Potential of on-board energy recovery systems to reduce the costs of diesel–electric mine truck haulage

On-board energy recovery systems (ERSs) are expected to reduce fuel consumption of open-pit mine haul trucks. However, the additional mass of an ERS would reduce the truck’s payload, hence reducing productivity, effectively increasing other haul-related costs. Using a simulation program incorporating appropriate models for a diesel-electric mine haul truck, capital costs, operating costs and four energy recovery technologies, this paper investigates how various ERS technologies would affect overall haulage cost. Two energy re-use strategies are considered. The power augmentation strategy, which aims to reduce cycle times, promises greater savings than the fuel replacement strategy, which reduces engine power using recovered power. The ERS technologies found to be best suited to the application are fast charging LiFePO4 batteries, and electro-mechanical flywheels. Using the power augmentation strategy, the potential cost reduction for both technologies under ideal conditions is 7%. Restrictions on exploiting the full potential of ERS systems are highlighted and discussed

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

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 (LiFePO) 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 LiFePO 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