PG&E may shut off power in parts of Napa County amid Bay Area heat wave

 

NAPA, Calif. - As the Bay Area endures scorching temperatures this week, a select number of Pacific Gas & Electric customers may lose power due to public safety power shutoffs. A public safety power shutoff, or PSPS, is when PG&E preemptively de-energizes power lines as a precaution against weather conditions that might damage equipment and spark a fire. 

Much of the Bay Area is under an excessive heat warning this week. The National Weather Service says inland temperatures could reach as high as 108 degrees, while coastal areas could reach 95 between Monday and Wednesday.

The excessive heat warning is in effect through Wednesday at 11 p.m. 

Here's a look at how the hot weather is affecting power and PG&E in the Bay Area.

North Bay

PG&E on Monday planned to shut off power in northwest Napa County as a preventative measure during the searing hot temperatures in the Bay Area.

Late Monday evening, PG&E said approximately 140 of its customers in Napa County were still in scope for a potential PSPS, but that they were not currently impacted. No customers have been deactivated, they said. 

The Napa County Sheriff had earlier said the power shutoff would affect 143 customers north of Tubbs Road from 6 p.m. Monday to 7 a.m. Tuesday.

Napa County is under a heat advisory, with temperatures ranging in the mid-90s on Monday and in the low 100s on Tuesday and Wednesday, according to the National Weather Service. 

A community resource center will be open at 1307 Washington Street in Calistoga. 

Tubbs Road was the site of the devastating Tubbs Fire in 2017; at the time, it was the most destructive wildfire in California history. 

Sonoma County was also under a power shutoff warning, PG&E said Monday.

But by the evening, Sonoma County had been removed from the PSPS, PG&E said. 

East Bay

Alameda and Contra Costa counties were under a power shutoff warning advisory earlier Monday. However, due to "an improvement in weather forecast models," the two counties were removed from the "scope of Monday's PSPS."

A total of 286 customers in Contra Costa County and 57 in Alameda County were estimated to be affected, the spokesperson said.

"PG&E contacted those customers Monday afternoon via text, email and automated phone call to inform them they were no longer potentially impacted," the utility said.

Northern California

Butte, Colusa, Glenn, Shasta and Tehama counties are under a power shut-off warning as of Monday.

Nearly 10,000 customers in these Northern California counties are already undergoing power shutoffs due to the heat wave. Most of those affected are in Shasta County, where nearly 8,000 customers have lost power, the PG&E spokesperson said.

Though the number of customers possibly affected by power shutoffs is small in Bay Area counties, less than 500, a power line in those areas could spark a major fire if not de-energized. October is the peak month for Diablo winds in the north and Santa Ana winds in the south. The winds blow offshore, often aggravating fire conditions to create some of the state’s largest and most destructive fires.

Red Flag Warning

Cal Fire says there are already Red Flag Warnings further north in California. Fire conditions like strong, steady winds with huge gusts, plus bone dry humidity, plus extreme heat, could develop this week in the Greater Bay Region. 

"That creates a recipe that could lead to the potential, if a fire were to start, for it to spread rapidly," said Cal Fire North Bay Headquarters spokesman Jason Clay.

There are no power shutoff warnings for Wednesday through Sunday at this time. 

For PG&E, a Red Flag Warning is not a precondition for Public Power Safety Shutoff since all of these new technologies customers are paying for are beginning to pay off. 

"We use machine learning models to improve our forecast to be very, very granular in terms of where we might need to shut off power for safety," said PG&E North Bay VP Dave Canny.

Cal Fire is ‘fully staffed at peak levels’

If a fire does start, many Bay Area Cal Fire crews just come back from Southern California's big fires. 

"We have all of our resources back in the units; 31 engines, we've got all of our aircraft, helicopters that are here, bulldozers, and crews. So, we're fully staffed at our peak levels," Clay said.

Power lines have been blamed for roughly half of the most destructive wildfires in California history, according to California’s Public Utility Commission. The agency ruled in 2012 that utilities had the right to shut off electricity to protect public safety, and the most recent guidelines were adopted in June 2020. 

That includes high winds that can blow down power lines, hurl branches or other debris into them or cause two lines to hit each other, causing sparks that could ignite tinder-dry grass. 

A power shutoff can affect just a handful of customers, up to millions. 

What’s believed to be the largest was in October 2019, when PG&E cut power to more than two million people from the San Francisco Bay Area to the Sierra Nevada.

The resulting chaos — phones and gas pumps, elevators, traffic lights and even water pumps stopped working — created furious criticism.

The utility, however, said it has been working to make the blackouts smaller, shorter and more targeted, as well as providing technical changes allowing more people to keep their power on. It calls such outages a last resort. 

PG&E usually gives two days' notice of a power shutoff. 

To see if your home will have power, enter your address in PG&E's map. 

Health advisory and cooling center 

Sonoma County will have several cooling centers open beginning Tuesday for residents who need to escape the heat. 

Health Officer Dr. Tanya Phares issued a health advisory Monday in response to the National Weather Service's excessive heat warning for much of the county, which runs through 11 p.m. Wednesday. 

The Associated Press and Bay City News contributed to this report.