The effect of peak load shift to off-peak periods on pumping systems

Demand Side Management (DSM) initially focussed on reducing the Eskom evening peak. However, over the last few years the electricity demand profile, although reduced during Eskom peak periods, broadened. Eskom also has a problem with base load supply between the morning and evening peaks during the day. Load shifting is therefore still necessary, but Eskom now requires the load to be shifted to night time periods when electricity demand is lower. In this paper the effects of shifting peak load to the off-peak periods is discussed. Simulations on different pumping layouts show that the success of load shifting projects can, inter alia, be attributed to sufficient water storage capacity. This paper shows that load shift on pumping systems are still possible within the new constraints.