17. Technology Selection and Sizing of On-Board Energy Recovery Systems to Reduce Fuel Consumption of Diesel-Electric Mine Haul Trucks

Installing an energy recovery system (ERS) on a mining haul truck has the potential to save a significant amount of fuel by recovering energy while descending into the pit and reinjecting this energy to reduce fuel usage for acceleration and ascent out of the pit. This chapter presents an initial investigation into the technical and economic feasibility of such an ERS for diesel-electric drive mine haul trucks. A simulation model incorporating the haul route, the truck and drive system characteristics, and the ERS is employed to evaluate the changes to fuel used and impact on payload for an ERS of a specific technology and size on a given pit depth, from which cost savings and fuel savings per tonne of material moved are inferred. Lithium-ion batteries and electrolytic double-layer capacitors were found to be generally infeasible due to, respectively, poor charging rate and cycle life, and low energy density. Both lithium-ion capacitors and electromechanical flywheels promise fuel efficiency improvements of greater than 10% for a large range of pit depths. Electromechanical flywheels are judged the most cost-effective option, with an expected payback period of less than 1.2 years.