RUTLAND, Vt. — Looking to eliminate the high peak power prices driven by summer air conditioning, Green Mountain Power (GMP) has started a pilot ice storage project in Rutland, Vt.

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

GMP is installing three Ice Bear energy storage systems, integrated with monitoring and control capabilities, in two downtown locations owned by MKF Properties. The units will serve the Citizens Bank building and the Gryphon Building, both of them historic Rutland buildings.

“We see this as an innovative way to determine how a broader program could positively affect individual customers through lower bills while benefiting all customers by reducing the amount of energy we have to purchase when power costs are often at their highest,” Powell said. “We’re hopeful that the pilot could lead to an expanded program that would benefit participating and non-participating customers alike.”

The Ice Bear consists of a large thermal storage tank that attaches directly to a building’s existing rooftop air conditioning system. The Ice Bear energy storage unit operates in two basic modes, ice cooling and ice charging, to store cooling energy at night, and to deliver that energy the following day.

“The Ice Bear uses the ice, rather than the air conditioning unit’s compressor, to cool the hot refrigerant, slowly melting the ice as the refrigerant travels through a series of copper coils,” said Greg Miller, executive vice president of Ice Energy, the system provider based in California. “A small, highly efficient pump pushes the ice-cold refrigerant through a modified evaporator coil installed in the conventional air conditioning unit.”

The project is being managed by GMP’s Energy Innovation Center, which is leading a variety of innovative pilot programs for the company, including a heat pump rental program already underway.

“We’re trying to create programs and innovations that will directly benefit the environment and our customers statewide, while contributing to Rutland’s revitalization,” said Steve Costello, vice president for generation and energy innovation. “By doing these pilots in Rutland City, we think we can accomplish all three things.”

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Publication date: 11/4/2013

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