Quick fix to Snettisham outage

Alaska Electric Light and Power’s Snettisham hydroelectric facility was back in service by mid-afternoon on Saturday, after a Thanksgiving Day power outage.

The workhorse of AEL&P’s generation system was turned back on about 2:30 p.m., two and a half-days after anchor bolts for tower guy wires failed and a tower leaned on a conductor, causing the outage.

Generation engineer Scott Willis says it’s not clear what caused the anchor bolts to fail. He says the tower was not damaged.

“So that tower leaned over and the conductor that tower was carrying –- the big wire that was carrying the electrical power — touched the guy wire of the tower next door—just downhill from it and that’s what shorted things out,” Willis says.

Estimated time of repairs had been three to seven days. But a repair crew was at the site late Friday afternoon; when equipment arrived the next day, the work went quickly, Willis says.

During the Snettisham outage, the company turned on back-up diesel generators. Willis says he began shutting off the diesel as soon as Snettisham was on line. Due to the Lake Dorothy project, he says the company was still able to draw nearly half of Juneau’s power from hydroelectric.

“Lake Dorothy was the key to keeping the amount of diesel generation lower. During the Snettisham outage, AELP was pulling 40 percent from hydro at peak times of the day.” Willis says power generation would have only been about 15 percent hydro without Lake Dorothy.

Willis says the cost of diesel used will not show up in customers’ bills for a couple of months. It will be spread out over a three-month period and covered in the routine cost of power adjustment. Though he doesn’t yet know the amount of the diesel surcharge, he expects it will be very small.

Meanwhile, a snow slide was NOT the cause of last week’s outage. The tower is not in the Snettisham avalanche zone.

For the third winter, AEL&P’s avalanche forecasting program is in place. The company has hired an avalanche specialist, who looks at snow conditions throughout the day, and when needed a snow-control crew brings down small slides before the snow builds up.