When electric haul trucks first rolled into Australian pit operations, the industry watched with measured skepticism. Two years on, we’ve got enough operational data to move beyond manufacturer claims and examine what’s actually happening at the coal face.

The TCO Reality Check

The total cost of ownership discussion around electric versus diesel haul trucks has been dominated by upfront capital costs. Yes, electric units command a 25-35% premium at purchase. But that’s where simple math ends and operational reality begins.

What the spreadsheets didn’t predict was the maintenance differential. Conventional diesel haul trucks in iron ore operations typically require major engine overhauls every 15,000-20,000 hours. The electric units? They’re not even close to needing comparable work at the same intervals.

Rio Tinto’s Pilbara trials have logged over 18,000 hours on their test fleet without major drivetrain interventions. The maintenance profile looks fundamentally different—no oil changes, no turbocharger replacements, no diesel particulate filter issues. The brake systems last longer too, thanks to regenerative braking handling most deceleration duties.

One operations manager at a Bowen Basin mine put it bluntly: “We’ve cut our haul truck maintenance crew by two fitters. The work just isn’t there.”

Energy Costs: More Complex Than Advertised

Here’s where it gets interesting. Electric haul trucks are cheaper to run per tonne-kilometre, but the margin varies wildly depending on your power supply setup.

Mines with grid connections and favorable electricity contracts are seeing energy cost reductions of 40-50% compared to diesel. That’s substantial. But remote operations relying on on-site generation—even with solar and battery support—are finding the economics tighter. The infrastructure investment in charging systems, power distribution, and backup capacity can run into tens of millions.

The Australian Mining Review reported last quarter that Fortescue’s electric haul truck trial achieved a 47% reduction in energy costs per haul cycle, but only after significant investment in on-site renewable generation. The payback period stretched to seven years when infrastructure costs were included.

Operational Patterns We Didn’t Anticipate

Battery thermal management emerged as the sleeper issue. In the Top End during summer, battery cooling systems consume 8-12% of total energy draw. That’s not trivial when you’re trying to maximize ton-miles per megawatt-hour.

Conversely, cold starts in Queensland winter have proven less problematic than feared. The battery management systems handle pre-conditioning well, and there’s no waiting for diesel engines to warm up before loading.

Haul cycle predictability has improved. Electric motors deliver consistent torque regardless of altitude or ambient temperature. Diesel performance drops off in hot conditions and at elevation—electric doesn’t care. Dispatchers can plan more accurately.

The regenerative braking benefit shows up strongest in pit operations with significant elevation changes. Mines with relatively flat haul profiles don’t capture the same energy recovery advantage. One coal operation in the Hunter Valley calculated they’re recovering about 18% of energy per cycle. That’s free tonnage.

What the Maintenance Data Shows

Two years of detailed maintenance logs reveal patterns that challenge both the optimists and pessimists.

Tire wear is higher on electric haul trucks. The instant torque and increased weight (batteries are heavy) accelerate tire degradation by roughly 15% compared to diesel equivalents. That’s a real cost that often gets buried in TCO projections.

But the elimination of diesel exhaust systems, cooling system complexity, and transmission components more than compensates. One mine tracking component-level costs found their cost per operating hour dropped from $847 for diesel to $531 for electric—a 37% reduction.

Unscheduled downtime tells a similar story. Electric haul trucks averaged 94.2% mechanical availability versus 89.7% for diesel in comparable operations. When electric trucks do go down, repairs are faster. There’s no waiting for engines to cool, no contaminated oil to drain, no complex diagnostics chasing intermittent sensor faults.

The Infrastructure Question

The elephant in the pit is charging infrastructure. Fast-charging systems capable of handling 220-tonne haul trucks require serious electrical capacity. Most mines are installing 1-2 MW charging points, which means power supply upgrades, transformers, and backup systems.

Some operations are exploring opportunity charging during loading cycles. If a haul truck spends 3-4 minutes getting loaded, that’s 3-4 minutes of potential charging time. Early trials show this can extend operational range by 20-30%, but it requires charging infrastructure at loading points—more complexity, more cost.

According to CSIRO research, the sweet spot for electric haul truck economics appears to be mines with stable pit designs, predictable haul routes, and access to low-cost renewable energy. That describes many Australian iron ore operations. It’s less compelling for coal mines with constantly shifting pit geometries.

Where We Stand

After two years, electric haul trucks have proven they can handle the work. The maintenance advantages are real and significant. Energy costs are lower if you’ve got the right power supply setup. But the capital intensity remains substantial, and the infrastructure requirements can’t be handwaved away.

The industry isn’t going to flip a switch and go all-electric overnight. What we’re seeing is targeted deployment where the economics align—stable operations with good power access and long equipment lifecycles.

The numbers are in. Now it’s about execution.