Pollen Season and Solar Panel Cleaning in Southern California
Spring pollen creates a yellow film on solar panels that hits production hard. Here's what to do.
Spring pollen in San Diego County is a notable production killer. A late-spring cleaning is one of the highest-ROI services we offer — recovering 8–12% of summer production in a single visit.
Why pollen sticks to hot glass
Pollen grains are sticky by design — they're built to attach to bees and pistils. On a 110–130°F panel surface, that stickiness combines with surface tension and bonds into a uniform yellow-brown film. Rain alone won't lift it; it needs agitation plus pure water.
How much production pollen costs
Independent soiling research and our own before/after monitoring across San Diego County put peak-season pollen losses at 6–12% on most residential systems. On a 7kW system that's $20–$45 every month from April through July — a full season of lost offset.
When to schedule the post-pollen cleaning
Late May is the sweet spot. Pollen counts have dropped, summer high-production days are about to start, and you capture the full benefit of the cleaning. If you only do one cleaning a year in San Diego, do it in late May.