What Triggers a PSPS Power Shutoff in California

A Public Safety Power Shutoff — also called de-energization — is when an electric utility turns off power to specific lines during extreme fire weather, so a wind-damaged line or piece of equipment cannot ignite a wildfire. It is a preventive measure, not a response to an outage that has already happened.

The legal basis in California goes back to a 2012 California Public Utilities Commission (CPUC) ruling that Public Utilities Code §451 and §399.2(a) authorize investor-owned utilities to de-energize lines for public safety. Today six investor-owned utilities run PSPS programs: Pacific Gas & Electric, Southern California Edison (SCE), San Diego Gas & Electric, Liberty Utilities, Bear Valley Electric Service, and PacifiCorp.

Why utilities accept the disruption: although electrical infrastructure causes well under 10% of California wildfires by count, those fires account for roughly half of the most destructive wildfires in state history. Shutting off a small number of high-risk circuits during a wind event is meant to remove that ignition source at the worst moments.

This is a common point of confusion for Los Angeles residents. LADWP has publicly stated, in its cited guidance, that it does not proactively shut off customer power before or during wind events the way the investor-owned utilities do. Because LADWP is a municipal (publicly owned) utility, it is not under the CPUC’s PSPS rules; instead it operates under SB 1028 (effective January 1, 2017), which requires each publicly owned utility to assess wildfire risk and adopt a Wildfire Mitigation Plan.

LADWP’s territory is heavily urbanized with comparatively few wildfire-prone areas, so its plan leans on construction standards, vegetation management, and inspections rather than customer shutoffs. This is a description of stated policy, not a promise about any future event — LADWP customers should still check current LADWP outage and emergency information during major wind events.

There is no single public wind number that automatically triggers a PSPS. The decision combines fire-weather data, fuel conditions, and circuit-specific engineering. For SCE, the main inputs are:

Utilities publish wind reference levels — for example, covered-conductor criteria have referenced roughly a 40 mph sustained / 58 mph gust level, and the National Weather Service wind-advisory levels (about 31 mph sustained / 46 mph gusts) are commonly cited. These are references reported in utility materials, not a guarantee that power will or will not be shut off at a stated wind speed. In large events, thresholds may be lowered so the highest-risk circuits shut off first.

Sources: CPUC Public Safety Power Shutoffs · SCE PSPS FAQ · verified August 4, 2026.

Only circuits in higher-risk areas are normally candidates for a PSPS. The CPUC’s High Fire-Threat District (HFTD) map classifies areas as:

• Zone 1 — USFS/CAL FIRE Tree Mortality High Hazard Zones.
• Tier 2 — elevated utility wildfire risk.
• Tier 3 — extreme utility wildfire risk.

About one-quarter of SCE’s service area sits in a high fire-risk area. You can look up an address on the utility’s or CPUC’s HFTD map to see whether it falls in Tier 2 or Tier 3. An HFTD result is general wildfire-risk information only — it is not an insurance determination, a property disclosure, an engineering assessment, or a guarantee that a specific address will experience a PSPS.

When forecasts allow, SCE works down a sequence of notifications. Exact lead times vary with how confident and how sudden the forecast is:

Notifications go out by text, email, or voice call, using the contact method on file. Fast-onset winds can leave little to no notice — SCE warns that advance forecasts may not capture the real-time onset of dangerous conditions.

Source: SCE — what to expect before a PSPS · verified August 4, 2026.

A PSPS may last more than 24 hours; there is no fixed length. Power does not come back the moment the wind drops. Before re-energizing, crews must patrol every de-energized line for damage. Restoration inspections typically take up to eight hours, and longer when daylight is required for ground or aerial (helicopter or drone) patrols. That is why a wind event can mean one to three days without power even after the weather calms.

These two events are often confused, but they have completely different causes:

• PSPS — utility-initiated, for fire safety, targeted to specific high-risk circuits during wind events.
• Rotating outages / Flex Alerts — initiated by the grid operator (CAISO) when there is a supply shortage (typically heat waves with not enough generation). They are supply-driven load shedding, not tied to wildfire-threat circuits.

PSPS programs operate under active CPUC oversight:

• 2018: CPUC Resolution ESRB-8 requires a post-event report within 10 days of each de-energization.
• 2019–2021: a three-phase rulemaking set notification, communication, and infrastructure guidelines.
• 2023: the CPUC established a citation program to enforce compliance.
• November 2024: SCE paid $2,339,690 and PG&E paid $1,753,100 in penalties for 2021 PSPS violations.

Source: CPUC — PSPS rules, reporting & enforcement · verified August 4, 2026.

Utilities are investing to make PSPS narrower and rarer:

• Covered conductor (insulated wire) can reduce ignition risk and may allow a utility to apply less restrictive shutoff criteria on some circuits.
• Sectionalizing switches let a utility de-energize a small segment instead of a whole circuit.
• Weather stations and cameras give finer real-time data to avoid over-broad shutoffs.
• Undergrounding is the permanent fix in the highest-risk spans, but it is expensive.

Standard grid-tied solar shuts down during any outage, including a PSPS. This is a required anti-islanding safety behavior — panels must not back-feed a line that crews may be working on. Keeping a home powered requires a correctly permitted and configured islanding system, which may supply selected loads within its power, energy, and operating limits — usually solar plus a battery, although some specialized systems (for example, Enphase IQ8 “Sunlight Backup”) can support limited daytime loads without a battery.

If you or someone in your home relies on electrically powered medical equipment, do not depend on a residential backup estimate. Maintain an emergency plan and follow current utility and emergency-agency guidance. For how to size and prepare a backup system, see our companion guide on solar + battery backup for outages and PSPS.

Figures on this page come from the primary sources below and, where noted, from Cali Energy calculations using the stated assumptions. Rates, incentives, and program terms change; each was verified August 4, 2026.

1. CPUC — Public Safety Power Shutoffs
2. SCE — PSPS FAQ & wildfire safety
3. SCE — Weather and Fire Detection
4. LADWP News — Santa Ana wind prep & PSPS