“Putting something on ice” doesn’t have to have a negative connotation. Sometimes, it’s the right thing to do.

That was the experience of officials with the University of Maryland, which used a thermal ice storage system to save on the college’s energy bills. Ice thermal storage uses a cooling tower and chiller to create ice on coils during low-demand hours. The ice is then melted to provide cooling during high-demand periods. Such systems, often used in conjunction with water-cooled HVAC systems, reduce dependence on electricity from utility companies.

At the University of Maryland, it used 8,900 ton hours of ice storage to save 1 million watts of energy.

John Vucci, the school’s associate director of HVAC systems, said the university saves approximately $70,000 a year by participating in a demand-response program.

Other schools using the technology include Nova Southeastern University, University of Pennsylvania, Johns Hopkins University and George Mason University.

Utility companies like the technology, too. John Nix, an engineer for Florida Power and Light, said ice thermal energy storage has helped the utility avoid building 13 power plants in the last 20 years.