A St. Charles public works building will get a new device called an "Ice Bear" as a way to trim cooling costs and promote energy conservation.

Through an agreement with Norwalk, Conn.-based Verde Energy USA, the City of St. Charles will receive the device, which is an air-conditioner about five or 10 times as large as a typical residential unit, complete with an attachment that fills with water, said Tom Bruhl, electric services manager.

Typically an air conditioner has a compressor, which runs whenever cool air is needed, he said. This device's attachment runs when energy is cheapest, freezing the water. It then runs off that ice, Bruhl said.