Vermont's largest electric utility is launching a potential power-saving experiment that would use ice created at night when energy is cheap to cool buildings during the day, potentially saving money on air conditioning.

Green Mountain Power is installing three energy storage systems, called Ice Bears, in two building in downtown Rutland.

"We hope to put the freeze on high-cost, high-carbon generation driven by air conditioning," said GMP President Mary Powell. "Through the pilot, we hope to demonstrate the ability to shift air conditioning energy demands from daytime to nighttime, saving customers money, reducing the environmental impact of generation, and controlling peak demand during the summer."

The system attaches to a building's existing rooftop air-conditioning system. During the day when it's hot, the system uses the ice, rather than the air conditioning unit's compressor, to cool the hot refrigerant, slowly melting the ice and cooling the building.

The units will serve the Citizens Bank and Gryphon buildings, both considered historic Rutland structures.

The project is being managed by GMP's Energy Innovation Center, which is leading the company's efforts to make Rutland the Solar Capital of New England by developing a variety of innovative pilot programs.

Ice Thermal Storage