Updated 8:55 a.m. Friday
In an apparent replay of the sequence of events that led to last year’s devastating Camp Fire in Butte County, PG&E reported Thursday that a failure on one of its high-voltage transmission lines occurred Wednesday night — minutes before the reported start of a fire that has burned more than 21,900 acres in Sonoma County and destroyed an unknown number of homes.
Green lines show location of PG&E transmission lines. Red marker shows the Kincade Fire’s approximate ignition location as reported by Cal Fire. Data on transmission lines from the California Energy Commission, ignition point location from Cal Fire.
PG&E confirmed Thursday evening that while the utility shut off power to their distribution lines in that area, it did not turn off the power to high-voltage transmission lines.
The utility wrote in a statement that “those transmission lines were not deenergized because forecast weather conditions, particularly wind speeds, did not trigger the PSPS protocol. The wind speeds of concern for transmission lines are higher than those for distribution.”
PG&E CEO Bill Johnson said in a Thursday night media briefing that the “general guideline” for anticipating damage to transmission lines includes winds gusting at 55 mph or higher.
“This really accounts for debris flying into the lines,” Johnson said.
Many weather stations in northeastern Sonoma County, including a PG&E weather station adjacent to the transmission line that experienced the malfunction, recorded gusts that exceeded that guideline on Wednesday night.
