1. Routine cleaning of PV systems: Danger from incorrect means

Cleaning photovoltaic systems is part of the standard program for many operators. It is intended to remove contamination and keep the energy yield stable. But exactly this supposedly simple one Maintenance step carries risks. A current study by the Fraunhofer Center for Silicon Photovoltaics (CSP) shows that incorrect cleaning methods can noticeably reduce the performance of solar systems.

As part of the study, the researchers found that certain cleaning agents can reduce the energy production of solar modules by up to 5.6 percent. This brings an aspect into focus that has previously been underestimated in the everyday lives of many operators. While contamination is seen as a clear performance factor, the effect of cleaning itself often goes unnoticed.

This topic is becoming increasingly important, especially against the background of increasing demands for efficiency and cost-effectiveness. Even small performance losses can add up to significant financial losses over the life of a system.

2. Why the module surface is so sensitive

A central component of modern solar modules is the anti-reflective coating on the glass surface. It ensures that as much sunlight as possible reaches the solar cells. Without this coating, some of the radiation would be reflected and would not be available for electricity production.

However, this layer is sensitive to chemical influences. If aggressive cleaning agents are used, they can attack and change the surface. The result: The light transmission decreases, and with it the energy yield also decreases.

What is particularly problematic is that this damage often remains invisible. The modules continue to appear clean and intact, while actual performance is already compromised.

3. Clear words from those responsible for the study

The relevance of the results is also reflected in the statements of the scientists involved. Marko Turek from Fraunhofer CSP emphasizes:

“The cleaners tested are market-leading products that are freely available on the European market.”

This classification makes it clear that these are not special cases. Rather, the problem affects products that are already widely used. For operators, this means that existing cleaning practices should be critically questioned.

At the same time, the need for clear standards is growing. As long as there are no uniform specifications, operators and service providers bear a high level of personal responsibility. If you proceed carefully here, you can minimize risks and ensure the performance of the system.

4. Study shows clear differences between cleaning products

For the study, the researchers analyzed various cleaning agents under controlled conditions. The aim was to measure the effects on the glass surface and its optical properties.

The results show a differentiated picture: not all remedies have the same effect. While some products caused no measurable changes, others resulted in significant losses in light transmission. These differences have a direct impact on the subsequent electricity yield.

This makes it clear that the choice of cleaning agent is not a detail, but a decisive factor for system performance.

5. Cleaning remains useful, but requires more care

Despite the risks, cleaning solar systems remains necessary. Deposits such as dust, pollen or industrial residues can also reduce performance. In certain regions, dirt can accumulate particularly quickly and significantly affect yield.

However, the correct implementation is crucial. In addition to the cleaning agent, the quality of the water, the tools used and the method of execution also influence the result. If you work inaccurately here, you risk damaging the module surface.

A differentiated approach therefore becomes key. Instead of blanket solutions, we need adapted processes that are both effective and gentle on materials.

6. Chemical influences often work in secret

A particular risk lies in the subtle effects of chemical processes. Strongly acidic or alkaline cleaners in particular can react with the glass surface and cause microscopic changes.

These processes usually go unnoticed. Visible damage rarely occurs. Instead, the impact only becomes apparent in the performance data of the system. This is exactly what makes the problem difficult to grasp.

Many operators only recognize the losses late, when deviations in yields add up over long periods of time. At this point, the damage can often no longer be reversed.

7. Consequences for operators and service providers

The study results have a direct impact on the operation of photovoltaic systems. Operators should review their cleaning processes and structure them more strongly. Clear documentation helps to understand possible causes of performance changes.

The selection of suitable cleaning products is also becoming more important. More and more providers are relying on demineralized water or specially tested products to reduce risks. At the same time, training maintenance personnel plays an important role.

For service providers, professional cleaning is increasingly becoming a quality feature. Customers not only expect clean modules, but also the preservation of technical performance.

8. Economic importance is often underestimated

The effects of incorrect cleaning are not only technical, but also economical. Even small power losses can lead to significant losses over the lifespan of a system.

Especially in large solar parks, a few percent quickly add up to relevant amounts. At the same time, indirect costs arise, for example through complex troubleshooting or reduced feed-in revenues.

Since damaged coatings generally cannot be restored, mistakes have long-term effects. This makes cleaning a factor that determines the profitability of a system.

9. Cleaning as a strategic factor in plant operation

The results of the Fraunhofer study clearly show that the cleaning of photovoltaic modules deserves more attention. It is not an incidental maintenance step, but rather part of a holistic operating strategy.

Operators should specifically adapt their processes and rely on tested procedures. Anyone who works carefully here not only protects the technology, but also ensures the economic viability of the system.

This makes it clear: Correct cleaning not only determines the cleanliness of the modules, but also directly influences the long-term energy yield, operating costs and the service life of the entire photovoltaic system.