Solar & Battery for California Wildfire & High-Fire-Risk Zones

California wildfire zones see regular Public Safety Power Shutoffs, or PSPS events, where utilities cut power to reduce fire ignition risk. PG&E alone has shut off power to over 2 million customers during high-wind, dry-weather periods since 2019. Outages last 2 to 7 days and occur with little warning.

Solar and battery backup systems provide resilience during PSPS events and year-round energy independence. But installing solar in high-fire-risk zones requires attention to fire safety codes, defensible space, and system design. Here is what California homeowners in wildfire zones need to know.

What Are PSPS Events and Who Is Affected?

PSPS, or Public Safety Power Shutoffs, are preemptive blackouts implemented by California utilities during extreme fire weather. When wind speeds exceed 25 to 30 mph, humidity drops below 20 percent, and vegetation is dry, utilities shut off power to reduce the risk of downed lines sparking wildfires.

PG&E, SCE, and SDG&E have all implemented PSPS programs. PG&E territory is most affected, covering Northern California foothills, Sierra Nevada, and rural areas from Redding to Fresno. SCE affects Southern California mountain and foothill communities. SDG&E covers San Diego backcountry and inland areas.

PSPS events are announced 24 to 48 hours in advance when possible. Utilities notify customers via email, text, and phone. Outages last 2 to 7 days on average, though some have stretched longer. Power is restored only after winds subside and utilities inspect lines for damage.

How Solar and Battery Systems Work During PSPS

Standard grid-tie solar systems shut down during blackouts, even if the sun is shining. This is a safety requirement -- solar systems must disconnect to prevent backfeeding power into dead lines, which would endanger utility workers. Without a battery, your grid-tie solar is useless during PSPS.

Solar-plus-battery systems with islanding capability keep running during outages. When the grid goes down, the system disconnects from the utility and switches to island mode. Solar panels charge the battery during the day. The battery powers your home at night. As long as the sun rises, you stay online.

Off-grid solar systems are immune to PSPS because they never connect to the grid. You generate, store, and use power on-site. The utility can shut off the grid for a month and you keep running. This is the ultimate PSPS resilience solution.

Sizing Solar and Battery for Multi-Day Outages

PSPS events last 2 to 7 days on average. Your system must produce enough solar during the day to run daytime loads and recharge the battery for nighttime use. Battery capacity must cover one night of usage plus margin for cloudy weather or increased heating/cooling loads.

A typical Northern California home uses 20 to 30 kWh per day. VoltSol focuses on the highest-value loads first: HVAC, refrigeration, lights, and electronics. A well-designed system with 4 to 6 kW of solar and 15 to 20 kWh of battery covers these essentials indefinitely during PSPS.

If you want whole-home backup including heavy appliances like electric stoves, dryers, and water heaters, the system grows significantly -- 8 to 12 kW of solar and 30 to 50 kWh of battery. This pushes costs well above $20,000. Most customers choose partial backup and keep heavy loads on propane or natural gas.

Fire Safety Requirements for Solar in High-Fire Zones

California Fire Code Title 24 requires rooftop solar to maintain fire department access pathways and setbacks. Panels must be set back 3 feet from the ridge, 18 inches from hips and valleys, and leave 4-foot-wide pathways for firefighters to access the roof. These rules apply statewide but are enforced more strictly in high-fire-risk areas.

Fire-rated roofing materials are required in Very High Fire Hazard Severity Zones. Class A fire-rated roofs resist ignition from flying embers. Most modern composition shingles, tile, and metal roofs meet Class A ratings. Wood shake roofs do not and must be replaced before solar installation in high-fire zones.

Rapid shutdown requirements mandate that rooftop solar systems shut down to safe voltage levels within 30 seconds of firefighter activation. This protects first responders from electric shock during roof ventilation or suppression. All solar systems installed after 2019 meet rapid shutdown requirements via module-level power electronics or optimizers.

Ground-mount solar systems avoid most rooftop fire safety issues. Panels sit on racking 10 to 50 feet from the house, outside the defensible space zone. This eliminates roof access concerns and reduces ember ignition risk. Ground-mount is ideal for high-fire zones if you have the land.

Defensible Space and Vegetation Management

California law requires 100 feet of defensible space around homes in high-fire zones. The first 30 feet must be ember-resistant -- no dead vegetation, wood piles, or flammable materials. Ground-mount solar must be placed outside this zone or designed with fire-resistant landscaping.

Rooftop solar is generally compatible with defensible space requirements because it does not add fuel load. Panels themselves are non-combustible -- glass, aluminum, and silicon. The concern is ember accumulation in gaps between panels and the roof. Keep gutters and roof valleys clear of leaves and debris year-round.

Battery enclosures must be non-combustible and located outside the 30-foot ember-resistant zone or inside a fire-rated structure. Most EG4 battery enclosures are metal or NEMA-rated plastic designed for outdoor installation. Place them on a concrete pad or gravel base, not directly on wood decking or dry vegetation.

Grid-Tie vs Off-Grid in Fire Zones

Grid-tie solar with battery backup is the most common choice in fire-prone areas with existing utility service. You stay connected to the grid for normal operation, export excess solar under NEM 3.0, and switch to battery backup during PSPS. This gives you resilience without fully disconnecting.

Off-grid solar makes sense for remote homes where grid extension is expensive or unreliable. If your property is in a high-fire zone and experiences frequent PSPS events, going off-grid eliminates dependency on the utility entirely. You are self-sufficient 365 days per year.

Hybrid systems -- off-grid for essentials with optional grid connection for heavy loads -- are popular in fire zones. Run HVAC, refrigerator, and lights on solar and battery. Keep the grid connection for electric stoves, dryers, and well pumps. During PSPS, you lose the heavy loads but maintain comfort and food storage.

Permitting and Insurance in High-Fire Zones

Solar permits in high-fire zones require additional fire department review. Expect longer permitting timelines -- 3 to 6 weeks instead of 1 to 3 weeks. Fire marshals check setbacks, access pathways, rapid shutdown compliance, and vegetation clearance. VoltSol submits fire-compliant plans upfront to avoid delays.

Homeowners insurance in high-fire zones is expensive and increasingly hard to get. Adding solar does not typically increase premiums, but insurers may require documentation that the system meets fire codes. Provide your insurer with installation records, inspection reports, and rapid shutdown certifications.

Some insurance companies offer discounts for homes with defensible space and fire-resistant upgrades. Solar is not usually a discount trigger, but battery backup systems that keep sump pumps and fire suppression equipment running during outages may qualify. Ask your agent.

Real-World PSPS Resilience Example

A VoltSol customer in the Grass Valley area has a 6 kW solar array, 20 kWh EG4 battery, and an 18,000 BTU mini-split heat pump. The system covers heating, cooling, refrigerator, lights, internet, and charging devices. Total daily usage is 12 to 18 kWh depending on season.

During October 2025 PSPS events that lasted 4 days, the system ran without interruption. Solar production averaged 20 to 25 kWh per day during clear fall weather. The battery charged fully by 2 PM each day and powered the home through the night. The customer reduced discretionary usage -- no laundry, minimal cooking -- but maintained full comfort and connectivity.

Neighbors without solar ran generators 8 to 10 hours per day, burned 2 to 3 gallons of gasoline per day, and dealt with noise and fumes. The solar customer paid nothing, heard nothing, and smelled nothing. This is the value of solar and battery resilience in wildfire country.