Institutional electrical energy requirements follow a bell curve with peaks during the day and valleys overnight. Local power plants must have the capacity to handle the peak periods. Power plants are often oversized to meet high demand peak periods and are forced to charge demand fees to offset the cost of additional equipment. During periods of low demand (evenings), plants must be kept running and producing electricity, often with excess capacity. In many cases, energy produced during low demand periods is offered to large commercial users at a reduced rate. Thermal Energy Storage (TES) takes advantage of these low rates by chilling water for the cooling systems at night and storing it in insulated tanks for use during times of peak demand. This is known as load shifting or peak shifting. Depending on the specific geographic location and utility incentives, the payback of the initial construction cost can be very short.
Another potential use of Thermal Energy Storage is to store chilled water during periods of low demand then use it to increase the capacity of the chiller plant by combining it with flow from the chillers to meet the needs during periods of high demand. This is called peak shaving.
Thermal Energy Storage can also be utilized as a source of emergency back-up for cooling systems. In the event of a sudden power loss, TES can be used to keep the cooling system running until the emergency back-up generators can be brought on line.
The concept of thermal storage results in a win/win relationship between the owner of the facility and the power company. Many times the benefit to the power producer is enough for it to offer financial incentives for the construction of these projects.
Click here to download a pdf of our Thermal Energy Brochure.