In the Pacific Northwest, we’re fortunate that regular rainfall naturally rinses away most dust, pollen, and debris from solar panels. For many homeowners, routine cleaning is rarely needed. But in some cases — especially during dry stretches or heavy pollen seasons — cleaning your panels can help ensure they’re performing at their best.
When Should You Clean Solar Panels?
If you notice:
- A visible buildup of dirt, pollen, or bird droppings
- A drop in your system’s energy production (especially during sunny weather)
…it may be time for a light cleaning.
How to Clean Solar Panels Safely
In most cases, plain water and a soft, non-abrasive brush are all you need. A telescoping brush with a flow-through handle (the kind used for washing RVs or windows) can make the job much easier — especially from the ground or with minimal ladder use.
If you’re dealing with stubborn film — like sticky pollen or air pollution residue — you can use a gentle cleaner that is:
- Non-abrasive
- pH-neutral
- Biodegradable
One safe option is Earth Friendly Window Kleener. There are other suitable products as well — just avoid anything with harsh chemicals, waxes, or coatings. Do not use Rain-X or similar treatments, as these can damage the panel’s surface and void warranties.
Additional Cleaning Tips
- Clear large debris (like leaves or branches) as it accumulates.
- For caked-on grime, start by gently scraping with a nylon pan scraper — never use metal tools.
- Clean while the panels are cool: early morning, late evening, overcast days, or even at night. Cleaning hot panels can cause water to evaporate too quickly, leaving streaks — and rapid cooling of aluminum frames can stress the modules.
- Snow removal isn’t usually necessary, but if you want to clear it, use a soft brush. Never try to chip off ice or scrape frozen snow — the risk of damaging your panels isn’t worth it.
How Often Should I Clean?
The frequency of cleaning varies widely depending on your site. Nearby trees, pollen-producing plants in your neighborhood, and local weather patterns can all impact how quickly your panels get dirty.
The best practice is to inspect your panels whenever someone accesses your roof — such as when treating moss, cleaning gutters, or performing roof maintenance. This way, you can assess the level of soiling and decide if cleaning is necessary.
Additionally, regular system monitoring can identify a significant drop in solar production, and hint that it’s time to clean – especially if the system never approaches peak output (in kW) on sunny days.
Safety First
If your panels are on a pitched roof and can’t be reached safely from the ground, we strongly recommend:
- Hiring a professional for cleaning
- Or using proper fall protection if you decide to do it yourself
Climbing on roofs is dangerous — your safety is more valuable than a minor production gain.
If you’re ever unsure whether your panels need cleaning — or you want a referral to a panel cleaner — reach out to Ecotech Solar Service. We’re happy to help you get the most out of your solar investment.