New PG&E wildfire prevention program in Napa could trigger sudden power cuts

Pacific Gas & Electric Co.'s new "enhanced" system designed to automatically shut off distribution power lines struck by an object before sparking wildfires is sparking concerns in Napa County.

Napa County Supervisor Diane Dillon's concern is that the system will cause an increase in unexpected power outages. She wants PG&E to share more information so people have an idea of what could be in store.

"The worst thing short of fire is for people not to be aware this might happen, not understand how often it might happen," she said. "There are businesses, there are people who are on medical devices."

PG&E officials on Tuesday presented initial information to the county Board of Supervisors. The utility will return at a future date with more details.

The new program is called "enhanced powerline safety settings," or EPSS. The safety settings automatically shut off a power line within a tenth of a second or less if something touches the line, such as a tree branch, PG&E officials said.

"I've seen bobcats touch an electric line ... we've had reports of turkeys or other birds fly into the lines," said Mark van Gorder of the utility.

The Napa Valley Register asked PG&E if local cities are likely to experience EPSS outages, or if the outages will be mostly in rural areas.

"It's unlikely downtown and the city of Napa would be impacted by EPSS enabled settings," responded utility spokesperson Deanna Contreras. "Same with American Canyon. However, customers who live in outlying areas with a Napa or American Canyon address could be impacted."

Most of St. Helena's downtown is fed by circuits that do have these settings, she said. The same is true of portions of downtown Yountville. All circuits in downtown Calistoga have EPSS settings.

The EPSS program is not to be confused with public safety power shutoffs that Napa County has periodically experienced.

A public safety power shutoff occurs when PG&E de-energizes lines in fire-prone areas during hot, windy weather. The shutoffs are planned ahead of time and customers are supposed to be alerted in advance.

An EPSS shutoff, in contrast, is not planned ahead of time and no advance notice can be given. Also, the safety settings might be used on lines in fire-prone areas even on days without red-flag warnings.

"They have already been enabled a few times in May," van Gorder said. "They will be enabled more frequently now that we're in June."

Just because the system is enabled doesn't mean there will be an outage, said David Meier of PG&E. An incident has to occur along the line.

PG&E launched the program as a pilot last year. The result was an 80% reduction in ignitions that must be reported to the California Public Utilities Commission, van Gorder said.

That 2021 pilot program was on 45% of the distribution lines in high fire-risk parts of PG&E's service area. Dillon said that caused 16 shutoffs in Napa County in two months.

"I know from last summer, you had (the sensitivity) set so high — and you were learning as well, it's just we hadn't been informed you were learning — that's why it went off as many as 16 times," Dillon told PG&E officials.

This year, the program has expanded to 100% of power lines in high fire-risk areas, which include much of Napa County.

Napa County last week experienced the Old Fire, which broke out May 31 and burned 570 acres near Old Soda Springs Road northeast of the city of Napa and prompted evacuations. Cal Fire subsequently asked PG&E for data on lines within that vicinity.

PG&E filed an incident report with the state saying the Pueblo line close to the fire location had a "fault" within minutes of Cal Fire's reported fire start time. However, the utility was unaware of any downed lines.

"This line was not EPSS-enabled at the time, because conditions did not meet EPSS criteria," the incident report said. "Our investigation is ongoing."

In related news, PG&E plans to underground 6 miles of power lines in the Aetna Springs-Pope Valley area. This is being done in phases this year and in 2023, according to information presented to Napa County by the utility.

The Fulton-Calistoga line that runs across Napa, Sonoma and Lake counties is being reinforced and will include structures that can withstand 60 mph winds. That project could reduce public safety power shutoffs by 25%, PG&E reported.