How To Properly Clean Solar Panels?

Our solar panels are typically exposed to various types of dirt, ranging from atmospheric dirt (commonly caused by dust and pollution) to extreme dirt (which occupies a large area of our panels with earth, branches, leaves, and so on), as well as less common but more intense dirt, such as bird droppings, which, in addition to reducing performance, can cause hot spots that damage the plates. It requires special care if the panels are exposed to this type of dirt.

Situations such as a “dust storm” might leave our panels dirty, leaving you wondering how to clean solar panels.

We’ll try to give you some pointers on what we need to know to properly clean our panels and thus gain the best potential performance from our photovoltaic system.


How do you know when to clean your solar panels?

To consider cleaning our solar panels, we must first assess the quantity of dirt they may have.

You have at least two choices for checking this. The first and most basic step would be to physically inspect the solar panels to see if there is dust, bird droppings, or other sorts of dirt to determine the intensity of said dirt.

Dirty Solar Panels
We can see distinct levels of filth here: the two solar panels on the top right are recently cleaned, while the two modules next to them contain the normal atmospheric dirt of panels that have not been cleaned in 6 months. Photovoltaic modules with excessive filth and a high degree of abandonment can be found in the four lower panels.

The second alternative would be to monitor whether our photovoltaic panel production is lowered. This option, however, is not only intricate but also subjective, dependent on elements other than the dirt that our solar panels may contain. When we have enough data to compare, we may examine this data more objectively using the monitoring platform of our installation.

As a point of reference, depending on the time of year and the location of the installation, your plates may be more or less exposed to certain forms of dirt: For example, in the spring and summer, when nature is reactivated, and the trees escalates its activity (particularly about birds), the likelihood of discovering bird droppings or other animal-related dirt increases. Summer is also when it rains less, which reduces the cleaning impact of falling waters. However, if you live in a densely forested area, autumn can be when the dirt from your solar panels accumulates as leaves start to fall from the trees. All of this depends heavily on where you live and where you have your solar installation because a residential installation in a community is not the same as an isolated photovoltaic installation in the countryside.


When is the most best time to clean solar panels?

Once we’ve determined that our solar panels require cleaning, we should examine the optimal time of day to do so.

To accomplish so, we must consider three factors: the time, the season, and the weather.

When it comes to the time of year if we consider that rain contributes to the cleaning of our solar panels, the greatest time for cleaning would be when it rains less, which is in the summer.

When it comes to cleaning our plates in the summer, the optimal times are early or late in the day. The cause is straightforward: the temperature. Solar radiation is stronger in the middle of the day, raising the temperature of our panels to dangerous levels. This is crucial to remember not only to avoid burns but also because when it is really hot, the thermal shock between the temperature of the water and the temperature of the plates can cause premature deterioration of our photovoltaic modules. As a result, the soapy water you’re using will evaporate fast, leaving residues or stains on the solar panels, limiting their effectiveness.

As a result, it is preferable to wait for it to cool down or to consider cleaning during a different time of year when the effect of solar radiation is not as powerful.

Another option is to clean the photovoltaic modules on cold, gloomy days to reduce the sun’s influence.

Of course, try to avoid cleaning on windy, wet, or snowy days since this increases the chance of falling and harming our physical integrity. Furthermore, the dirt that rises in the air can become stuck on the plates we are cleaning.


What materials do we need to clean our solar panels?

When choosing cleaning materials for our solar modules, there is one rule we must follow: do not use materials that can scratch the glass of our modules, either by scratching it with harsh brushes, burning it with too powerful cleaning agents, or spoiling it with too much water pressure. Because if our plates are scratched or damaged in any way, it will have an immediate impact on their performance, to a greater or smaller extent depending on the severity of the damage.

However, depending on whether we have a self-consumption facility, an industrial facility, or a solar garden, the materials we will need will differ based on the proportions of the surface to be cleaned.

