CHICAGO (CBS) — The coolest race of the year was held for a good cause.

The 5th annual Ice Box Derby was held at Daley Plaza. Girls ages 13 to 18 worked in teams to transform recycled refrigerators. They made them into electric and solar powered race cars.

ComEd organized Saturday’s event to encourage young women to pursue careers in engineering. The girls had fun and it was special for the mentors helping them too.

“It was awesome. They do everything,” said Emily Torres of ComEd. “It’s really great to see them grow and see them actually learn something every single day.”

The 30 participants in the derby each received a $1,500 scholarship from ComEd.