How Thermal Energy Storage Works
Thermal energy storage is like a battery for a building’s air-conditioning system. It uses standard cooling equipment, plus an energy storage tank to shift all or a portion of a building’s cooling needs to off-peak, night time hours. During off-peak hours, ice is made and stored inside Ice Bank energy storage tanks. The stored ice is then used to cool the building occupants the next day.
Ice at Party, A Simple Metaphor
Imagine holding a party. You’re not likely to make ice the moment people arrive. You couldn’t make it fast enough. You’d buy or make ice ahead of time, store it in your freezer, and use it as needed. The promise of thermal energy storage is similar, with this important stipulation. You still make the ice ahead of time, at night. But, the electricity you use to make that ice, is far less expensive at night than it is during the day.
During night time, off-peak hours, water that contains 25% ethylene or propylene glycol is cooled by a chiller. That solution circulates inside the heat exchanger within the IceBank tank, freezing 95% of the water that surrounds the heat exchanger inside the tank. The water surrounding the heat exchanger never leaves the tank.