Since PG&E announced that it would cut power to an estimated 800,000 customers this week due to high winds and dry conditions, people have been asking why the shutoffs are so widespread — covering large parts of Northern and Central California.
And as the power was turned off overnight Wednesday in parts of the Bay Area, some made comments like this one:
Ali Thanawalla on Twitter I don’t quite understand why @PGE4Me shut off the power in Kensington. It’s not windy or hot. But here we are.
We turned to PG&E and an academic for some answers.
Stanford University’s Michael Wara said the shutoffs were broad for two reasons:
1: The weather, specifically the wind. It’s the first time since the 2017 North Bay fires that we’ve had such a widespread offshore wind event, said Wara, director of the Climate and Energy Policy Program at Stanford’s Woods Institute for the Environment.
“The conditions justify a kind of widespread shutoff as opposed to more targeted” ones, he said.
NWS Bay Area on Twitter Peak overnight wind gusts as of 5:15 AM. The highest peaks have seen gusts over 70 mph. Winds will decrease later today but remain gusty especially in the North and East Bay Hills through the afternoon. #CAwx #CAFire
2: The grid. Californians have a right to power. If you move somewhere, an electrical company is required to power it.
“The infrastructure we have was not built with fire risk in mind,” Wara said. “It was built to, especially in the rural parts and suburban parts of California that are most at risk today, serve customers cost effectively and to keep power rates low.”
What that means in practice is that sometimes lines can take very winding routes through fire-prone areas to serve customers.
“You’ll have a power line that will serve one valley and then go up and over a ridge to serve the next valley. And that means that if you have to turn that light off, you could black out both valleys in addition to the ridge top — even though the risk is only on the ridge top,” Wara said.
PG&E spokesman Paul Doherty said the weather was a driver, noting that the National Weather Service had issued red flag warnings over the past few days across PG&E service areas from near the Oregon border down to Bakersfield in Kern County.
NWS Bay Area on Twitter Storm Prediction Center (SPC) Fire Wx Outlook. Note the “Extreme” threat is shifting to the SoCal Santa Ana but much of Northern California maintains “Critical” fire weather threat today. #CAwx #FireWeather #OneLessSpark
Still, it was “very possible” that people may be affected by a power shutoff even though they’re not experiencing extreme weather conditions, he added.
“This is because the electric system relies on power lines working together to provide electricity across cities, counties and regions,” Doherty said.
Due to changing weather forecasts, PG&E on Thursday decreased the number of customers expected to have their power cut in Kern County, from 43,000 customers to 4,000.
Last year, California’s utility regulator and Cal Fire set new standards in high-fire threat areas for utilities. They created special maps to identify those zones, taking into account areas with high winds and that are prone to burn. Utilities are required to audit their lines more frequently and have wider clearance areas in those high fire threat areas.
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