Chilled Water at Supply Temperature is stored inside a Pressure Vessel capable of being used later to meet air-conditioning load during emergency and power outage when chiller cannot operate During Power Failure in a Data Centre,  Server room air starts to heat up; There is Rapid rise in temperature. 

Heat will be absorbed by IT equipment and Servers would be prone to damage.

There is Unacceptable temperature rise in 5 mins. Restoring time – Start-up time (Generators + Chiller).

The Solution : Back up Chilled Water for Start-up time of Generators + Chillers

• The Thermal Energy Storage (TES) system starts to supply the stored chilled water to maintain data center temperatures. 
• The thermal reserve-maintains cooling of the server rooms during this period, to allow dissipation of residual heat from the servers.
• In the meanwhile, the generator power and chillers are restored.