California’s three big investor-owned utilities want to invest more than $10 billion over the next three years on reducing the threat of wildfires caused by their power grids. Now it’s up to state regulators to decide which parts of their plans will move forward. 

On Friday, Pacific Gas & Electric, Southern California Edison and San Diego Gas & Electric filed wildfire mitigation plans with the California Public Utilities Commission, laying out their three-year plans for preventing grid-caused wildfires where possible and limiting their damage when they do occur. 

The three-year plans are a sequel to the 2019 wildfire mitigation plans each utility submitted early last year. The plans included a major increase in tree-clearing and grid-hardening work, along with technologies like grid-sectionalizing equipment, weather stations and mountaintop cameras, and other tools for preventing grid failures from sparking wildfires during times of high winds and hot temperatures. 

The plans also encompass the controversial step of public safety power shutoff (PSPS) events, such as PG&E’s multiday blackouts that left millions without power this fall, or the much smaller outages conducted by SCE and SDG&E over the past year. 

The CPUC largely approved last year’s plans and could be expected to move quickly to approve spending on critical fire prevention activities in advance of this year’s fire season. But it has also released a scathing report of PG&E’s grid maintenance failures leading up to the 2018 Camp Fire and is investigating its PSPS plans after its poorly executed blackouts this fall, indicating that PG&E’s plan will come under tight scrutiny.

PG&E: Playing catch-up

PG&E’s wildfire mitigation plan is by far the most expensive of the three, with an estimated cost of $2.6 billion per year, or $7.8 billion in total. The utility, which is struggling to emerge from bankruptcy protection by June to gain access to the state’s $21 billion wildfire insurance fund, serves a larger and more mountainous and forested territory than SCE and SDG&E. It’s also under the most intense scrutiny from regulators and the public in light of its recent track record.

PG&E has been working at a breakneck pace to inspect power lines and poles, repair and replace worn equipment, and clear vegetation in high-fire-threat districts. But a lack of tree-trimming workers to take on the massive scope of its needed improvements has prevented it from moving as fast as it needs to.

Like its fellow utilities, PG&E will use up most of its multibillion-dollar budget on these kinds of improvements. This year alone, it hopes to clear vegetation from about 1,800 miles of power lines; inspect 22,000 transmission structures and 344,000 distribution poles; and harden around 241 miles of grid. Much of this work involves  “covered conductors,” or covering bare overhead wires with plastic sheaths to prevent tree-limb contact that can spark fires. Burying power lines, considered the safest option, is prohibitively expensive in all but the most pressing areas. 

PG&E has also installed hundreds of weather sensors and cameras to detect grid failures and fires in real time, building on the work done by SDG&E over the past decade. While the utility has reached multibillion-dollar settlements to pay fire victims, insurers and local governments, any fires started since its January 2019 bankruptcy filing would have to be borne directly — a threat that gives PG&E a hefty incentive not to cause any more fires, no matter the cost. 

But PG&E faces equal pressure to prevent a repeat of this autumn’s massive fire-prevention power outages, or at the very least, to limit their scope. Sectionalizing gear such as reclosers, relays and switches can allow the grid to automatically reroute power around grid pathways that have been de-energized to prevent fires, or give grid operators more flexibility in restoring power when the threats have subsided. 

PG&E deployed about 160 sectionalizing devices last year and noted that they helped restore about 48,000 customers of the nearly 700,000 that lost power in its blackout that occurred from October 9-11. Its new plan calls for installing 592 automated devices to better reconfigure the grid during PSPS events as well as 23 switches to its high-voltage transmission system. 

SDG&E: More of the same

SDG&E has pioneered much of the state of the art when it comes to utility wildfire mitigation, with more than $1.5 billion invested since deadly fires in 2007. Its new plan largely calls for expanding on the same kinds of investments, along with a more finely automated system for limiting outages at the distribution circuit level. 

SDG&E serves a much smaller territory than PG&E and SCE, but it includes remote communities served by power lines crossing tinder-dry mountains and steep valleys. To manage this challenge, SDG&E has invested in an in-house meteorology team, state-of-the-art weather forecasting and vegetation management technology, a fire-prevention power outage scheme that relies on strategically deployed grid sectionalizing gear to limit the scope of affected communities, and a hefty outreach and support system for those who must be denied power until weather conditions have improved.  

SDG&E also plans to make use of the massive quantities of data it’s collected over the years to tighten its PSPS protocols around fine locational differences. This kind of big-data analysis could help it more accurately forecast wind speeds from canyon to canyon, along with the “fuel loading” of the underlying vegetation based on the past year’s rainfall and temperature patterns.  

SCE: A focus on grid hardening

SCE’s wildfire history falls somewhere between PG&E and SDG&E but hews more closely to the latter utility. While SCE was found responsible for causing the Nov. 2018 Woolsey Fire and agreed to pay $360 million to cover the damages it caused, it doesn’t have nearly the same record of safety lapses and disasters as does PG&E. Its service territory is also smaller and less challenging than PG&E’s, though it does include mountain ranges and deserts subject to high winds and hot, dry conditions. 

SCE was able to limit the scope of fire-prevention outages last fall to about 80,000 customers at its peak, even as firefighters battled blazes in the affected region, in part through using existing grid automation and sectionalizing capabilities. It has also completed deploying 161 high-definition cameras to cover nearly 90 percent of its high-fire-risk areas and expects to add more than 1,000 weather stations by 2022 to the 482 it has already deployed. 

SCE’s new plan is expected to cost $3.8 billion, much of it tied up in vegetation clearing and grid hardening. But it’s also asking the CPUC for permission to add new technologies and data analytics capabilities to its roster. Some of them are aimed at catching grid faults in the milliseconds when they’re happening, like its Open Phase Detection pilot project, which is testing technology to sense and de-energize low-voltage power lines before they hit the ground. 

Other technologies are aimed at crunching data to predict faults, such as the distribution fault anticipation technology it’s evaluating, or tapping new sources of data from the grid itself, like early fault detection technology that can detect incipient grid failures from the radio frequencies emitted by grid equipment.