During BHP’s recent environmental, social and governance roundtable, the miner put a number to electrifying its haul truck fleet: static charging could cost a battery-electric truck about 1000 operating hours a year compared with a diesel equivalent.
Set out in BHP’s September 16 presentation, the estimate, the miner said, illustrated why it is preparing to trial Caterpillar’s Dynamic Energy Transfer (DET) system at its Jimblebar iron ore operation in the Pilbara during the 2027 financial year (FY27).
BHP’s comparison uses a theoretical, pre-commercial 220-tonne-class battery-electric truck with a three-megawatt-hour battery. It assumes six to eight static charging stops of about 30 minutes each over 24 hours, against one 15-minute diesel refuelling stop. Actual charging needs will depend on the truck’s haul cycle and energy use.
The 1000-hour figure is therefore a modelling estimate, not downtime recorded during BHP’s existing truck trials, but it points to a practical challenge for miners seeking to replace diesel without reducing the amount of material a fleet can move.
DET is designed to supply power to electric-drive trucks while they are moving around a mine site, and for battery-electric trucks, that could provide charging time without taking the vehicle out of the haul cycle.
BHP said it is assessing a combination of dynamic and static charging, as well as how the system would work alongside autonomous haulage.
The miner has already begun proof-of-concept trials with two battery-electric haul trucks on a dedicated test track at Jimblebar. Those trials are examining range, energy consumption, battery behaviour, charging performance, reliability, safety and overall productivity.
The DET program adds another test to that work, and BHP plans to commission high-power static charging infrastructure at Jimblebar in FY27 while continuing the truck trials. Results, the miner said, should help it judge whether an electric haulage system can match the demands of a large, continuously operating iron ore mine.
BHP and Caterpillar first announced their DET plans in 2024, including tests involving Cat 793 trucks at Jimblebar and Cat 798 trucks at Escondida in Chile. At this stage, the roundtable adds a clearer measure of the productivity challenge the technology is intended to address.
The question extends beyond the truck and charger, addressed in its presentation; BHP said fleet deployment must be coordinated with power supply and supporting infrastructure, with investments staged as equipment and technology mature. Charging demand at remote operations also raises questions about available power capacity and reliability.
The company said it is continuing to identify battery-electric equipment as its preferred long-term diesel displacement pathway, and its assessment gives dynamic charging a potential enabling role, while placing renewable diesel, hybrid trucks and other approaches in more selective applications.
BHP has also highlighted new safety risks associated with fleet electrification, including high-voltage systems, direct-current arc flash and batteries. It is working with equipment manufacturers on controls and validation before wider deployment.
For now, Jimblebar remains a test of how electric trucks, chargers, power systems and existing mining operations fit together. The FY27 trials will help determine whether charging can be built into the haul cycle without the substantial productivity loss BHP’s model illustrates.