Mining News: Yukon power line upgrades get under way

Infrastructure project is expected to connect northern and southern grids, enhance mine development opportunities along route

Rose Ragsdale

For Mining News

Work got under way in October on stage 2 of Yukon Energy’s Carmacks-Stewart transmission line, a long-needed infrastructure project aimed at dramatically improving access to and affordability of electricity in Yukon Territory.

Canadian and territorial government officials unveiled the enhancement of existing hydropower infrastructure at the Mayo hydrofacility along with stage 2 of the Carmacks-Stewart transmission line in the spring, noting that it would be the first project to be funded under Canada’s new C$1 billion Green Infrastructure Fund, which is part of the Government of the Ottawa’s Economic Action Plan.

The overall transmission line project involved construction of a new 138-kilovolt transmission line about 172 kilometers, or 107 miles, long from Carmacks to Stewart Crossing in central Yukon Territory, with a spur line to the Minto mine. Stage 1 of the project, from Carmacks to Pelly Crossing and the spur to Minto, was completed and energized in November 2008.

Yukon Premier Dennis Fentie said the Mayo B initiative will reduce the nation’s carbon footprint by displacing thousands of metric tons of greenhouse gas emissions each year, creating a greener Yukon. It is expanded to generate 5 additional megawatts of power.

“By proactively developing green energy, we are not only providing more cost effective energy, but also creating lasting employment for Yukoners,” Fentie added.

Due to Yukon Territory’s current reliance on diesel for much of its electricity, the project is expected to reduce forecast diesel generation in 2012 by more than 40 percent and, in turn, reduce greenhouse gases from energy production by 50 percent from current levels.

The governments of Canada and Yukon are jointly funding the project, with the Government of Canada providing up to C$71 million of the total estimated cost of C$160 million.

Upgrades to Yukon Energy’s existing Mayo hydroelectric facility will include building a new powerhouse downstream from the existing one, which will increase renewable power production, without the need for a new dam. Mayo B project planning has targeted late 2011 for the enhancement to begin generating additional power. To meet this schedule, an environmental review must be completed in time to allow construction to begin by summer 2010.

Stage 2 involves construction of about 74 kilometers, 46 miles, of power transmission line within a 60-meter right of way from Pelly Crossing to Stewart Crossing. It will connect the territory’s two established hydro-based transmission systems, the Whitehorse-Aishihik-Faro grid and the Mayo-Dawson system at a projected cost of C$40 million.

“Connecting the southern and northern grids will make power available to anyone all along the line,” Mike Burke, senior geologist for the Yukon Geological Survey, told Mining News.

“I’m very encouraged that work has started on the final phase of the Carmacks-Stewart line,” Yukon Energy President David Morrison said in a statement. “When it’s completed, it will link Yukon’s two electrical grids, improving reliability by giving us the flexibility we need to move power from one area of the territory to the other. Ultimately, this will reduce the amount of diesel we have to burn to produce electricity.”

Burke said having a more complete power infrastructure will also help considerably with mine development in Yukon Territory.

Stage 2 of the project also involves expansion of the existing Stewart Crossing substation north of the Stewart River to allow the connection of the two grids; and modifications to the existing Carmacks switching station and the Minto Landing substation, and provision of new facilities to serve Pelly Crossing.

Survey work and brush clearing got under way in October. Line construction is expected to start in February or March. Sections of the line will be built in wet areas, so it’s important, as an environmental protection measure, to do construction in these sections while the ground is still frozen, Yukon Energy said.

The transmission line is expected to be in operation by the spring of 2011, subject to delivery of a transformer at Stewart Crossing.