A penstock deep underneath Tyee Lake sends water from the lake to a powerhouse below. (Photo courtesy of the Southeast Alaska Power Agency)

A power outage kept Petersburg in the dark for two and half hours on Sunday. The outage started at about 2:00 p.m. 

The Southeast Alaska Power Agency (SEAPA) immediately investigated the outage and tried to restore power to Petersburg but they couldn’t find the problem. SEAPA is the wholesale hydroelectric power provider that generates electricity for Petersburg, Wrangell and Ketchikan.

In the meantime, Petersburg Municipal Power and Light put the town on back up diesel generators. Karl Hagerman, Petersburg Borough Utility Director, says it usually doesn’t take as long as it did for Power and Light to get the generators online but there were some system glitches that slowed the process. 

Hagerman says power was restored piece by piece throughout town so that the generators didn’t get overloaded.

Operators worked through the night Sunday to make sure the backup system continued running.

SEAPA is still trying to find the cause of the outage. They have narrowed it down to a ground fault on the Tyee Line near Wrangell. On Monday, they plan to have a helicopter fly the line to locate the problem. The borough hopes that Petersburg will be back on hydro-power by Monday afternoon.