Chicago clean power buildings cut emissions equivalent to removing 62,000 cars annually.
As of January 1, 2025, all of Chicago’s more than 400 municipal buildings, including two international airports and 98 fire stations, are powered entirely by renewable energy. This monumental shift to clean power is largely due to Illinois’ largest solar farm, the Double Black Diamond Solar project, which now supplies a significant portion of the city’s energy needs.
The transition to 100% renewable energy is expected to reduce Chicago’s carbon emissions by 290,000 metric tons annually. To put that in perspective, it’s equivalent to removing about 62,000 cars from the road each year. This move places Chicago among the leading U.S. cities, leveraging clean energy to fight climate change while boosting local economies.
The Chicago clean power building initiative began nearly a decade ago under then-Mayor Rahm Emanuel, who set a goal to power the city’s operations with carbon-free energy. Building on this vision, Mayor Lori Lightfoot finalized a 2022 agreement with Constellation, an electricity supplier, to source power from Swift Current Energy’s solar farm. Construction on the 3,800-acre, 593-megawatt Double Black Diamond Solar farm began shortly after, representing a $422 million investment.
Located in central Illinois, the solar farm is now the largest east of the Mississippi River and generates enough electricity to power over 100,000 homes. Chicago purchases half its output to cover approximately 70% of its municipal energy needs, with the remaining 30% supplemented by renewable energy credits.
For residents, the Chicago clean power buildings signify reduced pollution, improved air quality, and new economic opportunities. The initiative also showcases how cities can take meaningful steps to address climate change, even amid federal policy uncertainty. By reducing dependence on fossil fuels, Chicago is contributing to a more sustainable and healthier future for its citizens.
Additionally, the project brings direct economic benefits. Swift Current Energy projects $100 million in new tax revenue for Sangamon and Morgan counties, home to the solar farm. These funds can be reinvested in local schools, infrastructure, and community programs.
The economic ripple effects extend beyond the immediate environmental gains. A community benefits analysis highlights the direct and indirect advantages for Illinois residents. Local governments and organizations near the solar farm have reported job creation, with roles ranging from construction to long-term maintenance positions. These jobs often come with competitive wages, benefiting families and contributing to local economic stability.
Additionally, increased tax revenues have supported the enhancement of infrastructure, including roads and utilities, in Sangamon and Morgan counties. Residents are beginning to see tangible improvements in their communities, demonstrating the broader impact of renewable energy projects.
Chicago’s bulk energy purchase is part of a growing trend among U.S. cities to stimulate renewable energy development. By committing to 100% clean power, cities like Chicago and Houston are creating demand for new solar and wind projects, ensuring more renewable energy is added to the grid.
The city’s strategy emphasizes “additionality,” or the creation of new renewable energy sources, rather than relying solely on existing ones. This approach ensures that Chicago’s energy consumption directly contributes to expanding clean power capacity.
Solar farms like Double Black Diamond use photovoltaic (PV) panels to convert sunlight into electricity. These panels are arranged in vast arrays and are designed to capture maximum sunlight throughout the day. The energy generated is then transmitted to the grid and distributed to consumers, including Chicago’s municipal buildings.
Advancements in renewable energy technology have made solar farms more efficient and cost-effective. Modern PV panels can generate more electricity per square foot than earlier models, reducing the land footprint required for such installations. Energy storage solutions, like batteries, are also being integrated to store excess power, ensuring a steady supply even when sunlight is limited.
Chicago’s clean energy transition also includes a commitment to workforce development. As part of the deal, Constellation and Swift Current Energy will invest $400,000 annually in clean energy job training programs. These programs aim to prepare residents, particularly women and underrepresented groups, for careers in renewable energy and union trades.
Organizations like Chicago Women in Trades are leading these efforts, helping diversify the workforce while meeting the growing demand for skilled labor in the clean energy sector.
More than 700 U.S. cities and towns have signed renewable energy agreements since 2015. However, Chicago’s initiative stands out due to its scale and impact. According to the World Resources Institute, only Houston has a larger renewable energy deal. Yet, Chicago’s commitment has added the most new renewable power to the grid.
Experts say that local governments’ ability to shape energy markets is often underestimated. Chicago’s success demonstrates how municipalities can lead by example, setting ambitious goals and leveraging their purchasing power to drive change. These efforts prove vital as cities, states, and private sectors must shoulder more responsibility for climate action.
This milestone is just the beginning for Chicago. By 2035, the city aims to power all buildings, not just municipal ones, with renewable energy. If successful, Chicago would become the largest U.S. city to achieve this goal, further solidifying its leadership in clean energy.
As the city grows, the Chicago clean power building initiative serves as a blueprint for other cities. The project illustrates that ambitious sustainability goals are achievable with strategic planning, strong partnerships, and community-focused investments.
