Maintenance procedure for improved sustainability of DSM pump load shifting projects

Mine dewatering systems are energy intensive and present ample opportunity for the implementation of electricity cost saving measures. One such electricity cost saving measure is the implementation of load shifting projects to shift pumping load from the peak periods to the off-peak periods of the Eskom Megaflex tariff structure. However, past experience has shown that the electricity cost savings generated by a pump load shifting project can deteriorate without proper maintenance. The major causes of the deterioration were therefore investigated with the aim of developing a maintenance procedure. The maintenance procedure consists of four sections: data loss prevention, mechanical failure prevention, control & instrumentation maintenance and control parameter optimisation. The developed maintenance procedure was implemented on the dewatering systems of South African gold mines. Results indicate that the application of the maintenance procedure resulted in both increased electricity cost savings and sustained performance.