Solar Panel Cleaning Cost: $150 to $500 (HomeGuide 2026)

This is the detailed cleaning page. For the full yearly checklist (inverter, wiring, roof mounts, monitoring), see solar panel maintenance. If birds are nesting under the panels rather than just landing on them, that is a critter guard job, not a cleaning job.

How much does solar panel cleaning cost

Published US prices. HomeGuide's guide is bylined July 2024 and titled 2026. HomeGuide says most residential systems take 1 to 3 hours.

Panel count sets most of the price, which is why HomeGuide quotes $10 to $20 per panel. The rest comes from access. A two-story house, a steep pitch or a tile roof means more setup and more time on the roof, and the $100+ minimum most companies charge means a small array costs about the same as a medium one. Asking for cleaning and an inspection on the same visit is the cheapest way to get both: HomeAdvisor puts the combination at $390 to $720 a year, against $150 to $350 for an inspection alone. Aurora Solar says a two-visit annual contract often cuts the per-visit price 15% to 20%.

Is solar panel cleaning worth it

Often not, on tilted panels in a place that gets regular rain. The best-known study comes from UC San Diego engineers Jan Kleissl and Felipe Mejia, who tracked 186 solar sites across California. Panels that went 145 days with no washing and no rain lost 7.4% of their efficiency, a little less than 0.05% per day. Washing a typical 5 kW home system midway through summer would have added only about $20 of electricity before the rains came back. Against a $150 to $500 cleaning, that does not pay.

Other measurements land in the same range. On NREL's soiling map, which covers 255 US soiling stations and solar sites, a soiling ratio of 0.95 means a 5% annual energy loss to dirt; the real figure depends on local climate. The question is whether your panels lose more than that, and whether the lost power is worth more than the visit.

When cleaning pays: dust, pollen, bird droppings and flat panels

• Dry, dusty climates. HomeAdvisor says drier areas may need cleaning more often than once a year, and Aurora Solar suggests annual or semiannual cleaning in the Southwest, which covers Phoenix and Las Vegas. Aurora also cites NREL that California's Central Valley is a place where cleaning more than once a year may pay.
• Heavy tree pollen. A study by NREL, Duke and others of five North Carolina solar plants found pollen cut efficiency by as much as 15% in peak season, and uncleaned panels lost about 10% of annual production even with rain. Wet-brush cleaning after rain raised output 5% to 11%. Cypress, juniper, pine and oak pollen were the worst. Those were large utility plants tilted at 20 degrees, not homes, but the finding that rain alone does not clear pollen applies to any panel.
• Bird droppings. Aurora Solar notes that droppings block individual cells, can create hot spots with outsized losses, and once dried do not wash off in the rain. Clean them when you see them.
• Flat or low-tilt panels. Rain runs off a tilted panel and carries dust with it. On a flat roof it pools and dries. Bob Vila lists flat roofs, dry regions and nearby construction as reasons to clean more than once or twice a year. The flat roof solar page covers the racking side.
• Wooded lots and after storms. HomeGuide recommends inspecting and cleaning 1 to 2 times a year, more in wooded, extreme-weather or high-pollution areas and after major storms.

How often to clean solar panels

Published guidance. Production data is the better trigger.

Birds nesting under solar panels

If droppings keep coming back because pigeons live under the array, cleaning is a short-term fix. Nesting birds bring debris and can damage wiring, and a mesh guard around the array edge is the repair; the critter guard page linked above has prices and what the law says about removing nests.

Solar panel washing: what manufacturers allow

Panel makers publish cleaning rules, and breaking them can void the warranty. REC and Canadian Solar, the two manuals we checked, agree on the basics:

• No pressure washer. REC: "The use of high pressure hoses for cleaning is not permitted," and pressure or steam cleaners "will invalidate the warranty." A garden hose at household pressure is fine. Canadian Solar caps water pressure at 4 MPa (40 bar).
• Clean water, low in minerals. REC prefers de-ionized water, with rainwater or tap water as a fallback. Canadian Solar asks for low-mineral water with a pH close to neutral (6 to 8). Hard water leaves spots.
• Soft tools only. A soft sponge, microfiber or soft non-abrasive brush. Canadian Solar adds that brushes must be non-conductive. No knives, blades or metal sponges. An industry source in pv magazine warns stiff brushes can permanently damage anti-reflective coatings.
• Cool panels. Clean early in the morning, before the panels reach working temperature (REC), and avoid the hottest hours of the day (Canadian Solar). Cold water on hot glass risks thermal shock.
• No harsh chemicals. A mild biodegradable soap is acceptable to REC; acid or alkali detergents are not. Canadian Solar rules out hydrofluoric acid, alkali, acetone, abrasive cleaners and degreasers.
• Never scrape dry. Canadian Solar says dry scraping causes micro-scratches and that "Damages induced by inappropriate cleaning procedures will void Canadian Solar warranty."

Ask any cleaning company what water and tools it uses before it books. If the answer is a pressure washer, find another company. The solar panel warranty page covers what else the manufacturer warranty requires.

Should you clean solar panels yourself

From the ground, yes, if the panels can be reached with a hose and a soft brush on an extension pole. Do not climb onto the roof or work from a ladder to do it. The CDC says more than 500,000 people a year in the US are treated for ladder-related injuries and about 300 die. A wet panel is slick glass.

Never walk on the panels or spray the wiring underneath. If you see cracked glass, scorch marks or loose wiring, stop and call for solar panel repair instead.

Solar panel cleaning robots

Cleaning robots are uncommon on US homes, and we found no US data on how many households use one. The residential rooftop robots we found were products sold in India and a university student project. For a home array, a cleaning company or a hose from the ground is what is available today.

Solar panel cleaning service near me: what to ask before you book

1. Per panel or flat rate, and what is the minimum? Have your panel count ready. HomeGuide says most companies charge a $100+ minimum.
2. What water and tools? You want de-ionized or filtered water, soft brushes and household pressure, per the REC and Canadian Solar rules above.
3. How do your crews stay safe on the roof? Ask about fall protection, especially on a two-story house or a steep or tile roof (see solar on tile roofs).
4. Will you note anything you see? Ask the crew to photograph any cracked glass, nests or loose wiring, and ask whether an inspection can be added to the same visit.

Calls go to an independent company that serves your area and takes cleaning jobs. How calls work.