bringing new resources into the market and onto the grid here,” said Popkin. “They were the largest municipal deal to do this.”

Sun-Times file

Chicago also secured a $400,000 annual commitment from Constellation and Swift Current for clean energy workforce training, including training via Chicago Women in Trades, a nonprofit aiming to increase the number of women in union construction and manufacturing jobs.

The economic benefits extend past the city’s limits. According to Swift Current, approximately $100 million in new tax revenue is projected to flow into Sangamon and Morgan counties over the operational life of the Double Black Diamond Solar site.

“Cities and other local governments just don’t appreciate their ability to not just support their residents but also shape markets,” said Popkin. “Chicago is demonstrating directly how cities can lead by example, implement ambitious goals amidst evolving state and federal policy changes, and leverage their purchasing power to support a more equitable renewable energy future.”

Alex Dane, WRI’s senior manager for clean energy innovation and partnerships in the U.S. energy program, said many cities have set two renewable energy goals: one for municipal operations and a second goal for the community at large. Even though the latter is “a little bit harder to get to, and the timeline is a little bit further out,” said Dane, as more and more cities make the 100% clean energy transition, the community-side goals begin to seem less lofty.

Chicago will meet its goal of transitioning all its municipal buildings to renewable energy by 2025, the first step in a broader goal to source energy for all buildings in the city from renewables by 2035 — making it the largest city in the country to do so, according to the Sierra Club.

With the incoming Trump administration promising to decrease federal support for decarbonizing the economy, Dane said it will be increasingly important for cities, towns and states to drive their own efforts to reduce emissions, build greener economies and meet local climate goals. He said moves like Chicago’s prove that they are capable.

“That is an imperative thing to know, that state, city, county action is a durable pathway, even under the next administration, and [it] needs to happen,” said Dane. “The juice is definitely still worth the squeeze.”

This coverage is made possible through a partnershipbetween WBEZ and Grist, a nonprofit environmental media organization.