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The Alachua County Library Headquarters in Gainesville, Florida is using its IceBank® energy storage tanks to reduce operating costs and save taxpayer money. CALMAC’s technology enables the 80,000 square foot library, which was built in 1992, to shift cooling load.

Using approximately 125kW of CALMAC’s eight foot by eight foot energy storage tanks, the library is able to capitalize on significantly less expensive night-time energy, which costs $0.023 per kWh, as opposed to creating instantaneous cooling during the day that could cost as much as $0.072 per kWh. That’s a 68 percent savings just by using thermal energy storage! Additionally, with thermal storage, monthly demand (kW) could be slashed in half. That’s up to 50% off in demand charge savings by just using thermal storage! This is a significant figure since 40 percent of the headquarters’ total electric costs for the year can be directly attributed to cooling the structure, which is open seven days a week.

CALMAC’s ice-storage system is paired with four different modes of operation through the structure’s Building Automation System (BAS): chiller only, ice only, combination and free cooling. The chiller only mode makes the system act as a traditional system where instantaneous cooling is created by the chiller. The ice only mode relies purely on cooling that was created and stored the previous night. Combination mode enables the building to use both stored cooling and the chiller simultaneously to meet the day’s cooling demands. Throughout the colder months, the free cooling mode can utilize outdoor air to chill the water used in the air conditioning system in place of a chiller.


Ice Thermal Storage


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