Clean Energy SF: San Francisco, fog then sun, est. 2026

Vol. 1 - No. 14 - Thursday, September 24, 2026 - Free to readers

Grid ยท Analysis

Undergrounding the wires: PG&E's slow answer to fire season

PG&E is burying thousands of miles of power line to cut wildfire risk. In San Francisco, where the grid is already underground, the real question is what you pay for work happening out in the hills.

Filed September 29, 2026 By the Clean Energy SF editors Reading time: 6 minutes

I. What burying a line actually changes

An overhead power line starts a wildfire in a familiar way: wind knocks a branch into it, or the line slaps against itself, and a spark drops into dry grass. PG&E has two main tools short of burying the wire. One is the Public Safety Power Shutoff (the planned outage the utility calls when hot, dry wind makes overhead lines dangerous). The other is what PG&E calls Enhanced Powerline Safety Settings (fast-trip settings that cut power within about a second when the line senses a fault), which trades big planned outages for many short, sudden ones.

Undergrounding removes both problems on the stretch that gets buried. No overhead conductor means no wind-driven ignition and no reason to shut that segment off, per PG&E's own description of the benefit. The catch is that it is the slowest and most expensive of the three options, so the utility proposes it only for the highest-risk miles, and regulators have pushed back on how many of those miles are worth the price.

II. The honest math on cost and pace

PG&E's headline goal, announced in 2021, is to bury roughly 10,000 miles of distribution line in its highest fire-risk areas. At last public report the cost runs on the order of a few million dollars per mile, and PG&E says it has been working to bring that figure down. Spread across a service area of millions of customers, that spending shows up in the delivery charges that have driven Bay Area bills steadily higher.

Pace is where the fight sits. In PG&E's 2023 General Rate Case (the multiyear proceeding where the California Public Utilities Commission sets how much a utility can charge), the commission approved far fewer undergrounding miles for the 2023 through 2026 period than PG&E requested, on the order of roughly 1,200 miles, and pointed the utility toward cheaper insulated overhead wire on many segments. A 2022 state law (SB 884) separately set up a faster review at the state Office of Energy Infrastructure Safety for a longer ten-year undergrounding plan, which is still working through that process.

III. San Francisco versus the hills

Almost none of the 10,000 miles runs inside San Francisco. The city sits outside the state's High Fire-Threat District (the CPUC map of areas where fire risk justifies extra measures), and its distribution lines were largely put underground decades ago. The Bay Area segments that do face shutoffs and ignition risk are up in the hills: the East Bay ridges above Oakland and Berkeley, the North Bay in Napa and Sonoma, the Santa Cruz Mountains, and the Peninsula ridgelines in San Mateo County.

That geography sets up the honest tension for a San Francisco ratepayer. If you buy your power from CleanPowerSF, the city's public electricity provider, PG&E still owns the poles and wires and still bills you for delivery, so you help pay for undergrounding either way. The fog that keeps the city cool and damp is, in effect, one reason San Francisco carries lower fire risk than the sunbaked ridges whose lines your bill is helping to bury.

IV. Worth watching this month

1. Twice-monthly CPUC voting meetings are where any decision on PG&E undergrounding cost recovery would surface, on the agenda posted at cpuc.ca.gov.

2. A ten-year undergrounding plan under SB 884 is still moving through review at the state Office of Energy Infrastructure Safety, which sets the longer-term mileage.

3. Fall Public Safety Power Shutoff notices from PG&E are routine now, and they will show whether any Bay Area circuits near the East Bay or Peninsula hills are flagged for a possible shutoff.

4. Your next PG&E statement is worth a look, since rate changes tied to wildfire and grid work take effect at intervals through the year.

5. Red flag fire-weather warnings from CAL FIRE and the National Weather Service are what actually trigger a shutoff decision, buried lines or not, so they stay the thing to watch in dry, windy stretches.

Frequently asked questions

Will undergrounding lower my PG&E bill?

Not in the near term. Burying line is expensive and shows up as higher delivery charges first. The payoff, fewer fires and fewer shutoffs on those segments, comes over the long run.

Does San Francisco even get Public Safety Power Shutoffs?

Very rarely. The city is dense, mostly underground, and outside the high fire-threat district, so shutoffs almost always hit outlying and higher-elevation areas instead.

I am a CleanPowerSF customer. Am I paying for this?

Yes. CleanPowerSF supplies your electricity, but PG&E owns the wires and charges every customer in its territory for delivery and wildfire work, including undergrounding.

Is burying the line always better than overhead wire?

It depends. Undergrounding removes the risk most completely but costs the most and takes the longest. Insulated overhead wire, often called covered conductor, is cheaper and faster, and regulators have favored it on many miles.

References