Thermal Energy Storage (TES) allows excess thermal energy to be collected and stored for later use. TES technology is like a battery for a cooling or heating system. Instead ofrelying solely on electrical power to heat or cool large facilities, TES reservoirs reduce energy consumption by pulling thermal energy from the self-contained system.
The process systems for TES vary widely, but the basic technology is largely the same. Most systems use standard cooling equipment and an energy storage reservoir. During off-peak periods, when electrical rates are lower, the chilled TES tank is charged. To charge the tank, the water is cooled with conventional water chilling units then returned to the bottom of the tank.
Later, when cooling is needed, chilled water is removed from the bottom of the chilled TES tank and flows to the air-conditioning system. As the water exits the tank, some amount of water from the air-conditioning system flows in to await the next cycle. Hot water TES tanks essentially work the same way but distribute hot water instead.
Benefits of Thermal Energy Storage
One of the primary benefits of a TES reservoir is a reduction in operating costs. These systems leverage peak/off-peak utility rates. Shifting a large portion of a facility’s energy consumption to off-peak hours can produce tremendous cost savings. This is one of the reasons universities, airports, convention centers and other large facilities choose to install TES systems. Many utility companies also offer direct cash incentives or rebates for TES. This can help organizations see a return on their investment in just a few short years.
Some facilities, like hospitals and data centers, need redundant cooling systems. TES can be designed to supply cool air to critical areas even if the main air conditioning system is down. Additionally, chilled TES tanks can supply water for fire suppression systems.
Maintenance of a chilled TES water tank is minimal. Installing a TES system can help reduce overall maintenance costs because it reduces the operating load placed on chillers. When fewer and lower capacity chillers are required, it reduces the amount of maintenance and the associated costs needed to support those units.
TES systems can be retrofitted to an existing system or included in new construction projects. The diffuser can be custom designed to suit the shape of the reservoir. Tanks can be placed aboveground as stand-alone steel structures or tucked underground in a basement. Diffusers can be designed as octagonal, H-shaped or radial to minimize disruption to the water layers during charging and discharging.
As you can see, a TES water reservoir provides numerous benefits for your facility. Whether you are looking to reduce operating costs, install a redundant cooling system or take advantage of utility company incentives, TES systems are a smart choice.