A landmark study for a new underground nickel mine at the giant Cosmos Nickel Project in Western Australia says the underground fleet could be all-electric and deliver cleaner and cheaper outcomes than the conventional diesel fleet.
The study – delivered by Australian mining services group Perenti and Swedish–Swiss technology firm ABB for Perth-absed miner IGO Ltd – is one of the first pre-feasibility level analyses of the technical and economic aspects of converting an Australian underground mine’s fleet from diesel vehicles to BEVs.
Perenti and ABB assessed the feasibility of electrifying the entire Cosmos underground diesel fleet, including heavy vehicles such as trucks and loaders, ancillary vehicles including drills and charge rigs, and light vehicles including 4WD utes.
The study found that BEV fleet offerings matching the productivity of the Cosmos diesel mobile fleet are already available on the Australian market and that the estimated cost to electrify the fleet was not prohibitive over the presumed lifetime of the mine, even based on conservative productivity and cost assumptions.
Moreover, Perenti and ABB found that a BEV fleet would result in a significant reduction in cooling and ventilation demands compared to the existing diesel fleet, helping to offset the additional power required by a fleet of all-electric vehicles.
In fact, the study found that the estimated overall power balance of an electrified fleet of underground mining vehicles at Cosmos would on average be less than that of the existing diesel operation.
“An all-electric mine is closer than ever, with the right equipment available and the mindset of the industry changing,” said Raj Ratneser, Perenti Group executive sponsor for electrification and decarbonisation.
“As BEV technology develops, and our understanding of how these vehicles can be best integrated into an operating mine improves, we expect electric mining solutions to only become more competitive against existing diesel powered options.”
The report acknowledged that a fleet of fully electric underground mining vehicles would be inherently more complex to manage than a diesel fleet, but found that a combination of strategically located battery swapping stations and charging points would help to minimise downtime.
The study found that two 65-tonne BEV trucks could replace and match the haulage capacity of the two 63-tonne diesel trucks originally planned for Cosmos. These trucks would utilise battery swapping stations, with swaps taking place every 3 to 5 haul cycles at a time of only 8 to 10 minutes each.
The study took an intentionally conservative approach to things, and so the original plan for three diesel loaders would need to be replaced by four BEV loaders – pending more detailed modelling and field trial data to verify real-world capabilities.
These BEV loaders would similarly utilise battery swapping stations and would require a fresh battery around 2 to 3 times per shift.
Finally, ancillary diesel equipment such as graders, grills, and light vehicles could all be replaced by BEV equivalents, but due to the lack of existing battery swap technology for these smaller pieces of equipment, they would have to be plugged in to charge.
The study therefore found that unproductive time could be minimised by strategically locating charging stations at common areas to enable “opportunistic charging” during periods such as crib time, shift change, or while loading and unloading consumables.
“Mines can become even more energy efficient with vastly reduced levels of CO₂ emissions, while at the same time staying competitive and ensuring high productivity, in part due to the higher tramming speeds of electric loaders and trucks compared to their diesel equivalents,” said Max Luedtk, ABB Business line manager for mining.
“We have been investing in electric mining transport through our eMine portfolio for several years now and have seen the technology go from strength to strength.
“We expect the outcome of this study to provide more momentum for electrification so our industry can continue to make real progress in lowering its emissions, while improving the health and safety of our people.”
“IGO is pleased to share this study with the wider industry as it demonstrates that the electrification of underground mining fleet is technically feasible, in the right circ*mstances,” said Chris Carr, IGO Limited acting chief operating officer.
“The electrification of fleet at mining operations will be pivotal in the industry’s commitment to advancing towards net zero emissions. In addition, the removal of diesel from underground operations will eliminate diesel particulate matter and other diesel exhaust gases, resulting in improved working conditions and better health outcomes for employees.”
Joshua S. Hill
Joshua S. Hill is a Melbourne-based journalist who has been writing about climate change, clean technology, and electric vehicles for over 15 years. He has been reporting on electric vehicles and clean technologies for Renew Economy and The Driven since 2012. His preferred mode of transport is his feet.
