The short answer
Cleaning itself does not normally affect a solar panel warranty. Cleaning the wrong way can. Pressure washers, abrasive tools, harsh chemicals and standing on panels can cause damage that a manufacturer may not cover. Read your panel's installation or maintenance manual, follow its cleaning instructions and keep a simple record of each clean.
The short answer
Cleaning does not normally put a solar panel warranty at risk. Damage does, if it comes from something the manufacturer considers misuse. So the question is really how the panels are cleaned, not whether.
We are not able to tell you what your specific warranty says. Warranties differ between manufacturers and models and can change over time. Your warranty document, the panel manual and your installer are the people and papers to check. What we can do is explain the cleaning methods that commonly cause problems, so you can avoid them.
Methods that can cause damage
Pressure washers
High-pressure water can damage the seals around the frame, force water into the junction box on the back and wear away the anti-reflective coating on the glass. Many manuals advise against it. A soft brush and plenty of low-pressure water does the job.
Abrasive tools
Scouring pads, stiff brushes, scrapers and razor blades scratch the glass and the coating. Scratches scatter light and hold dirt, so the panel gets dirty faster afterwards.
Harsh chemicals
Solvents, strong detergents, acids, alkalis and household glass sprays can attack the coating, the frame seals or the backsheet. If the manual allows a mild soap, use very little and rinse well.
Walking or kneeling on panels
Panels are glass over fragile cells. Point loads from feet or knees can crack cells in ways you cannot see but that reduce output and can create hot spots. Frames are not ladders either.
Temperature shock
Spraying cold water onto glass that has been baking in the Maltese sun is best avoided. Clean early in the morning or late in the afternoon.
What a safe clean looks like
- Purified or deionised water, so the glass dries without hard-water spots.
- A soft brush, often water-fed, on a pole, used from the roof surface.
- No pressure, no abrasives and no harsh chemicals.
- Cool glass, at the start or end of the day.
- A quick check for cracks, loose cabling or damaged frames before starting, with anything found reported to the owner.
That is how professional cleaners work. If you clean yourself, the same rules apply. See can you clean solar panels yourself.
How to find your panels’ cleaning instructions
- Look at the label on the back of a panel, or in your installation paperwork, for the manufacturer and model number.
- Find the installation or maintenance manual for that model. Installers often hand it over with the system documents, and manufacturers usually publish it online.
- Look for the cleaning section. It usually covers water type, pressure, brushes, chemicals and frequency.
- Ask your installer if anything is unclear. They know the products they fitted.
Keep a simple cleaning record
A short log is useful whatever your warranty says. For each clean, note:
- the date,
- who cleaned (you or a company),
- the method (for example, soft brush and purified water),
- anything noticed: a crack, a nest, loose cables, a corner that never dries,
- before and after photos if you can.
It helps you spot patterns, gives your installer useful information if something goes wrong and shows the panels have been looked after.
Why cleaning still matters in Malta
Skipping cleaning to “protect” the warranty does not make sense here. Months without summer rain, Saharan dust, sea salt and pigeons all leave a film that rain does not shift. Baked-on bird droppings can shade part of a panel for months. See does cleaning solar panels increase output and how often to clean solar panels in Malta.
Booking
We arrange solar panel cleaning across Malta and Gozo with purified water and soft brushes, and point out any visible damage before we start. Get a quote.