Solar Guide

How often should solar panels be cleaned?

Short answer: once or twice a year for most California homes — more often if you're near orchards, dairies, or dirt roads.

The honest answer (from a local cleaner)

Most solar manufacturers say cleaning isn't required. That's true in places with regular hard rain. It's not true here. In California's Central Valley we go six months without real rain, and "dust" includes pollen, ag spray, almond bloom, dairy particulate, wildfire smoke, and bird droppings. All of it bonds to glass.

Real-world output loss on a dirty Central Valley system is typically 15–30%. On a 20-panel residential system that's a meaningful chunk of your electric bill every month.

Recommended schedule by location

• Urban Visalia / Fresno / Clovis: twice a year (spring + fall).
• Near orchards or farms (Tulare, Exeter, Lindsay): 3–4 times a year.
• Near dairies or unpaved roads: quarterly.
• Commercial rooftop systems: quarterly with annual deep clean.

5 signs your panels are overdue

1. Your monitoring app shows production trending down for no obvious reason.
2. You can see streaks, white spots, or bird droppings from the ground.
3. It's been over 12 months since the last clean.
4. You live within a mile of an active orchard or dairy.
5. There's visible bird nesting under the array.

How much does it cost?

Most pros charge $4–$10 per panel. We're flat $5 per panel anywhere in the Central Valley, with no travel fee, no fuel surcharge, and a free photo report when we're done.

DIY vs. hiring a pro

You can clean panels yourself with a soft brush and a hose. Two real downsides: (1) tap water in the Valley is hard, so it dries with mineral spots that reduce output, and (2) rooftop falls are the leading cause of DIY home injuries. Pros use deionized water (zero residue) and proper fall protection.