Mayor Rahm Emanuel says 5 percent of the electricity provided to the city through its new aggregation program will come from Illinois wind farms.
Emanuel's office announced Tuesday that it had reached a deal with the city's energy suppliers to double the amount of wind energy consumers get though Commonwealth Edison.
The city last year chose Integrys Energy Services to supply electricity to Chicago customers as a way to save money, and to ease pollution by eliminating coal-based power.
ComEd still is responsible for delivering electricity and fixing outages.
Businesses and residents can opt in or out of the aggregation, and the city says 750,000 customers have participated in the program since February.
Sierra Club Illinois Director Jack Darin says greater reliance on wind power will help prevent health problems.