A bolt of lighting and a utility pole fire caused two separate area power outages Sunday morning, Alaska Electric Light & Power office manager Gayle Wood said.
The first outage occurred at approximately 2:15 a.m. Sunday, when lightning struck a line near the Snettisham line and caused an area-wide outage.
"(Lightning) just puts a massive surge on the system," Wood said. "It opens the relays and the protectives that keep our power plant and transformers from damage."
Power was restored to some parts of downtown within 20 minutes. The Valley waited longer. Complete power was not restored for more than two hours, as AEL&P nursed the system back with diesel generation.
"It was just kind of a coordination problem for that hour of the morning," Wood said.
The second outage began around 10 a.m. Sunday, after the top of a AEL&P utility pole behind Western Auto caught fire. The pole runs AEL&P's heavy 69 kilovolt (69,000 volts) transmission lines and has two feeders - one for the Lemon Creek area, and one for Salmon Creek. A 5-foot length of the pole burned off and toppled into one of the feeders, knocking out the system.
It created a short-term outage downtown, and a much longer outage in the Valley. Parts of Lemon Creek were without power until mid-afternoon. The Lemon Creek feeder was kept off as repairs continued on the top of the pole.
"The fire had probably been simmering for awhile, and it actually burned enough to cause the pole to break," Wood said.
The fire may have been caused by a faulty insulator, Wood said. Insulators are used to keep electricity on the line and away from the poles. If insulators are compromised, Wood said, electricity can flow into the pole, creating a fire.
"Insulators can cause problems once in a while," Wood said. "It's just that we have a massive number of them, so you can't inspect all the insulators."
AEL&P workers were expected to finish repairs on the burnt pole sometime Sunday night.
"There was a significant amount of work that was done so most of the area could have power," Wood said. "There was a lot of backtracking to get the system to run through a normal configuration."