Planning guide
How often should solar panels be cleaned?
Many Southern California homeowners clean once or twice a year, more often in dusty inland areas or near trees, farms, freeways or after wildfires. Your monitoring app and a look at the panels are the best guides.
Signs it may be time
- Visible dust, pollen or droppings on the panels
- Lower output in your monitoring app compared with similar sunny days
- Ash after a wildfire nearby
- Birds nesting under the array
What affects buildup
- Distance from freeways, farms, construction or desert
- Trees and birds nearby
- Panel tilt (flatter panels hold more dirt)
- How much rain falls in a given year
Good to know
Output also depends on season, heat and shading. If production drops sharply, ask your installer to check the system as well.
Typical cleaning frequency by area
| Area | Often |
|---|---|
| Coastal LA and Orange County | About once or twice a year |
| Central LA and San Gabriel Valley | About twice a year |
| Inland Empire | Twice a year to quarterly |
| Antelope Valley and desert edges | Quarterly or more |
These are common patterns, not rules. Your own panels and monitoring app are the best guide.
Using your monitoring app
Most systems come with an app that shows daily production. Compare similar sunny days over a few weeks. A steady drop that isn't explained by season or shade can mean it's time to clean, or time to ask your installer to check the system.
Seasonal timing in Southern California
Many homeowners clean in late spring, after pollen season and before the long summer days when panels produce the most. A second cleaning in fall, after the dry summer and any wildfire smoke, is common too. Inland homes with more dust may add a mid-summer visit. The first winter rains can rinse some dust, but they often leave streaks and don't remove droppings.
Questions
Does rain clean panels?
Rain helps but often leaves residue, and SoCal can go months without it.
Should I clean after a wildfire?
Ash can build up quickly. Many homeowners schedule a cleaning once air quality improves.
Does tilting help panels stay clean?
Steeper panels shed dirt better in rain. Flat arrays hold more debris.
Should I clean before summer?
Many homeowners clean in spring so panels are clear for the longest days.
Ready for clean panels?
Send the details once and hear back from local solar cleaning companies.