Chicago is now the first major city in the US to run its municipal buildings on 100% renewable energy.
411 municipal buildings, including fire stations, international airports, libraries, and the City Hall, now run on renewable energy.
The chief sustainability officer for the city of Chicago, Angela Tovar, made a statement for the Chicago Tribune.
"Every Chicagoan interacts with a city-owned building, whether the cultural center, City Hall, Harold Washington Library, O'Hare and Midway (international airports) or your local library. To be able to achieve this milestone on behalf of city residents is exciting."
Most of the buildings have a 900,000 MWh annual power demand. The demands are now met through a 4,100-acre solar farm called Double Black Diamond.
About 30 miles from Springfield, Illinois, the Double Black Diamond is operated and developed by Swift Current Energy.
According to NPR, "The city has also collaborated with Constellation and Swift Current Energy on a $400,000 annual deal for clean energy job training".