Thermal Energy Storage System (CWTES). This system utilizes only the sensible heat of water for cooling energy storage in a chilled water storage tank and discharges the stored coldness for air-conditioning during the on-peak time. The key technology of Chilled Water Storage system is the diffuser design which ensures thermal stratification of chilled water and warm water by density difference. FTEnEâ??s technology is the state of the art technology which is recommended in ASHRAEâ??s design guide. They have a long history of installation around the world including U.S.A., Japan, Korea and middle-east Asia. Some key features of Chilled Water-Thermal Energy Storage Cooling: Lowest initial investment cost 30-40% energy saving by utilizing conventional chillers whose Efficiency is higher than low temperature chillers Simple system with easy controls without additional heat Light in weight compared to Si-Br. Exchangers and less equipment Efficiency of discharging coldness is very high Easy to convert conventional system into CWTES system by Adding only chilled water storage tank Convertible to heating purposes Environmentally friendly system free from brine Storage water can be utilized for fire-fighting in emergency