A simple demand-side management solution for a typical compressed-air system at a South African gold mine

Abstract

Once designed, mine compressed-air systems tend to operate at peak levels throughout the life of the mine, despite there being significant periods when this air quantity is not required. This is mainly due to lack of appropriate compressor controls. Consequently, such compressed-air systems are inefficient and wasteful. A compressed-air system at a South African gold mine was retrofitted with an automatic compressor control system featuring compressor cascading and pressure bandwidth control. The goal was to implement a simple demand-side management (DSM) strategy to afford meaningful electrical energy savings. The automatic control strategy realised a saving of 1.25 MW (on a baseline of 7.22 MW) during Eskom’s evening peak demand window. This represents a reduction of 17.3% in electrical power consumption during the evening peak period, and savings of nearly R2.9 million per year.