Ice Energy: Thermal Energy Storage-Load Shifting Device
November 21, 2011
By tapping into the electrical grid when it’s used the least, the Ice Bear® ice storage air conditioner uses electricity at night to store energy in the form of ice. By making the ice when electricity is less expensive and more abundant, the unit uses that stored energy during the day to provide cooling with less electrical input during times of peak demand. The actual system is about the size of a regular commercial a/c unit, and it attaches to the pre-existing unit. The Ice Bear system functions like a regular a/c unit, but uses its onboard compressor, expansion valve, and large copper cooling coils containing 250-400 pounds of copper, to freeze 450 gallons of water into ice overnight. According to the manufacturer, copper is used because it’s durable, easy to use, and a good thermal conductor. During the day and times of peak demand, the stored ice is used to cool refrigerant within the system and transfer it to the condenser coil in the companion air conditioning unit rather than running the unit’s compressor. The cold refrigerant is routed through the Ice Bear and the existing a/c unit by a small pump, rather than a compressor, cutting down on electricity usage to 100 W. Each Ice Bear can cool about 4,000 square feet.