Repair work could begin this week on the downed Snettisham transmission tower, but Juneau's electric utility doesn't know how long it will take to restore cheaper hydroelectric power.
The city electrical grid has been powered by backup diesel generators since Monday, when an avalanche took down a tower on the line from the Snettisham Hydroelectric Project. City residents will likely pay higher electricity rates to cover the cost of diesel burned until the line is repaired.
Alaska Light and Power Co. spokesman Scott Willis said engineers are looking at whether the line could be repaired to bypass the fallen tower, which is in a steep, avalanche-ridden area.
Those brainstorming solutions with AEL&P include engineers from Dryden & LaRue and City Electric, Anchorage-based engineering and construction firms that worked on last spring's Snettisham repair.
The first task is to cut the downed conductor and tie it off. That is to prevent another avalanche from coming down, catching the downed tower and pulling so hard on the wire that another tower falls.
Willis said linemen are expected to get to the site today.
Diesel less costly this winter
AEL&P says it will pay significantly less for diesel than it did last spring, when Juneau residents paid rates that were 450 percent higher than usual.
Regulators allow AEL&P to pass the cost of diesel on to customers in what's known as an emergency cost-of-power adjustment.
Willis said he expected an estimate this week, though filing with regulators could come later. He said it would only be applied to energy consumed after the avalanche.
The company is meanwhile buying fuel on a line of credit.
For the first few days on diesel, the company is using fuel it purchased last year at around $3.75. That puts the 84,000 gallons burned Tuesday at a cost of $178,080.
Diesel bids came in this week at $2.25.
Last spring, prices ranged up to $4.17 a gallon, and customers paid an average price of $3.89 a gallon.
The fuel will be supplied by Petro Marine, Willis said. Petro Marine Services is a subsidiary of Seward-based Harbor Enterprises Inc.
Twice in nine months
A study on how AEL&P could protect the Snettisham transmission line from future avalanches in the long term was due this winter but was delayed.
The options include submarine cable, underground cable or deflective barriers around the existing towers. Both initial costs and maintenance costs would be folded into an analysis with recommendations.
AEL&P hired a company to aerially photograph and map the Snettisham line. The clear days needed didn't come until December, Willis wrote in an e-mail.
"We knew it would be a couple of years before a project like this could be properly analyzed, designed and constructed," Willis wrote.
The plan was that avalanche experts would protect the line until then.
Sunday, they dropped explosives to set off small avalanches. But a low cloud cover kept them from flying all the way up the mountain.
Long-term: Lake Dorothy
AEL&P is banking that its investment in a new hydroelectric project will mitigate future energy crises.
The company has invested $65 million into building the Lake Dorothy project, according to estimates earlier this year. Its generators are expected to increase Juneau's hydroelectric output by 20 percent.
If it were online now, it would reduce Juneau's diesel use by 35 to 40 percent, Willis said.
The Lake Dorothy transmission line connects to the Snettisham line at mile 30, about 10 miles from town.
The section of line the two projects will share has been "extremely reliable," according to Willis.
"All the bad stuff that's ever happened has happened in the first 30 miles" from Snettisham, said Willis. "We really have never had a problem on this side of the Taku."
Lake Dorothy is scheduled to come online between August and October next year, depending on how early crews can get started, said Willis. Most of the construction is shut down for the winter.
In 2008, the company tapped the lake. The transmission line, which connects to the Snettisham power line, is also done. The power plant building is up.
The company must still install the penstock, the steel pipeline that runs from the lower Lake Bart two miles into the power plant. A 10-foot dam must be built. And major equipment for the power plant, including the water wheel and the generator to which it attaches, is still to come.
• Contact reporter Kate Golden at 523-2276 or email@example.com.
For complete coverage of the Snettisham avalanches including tips on how to conserve energy, video reactions and links to local resources go online to juneauempire.com/powerline.