What Is a Public Safety Power Shutoff?#
A Public Safety Power Shutoff (PSPS) is a deliberate de-energization of electrical transmission and distribution lines by California utilities — primarily PG&E, SCE, and SDG&E — during periods of extreme fire weather. When wind speeds, low humidity, and dry vegetation combine to create conditions where a sparking power line could ignite a catastrophic wildfire, utilities cut power preemptively across the affected areas.
PSPS events are not rolling blackouts driven by grid demand. They are intentional outages that can last 24 to 96 hours or longer, affecting thousands of customers across entire counties. Unlike infrastructure failures, you receive advance notice — typically 24 to 48 hours — but the shutoff proceeds regardless of your operational needs.
How Often Do PSPS Events Happen?#
PSPS has been a reality in California since PG&E began proactive shutoffs in 2018. Since then:
- 2019 was the most severe year: PG&E shut off power to over 730,000 customers across 36 counties in October alone
- 2020–2021 saw improvements in utility targeting, but events still affected hundreds of thousands of customers
- 2022–2025 have maintained a pattern of 3–8 significant PSPS events per year in Northern California, concentrated between September and November
The areas most affected are the same each cycle: the Sierra Nevada foothills, North Bay wine country (Napa, Sonoma, Lake counties), the East Bay hills, and the inland valleys of Southern California. If your facility sits in or near a Tier 2 or Tier 3 High Fire Threat District (HFTD), PSPS is not a theoretical risk — it is a recurring operational challenge.
Who Is Most Affected — and What Does It Cost?#
Restaurants and Hospitality#
A 72-hour PSPS during a weekend in wine country can represent a complete loss of revenue for a restaurant — plus spoilage of refrigerated and frozen inventory. Industry estimates put food spoilage losses at $3,000–$8,000 for a typical sit-down restaurant per extended outage. For a boutique hotel, a single cancelled weekend can cost $15,000–$40,000 in direct revenue.
Beyond direct losses: guests who experience a power outage at your property do not return. The reputational damage of a dark hotel lobby, cold guest rooms, and no internet during a premium stay can outlast the outage itself.
Small Businesses and Professional Services#
Medical offices, pharmacies, law firms, accountants, and small retailers face a simpler calculus: no power means no operations. For a dental practice, a canceled day is $5,000–$12,000 in lost production. For a pharmacy, maintaining refrigerated medication temperature is a regulatory requirement, not just a convenience.
Luxury Residential#
High-net-worth homeowners in the Oakland Hills, Marin County, or the Napa Valley wine country face PSPS events that disable security systems, gate access, pool equipment, and the HVAC systems required to protect wine collections and art. Whole-home generator systems have become a standard feature in premium real estate in California's high-fire-risk zones.
Generator Protection: What You Need#
Sizing for Your Facility#
The first step is determining what you need to power. Three common approaches:
| Coverage Level | What It Powers | Typical Size |
|---|---|---|
| Critical loads only | Refrigeration, lighting, POS systems | 20–45 kW |
| Essential operations | Above + HVAC, kitchen equipment | 60–100 kW |
| Full facility | Everything | 125–500 kW+ |
For a small restaurant or retail space, a 30–45 kW natural gas or propane generator is often sufficient to maintain refrigeration, minimal lighting, and point-of-sale systems. For a hotel or resort, full-facility backup typically requires 150 kW or more, with transfer switch capacity matched to the building's main service.
Automatic Transfer Switch#
A generator without an automatic transfer switch (ATS) requires manual intervention to start and connect the load — which means someone must be on-site and awake when the outage begins. For facilities with remote management or that operate during hours when staff may not be present, an ATS is not optional. The ATS detects utility loss within seconds and transfers your facility to generator power automatically, typically in 10–30 seconds.
Fuel Considerations for PSPS Events#
Natural Gas vs. Diesel for PSPS#
Natural gas generators have a significant advantage during PSPS events: they draw from the utility gas distribution system, which remains pressurized and operational during power outages. You will not run out of fuel after 72 hours the way a diesel system with a fixed tank will. For facilities in urban and suburban areas with natural gas service, this makes gas standby generators particularly well-suited for PSPS protection.
Diesel generators offer greater independence — fuel is stored on-site and is not dependent on any utility infrastructure. However, diesel tanks have finite capacity. A 500-gallon tank running a 60 kW generator at 50% load will last approximately 48–72 hours before requiring a fuel delivery. In widespread PSPS events, fuel delivery schedules can be disrupted by increased demand.
For propane: aboveground propane tanks in the 250–1,000 gallon range are common in rural areas without natural gas service. Runtime is similar to diesel — calculate your consumption rate and ensure your tank is at least 80% full entering fire season.
Fuel Polishing and Tank Maintenance#
If your backup generator is diesel-fueled and sees infrequent use, fuel quality is a critical variable. Diesel stored more than 12 months degrades: water accumulates through condensation, microbial contamination grows at the fuel-water interface, and oxidation produces sludge that clogs injectors at the worst possible moment.
Annual fuel polishing — filtering and treating stored diesel — is a best practice for any diesel standby system that may sit unused between test cycles. For facilities in PSPS-prone areas, schedule fuel polishing and treatment each August, before fire season peaks.
Testing Schedule During Fire Season#
A generator that has not been exercised recently is a generator you cannot trust. The standard monthly test under load required by NFPA 110 should be performed year-round — but fire season (July through November in Northern California) warrants additional attention:
- August: Run a full load bank test to confirm the system can carry 100% rated load. Verify all transfer switch timing. Check fuel levels and top off.
- September 1: Inspect coolant concentration (summer heat stresses cooling systems), verify battery condition, check all connections.
- Monthly through November: Verify the automatic exerciser is running as scheduled; review the control panel for any new fault codes.
- After each PSPS event: Log the run hours, check oil and coolant levels, and note any anomalies in the maintenance record.
How to Prepare Now#
- Assess your risk zone — check your address against the CPUC High Fire Threat District map
- Calculate your critical load — work with an electrical contractor or generator dealer to size correctly
- Consider natural gas if you have the service — eliminates the runtime-limiting fuel problem during multi-day PSPS events
- Install an automatic transfer switch — manual connection is not a reliable PSPS strategy
- Schedule your annual service before July — avoid the August backlog when everyone else is thinking about this
- Establish a fuel supply contract if you are diesel-fueled, with PSPS event priority delivery clauses
Ready to protect your business or property from California's fire season power shutoffs? Contact our team to discuss the right backup power solution for your facility, or request a quote for a complete assessment.