Smoke and Wildfire Impact on Solar Panels in San Diego
Wildfire ash and smoke create heavy, persistent soiling. Here's what to do after the fire.
Wildfire ash is heavier and stickier than ordinary dust. After a major fire event in or near San Diego County, professional cleaning is essential to recover production.
What ash does to panel output
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.
Why DIY cleaning of ash is a bad idea
Ash + tap water = an alkaline slurry that smears across the panel and bakes in. Pressure washing rubs ash particles across the AR coating like sandpaper. Pure-water cleaning with soft-brush agitation is the only safe method for ash removal.
When to schedule post-fire cleaning
Schedule the cleaning within two weeks of the ash event, ideally after the air-quality advisories lift but before the first rain. Cleaning before the rain prevents the alkaline ash from chemically bonding to the glass during the first wet cycle.