Basic cleaning supplies for solar panels in a household setting:

  • A bucket of water, if possible warm, with a drop of dishwashing soap (laundry detergents and other chemicals can be too strong and negatively affect the solar panel) because throwing a lot can form foam, which can leave residues if not rinsed thoroughly. In places where the water contains a lot of salt, which might leave deposits on the surface of the solar panel, osmotic water is preferred since it evaporates without leaving a trace.
  • To apply the soapy water and rub the spots, use a soft sponge or cotton towel (that does not shed fibers or lint). Remember, we don’t want to scratch the surface.
  • To remove extra water without scratching the glass and drying the panel, use a cotton cloth, a polyester brush with thick bristles, or a rubber brush.
  • If portions of the installation are difficult to reach, it may be good to obtain a pole or telescoping handle to which a brush, sponge, or cloth can be attached.
  • If your installation is subjected to a large volume of traffic, whether from trucks or planes, it would be good to acquire a bottle of isopropyl alcohol, which is suggested for oily stains on solar panels.
  • If you have enough hose to reach the ceiling, keep in mind that you should not use much pressure to clean the panels. Thus pressure washers with high water pressure are not recommended because they could harm the panels.
  • Always follow the manufacturer’s instructions while cleaning your solar modules, and if in doubt, ask your supplier or installer whether there are any special considerations you should make when cleaning.


How To Properly Clean Solar Panels?

The first thing to remember once we get started is to treat it with the same love and care that we would if we were cleaning a new car or a beautiful old piece of furniture.

How To Properly Clean Your Solar Panels

From here, the processes are relatively straightforward, so much so that they may remind us of cleaning the house windows:

  • Pour a lot of water (without much pressure) on the modules to clean dust, insects, and other surface dirt so that the most intense dirt soaks up and softens, making it simpler to clean.
  • Moisten the sponge or rag and pass it around the panel in a zigzag motion, covering the entire surface and concentrating more on the most stubborn filth. Also, remember to rinse the sponge or rag in soapy water regularly. And, if the water in the bucket is very dirty, it is best to change it to avoid dirt residues.
  • Rinse the soap and dirt residue with plenty of water.
  • Remove any remaining unclean water with the rubber brush or brush.
  • Dry the surface with a clean cotton cloth, making sure no fibers or lint remain in the solar panels.

Because photovoltaic modules are built to survive rough weather in the open, we wouldn’t have to worry about damaging the inside circuits when cleaning solar panels because they are completely sealed.

In addition to what has previously been stated, we should try to clean from the plate-free area, taking care not to damage the remaining tiles or coating.

It’s also a good idea to organize the materials we’ll need ahead of time to avoid trekking up and down the roof more than necessary.

As a result, maintaining the best performance of your photovoltaic modules is a very simple but critical operation.


How often should solar panels be cleaned?

The number of times per year that solar modules should be cleaned is determined by weather conditions and closeness to dirt sources (presence of birds, proximity of traffic, wooded area, etc.).

Generally, one cleaning per year should be enough if you are exposed to air dirt (dust, pollution). However, if your plates are subjected to more severe dirt, it is recommended that you undertake three or four cleanings per year, depending on the quantity and strength of the dirt specks to which the solar panels are subjected.

Other factors to consider are rains and breezes, both of which might help clean the modules. They can, however, contribute to soiling with mud deposits and leaves. However, if you live in a rainy environment, you will have less need to clean than individuals who live in non-rainy places.

Is it necessary to engage a cleaning service for solar panels?

The type of installation determines it. Cleaning our solar modules in a residential installation doesn’t have to be difficult, and we can do it ourselves or with the help of someone willing to assist us.

However, if your installation is on the roof, is difficult to access, or does not see yourself performing this task to avoid unnecessary risks, there are professional options that can be responsible for the cleaning and maintenance of your installation while providing all necessary security guarantees.

Cleaning services may be required in the case of an industrial installation or a solar garden, depending on the nature and size of the installation.