Solar panel cleaning
Solar panels covered in pollution, bird droppings or moss produce less when the sun shines. Toiture Wash cleans them, on their own or at the same time as the roof: €20 per panel excl. VAT.
Updated on 20 October 2026
Do you need to clean your solar panels?
Not necessarily every year. Rain rinses off part of the dust, especially on a well-pitched roof. Rain is not enough when the dirt sticks:
- bird droppings, especially from pigeons, which leave opaque stains;
- pollution near a road or an industrial area, which leaves a grey or black film;
- nearby trees, which deposit pollen, sap and leaves;
- moss and lichen that spread to the frames and the bottom of the panels when the roof itself turns green.
A good habit: compare the output of your panels from one spring to the next, in similar sunshine, and look at the panels from the ground or in a photo.
How much does a dirty panel lose? Less than you might think, generally. A European study published in 2025 puts the average annual loss due to soiling at 0.9% in Europe when the rain cleans well, and up to 5.3% when it removes only a small part of the deposits; in the Benelux, frequent rain makes these losses fairly regular over the year. Test-Achats notes that a good ten-minute shower already cleans the panels, that output can drop by up to 25% in extreme cases, and that professional cleaning is mostly justified for bird droppings or lichen. So decide on cleaning based on what you see and on your output, not as a matter of principle.
The manufacturers' instructions
Panel manufacturers give cleaning instructions, and the warranty sometimes depends on following them. The European manual from JinkoSolar, for example, asks for a soft cloth, low-mineral water, no abrasives, cleaning early in the morning or late in the afternoon, and no chemical products, which could affect the manufacturer's warranty and the output.
Panels and roof, a single job
A roof that turns green dirties the panels it carries, and moss removal throws water and debris onto the panels. The two are therefore done together, and the panels do not lengthen the job: 100 to 150 m² of roof takes about one day, with or without panels. In Chièvres, in June 2024, the solar panels were cleaned during the same job as the roof and the roof treatment. See the job
How often?
It depends on the environment: more often near trees, a very busy road, a farm or a dovecote; less often on a steeply pitched roof in a windy spot. The JinkoSolar manual mentioned above advises cleaning once a year if possible, more often in dusty surroundings: check what the manual for your own panels says.
Solar panel cleaning prices
| Service | Unit | Price excl. VAT |
|---|---|---|
| Solar panel cleaning | per panel | €20 |
| Roof moss removal and cleaning, treatment and gutters included | per m² of roof | €10 |
The price is charged per panel, and it is fixed: €20 per panel excl. VAT. For work under €1,000 excl. VAT, travel and set-up costs are added, and your quote itemises them; from €1,000 excl. VAT, they are not charged. Your quote states the VAT rate, a single one for all the work.
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Businesses
If you are a VAT-registered business, the reverse charge may apply (you account for the VAT yourself): mention it in your request.
Frequently asked questions
Who can clean photovoltaic panels?
You can, from the ground with a pole and clean water, if the panels are reachable without climbing. As soon as you have to go up on the roof, it is work at height: call a professional.
Which product should I use to clean solar panels?
Rainwater or demineralised water, which Test-Achats prefers to tap water, which can leave limescale, and a soft brush or cloth. No chemical or abrasive product: the JinkoSolar manual rules them out. Check the manual for the brand installed at your home.
Can solar panels be cleaned with a high-pressure washer?
No. Test-Achats warns that a high-pressure washer can damage the panels. Each manufacturer sets its pressure and equipment limits in its manual.
How long does cleaning take?
With a moss removal, the panels make no difference to the duration: allow about one day for 100 to 150 m² of roof, sometimes two beyond that.