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.
Cleaning isn't guaranteed to pay for itself. Estimate its value using measured additional generation, your actual electricity or export rate, and the service cost. Seasonal changes, weather, shading, and equipment faults can also affect output.
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
Dirt and debris can block sunlight, but the effect varies with the amount of buildup, panel tilt, rainfall, shading, and equipment condition. We don't have a verified typical loss figure for San Diego homes. Compare monitoring data under similar weather conditions before and after cleaning rather than expecting a fixed percentage gain.
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.