Mayor Rahm Emanuel and the Department of Fleet and Facility Management (2FM) announced Tuesday that they have picked Constellation NewEnergy, an Exelon company, to provide electricity for the city of Chicago’s municipal buildings and street lighting using coal-free energy. 

The contract between the city and NewEnergy is set to last 25 months.

The agreement will provide a 2 percent discount from the city’s previous electricity contract, which will lead to a $1.2 million reduction in city energy costs over two years, according to the mayor's office. The announcement also adds on to a municipal aggregation agreement the city council approved in December 2012 to eliminate coal from Chicago's electricity source.

“Through the success of the municipal aggregation program, the city of Chicago has decreased its carbon footprint while delivering savings to residents and small businesses,” Emanuel said in a news release. “Our agreement with Constellation will build on this success while creating a cleaner, healthier environment for our children.”

Jack Darin, director of the Sierra Club Illinois chapter, released the following statement in response to Tuesday's announcement:

Mayor Emanuel’s announcement is an important next step toward eliminating dirty energy from Chicago’s energy mix. Chicago’s most important buildings like City Hall, O’hare and Midway airports, city libraries and police and fire stations will all be powered by coal-free energy.

Municipal aggregation is already saving Chicago residents money on their electric bills, and Chicago’s coal-free goals are reducing emissions from dangerous coal-fired power plants. Choosing to get rid of coal in the city of Chicago means cleaner air and better rates for our city.