As Hawaii’s electric utility faces scrutiny for active power lines that fell in high winds during last week’s catastrophic fires, Pacific Gas & Electric says it’s prepared to cut the power as a precaution to prevent wildfires in California this fire season.
Its customers could see four “public safety power shutoffs” in the coming months, the utility said, darkening the homes of an estimated 320,000 homes and businesses.
The intentional cutoff — while unpopular with residents — is expected to lower the risk posed by power lines by 94% this year, up from 90% last year, PG&E officials said at a recent meeting of the California Public Utility Commission. The forecast is an average, based on computer models, the current grid and a decade-long historical analysis.
Recent improvements in the so-called PSPS strategy will make the outages “shorter, smaller and smarter” than in previous years, said Dave Canny, senior director of wildfire mitigation at PG&E.
The public-safety power shutoffs come with advance warnings during severe fire weather and are different from the many unpredictable and increasing outages that are plaguing thousands of PG&E customers this summer. Those outages, which PG&E calls Enhanced Powerline Safety Settings, are caused when a circuit breaker instantly cuts power after, for example, a tree branch falls on a line.
While no single cause of the devastating Hawaiian fire has been determined, a lawsuit filed on Saturday claimed that Hawaiian Electric, the parent company of the power provider on Maui, kept power lines electrified despite warnings of high winds.
“There should have been greater alarms raised” for the utility to implement a shut-down program, Jennifer Potter, a former Hawaii Public Utilities Commission member, told the Honolulu news site Civil Beat. “We did not follow best practices.”
Meanwhile, an Oregon jury recently found utility PacifiCorp liable for causing devastating wildfires across Oregon during Labor Day weekend in 2020. The utility failed to shut off power to its 600,000 customers during a windstorm, despite warnings from then-Gov. Kate Brown’s chief-of-staff and top fire officials, plaintiffs alleged.
PG&E also learned the hard way, after the utility was blamed for a series of deadly blazes in Northern California. This is the sixth summer of pubic safety power shutoffs, part of the company’s multibillion-dollar plan to prevent the kind of fires that sent it into bankruptcy. PG&E adopted the strategy after fierce winds and a faulty electric transmission line ignited the November 2018 Camp Fire in Northern California’s Butte County, killing 85 people and destroying the town of Paradise.
As another wildfire season looms, California is starting to see an uptick in blazes, Frank Bigelow of Cal Fire’s Community Wildfire Preparedness & Mitigation unit told the Aug. 3 CPUC meeting. This year’s season got off to a slow start, due to winter rains, but now the weekly average is climbing, he said.
So far this year, the state has experienced 4,337 wildland fires, below the five-year average of 4,616 fires. The 34.19 inches of rain received last winter are no guarantee that a future fire won’t ignite, Bigelow said. That’s only two inches more than the 32.34 inches of rain that fell in the winter of 2016-2017, after which the Tubbs Fire and other blazes claimed over 1.5 million acres, destroying nearly 11,000 structures and 47 people died.
“We really benefited the first couple months of the year from all that moisture…But we’re now experiencing pretty similar conditions to where we were in 2022,” said Scott Strenfel, PG&E’s senior director of meteorology and fire science. “We’re now starting to see live fuel moistures dry out.”
The number of pre-emptive power shutoffs has declined in recent years due to new technologies and improvements to the electric system infrastructure, according to PG&E. In 2019, when winds gusted up to 102 miles per hour, there were seven PSPS events, affecting 2 million customers in 17 counties with an average outage time of 43 hours. In 2020, there were six PSPSs, affecting 653,000 people. In 2021, there were five PSPSs, affecting 80,400 people.
No preemptive power shutoffs were necessary last year, but weather models indicate that several are likely this year.
Compared to previous years, PG&E says it expects that outages will be shorter — and fewer people will be affected, because the restoration maps are updated and digitized so they can be used on mobile devices by field crews, helping speed up the process to bring the power back on, said Canny.
They are smaller through the installation of 1,200 devices that break up the grid into tiny sections, reducing the number of homes on each circuit. That has removed about 26,000 customers from risk of a PSPS.
And they are “smarter” because of improved computer models, Canny said. Weather forecasts are more granular — focusing on two-square-mile grids — and can peer five days into the future. Every night, this weather data is combined with other data, such as the moisture levels of grasses, and a computer simulation predicts where and when risk of potentially catastrophic risk of ignition.
In addition, the utility said it will underground 350 miles of power lines this year, reducing the need for preventive shutoffs. Among those is a 2022 project in Walnut Creek serving 2,600 customers.
An additional 110 miles of power lines have been made more resilient by erecting stronger poles or covering live wires, said Canny.
PG&E has also created a “remote grid program” to serve small clusters of isolated homes on the edge of wilderness, so dangerous overhead lines that serve them can be removed, said PG&E spokesperson Paul Doherty.
So far, it has installed four of these independent power systems using solar, batteries, and back-up generators to homes in Tehama County and Mariposa County. By 2026, the company aims to expand the program to more than 30 communities in rural parts of the state.
Despite these efforts, the wildfire risk continues as the climate grows hotter and drier, said Canny.
“Even with the improvements we’ve made,” he said, “we know our work is never done.”
Source: www.mercurynews.com