If two copper mines near Minto and Carmacks start using hydroelectricity, Whitehorse’s diesel generators will be required during peak energy use periods, the Yukon Utilities Board heard Thursday.
This week, the Yukon Energy Corporation’s 20-year-plan is being reviewed by the Yukon Utilities Board.
The biggest project in that plan is a 178-kilometre hydroelectric transmission line the corporation wants to build between Carmacks and Stewart Crossing, linking the territory’s northern and southern power grids.
Sherwood Copper Corporation, which owns the Minto mine, and Western Copper Corporation, which owns the Carmacks Copper mine, would be responsible for building the spur lines to bring hydroelectricity to their projects.
Currently, both industrial projects plan to burn diesel.
But once tapped into the hydro grid, the mines would pull 82-gigawatt hours of electricity per year, reducing Yukon Energy’s hydroelectric surplus to almost nil.
That would force diesel generators in Whitehorse to fire up during peak morning and evening periods in cold winter months.
“The surplus will get eaten up,” said Yukon Energy president David Morrison.
“In order to meet the load on the system, we would probably have to turn some diesel on once the mines were in operation.
“When we talk about peaking diesel, we’re talking about not a lot of hours of diesel.”
But burning any diesel is not desirable, especially if alternatives could be used, said Whitehorse city engineering manager Wayne Tuck.
“The city is trying to ensure that we’re not operating our diesel generators here any more than is absolutely necessary, because of greenhouse gas emissions and environmental concerns,” said Tuck on Wednesday after questioning the Yukon Energy executive at the hearing.
The city is concerned about noise, air pollution and greenhouse gas emissions from the diesel generators. It expressed that concern to the utilities board in a written submission dated July 6.
Whitehorse is growing, and selling power to any one customer should not trump the city’s needs, said Tuck.
“If you have to run diesels here to power the mines, then you should be running the diesels that are at the mines.”
Yukon Energy’s solution, outlined in its 20-year plan, is building a third turbine at the Aishihik Lake facility.
At peak, that third turbine would boost the hydroelectrical production of the Whitehorse-Aishihik-Faro power grid by seven megawatts.
It would also provide about 5.4 gigawatt hours per year of long-term average hydroelectric supply, according to the plan.
“We wouldn’t put (the third turbine) in place until we see the need for peaking diesel,” said Morrison.
“It’s a timing question. If we’re going to get peaking diesel, when are we going to get it and how quickly can we get the Aishihik third turbine in place, which would replace the peaking diesel?”
However, even with that third turbine, a small amount of “peaking diesel” might be needed, added Morrison.
The third Aishihik turbine would cost about $7 million, according to Yukon Energy estimates.
And it probably can’t be built until 2011, well after the mines are operating, said Morrison.
So Whitehorse will probably have to burn diesel for several years.
Minto is scheduled to come into production by April 2007, and Western Copper plans to get its Carmacks Copper mine into production by summer 2008 — about the same time Yukon Energy hopes to have the first phase of the Carmacks-Stewart transmission line built to Pelly Crossing.
“If we’ve only got Minto, I don’t think we’ll need peaking diesel,” said Morrison.
“If (both) mines go in and Aishihik third turbine goes in, there’s a greater benefit to the ratepayers than the cost of running a few hours of peaking diesel in the winter.
“Millions of dollars of benefit to the ratepayers, because the customer at the mine buys surplus power from us, so the benefits overall to the system are millions of dollars over the life of the mines.”
During emergencies, such as the massive power outage of January 29, 2006, that afflicted the entire Yukon and left parts of the territory without electricity for 13 hours, industrial customers, like the mines, will be disconnected from the grid and forced to use their own diesel generators, Morrison said.
But even if Yukon Energy eventually builds the third Aishihik turbine to reduce reliance on diesel to almost nothing, its 20-year plan makes no provisions for renewable energy sources or demand-side management, said Tuck.
In its 1992 review of Yukon Energy’s previous resource plan, the utilities board recommended using demand-side management tools to reward non-industrial consumers for reducing their energy use during peak periods, he said.
Since then, successive governments have not directed Yukon Energy to adopt policies that would prompt consumers to reduce their peak energy usage, said Tuck.
“The intent of demand-side management is to reduce power at peak times,” said Tuck.
“There needs to be incentives, like lower bills for reducing your power consumption during the peak period, or rebates for building efficiencies into your home.”
The utilities board must make recommendations about Yukon Energy’s 20-year plan to the Yukon commissioner and government cabinet by January 15.