Abstract:
Uninterruptible power supplies (UPSs) are extensively used as standby source of electricity when utilities employ load shedding frequently as a demand side management tool. UPS charges batteries from utility supply when it is available and, subsequently, restores the power when utility supply becomes unavailable. This study examines the impact of UPS charging on energy consumption and demand at the utility side for Karachi which is the largest city of Pakistan. The paper also showcases the effects of improving UPS efficiencies on grid wide energy consumption. Potential bearings for the utility in the context to UPS charging are discussed and actions are recommended for optimising demand surges which result from simultaneous UPS charging at the onset of restoration of power at the end of a load shedding period.