Surface mines and aggregate quarries move massive amounts of material every day, and for most operations the costs of that movement are among the biggest hits to the bottom line. Diesel fuel powering off-road trucks that haul that material from place to place within the operation, or in some cases over the road for delivery to other facilities, is getting more expensive every day.
Maintenance for all of those trucks is costly as well, and even with today's cleaner burning engines the issue of carbon emissions remains. That's why some companies are exploring the potential of electrification to reduce costs and emissions together.
One Canadian company is developing electric vocational trucks for mine and quarry sites with an aim to provide smaller units that can work through a 24-hour period without burning diesel or producing significant emissions. Terra EV brings an expertise in electrification of underground mining equipment from MEDATech Engineering and pairs it with a tough Western Star vocational truck chassis from Tardif Diesel to produce vocational trucks that can work in a variety of hauling roles.
"We saw that the OEMs are more focused on highway [applications] - it's an easier space to electrify, in some respects . . . this off-road vocational space is a very niche market, but it's an important market because we see these trucks as actually quite suitable for electrification," explained Terra EV co-founder and Vice President of Business Development Jeff Taylor. "They don't go far from home, they stay in a circuit - they're last-mile operators. It's a good environment for electrification, but they need to be ruggedized for vocational use."
Experienced trio joins forces to develop EVs
Terra EV was started with the participation of three people: experienced entrepreneur Taylor, Western Star truck dealer Jean-Marc Tardif of Tardif Diesel, and Robert Rennie, president of MEDATech Engineering. Rennie's company produces electric drivetrains for various types of equipment, initially targeting the underground mining sector, and that experience provided the basis of the Terra EV project.
"ALTDrive technology has been around for about eight years now . . . the actual ALTDrive system, the batteries, electric motors, inverters, cooling system, and software to run everything has been installed in other types of machinery for underground mining," Taylor described.
The major components of the system are sourced from within North America, Taylor noted.
Terra EV has worked with MEDAtech Engineering and its ALTDrive system to turn Western Star's heavy-duty XD truck chassis - chosen for its premium quality and reliability in off-road operation - into an electric vehicle that can serve the needs of the mining and quarry sectors.
"You have to look at the duty cycle of the vehicle; it's very site-specific. If you are on a level surface, or hauling loaded downhill, electrification works great, but if you have steep out-of pit conditions or a very long trip, that can be more challenging," he described. "That doesn't mean it can't work, it is just more challenging because you're using that energy while climbing out loaded. You have to understand if you have enough energy on board to get to the top of the circuit so you can plug in to recharge or use regenerative braking while you travel back down."
Opportunity charging important for vocational trucks
For vocational trucks, opportunity charging will be an important part of the process, Taylor noted. That means finding space in the duty cycle to plug in for a short period and get enough of a charge to continue the next cycle.
"When you go to any operation, everyone says that their vehicles are operating all the time, but they're not - there's usually some idle time there. You can build those idle periods into opportunity charging," he said. "There's going to be a lunch break, a shift change, a midday break - in all those cases, if you do a little bit of charging here and there, overall you will move the same amount of material through 24 hours."
Advance planning of charging times is one part of keeping battery-electric vocational trucks moving through the day. Increasing the charging speed is another approach. An ultra-fast charging system developed by ABB is available and can bring the battery to full state of charge in ten minutes or less, Taylor added.
Terra EV is intending to offer two models of truck based on the proven Western Star 4900 XD and 6900 XD chassis provided by Tardif Diesel, each with multiple potential configurations for hauling, trailering, or other roles around the job site.
The Boss model, based on the 4900XD, is a 22-ton truck that has two versions to be offered by Terra EV. The 310 is a straight truck that can be equipped with a dump box, water tank, crane, or service body depending on the needs of the user, while the 466 is a tractor configuration with a fifth-wheel for trailering. Load capacity of the 466 model is up to 120 tons, Terra EV claims. Both versions have a variety of options available.
Built on the 6900XD platform, the Master model is also available in two configurations, a straight truck or tractor, with load capacities of 36 and up to 180 tons respectively.
"It really depends on what the customer wants to do. Do they want to have a lighter-duty service truck that can run around the yard, or do they want a heavier-duty service truck? Are they looking to pull bigger loads? It really depends on what they're trying to achieve with the truck," Taylor said.
The tractor-trailer combination is one that Taylor said may prove interesting to buyers in the mining and aggregates sectors as an alternative to larger rigid-frame trucks.
"They're used to their diesel trucks, and the diesel trucks work great . . . but at the same time, we have to find a way to do certain things better. Rigid-frame trucks are amazing machines, but they are incredibly inefficient because they carry all their weight on the body and rolling resistance is super high," Taylor noted.
"That's what makes the tractor trailer combination so attractive - we have way less rolling resistance, therefore we can make an electric truck work to move the same amount of material as, let's say, a rigid frame 80-ton truck. To electrify a rigid frame 80-ton truck, you have to use two and a half times the batteries we have . . . then it becomes a law of diminishing returns, because the more batteries you add, the less payload you can carry."
Pilot project combines off-road and on-road operation
Currently, Terra EV has a demo truck that has been used by a number of operators. The demo unit gives potential clients the opportunity to get the EV's performance, capability, and ease of use.
Starting this year, Teck Industries will be using a fifth-wheel Western Star with ALTDrive on a combined off-road and on-road haul at its Highland Valley Copper mine in British Columbia. The truck will haul copper concentrate - the first time in the world a battery-electric truck has done so - from HVC to a rail loading facility in nearby Ashcroft.
"The fully electric ALTDrive system is designed for this haul cycle at HVC, requiring a vehicle that weighs 65,000 kg full and 25,000 kg unloaded, and completes the same four to five 95-km round trips every work day," Rennie stated of the Teck pilot. "Since the truck batteries will charge on the downhill haul through regenerative braking, the rig will require only a short battery recharge at the Ashcroft rail terminal so the haul cycle time is expected to be the same as a conventional truck."
Teck, which has engaged in a number of innovative projects evaluating new hauling technology, has a goal of becoming carbon-neutral by 2050, and electric vehicles are one of its key points.
"Testing and implementing new electric vehicle technologies is one way we are taking concrete steps towards achieving our goal of being carbon neutral across our operations," said Don Lindsay, Teck president and CEO. "Teck is already one of the world's lowest carbon-intensity producers of copper, zinc, and steelmaking coal, which are key materials to enable the low-carbon transition, and we are committed to further reducing the carbon intensity of our operations to support a cleaner future."
Expectations are for the truck to eliminate 418 tonnes of CO2 annually, while also cutting fuel costs.
Taylor said that demonstrations like this one and others are the key to encouraging the purchase of electric vehicles for these sectors. It may take some more convincing, but he feels there is plenty of interest.
"It's a matter of getting customers to start thinking about this, and we encourage them to drive the demo truck. Then, if they place an order, work it into their operations. Don't go replacing your whole fleet right away," he advised. "Start with one, see where it's more efficient, see where it's less efficient, and then build a plan that works for your mine."
