Dive Brief:

• Chicago Mayor Rahm Emanuel announced over the weekend that more than 900 city-owned buildings will shift to all renewable energy by 2025, making it the largest municipality in the country to make such a commitment.
• The goal is a heavy lift — the city's buildings, colleges, public schools and others, use almost 1.8 billion kWh of energy last year, or about 8% of the city's total use. The city will acquire renewable energy credits (RECs), purchase renewable power from utilities and increase on-site generation to offset the building demand. 
• The green energy trend for municipalities has been growing: Aspen, Colo., Burlington, Vermont, Georgetown, Texas, San Diego and San Francisco have all set similar goals.

Dive Insight:

Beginning next year, the city of Chicago will begin acquiring renewable energy and investing in on-site generation to offset the demand from about 900 city-owned buildings.

In a statement, city officials said they would purchase both RECs generated under the Illinois Renewable Portfolio Standard and directly buy renewable energy from utilities. 

Acquiring enough renewable power to compensate for the building load is estimated to add 1% to power costs for the city initially, CBS Chicago reports, but will ultimately generate savings.

Mayor Emanuel, formerly President Obama's White House chief of staff, framed the move as a deliberate step away from the environmental policies of the Trump administration.

“As the Trump administration pulls back on building a clean energy economy, Chicago is doubling down,” Emanuel said in a statement. “We are sending a clear signal that we remain committed to building a 21st century economy here in Chicago.”

The electricity used by the city's agencies is the roughly the same amount of energy created by over 300 wind turbines in one year, or the equivalent to powering approximately 295,000 Chicago homes. 

The mayor also announced a new commitment on the rooftop of Shedd Aquarium, which installed over 900 solar panels to reduce their energy use by 50% by 2020. The aquarium has also retrofitted nearly 1,000 of its own light bulbs to LED and installed a 1 MW battery.

Chicago has already been working to clean up its energy mix: In 2013, the city eliminated coal from the over 1 billion kWh of energy it buys on an annual basis. The city also has an ambitious energy benchmarking ordinance for buildings, requiring properties more than 50,000 square feet to report whole-building energy use annually and verify the data every three years.