Potential of on-board energy recovery systems to reduce haulage costs over the life of a deep surface mine

Abstract

The installation of energy recovery systems (ERSs) on-board diesel-electric mine haul trucks to capture energy when braking and re-inject stored energy on acceleration and ramp ascent, is proposed to reduce haul costs in surface mining. ERSs would add to equipment cost and reduce truck payload, reducing productivity and effectively increasing other haul-related costs. However, stored energy could reduce fuel consumption and could be used to reduce cycle time thereby improving productivity when conditions are favourable. This paper investigates how the installation of fixed size electro-mechanical flywheel (EMFW) or lithium iron phosphate (LiFePO₄) based ERSs could affect the overall cost of truck haulage over the 20-year life of a metalliferous surface mine reaching 600 m deep. The simulation study suggests LiFePO₄ technology can be expected to provide significantly greater haul cost reductions than the EMFW technology by reducing haul costs by 1.4–6.2% depending on the energy re-injection strategy employed.