Pacific Gas and Electric has notified about 21,000 customers that a Public Safety Power Shutoff may be initiated as hot and dry conditions combined with high winds over the weekend and in the coming week could pose a risk to the electricity grid system and has the potential to ignite fires.
An estimated 21,000 customers in portions of three Northern Sierra and North Valley counties might be affected by the Public Safety Power Shutoff and received notifications Sept. 24, PG&E said in a statement. The customers affected represent fewer than 1% of PG&E's customers.
"Due to forecasted extreme weather conditions, PG&E is considering proactively turning off power for safety," PG&E said. "Windy conditions, like those being forecast, increase the potential for damage and hazards to the electric infrastructure, which could cause sparks if lines are energized. These conditions also increase the potential for rapid fire spread."
PSPS is a proactive outage when severe weather threatens a portion of the electricity system.
Red flag warning
A red flag warning is in effect from the evening of Sept. 26 through Sept. 28 for portions of interior northern California with wind gusts of up to 55 mph expected, with the highest wind speeds expected the evening of Sept. 26 through Sept. 27, especially for the west side of the Sacramento Valley and Sierra foothills, according to the US National Weather Service.
This weather event is localized to the Sierra Foothills, so customers in the Bay Area and southern parts of PG&E's service area will not be impacted, according to PG&E.
"PG&E will then inspect the de-energized lines to ensure they were not damaged during the wind event," it said. "PG&E will safely restore power in stages as quickly as possible, with the goal of restoring most customers within 12 daylight hours, based on once the weather 'all clear' is provided."
Numerous wildfires are already ongoing in the state. The wildfire season spans July to November, peaking in September and October.
California wildfires
There are currently 25 major wildfires burning across California, according California Department of Forestry and Fire Protection.
There have been more than 8,000 wildfires since the beginning of the year that have burned over 3.6 million acres across California. Since August 15, when California's fire activity increased, there have been 26 fatalities and over 6,900 structures destroyed.
Five of the 20 largest wildfires in California history have occurred in 2020, according to CAL FIRE.
Labor Day weekend outages
Over the Labor Day weekend, several local utilities initiated Public Safety Power Shutoffs due to fires threatening transmission lines, to assist in firefighting efforts and lingering hot weather not allowing equipment to cool down over night, according to utilities.
At the peak of the Labor Day weekend heat wave and wind-driven wildfires, PG&E had about 175,000 customers – out of 5.1 million total electric customers – without power across 22 counties as part of the PSPS.
The California Independent System Operator has not declared any transmission emergencies this summer, but did order rotating outages Aug. 14 and 15 to maintain grid reliability during the heat wave, the first time it had done so since 2001.