The worldwide mining industry is being pushed more into the reduction of Scope 1 greenhouse gases in every facet of its operation. The electrification of fleet vehicles happens at two different rates, depending on whether they are used underground or on the surface. Underground operations have reached a commercially mature state because of the health benefits for employees and the reduced ventilation costs.
There are strict atmospheric considerations within underground mines when it comes to temperature, diesel particulates, and other noxious exhaust gases. The electric haulage trucks do away with tailpipe emissions and cut down on the amount of ventilation equipment needed. In a notable case study, it was seen at the Cosmos Nickel Project in Western Australia that a fleet of electric machines used less energy in total than the diesel machines used. For underground machines, battery capacity is much lower at under 500 kWh, and it is more feasible than for large earth-moving machinery above the ground.
Diesel haul trucks produce between thirty and fifty percent of direct mine emissions, and they also have substantial operational costs. One 150 tonnes haul truck uses more than 850,000 US dollars worth of fuel per year, whereas total energy savings through electrification are more than 5.5 million US dollars per truck. The ultra-class surface haul trucks need very large battery packs that exceed 1 MWh to 2 MWh. This huge energy requirement needs high-powered charging systems, including Megawatt Charging Systems with power ranging from 1 MW to 6 MW, trolley assistance, or dynamic charging while moving. The electrification on surface has moved towards implementation, and this includes Caterpillar 793 XE Early Learner tests with BHP and Rio Tinto in the Pilbara, Fortescue’s 240 tonnes fleet along with 6 MW fast charger, and Rio Tinto’s surface battery swapping test at Oyu Tolgoi.
Primary engineering concerns have been transformed from those associated with vehicle design to the development of energy infrastructure at the sites. The operations will need to handle the issues of high voltage power transmission, charging scheduling, and the availability of renewable microgrid energy sources. Mine owners reduce their risks associated with investing in the capital by choosing vehicles that have the capability of being powered either by diesel engines or electricity (Komatsu 930E and Caterpillar 793), thus converting from diesel to electric power as the energy infrastructure improves.
Electrification of underground mines is a fact that already exists and brings immediate benefits both for ventilation and safety issues. Rapidly following it comes the electrification of surface operations, evolving from pilot field tests to megawatt systems. In the future, success over the next decade will largely depend on the coordination between the three elements mentioned above.
