How electrification reduces the total cost of ownership in mining

Total Cost of Ownership (TCO) is one of the most important drivers for the adoption of any new technology or process in the mining industry. It is a financial estimate of the direct and indirect costs associated with the purchase and running of a mining vehicle throughout its lifetime, and considers everything from the cost of energy, labour and maintenance to the expense of productivity losses due to downtime.

A vehicle with a low TCO means it is cheaper to run and/or is extremely productive, whereas a high TCO indicates a vehicle is expensive to operate and/or is less productive. For mining companies to maximise productivity and therefore profitability, every effort is made to reduce the TCO, because even a minute gain scales up to a significant benefit when running a fleet of mining vehicles operating 24 hours a day, 7 days a week, 365 days a year.

The benefits of batteries

This is why electrification is an attractive alternative. Recent studies show that switching a mining haul truck from diesel to electric can reduce the TCO by an astonishing $2.5m USD (approx $3.9m AUD, ￡2m GBP) over the vehicle's lifetime [1].

A large proportion of this is due to electricity being much more affordable than diesel. Consider a 150-tonne haul truck with a 10 year lifetime equating to 72,000 hours. The typical energy consumption of a diesel truck is 0.8 L/tonne/hour and an electric truck is 1.91 kWh/tonne/hour [1]. Over the lifetime of a truck, this equates to 8,640,000 litres of diesel and 20,628,000 kWh of electricity.

However, if we take the price of diesel as $1/L USD (approx $1.5 AUD, ￡0.8 GBP) and the price of electricity as $0.15/kWh USD (approx $0.23 AUD, ￡0.12 GBP), the total cost of diesel becomes $8.6m USD (approx $13.3m AUD, ￡6.7m GBP), while the total cost of electricity is $3m USD (approx $4.6m AUS, ￡2.3m GBP) – so switching to electric can save over $5.5 million in energy costs alone.

Furthermore, the fewer moving parts of an electric drivetrain compared to diesel results in around 50% less maintenance costs, 15% of which are from the power unit and 35% are from the driveline [1]. This significantly reduces the downtime required to maintain and repair vehicles, boosting productivity.

Aside from the economics, there are other advantages to electrification. The higher torque, speed and acceleration of an electric powertrain helps vehicles travel up inclines faster. With no CO2 emissions at the tailpipe, the air quality for the miners improves and reduces ventilation requirements. While the safety risks relating to the heat, noise and vibration of a diesel engine are completely removed.

The charging conundrum

So why is the shift to electrification in mining taking longer than expected? Well, there are two main reasons:

1) The time it takes to recharge a battery

2) How long a battery lasts

A diesel truck only needs to refuel for 10 to 20 minutes, once a day [1], whereas an EV haul truck using conventional battery chemistries take 2 to 3 hours to recharge and needs to recharge 3 to 5 times a day, significantly eating into its productivity.

A diesel truck will use 2 to 4 engines throughout its lifetime, while typical battery chemistries need to be replaced 3 to 12 times, costing time and money.

The potential of XNO?

However, innovative anode materials such as the niobium-based XNO? from Echion Technologies solves these problems, helping EVs to not only match but exceed the productivity of diesel trucks.

"We have developed XNO? specifically for fast charging," explains Harry Geary, Cell Engineering Manager at Echion. "This allows batteries with XNO? to fast charge safely in around 12 minutes or less, instead of 2 hours which drastically cuts the downtime of electric mining vehicles."

"Furthermore, XNO? has extremely high cycle life, lasting for over 10,000 cycles," continues Geary. "In a mining application, this means the battery will be replaced less frequently. This transforms the TCO of an electrified mining truck, making them a more profitable, safe and sustainable alternative to diesel."

Do you think electric is a better solution to diesel for mining vehicles? Let us know in the comments.

References

[1] 2024. EV vs ICE Haul Trucks: Total Cost of Ownership (TCO) [Online]. IDTechEx