Thermal Energy Storage 20101

Thermal Energy Storage

Energy storage allows a mechanical system to be designed for the average load rather than the greatest load of the day. Most people make use of energy storage in their homes by using a hot water tank. A small amount of energy operating all night provides hot water for your morning shower. Without a storage tank, much more energy would be needed for a short time while you shower.

Most large buildings such as office buildings, hotels, retail stores, schools, etc. need cooling when they are occupied because of heat given off by people, lights, electrical equipment and solar heat through the windows. The cooling loads typically occur for 6-8 hours during the day. By building ice during the remaining 16-18 hours, smaller capacity equipment can be used and a smaller, less costly ground heat exchanger (GHX) can be used.

In some situations energy taken from the ice can be recovered to heat the building, produce hot water etc. The recovered energy can greatly reduce heating costs in the building.

Buildings with large hot water demands, such as hospitals, hotels, apartments and condos can benefit from thermal energy storage as well. Large hot water storage tanks reduce the capacity of heat pumps required. More importantly, the size of the GHX can be reduced.