Investigating load shift and energy efficiency of new technology loco battery chargers

Abstract

An investigation was conducted into the potential to do demand side management on the locomotive battery chargers on South African mines. The potential to do load shift and energy efficiency on new technology battery chargers was examined. A simulation model was drawn up to simulate the potential to do load shift on the currently installed battery chargers. This model was further extended to include the high frequency battery chargers, to enable the simulation of load shift and energy efficiency of these chargers. Electricity utilisation on the locomotive battery chargers on a mine can be increased from about 50% to 96% by replacing the currently installed ferro resonant chargers with new technology, high frequency battery chargers. This results in an energy efficient implementation. It is also possible to realise load shift on these high frequency battery chargers to realise more electricity cost savings, as well as to reduce the electrical load in Eskom's peak time(s). Electrical energy cost savings of up to R442 600 is possible by replacing all the chargers with high frequency chargers and doing load shift in Eskom's peak times. The payback can be as short as 2.7 years. It is also possible to realise load shift on the currently installed ferro resonant battery chargers on a mine. Annual electrical energy cost savings of up to R234 200 is possible by implementing load shift in Eskom's morning and evening peak periods. A case study was done at Kopanang gold mine to test the simulation model, as well as the feasibility of these new technology chargers for energy efficiency and load shift. There exist potential to do energy efficiency and load shift on these chargers, and it was proven possible.