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Mount Milligan strikes gold with electrification

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BC Hydro's low carbon electrification program helped the Mount Milligan Mine electrify some of its operations, reducing its yearly operating costs by around a million dollars.

Diesel-powered generators offer an electrification opportunity

The Mount Milligan Mine, owned by Centerra Gold Inc., is a large open pit copper and gold mine located 155 kilometres northwest of Prince George. It processes approximately 60,000 tons of ore per day, resulting in 400-500 tons of concentrate production.

To enable the milling process, Mount Milligan is licensed to divert water from nearby resources Philip Lake and Rainbow Creek – along with three groundwater wells located in the Lower Rainbow Valley. The wells were originally powered by one of two 500 kilowatts (kW) diesel-powered generators – with one primary, and one on standby.

Lower costs, lower carbon emissions

Operational efficiency and emission reduction are big priorities at Mount Milligan. And as part of BC Hydro's Industrial Energy Manager program, the mine is committed to energy conservation.

"The generators were consuming a substantial amount of fuel, so we started looking at electrification opportunities," says Craig Nordquist, Reliability Engineer (Electrical) at Mount Milligan. "Prior to this project, we also had a study done relating to our water sources. BC Hydro paid for us to have a consultant come and complete a low-carbon electrification study. But there was no distribution line nearby. So to electrify our system, we had to install a 3.5 kilometre 25 kilovolt (kV) overhead distribution line."

With the line installed, the team was then able to install transformers to take the 25 kV supply down to 600 volts to create a lower voltage distribution line around Lower Rainbow Valley. This now operates the three well pumps and a large booster pump.

"BC Hydro supported the project with their low-carbon electrification program," says Craig. "Our Key Account Manager has helped us enormously. His team was involved in reviewing the low-carbon electrification study and advising us with the incentive claim."

Payback in less than a year

The results of electrification have been felt immediately. "We saw the benefits straight away," says Craig. "We estimated that electrification of the pumping system would reduce operating costs by around a million dollars a year, depending on the volume of water we pump. We have also realized higher mechanical availability of the pumping system as the 25 kV distribution network is more reliable than diesel generators."

Achieving results like this was not easy, though. "It took a lot of work to obtain a right of way along the forest service road, and to plan where the line was going to go," admits Craig. "But payback for the project should be less than a year, so it was worth while."

With electrification complete, Mount Milligan is projecting to reduce approximately 23,000 tonnes of carbon dioxide equivalent emissions through to 2028. That's equivalent to taking more than 7,000 passenger vehicles off the road for one year.

Is your facility ready for electrification?

If you're interested in exploring electrification, we'd like to hear your ideas.

At a high level, the process isn't as complex as you might think. Dave Hargreaves, Senior Manager, Industrial Marketing at BC Hydro breaks it down: "It's really the same three things we use to help customers find areas for saving electricity. First, identify the opportunities by thoroughly examining your facility, the equipment you have and how it gets used. Then, investigate what the business case for change might be, evaluating the upfront cost, the long-term cost and any available incentives. And finally, when you've got a plan, it's time to find the smartest way to implement."

Contact your Key Account Manager or Regional Energy Manager to find out more about electrification and the difference it could make.