Do Solar Panels Work During a Power Outage in California?

Counterintuitive but important: a grid-tied solar system without a battery will NOT power your home during an outage. It shuts off automatically for safety — to prevent backfeeding energized electricity onto the grid while utility crews are working on downed lines. If you want your solar to keep running during California outages (including PSPS events), you need a battery. Here's exactly why, and what it takes.

Why Grid-Tied Solar Shuts Off During Outages

This is called "anti-islanding" protection and it's required by UL 1741 and IEEE 1547 safety standards. During a grid outage, utility line workers may be restoring service. If a solar home's panels kept producing and pushed electricity onto the "dead" grid, it could electrocute a line worker or damage equipment. So every grid-tied solar inverter senses when the grid is down and immediately stops exporting — and by extension, stops producing at all.

This is true whether it's a planned PSPS (Public Safety Power Shutoff) for fire mitigation, a storm-caused outage, or an equipment failure. The moment the grid goes down, your grid-tied solar-only system goes dark.

How a Battery Changes This

A solar + battery system with islanding capability (Tesla Powerwall 3, Enphase IQ Battery, FranklinWH aPower, Generac PWRcell, and others) disconnects from the grid during an outage but keeps your solar panels and battery operating as a self-contained microgrid within your home. Your house stays powered; the grid stays safely de-energized.

Most modern battery systems support this automatically — no manual switching. When the grid goes down, the battery's inverter opens a physical relay between your home and the grid, then continues running your home from solar + stored battery capacity. When the grid returns, the relay closes again and normal grid-tied operation resumes.

PSPS and California

Public Safety Power Shutoffs — planned outages during high-fire-risk weather — are unique to California and a major reason to include battery storage with solar. PSPS events can last 24-72 hours or longer, typically in Tier 2 and Tier 3 High Fire Threat District (HFTD) zones across PG&E, SCE, and SDG&E territory.

A properly sized solar + battery system rides through a typical PSPS without noticeable impact to daily life. Sun charges the battery during the day; battery carries you through the night; sun recharges it the next day. For homeowners in high-fire-risk areas, this alone often justifies the battery cost — losing a freezer full of food during a 3-day PSPS is worse than just an inconvenience.

How Long Will a Battery Last in an Outage?

Depends on battery capacity and your home's load. A full 13.5 kWh battery (like Powerwall 3) typically runs a California household's critical loads (refrigerator, lights, internet, one AC or heat pump zone, phone charging) for 12-24 hours without solar recharging. If the sun is up and charging the battery, it can run indefinitely on normal California load.

Large loads burn through battery fast. An EV charging on the battery can drain it in a few hours. A pool pump running full-time will empty a single battery overnight. During outages, most homeowners switch to load-managed mode — powering essentials only — or have their battery system configured for critical loads only.

SGIP Resiliency Rebate

California's Self-Generation Incentive Program (SGIP) offers enhanced rebates for battery storage when installed by customers in high-fire-risk zones, Medical Baseline customers, or other qualifying resiliency-priority groups. The rebate for Equity Resiliency customers can exceed $1,000 per kWh — potentially offsetting most of the battery cost. Your installer should check SGIP eligibility before quoting.

Frequently Asked Questions

Can I use my solar during a PG&E outage?

Only if you have a battery. Solar-only systems shut off during grid outages for safety. Solar + battery continues running your home as a self-contained microgrid until the grid returns.

Why does my solar shut off when the grid is out?

Anti-islanding safety — UL 1741 and IEEE 1547 standards require grid-tied solar to stop producing during outages, so utility line workers aren't exposed to energized lines they think are dead.

How much battery do I need for a 3-day outage?

With sun during the day, one 13.5 kWh battery covers typical daily loads indefinitely by recharging daily. For multi-day cloudy outages (rare in CA), two batteries buffer through. Consult with your installer on your specific load profile.

Does a generator work as a backup to solar?

Yes. Some California homeowners combine solar + battery + a whole-home gas generator for extended multi-day outage coverage. Typically the battery handles day-to-day; the generator only kicks in if the battery and solar can't keep up over days of bad weather.