Dorothy Westerman
Northern News Services

Yellowknife (Jan 18/06) - Blame heavy frost-laden power lines, not ravens, for last weekend's massive power outage, says a spokesperson for Northland Utilities.

The entire city of Yellowknife and the communities of Rae/Edzo and Dettah were without power for hours, Jan. 14, due to a break in a skywire used to intercept lightning, says Al Mueller.

"Ice had formed on it and it stretched down into the phase wires and eventually broke, causing a short circuit," Mueller said.

"To compound the problem, it crumpled a tower on the line going over to Rae," he said.

That tower was located at the Smiley Lake turn-off to Rae-Edzo.

There is no estimate yet of the cost to repair the tower.

The Bluefish hydro plant which supplies Dettah shut down as a result of overload. However it was restored within several hours.

Because of the problem, residents in Rae/Edzo are being asked to conserve power until the end of this weekend, when the tower can be repaired.

The blackout began at 12:11 p.m. Saturday, said Randy Patrick, North Slave regional director of the NWT Power Corporation.

"It wasn't until the next day, when we could physically fly out to see the towers," Patrick said of the lack of daylight needed for the helicopters to inspect the 130 km of line.

It was about 2.5 hours before power in Yellowknife was restored via Jackfish Lake diesel generators Saturday, he said.

But several areas of Yellowknife, including the Northern Heights condominium tower's apartments, remained without power. Emergency power kept one elevator and hall lights going in the 17-storey building.

Hydro power was restored in Yellowknife after about 30 hours.

On Sunday, power was out in Yellowknife intermittently for about 1.5 hours at the airport, Giant Mine and residential areas, along Old Airport Road, Kam Lake and Frame Lake.

"It was a line in town that caused problems," Patrick said.

Power in Edzo was restored by 3:30 p.m., while power in Rae was fully restored by 10:30 p.m. Saturday, both through the diesel generator at Frank Channel.

Because the power limit is reaching maximum load, conservation is needed, Patrick said.

There are eight generators at Jackfish Lake, with one currently down for maintenance.

"They go continuously," Patrick said, but the system can run indefinitely with a fuel supply.

"Until fairly recently, it was used to power the community almost on a full-time basis," he said.

The call for conservation is necessary because, while the generators are ready for winter loads, they do not have excess capacity in winter.

To solve that, conservation is required, especially during peak times, such as during the evening dinner hour.

Patrick could not say what the maximum peak load in kilowatt hours is because it varies from day to day.

Had the situation been a city emergency, "We would bring on emergency generation," Patrick said. "If we didn't have enough, power rotations would come into effect and we would ask people who have generators to use them and to reduce consumption," Patrick said.

Most power outages are localized, not on the transmission line, he said. "And most of the problems with that are in the summer with lightning strikes. Anything that happens to the hydro line will put the town out."

This year's frost in the region is highly unusual, he said.

"Typically, we have frost on one end of the line. This year, we have frost on the entire line. That's the difference between most normal years," Patrick said.

"This area isn't usually a big frost area."

Nevertheless, crews fly helicopters directly above transmission lines on a regular basis, several times weekly, to knock frost or ice buildup from them.

Crews were out just days before Saturday's outage, he said.

Northland Utilities fielded more than 250 calls from residents inquiring about the duration of the outage, Mueller said.

The outage affected 7,400 customers Saturday and 3,900 customers Sunday, or about one-half the city.