Despite de-energizing distribution lines in the vicinity consistent with its public safety power shut-off policy, Pacific Gas and Electric Co. had a problem with a transmission line that was still in service near where the Kincade fire appears to have started minutes later northeast of Geyserville, Calif.
In a report sent to state regulators, the utility, or PG&E, said it became aware at about 9:20 p.m. PT on Oct. 23 of a transmission level outage on the Geysers #9 Lakeville 230-kV line that occurred when the line relayed and did not reclose. According to the California Department of Forestry and Fire Protection, or CAL FIRE, website, the Kincade fire in Sonoma County started at 9:24 p.m. PT on that date.
The transmission problem occurred near Kincade Road and Burned Mountain Road, PG&E reported, which is the same location to which CAL FIRE said firefighters were first dispatched.
The utility told the California Public Utilities Commission that a "PG&E troubleman" went to the scene at 7:30 a.m on Oct. 24 and saw that CAL FIRE had taped off an area around the base of a transmission tower at the Kincade Road location. At that time, CAL FIRE personnel pointed out what appeared to be a broken jumper on the tower, PG&E said in its report.
PG&E said it had inspected the tower earlier this year as part of its wildfire safety inspection program.
According to CAL FIRE's website as of 9:30 a.m. PT on Oct. 25, the 21,900-acre wind-driven fire was only 5% contained and 49 structures had been destroyed, but no injuries or deaths had been reported. About 1,300 personnel from multiple agencies were responding and all roads east of Highway 101 in the Geyserville area were closed.
In an effort to prevent its electrical equipment from starting wildfires during a period of high winds and dry vegetation, PG&E called a public safety power shutoff event sometime before 3:00 p.m. PT on Oct. 23, which resulted in the loss of power to 27,837 customers in Sonoma County, including Geyserville and the surrounding area. During that event, distribution facilities in the area at issue were shut off but transmission lines remained energized.
"Those transmission lines were not deenergized because forecast weather conditions, particularly wind speeds, did not trigger the PSPS protocol," PG&E said in an Oct. 24 press release. "The wind speeds of concern for transmission lines are higher than those for distribution."
PG&E shut off power to 178,000 customers in 18 counties from the Sierra Foothills to the North Bay, as well as to San Mateo and Kern counties, late Oct. 23, but reported that by early Oct. 25, it had restored power to nearly 165,000 customers. Due to expected wind storms, more power shutoffs may be on the way starting late Oct. 26 through Oct. 28, and an estimated 680,000 customers could be without power in 32 counties across the state, according to PUC Executive Director Alice Stebbins.
PG&E is a subsidiary of PG&E Corp.