The push to electrify underground mining fleets has been underway for several years now. Major equipment manufacturers have released electric loaders, trucks, and utility vehicles. Some mines have gone fully electric. Others have pilot programs running.

Enough time has passed to move beyond manufacturer promises and examine actual operational experience.

The Ventilation Dividend

The primary driver for underground electrification has always been air quality. Diesel equipment in confined spaces requires massive ventilation systems. Electric equipment doesn’t produce exhaust.

On this front, electric fleets are delivering. Operations that have transitioned report significant ventilation power reductions—some claim 30-40% decreases in ventilation electricity costs.

This matters because ventilation is often the largest single power consumer in underground mines. Reducing it doesn’t just cut direct costs; it changes thermal management calculations and allows access to deeper, hotter ore bodies.

One Canadian gold operation told industry press they were able to defer a $20 million ventilation upgrade by electrifying their loading fleet. That’s not an annual saving—it’s capital avoided.

The Productivity Reality

Here’s where the picture gets more complex.

Early electric mining equipment had limited battery capacity. Machines needed frequent charging or battery swaps. Productivity per shift suffered compared to diesel equivalents.

Battery technology has improved. Current-generation equipment can run a full shift on a single charge in many applications. But “many” isn’t “all.”

High-duty applications—continuous hauling on long inclines, for instance—still challenge battery endurance. Some operations have had to redesign their cycles around charging windows.

The most successful implementations have involved careful analysis of actual duty cycles before purchasing equipment, rather than assuming electric can slot directly into existing diesel workflows.

Charging Infrastructure Challenges

You can’t just swap diesel tanks for chargers. The infrastructure requirements are different.

Underground charging stations need:

• Appropriate electrical supply (often substantial upgrades)
• Fire suppression specific to battery risks
• Physical space in often-constrained development
• Redundancy for operations that can’t tolerate downtime

Mines that underestimated infrastructure costs have had rocky transitions. One Australian operation publicly acknowledged that their charging infrastructure cost nearly as much as the vehicles themselves.

Planning for electrification needs to start with power supply. If the mine doesn’t have the electrical capacity to charge a fleet, adding it is a major capital project.

Maintenance Profile Shift

Electric mining equipment has fewer moving parts than diesel. No engine rebuilds. No transmission overhauls. Fewer fluid changes.

Maintenance departments are reporting lower routine costs. One Sudbury operation documented 40% reduction in scheduled maintenance labour hours after transitioning loaders.

But the maintenance that remains is different. Battery management requires new skills. High-voltage systems need specialised training. Diagnostic procedures are software-heavy rather than mechanical.

Some operations have struggled to retrain maintenance teams. Others have found that younger technicians adapt readily to the new systems while veterans resist.

The skills gap is real and shouldn’t be underestimated in transition planning.

Total Cost of Ownership Calculations

Manufacturers’ TCO models typically show electric equipment winning over 7-10 year life cycles. High capital cost offset by lower operating costs.

Real-world results are varied.

Operations with high electricity costs (often in remote locations relying on diesel generation) find the economic case weaker. The cost advantage of electric depends heavily on the cost of electricity.

Operations with existing electrical capacity and relatively cheap power see the strongest economic returns.

Currency matters too. Electric equipment is often priced in USD or EUR. Australian miners have found that exchange rate movements can significantly affect the capital cost comparison.

Safety Considerations

Electric fleets eliminate one significant hazard: diesel particulate exposure. Long-term health outcomes for underground workers should improve.

They introduce different hazards. Battery thermal runaway, though rare, requires specific emergency response protocols. High-voltage systems demand lockout procedures that diesel doesn’t.

The net safety picture appears positive, but mine safety teams need retraining, not just equipment operators.

Where It Makes Most Sense

Based on operational experience to date, underground fleet electrification delivers clearest value in:

• Mines with existing electrical capacity and reasonable power costs
• Operations where ventilation is a significant constraint
• Relatively consistent duty cycles that match battery endurance
• Organisations with technical capacity to manage the transition

It’s more challenging in:

• Remote operations dependent on diesel generation
• Applications requiring maximum continuous output
• Older mines where infrastructure upgrades are difficult
• Organisations lacking technical depth for new maintenance demands

Looking Forward

Electric underground equipment will continue improving. Battery energy density increases annually. Charging speeds improve. Manufacturers are gaining operational feedback that informs better designs.

The question isn’t whether electrification will happen—it’s the pace and sequence. High-ventilation applications will likely electrify first. Heavy haulage may take longer.

Miners evaluating electrification should focus on their specific operational parameters rather than industry generalisations. The technology works, but whether it works for your operation depends on details.