Battery Electric Underground
Goldcorp Inc., a gold producer based in Vancouver, BC, recently announced plans to build the world’s first diesel-free hard rock mine near Chapleau, Ontario.
Going diesel-free is an ambitious goal. A typical mine can have dozens of diesel engines across its heavy equipment fleet. Going electric means enormous up front costs, and massive retraining. It means turning away from an entire industry that exists to maintain and replace machines on demand. Most of all, it means embracing the reality that until recently, the technology to create a diesel-free mine was barely a realistic possibility.
So why do it?
To justify their investment in the EV (electric vehicle) future of mining, Goldcorp is drawing on recent experience at their operation at the Éléonore mine in the James Bay region of Québec, Canada.
At Éléonore, Goldcorp is able to track the precise underground location of every worker and every piece of machinery using RF chips and a high-tech network. This allows management to make strategic use of ventilation, turning it on when workers and machines are present and shutting it down when they are not. Ventilation of course is an underground mines highest consumer of power and any reduction in its use means major savings for the operator. There is a limit however to how much the ventilation can be re-routed so Goldcorp’s new approach is to reduce the demand by going Electric. Battery Electric Equipment allows the mine to unlock a trifecta of benefits: improved health and safety, reduced greenhouse gas emissions, and decreased operating cost.
The Diesel Downside
After more than two centuries of development, the internal combustion engine has evolved into an accepted, affordable way to get work done. What works in the open air, however, can be a serious liability underground.
Combustion engines are heat engines. They burn fossil fuels, particularly diesel in the case of most heavy equipment, and even the most efficient industrial engines are still…well, inefficient. The combustion process produces a number of by-products, including, heat, noise and the most challenging, emissions.
Emissions are troubling at the surface, but take them underground, and they quickly become deadly. Particulate matter, and gasses like nitrogen oxides (NOX) and sulphur dioxide (SO2) are hazardous to humans. The moment you fire up a diesel engine underground, you’re faced with the challenge of removing those emissions from the mine.
Doing that, however, is no mean feat. Removing emissions from even a few metres, never mind kilometres, below the ground requires massive ventilation infrastructure—shafts, equipment, and enormous amounts of electricity to run the machinery.
And it all costs money. Lots and lots of money.
The EV Payback
Take Éléonore for example. A mine that size might require 1.2 million cubic feet per minute of ventilation—a staggering amount of air to move, and a staggering cost to go along with it. But this is where Goldcorp’s tracking program pays off. By knowing the exact location of equipment and workers underground, the mine is able to deliver ventilation on demand, servicing only needed areas. The result is a savings of nearly 50% in ventilation requirements.
That reduction in ventilation requirements translates into serious savings—for health, the environment, and the Goldcorp profit sheet.
“Moving away from diesel and by achieving other reductions associated with the use of clean technologies, Goldcorp can avoid more than 7,500 tons of CO2 and eliminate 3 million litres of diesel fuel, 1 million litres of propane and 35,000 megawatt hours of electricity every year.”
And the cost savings for all this?
“The cost of ventilation is about 5-10 dollars per cubic foot,” said Paul Cholewa, Electrical System Designer here at MEDATECH. “Each horsepower of diesel engine underground requires about 100 cubic feet per minute of fresh air pumped down underground. Depending on the cost of electricity at a particular mine, that can run about $150,000 on average per machine, just in ventilation costs.”
Going electric eliminates that cost. As Marc Lauzier, mine general manager at Porcupine Gold Mines (PGM) in Timmins, said, “It’s cheaper to charge a battery than it is to run a fan,”
The Road to EV Mining
Running the Borden mine will take more than a single battery. Plans call for an entire fleet of EV vehicles, including battery-operated drilling and blasting equipment, electric bolters, personnel carriers and eventually, even a 40 metric tonne battery-powered haul truck which MEDATECH currently holds a provisional patent for.
It’s not only a huge up-front capital investment, but the actual technology is still being developed. “Once we get closer to our actual production dates,” said Brent Bergeron, executive vice president of Corporate Affairs and Sustainability at Goldcorp, “We hope that the battery technology will be there to accommodate the production numbers we’re going to be looking for.”
Bergeron’s bet fits well with what MEDATECH sees for the sector, and the changes in technology. “Demand is going to escalate in the mining sector,” said Paul Cholewa. “The next three to five years will be all about battery-powered electrical vehicles.”
MEDATECH President and CEO Rob Rennie sees technical advantages beyond cost, too. “Efficiencies and ability to deliver power to the wheels far exceeds what you can do with an internal combustion engine. We’re going to see demand grow quite quickly. It’s definitely one of the biggest opportunities we’ve had in the history of our company.”