Deep in the bowels of PG&E headquarters in downtown San Francisco, the utility’s emergency operations center Wednesday hummed with the activity of nearly 100 people in different colored vests orchestrating the largest planned power shutdown in Northern California history.
On a map of the region projected on one wall, squiggling white arrows cascaded across roughly half the state, illustrating the wide reach of the fierce Diablo winds bringing hot and dry air from the northeast forecast to begin pummeling the region about 5 p.m.
These winds combined with the state’s dry climate pose a formidable threat to nearly 25,000 miles of PG&E distribution lines and 2,500 miles of high-powered transmission lines, said Aaron Johnson, a vice president of PG&E’s electrical operations.
“Our system is designed to handle high winds, but it’s not built to withstand the force of a falling tree,” Johnson said.
Command central for the utility’s unprecedented preemptive power shutdown expected to turn the lights out for more than a million customers in Northern California is centered in the only Bay Area county expected to retain power throughout what company officials warned could become a five-day blackout.
Wednesday morning, the power was already turned off for more than 500,000 customers in 22 counties and utility workers were preparing to cut power for another 243,000 customers early in the afternoon. A customer refers to a household, business or public agency, making the number of Californians affected by the shutdowns are likely in the millions.
The advance timing of the shutdown is crucial, Johnson said.
PG&E officials expect it will take about four hours to cut power for that many customers in the second wave of shut-offs and troubleshoot any problems that arise, which was the case Tuesday night when an automated shut-off system failed in one area so crews had to turn the power off manually.
At about a dozen long banks of computers in the utility’s San Francisco operations center, staff were split in teams. Red vested workers managed planning and intelligence critical to the power shutdown. Blue-vested staff focused on electrical system operations with the yellow team coordinating logistics. Staff in white vests were communicating with local governments in nearly two dozen counties.
The intelligence team included meteorologists from the utility’s new wildfire safety operations center, a full-time program established earlier this year that keeps constant watch over weather conditions and other risks to the power grid.
PG&E’s emergency operations center is designed like those well-established systems used by local governments and other public agencies, a company spokeswoman said. They have been used for many years, but this is the seventh time the system has been activated to manage a public power shutdown, first deployed by PG&E last year to try to reduce of the risk of its equipment ignited a blaze.
The public safety power shutdown is a key part of the company’s wildfire mitigation plan that is also augmenting its focus on clearing vegetation from lines and hardening its power grid.
The utility has an army of about 5,000 personnel positioned throughout its service territory to help restore power, including vegetation removal crews and technical teams ready to repair any damage to the power grid.
Johnson said teams are assigned a particular circuit, which could cover anything from a 20-mile area to 100 miles, and over the summer ran practice drills to ensure they know how to access all of the power lines, either by air, by truck, off-road vehicle or on foot.
Air crews manning 24 helicopters are poised to begin inspecting PG&E’s power lines and other equipment to look for damage and dispatch crews to make repairs.
They will deploy a combination of fast-moving roving patrols looking for signs of significant damage to power equipment and other teams conducting the slow, methodical inspections of transmission and distribution lines.
But none of that can begin until the winds, expected to pick up throughout the day and night, die down. That could take a full 24 hours, meaning the long work of restoring power may not begin until midday Thursday. PG&E said Tuesday it hoped to start restoring power Thursday at noon, and the restoration could take up to five days.
“This is not something we take lightly,” Johnson said. “But it’s the right thing to do to keep everyone safe.”
—By Julie Johnson
The Press Democrat, Santa Rosa, Calif.