As of January 1, 2025, all 400+ municipal buildings in Chicago, including fire stations, airports, and water treatment plants, are now powered entirely by renewable energy. This shift is largely driven by Illinois’ largest solar farm, the 593 MW Double Black Diamond Solar project, developed by Swift Current Energy. The initiative is expected to cut 290,000 metric tons of carbon emissions annually—equivalent to removing 62,000 cars from the road.
The transition is part of a $422 million agreement with energy supplier Constellation, aimed at reducing reliance on fossil fuels and boosting local clean energy development. While 70% of Chicago’s municipal electricity will come directly from the solar farm, the remaining 30% will be offset through renewable energy credits. The city aims to eventually replace these credits with locally sourced renewable energy.
Chicago has also secured $400,000 annually from Constellation and Swift Current for clean energy workforce training, supporting programs like Chicago Women in Trades. Additionally, the solar project is expected to generate $100 million in tax revenue for Sangamon and Morgan counties, further strengthening local economies.
Chicago’s move follows a growing trend among U.S. cities leveraging bulk energy purchasing to drive clean energy expansion. With a goal to power all buildings citywide with renewables by 2035, Chicago is positioning itself as a leader in urban decarbonization and climate action.