PG&E examining power equipment at center of Kincade fire investigation
PG&E told a federal judge on Friday that it is investigating whether a fundamental problem existed with a piece of power equipment on its transmission towers that was blamed for causing the 2018 Camp fire and may be linked with the start of the Kincade fire in Sonoma County last month.
The utility’s inquiry centers on whether jumper cables on its transmission towers are “susceptible to failure” and pose a systemwide risk of sparking wildfires. Broken jumper cables were found at or near the origins of both blazes, and PG&E said it is now looking at the setup of the cable in The Geysers — where the Kincade fire started — to determine if the configuration “contributed to its failure,” according to a Friday filing by the utility in federal court.
PG&E lawyers claimed the company had no information suggesting its jumper cables are prone to fail.
“In the event PG&E becomes aware of any condition affecting a jumper cable that could lead to failure or otherwise presents a public safety risk, it will take corrective action,” the court filing states.
The company also responded to the judge’s questions about damage found with its equipment during the planned power shut-offs in late October, when the utility cut electricity to hundreds of thousands of customers to curb the risk of its equipment sparking fires amid high winds.
PG&E filed the report with U.S. District Court Judge William Alsup, who is supervising PG&E’s criminal probation for the 2010 deadly gas explosion in San Bruno. In that disaster, PG&E was found guilty of six felony crimes for its failure to inspect its gas lines and ensure safe operations.
Alsup has repeatedly lambasted PG&E’s safety record. He has criticized the utility for neglecting its electrical system and ordered company lawyers to provide detailed reports about power line inspections and maintenance and also account for political contributions during a period in which he said the utility had put off needed grid repairs.
After the Kincade fire, PG&E told state utility regulators that it had documented an equipment failure about the same time and place as the fire’s start — 9:20 p.m. Oct. 23 near a transmission tower in the Mayacamas Mountains of northeastern Sonoma County. Cal Fire investigators had singled out a jumper cable that had broken on that tower — a problem that can cause electricity to shoot through the air until it meets another surface, called arcing.
Acting on PG&E’s report to regulators, Alsup on Nov. 4 ordered the utility to answer a set of questions about jumper cables. He also asked the utility to detail its findings from damage inspections conducted after the series of October windstorms that helped fuel the Kincade fire and triggered many of the power shut-offs.
Alsup indicated he lacked confidence in PG&E’s inspection program.
“Should we now be worried that other jumper cables inspected in the same manner have potential failures that have gone undetected?” the judge asked in the Nov. 4 order.
In its response Friday, PG&E said the affected tower in The Geysers had been inspected four times earlier this year and was deemed in working order, apart from some surface rusting on the tower’s bolts. The prior inspections included two visual inspections from the ground on July 11 and 18, a May 23 examination of detailed drone photographs of the tower and its components, and a Feb. 6 visit when a contractor climbed the tower and checked its equipment, including the jumpers.
Alsup asked PG&E to explain scenarios that could cause a jumper cable to separate from a transmission line during a windstorm. PG&E said the wind could exacerbate problems with the cable, such as corrosion or metal fatigue, or cause a mechanical failure on an otherwise working device.
“Another potential scenario is that during a particularly severe wind event, debris carried by the wind could strike the jumper cable and cause it to sever,” the utility said in the court document.
The company deployed inspectors across its vast service territory in Central and Northern California to look for grid damage caused by the late October windstorms. The inspectors found 218 instances in 24 counties — including 35 in Sonoma County — when damage to its equipment could have caused arcing if the lines were carrying electricity, PG&E told Alsup.
The judge also asked PG&E to answer whether its lower-voltage distribution lines had started any fires this year. The utility said they had not.
You can reach Staff Writer Julie Johnson at 707-521-5220 or firstname.lastname@example.org. On Twitter @jjpressdem.