Sahara Sand and Efficiency of Solar Panels in Switzerland: Should We Clean?

For owners of photovoltaic installations, this phenomenon is not just a visual nuisance on car bodies. A thin film of ocher sand on your modules can cause loss of yield significant. The question then inevitably arises: is Swiss rain enough to wash your panels, or has professional cleaning become essential?

In this article, we analyze the real impact of natural elements on your energy production and decipher the dilemma that every homeowner faces: should you clean your panels yourself or call a professional?

The Impact of Swiss Natural Phenomena on Yield Loss

The Sand of the Sahara (Sirocco)

Every year, millions of tons of Saharan dust travel to the Swiss Alps. When they are deposited on solar panels, they block the capture of UV rays. If heavy rain follows, the problem is quickly solved. However, light rain turns this dust into a stubborn layer of mud that sticks to the glass. This opacity can cause a drop in production ranging from 5 % to 15 % depending on the intensity of the deposit.

Spring Pollen

In spring, the intense flowering in our valleys and forests releases sticky pollen. Combined with morning dew or Sahara sand, pollen creates a greasy film. Particularly wooded or agricultural cantons (such as Vaud, Bern or Aargau) are often the most affected.

Snow in Winter

Although snow reflects light and can increase efficiency (albedo effect) when it is around the panel, a thick layer accumulated on the panel completely stops production. Fortunately, thanks to the slope of the majority of Swiss roofs, snow tends to slide off on its own, often taking dirt with it.

When Should You Consider Cleaning Your Panels?

The most common mistake is to clean your panels systematically, without checking whether it is financially justified. Here are the key indicators to take action:

• Visual inspection: A yellowish or brownish film is clearly visible from the ground. The bottom corners of the panels (the frame) generally accumulate the most dirt.
• Analysis of production data: Consult theapplication of your inverter (Huawei, Enphase, etc.). If you notice an unexplained drop in daily production compared to an equivalent sunny day the previous year, dirt is probably to blame.
• The type of installation: Panels with a slight inclination (less than 15 degrees) or installed on flat roofs, which self-clean poorly with rain, require increased attention.

Cleaning: Do It Yourself or Call a Professional?

Faced with panels covered in Sahara sand, two options are available to you. Here is a direct comparison to help you decide.

The DIY Option (Do It Yourself)

Cleaning your solar panels yourself is possible, but it requires strict precautions to avoid damaging the equipment or injuring yourself.

• Golden rule: Do not use never tap water. The water in Switzerland (especially in the French-speaking and Jura cantons) is often very limestone. Limescale leaves permanent white marks which reduce the power of the panel. It is imperative to usedemineralized water or osmosis.
• Materials required: A soft telescopic brush, a specific squeegee, and a pure water pumping system.
• The risk: Roof falls are common. If your panels are difficult to access, the risk to your safety far outweighs the savings.

The Professional Option

Calling on a specialized Swiss company guarantees optimal and secure cleaning.

• Advantages: Professional equipment (20 m carbon poles, cleaning robots, 100% pure osmosis water), guaranteed safety, and insurance in the event of damage to photovoltaic cells.
• Bonuses: The professional often carries out a visual inspection of the installation (cables, fixings, micro-cracks).

Comparison Table: DIY vs Professional

Business Case: Is Cleaning Worth the Cost?

To determine if the cost of a professional is justified, you must calculate the value of the energy lost.

In this specific case, paying for professional cleaning at 250 CHF is not not immediately profitable. However, if dirt accumulates over several years or you have a large agricultural or commercial facility, the return on investment for cleaning becomes very positive.

Conclusion

The sand of the Sahara and the Swiss climatic conditions put your installations to the test, sometimes causing a frustrating loss of output. While the desire to clean your installation yourself may seem like a good idea to save money, the safety risks and damage from limescale make the operation perilous.

Before making a decision, carefully monitor your inverter data. If the drop in production is obvious and persistent despite heavy rains, the intervention of a local expert is the safest solution to protect your investment and guarantee your long-term energy independence.