Heading into California’s peak wildfire season, Pacific Gas & Electric Co. has shifted its strategy to avoid sparking another devastating blaze: It’s focusing less aggressively on trimming trees that pose hazards near electrical wires and relying more on technology to quickly de-energize damaged lines.

The pivot at Northern California’s beleaguered utility giant has raised questions among regulators, who have given PG&E until Monday to respond. The shift has been in the works for more than a year, but began in earnest in January when PG&E ended its “Enhanced Vegetation Management” program of stepped-up vegetation removal around power lines.

The utility concluded that program, started in 2019 after a series of destructive wildfires were sparked by trees or limbs falling on electrical equipment, hasn’t been cost effective. PG&E says that a combination of routine and select tree work and new power grid technologies will deliver more protection at a lower price. But there are concerns it could lead to more customers without power, longer.

“We develop and implement our wildfire mitigation programs based on the best information and data that we have at the time, and our capabilities have continued to evolve and mature since 2019,” PG&E spokesman Matt Nauman said.

“We realized we needed to evolve to engineered controls” — things like Enhanced Powerline Safety Settings that cut power within a tenth of a second in the event of a line fault — “because we cannot identify every tree that may pose a risk.”

Regulators and watchdogs aren’t convinced. The Office of Energy Infrastructure Safety, a new department within the California Natural Resources Agency, reviews utility plans for preventing equipment from sparking wildfires. It told PG&E in June that its new 2023-2025 wildfire mitigation plan is inadequate, and ordered the utility to respond to its concerns by Monday, Aug. 7.

Among the issues Energy Safety cited were that PG&E’s plan doesn’t adequately address risk from hazardous trees, doesn’t provide targets for vegetation inspection programs, and doesn’t show how it will address its growing equipment repair backlog. The department also said the utility’s plan to bury power lines underground in highest fire risk areas is insufficient. And the power line safety settings could lead to unnecessary preemptive power shut downs — know as Public Safety Power Shutoffs, or PSPS — during wind storms.

Energy Safety officials wouldn’t comment, citing concerns about prejudicing their review of PG&E’s plan.

The department, established in 2021, pushed back on PG&E’s plan last year as well, but has not yet taken action on the state’s two other major private utilities, Southern California Edison and San Diego Gas & Electric, which also are required to submit wildfire mitigation plans.

PG&E, which serves more than 5 million households in the northern two-thirds of the state, has been uniquely troubled. The utility was convicted in federal court of criminal safety violations involving a 2010 natural gas pipeline explosion in San Bruno that killed eight people and destroyed more than 30 homes. Its electrical equipment has since been linked to some of the deadliest and most destructive wildfires in the state, including the 2015 Butte Fire, Wine Country fires in 2017 and the 2018 Camp fire. The utility filed for bankruptcy for a second time in 2019.

Filsinger Energy Partners, which serves as PG&E’s independent safety monitor for the California Public Utilities Commission, also took note of the company’s shift in wildfire prevention strategy in an April status report. It noted that arborists working for PG&E told the firm they were abruptly told to stop tree work last year “due to budgetary constraints well before the end of 2022.”

PG&E told the firm that while it reduced its vegetation management budget from $1.8 billion to $1.4 billion last year, it was due to the utility’s “risk-informed shift to operational mitigations,” and the overall wildfire budget would remain the same at about $6 billion.

The firm also noted that PG&E said its aggressive vegetation program led to “an increase in negative customer interactions” and that a “higher volume of customer refusals from its increased tree work was impeding its ability to reduce risk associated with removing identified hazard trees.”

PG&E’s Nauman stressed that in its strategy shift, the utility is by no means abandoning tree work altogether. While it is dropping the stepped-up clearance program, PG&E will continue with routine maintenance while focusing tree inspections in high fire-risk areas and places with a history of vegetation-caused outages.

At a CPUC safety review hearing last month, PG&E executives said their own analysis found that a combination of newly installed grid technologies, including the Enhanced Powerline Safety Setting shutoff switches, reduced equipment-sparked fires last year 68% over 2018-2020 levels, compared to just 7% for the vegetation management program.

“That’s why we feel confident that what we have proposed in terms of layers of protection is the appropriate path forward both in terms of reducing risk and ensuring we’re doing it in the most cost effective manner for our customers,” said Sumeet Singh, PG&E’s chief operating officer.

But Energy Safety’s revision notice to the utility said “none of these programs, alone or in combination, maintain or replace the detailed approach to hazard tree mitigation conducted under EVM,” the Enhanced Vegetation Management plan.

Residents in fire-risk areas, including the Santa Cruz Mountains, have mixed feelings about the utility’s directional shift.

Colleen Miller of Boulder Creek, a town scorched by the 2020 CZU Lightning Fire, said she’s been plagued by power outages from hair-trigger safety circuits even when there haven’t been winds or fires to warrant them.

“We’ve had weeks of power outages,” she said.

But Boulder Creek resident Chris Finnie said many residents opposed the aggressive tree cutting, blaming it for destabilizing slopes, and urged PG&E to use circuit cut-offs instead.

“We want those new switches,” Finnie said. “We don’t want slash-and burn tree cutting.”