Every major mining company has a decarbonisation project, and a large part of it is moving from diesel to electrical energy, as Drew Turney reports
Electric cars are becoming increasingly common on Australian roads, and industrial players are investigating their use in commercial fleets, with one recent study from the University of Michigan finding electric trucks can reduce air pollution and greenhouse gas emissions by between 13% and 35%
Research firm IDTechEx expects electric trucks to become a US$15bn industry. Could the same change transform mining? If so, we’re a long way off—a 2022 study said only 1% of industry power came from electricity—but plans are accelerating.
Several Australian industry players and their supply chain partners are members of the Electric Mine Consortium, a think tank driven by the mission to accelerate progress towards a fully electrified zero-CO2 and zero-particulates mine.
As a spokesperson from automation technology provider Rockwell Automation told us, mine site tools are fertile ground for adopting wide-scale electric power. “Most mines are in places with lots of renewable energy, and many are a long way from the grid and have to run generators,” he said. “It’s not just more sustainable; it’s more affordable to capture energy on-site rather than shipping fuel to a remote location.”
Change in a different climate
In many ways, it’s not just an opportunity but the response to an urgent problem as power needs at mine sites increase. In just one example, BHP operates two major locations in Chilé. The power needs of both, which were seven terawatt-hours per year in 2022, are set to increase to 12TWh/y by 2033, an increase of 70%. Without electrification, there would be a lot more diesel carbon emissions.
The company’s June 2023 decarbonisation report said the diesel displacement in the Chilean sites’ cathode operation boilers would mean 1,000 fewer round trips by diesel trucks every year.
The report said that the 2020s would be characterised by mine electrification challenges thanks to further increases in power consumption. BHP intended to meet these tasks by exploring solar generation and storage and power purchase agreements from renewable sources. As the report said, ‘Our preferred pathway to eliminate diesel is via electrification.’
The mining giant has already announced a partnership with heavy industry manufacturer Caterpillar to replace the diesel fleet at one Chilean site completely, bought four battery-powered locomotives for its WA iron ore operations, and announced a partnership with Rio Tinto to conduct trials of battery-electric haul trucks in both companies’ Pilbara, WA operations.
As the above makes clear, most of the activity around electrification so far is in vehicles. IDTechEx reports that the mining industry produces 2-3% of the world’s CO2 emissions, with around half of that total coming from diesel vehicles.
However, the Australian mining and resources industry needs about two gigawatts of off-grid power. Some support operations can come from small-scale solar (think of the technology behind those remote highway solar-powered emergency phones powering the rec area barbecue), but offloading the burning of diesel to generators that provide electric power for heavier use will only move the problem, not solve it.
So there are plenty of other areas where electrification can make a difference like conveyor belts, hoist systems, grinding machinery, etc. “The first thing that comes to mind is, of course, battery electric vehicles to reduce diesel,” says Thomas Steigler, research engineer of energy solutions provider Ampcontrol. “They not only reduce CO2 emissions, they eliminate diesel particulates and generate less heat, so reduced underground ventilation saves energy.”
Steigler calls Ampcontrol, a 55-year-old energy industry provider based in Newcastle, one of the primary suppliers of electrical equipment to the resource industry. The company also services the energy and infrastructure industries and has recently made inroads into electric vehicles with the Driftex battery electric personnel carrier and BEV chargers.
“It’s the first battery electric vehicle certified for use in explosive atmospheres, which is required in underground coal applications,” he says.
One of the biggest challenges to overcome in electric vehicles is range—batteries don’t power a big mine truck as long as an onboard tank of diesel fuel—which is why much of the industry is concentrating on the surrounding infrastructure first, either as a proof of concept or because it’s an easier market to develop.
Cost vs environment
So what’s driving all this – will it save money or the planet? Happily, both those aims can advance in lockstep. One WA gold mine hopes to get most of its power from an on-site solar and wind farm (more below), which will save a lot of diesel, not to mention the costs of purchasing and transporting fuel.
The industry has also undertaken modelling to compare diesel against electrified mine operations, with illuminating findings.
The research finds that while CapEx for electrified mines is higher than that of diesel mines, OpEx is lower. The net result is that electrified mines and already economically viable when compared to diesel operations. The savings in smaller scale operations were more marginal depending on the operation, but in a bigger mine, the net result was clearly positive.
Depending on variables such as what the operation was extracting, commodity prices, etc., the study found that the costs of electrification would pay for themselves within eight to twenty years.
“Estimates vary,” agrees Pranav Jaswani, Technology Analyst at IDTechEx, “but broadly speaking, electric machines have shown they’ll cost 40-80% less to operate than equivalent diesel ones.”
In fact he’s even more optimistic, saying most electric surface mining vehicles will pay for themselves in saved fuel and maintenance within two to four years – one to two years in underground operations.
Identifying and managing those costs is a whole other ball game. You don’t just buy an EV and scrap an existing truck.
One is training. Jaswani says there’ll be a period of adjustment, just like you or I would need when going from a petrol to an electric car. Still, mine vehicles have far more intensive license and training requirements, so most drivers and operators will pivot quickly.
“It’s a similar story with maintenance workers, who’ll need some training to provide proper care for an electric machine,” he says. “But so far, members of the equipment manufacturer’s teams have helped train mining company staff so they can monitor and maintain the equipment thoroughly.”
The real learning curve will be imposed on mine managers, engineers, and planners. “They’ll need to understand the intricacies and nuances of operating an electric fleet, understanding all the different levers you can use to make improvements,” says Steigler. “Where do you put your chargers? How fast do you charge? What data measurements do you take to optimise operations?”
Secret source
But where will the energy come from to recharge batteries and power the electric mine? As mentioned above, a gold mine in Leinster, around 1,000km northeast of Perth, has its own solar and wind farms, operated by sustainable distributed energy system provider EDL.
The Agnew Hybrid Renewable Microgrid is intended to power the mine using 50-60% renewable energy over the long term, the equivalent of the power needs of around 16,000 homes every year. Solar, wind, battery, and gas engines produce over 14,000kW of power without a single drop of diesel.
But it’s much harder than throwing up a paddock full of panels or windmills. “Charging and power infrastructure is one of the biggest challenges for electric mining,” says Jaswani.
“Current infrastructure can vary widely. Renewables like solar and wind are already popular and expected to become even more widely used. Some companies also set up microgrids – smaller and entirely self-contained grid systems using local energy generation, transmission, and storage. Some shorter-term solutions are diesel or hydrogen-powered mobile charger units, but they’re both more expensive and less energy efficient.”
This means the Australian mine is going electric by hook or by crook, and the race is on to find the most cost- and energy-efficient way to do it. With the price and demand for energy not heading down any time soon and the climate changing on a seemingly yearly rather than a generational basis, can we afford not to?