Why should PV Modules and Mounting Systems be Cleaned and how Often should this be Done?

Today, both individuals and companies are opting for the installation of photovoltaic systems. Many micro-systems are being built, as well as huge solar parks. Photovoltaic systems are erected both on open areas and on roofs, and numerous carports are also being constructed. Regardless of who invests and what type of investment in a photovoltaic system one chooses, the following question arises – should the PV modules and mounting systems be cleaned? In the following article, we answer this question in detail.

Do PV Systems and Substructures Need to be Cleaned?

Although the topic is somewhat controversial, the matter is actually clear – cleaning PV mounting systems from time to time is a necessity. Opponents of this claim argue that the modules do not require this at all and that washing can even destroy them. In fact, uncleaned modules, as well as mounting systems for PV systems, lose efficiency and are often damaged. The cleaning of the modules should be carried out very carefully and using suitable means. It is also not advisable to clean too often. It is considered optimal to clean the modules 1-2 times per year. For mounting systems, cleaning can be done somewhat more frequently. In reality, however, these are just some general guidelines, as the frequency of cleaning a system depends on several factors that we will discuss later in the text.

Let’s now turn to the factors that are decisive for the need to clean a PV system:

• Maintaining the efficiency of the modules – contamination that settles on the surface of the system prevents sunlight from reaching the cell, which inhibits energy production. This includes large mechanical impurities such as leaves, but also impurities such as dust.
• Protection of modules from damage – bird droppings can settle on the surface of the modules, which has a corrosive effect and often leads to damage to the cells. In addition, there are also particles in the air that can damage the surface of the modules or even the cells. When they settle on the modules, they pose a real danger to them.
• Maintaining the high aesthetics of the system – no moisture spots and no old dirt mean higher aesthetics for photovoltaic modules, but also for the substructure on which they are mounted. In particular, the installation of photovoltaic systems in open areas necessitates the need to also clean the substructure, which in this case is much larger and therefore more visible.

How Often Do PV Mounting Systems Need to be Cleaned?

As mentioned earlier, several factors are decisive for the required frequency of cleaning photovoltaic systems. One of the most important is the installation of the photovoltaic systems. This refers to their location, both in a broader and narrower sense. In a city where air quality is generally poor due to smog and particulate matter pollution, the efficiency of the modules decreases quite quickly due to the deposition of contaminants. In any case, faster than in the countryside, where air quality is usually better. Other factors, such as proximity to a highway or an industrial plant, can also affect air pollution. In a narrower sense, the location of a system is important in terms of nearby sources of contamination. For example, sandy terrain near a system can pose a certain risk, as sand particles can be carried by the wind and settle on the surface of the modules.

Installation of a Photovoltaic System on Open Ground and the Special Cleaning Requirements

Today, more and more users are opting for the installation of photovoltaic systems on open ground due to the many advantages of this solution. However, it should be noted that installing a photovoltaic system on open ground also means that the modules and substructure need to be cleaned more frequently. Compared to a roof system, the ground-mounted system is very low, which increases the risk of falling leaves or larger amounts of dust carried by the wind. In this case, the nature of adjacent properties and other possible sources of contamination are of even greater importance.

The advantage of ground-mounted photovoltaic systems is that while they need to be cleaned more frequently, they are more easily accessible. With ground-mounted systems, there’s no need to climb to heights, allowing for effective and safe cleaning even without professional assistance.

It is Advisable to Clean PV Mounting Systems as Well

We have already discussed the necessity of cleaning photovoltaic modules in detail. There is no doubt that this should be done regularly, but not too frequently. But what about the PV mounting systems, i.e., the supports on which the modules are installed? Our photovoltaic mounting systems are predominantly made of steel. An innovative solution in the form of Magnelis® coating is used here. The magnesium-based coating provides effective corrosion protection and offers up to 10 times higher corrosion resistance than zinc, which is the most commonly used rust protection. Additionally, the substructure is equipped with protective materials that guard against chemical and mechanical damage and facilitate cleaning. The surface is protected from dirt deposits, but to maintain its full shine, it’s worth conducting a cleaning from time to time. A few times a year is sufficient.

Even though the topic of cleaning photovoltaic systems is sometimes widely discussed and may seem questionable to some people, the matter is actually clear. For professionals, there is no doubt that the modules need to be cleaned. Special cleaning agents and distilled water are used for this purpose. Detailed instructions on cleaning photovoltaic modules can be found in our other article that exclusively deals with this topic.