In the biggest planned electric shutdown in state history, the utility, which is known as PG&E, started turning off the power that residents and businesses use for lights, television sets, computers, stoves and air conditioners in rolling blackouts planned for 30 counties with almost 800,000 paying accounts, affecting more than a million people.
The shutdown was aimed at keeping power off live wires on a warm and windy day, ideal for the spread of wildfires, a state elected official slammed the rolling blackouts as "unacceptable."
Schools around the region were closed in anticipation, and some morning commuters were slowed by non-functioning traffic signals, forcing police to direct drivers.
Severe backups around Napa county as traffic lights at major intersections are down. Here’s the hwy 29 & 12 intersection near the Napa airport pic.twitter.com/5reEBa965h
State Sen. Scott Wiener, a Democrat representing the San Francisco area, called the blackouts "unacceptable," estimating that 2.5 million people could ultimately be affected.
"It's hard to overstate the impact of this massive rolling blackout, affecting 2.5 million people," Wiener said in a statement. "People rely on electricity for their medicine, their food and their livelihoods. This is a completely unacceptable state of affairs. We can't let PG&E normalize these mass blackouts."
But the scale of this week's measures dwarfs what's happened in the past.
Within Wednesday's mass shutdowns, some important services still had electricity.
For example, lights remained on inside the Caldecott Tunnel, cutting through the Berkeley Hills into suburban Contra Costa County, and the Tom Lantos Tunnel, a stretch of State Route 1 through Devil's Slide in Pacifica, the state Transportation Department said.
David K. Li
David K. Li is a breaking news reporter for NBC News.