Cleaning solar panels depends on the type of roof and the inclination of the panels. In general, on sufficiently sloping roofs (above 20 to 25 degrees in Belgium), rain is often sufficient to clean the panels, except in very dusty environments such as near building sites or quarries.
However, if cleaning is necessary, here's how to proceed:
- Cleaning frequency :
- Pitched roofs: Generally, every 3 to 5 years.
- Flat roofs: Also every 3 to 5 years, as water cleans less effectively on less sloping surfaces.
- Cleaning method :
- If you don't want to climb onto the roof, hire a specialist cleaning company.
- Or if you're very good at climbing or feel comfortable doing it yourself, use a microfiber cloth and demineralized water. Avoid chemicals, hard water and tools that could scratch the glass.
- Rub gently with the cloth and demineralized water. The nail can also be used for light scraping.
- Avoid using soap, even neutral soap, as this can leave marks. Choose a soap-free method.
- Beware of thermal shock: Avoid cleaning with hot water in very cold weather, or with cold water in midsummer (solar panels can reach 60°C).
- Ideally, clean the panels at the start of the day when the sun is not yet shining directly on them, to avoid thermal shock.
Solar panel cleaning can be carried out with a few simple precautions, favoring a gentle approach to maintain panel efficiency over time.
