San Francisco Chronicle
PG&E: More fire-risk shut-offs likely
New technology cuts power faster, might have halted huge Dixie blaze
Pacific Gas and Electric Co. will cut power more aggressively in fire-prone areas when problems are detected, using new technology installed after the Dixie Fire started in July, company officials said in court filings Friday. The utility said the technology might have prevented California’s secondlargest wildfire from starting on July 13 if it had been in place.
Called “fast trip mitigation,” the new settings boost circuit sensitivity so the devices that cut power will act more quickly when sensors detect a problem. PG&E executives told a federal judge in court papers they expect the new settings will make its electric grid safer and less likely to start wildfires, but it comes with a trade-off that people will be inconvenienced with “more frequent and longer unexpected outages.”
PG&E described its new program in response to questions from U.S. District Judge William Alsup about why employees didn’t immediately shut off power after detecting a problem July 13, given the high risk for fire in the forested, mountainous region that was close to the footprint of the deadly 2018 Camp Fire that destroyed the town of Paradise.
It took more than nine hours from the first report at 7:20
a.m. of an abnormal current in a remote area of the Feather River Canyon in Butte County before a PG&E troubleman found a power line broken by a fallen Douglas fir — and a fire on the ground.
The troubleman emptied two fire extinguishers in an attempt to put the fire out and alerted the company’s dispatch center over the radio at about 5 p.m.
“It’s small now but it’s picking up,” he told them, according to court documents and testimony.
By that point the fire was impossible to control, and over the next nine weeks would burn 960,581 acres in five counties around Lake Almanor in the northern Sierra Nevada and Lassen National Forest. The Dixie Fire was 86% contained as of Friday.
PG&E told the judge that the troublemen and dispatchers didn’t have authority to cut power in the early hours of the fire. Only distribution operators can make that decision, and the one on duty that day reviewed available information remotely, which showed that the circuit was energized and there was “no excessive ground current,” according to the court filing.
“The (distribution) operator knew of no other indication of an emergency — such as an indication of a hazard or fire — that would have caused him to de-energize,” the company stated.
Cal Fire has not finished its investigation into the cause of the Dixie Fire, though PG&E reported to state regulators that a troubleman found blown fuses and what appeared to be a healthy, 70-foot-tall green tree lying on a power line where the fire started.
PG&E started using the fast-trip system this summer, but only when linesmen were working with live electrical lines. The company expanded that program beyond that scenario “to help address new and changing threats posed by extreme drought conditions and the possible cause of the Dixie fire,” according to the court filing.
“To the extent the Dixie Fire was started, as the court suggests by the fact that the third phase of the Bucks Creek 1101 remained energized following the initial fault event, Fast Trip Mitigation would have prevented that fire,” the company stated, using the name Bucks Creek 1101 for that area of the utility’s grid.
The heightened safety settings have been installed on circuit devices across more than 11,500 miles — or 45% — of lines the utility has designated as located in high-risk areas for wildfires.
The company reported to the court that this technology cut power 279 times on these circuits between July 28 and Sept. 14, with just one small fire reported to state regulators as potentially connected to PG&E equipment. To compare, PG&E reported on average 41 fires to state regulators during that same period each year going back to 2018.
Company executives told the court they believe the new system has “already prevented ignitions.”