An introduction to the use of stratified chilled water storage in Saudi Arabia for electrical demand reduction and energy conservation in large air conditioning systems.

Thermal Energy Storage (TES) technologies particularly chilled water storage are being applied increasingly by Services Engineers in the Kingdom of Saudi Arabia to reduce electrical demand and lower energy consumption in buildings. This development has received added impetus by the introduction in 1995 of the Load Reduction Programme by the electricity supply authority. The programme aims at managing the shortfall between available electrical supplies and the rapidly increasing demand. Limits are being imposed on electrical supplies to new buildings, and new and existing projects are being subjected to restrictions on the power available to operate chillers during peak periods. This paper shows how chilled water TES offers a means of reducing the electrical demand in large commercial buildings and, by load shifting, dealing with restrictions on chiller operation. Additionally it is seen that power bills can be reduced as air cooled chillers are run overnight in cooler air when their operating efficiencies are higher. The "favouring factors", that is the conditions that must exist before T.E.S. can be considered viable are examined, as are the concepts behind chilled water based T.E.S.; its operating strategies, applications and design features. TES economics are considered and a cost analysis presented to illustrate the potential savings that can be achieved by the use of Thermal Energy Storage.