The accumulation of dirt and dust on photovoltaic panels reduces their electricity production because it prevents sunlight from directly reaching the surfaces of these panels. Therefore, they must be cleaned periodically depending on the nature of the accumulated dust and the weather conditions at their installation site, in order to maintain their efficiency in producing electricity and reduce the costs of producing this energy.
The methods for cleaning solar panels can be summarized in two ways:
1- Dry cleaning
The surfaces of the panels are wiped with a semi-dry cloth in the case of small systems, or using special cleaning machines if the system is large. The importance of dry cleaning lies in areas that suffer from water scarcity and difficulty in providing it when needed.
2. Wet cleaning
Clean, demineralized, and non-oxidized water is used to clean photovoltaic panels, because saline water with high oxidation levels causes spots to form on the surfaces of the panels, leading to a reduction in the system's performance efficiency.
Regardless of whether the cleaning method is dry or wet, it is performed using one of the following mechanisms:
· Truck-mounted cleaning systems.
· Semi-automatic cleaning systems.
· Fully automated cleaning systems.
· Portable cleaning systems
· Manual cleaning of solar panels.
It is important to clean the panels periodically, and the frequency of cleaning varies depending on the weather in the area of the panels, but regularly inspecting them ensures that dirt is noticed before it accumulates significantly and becomes harmful.
Since cleaning photovoltaic panels involves using water, and the temperature difference between the panels and the water can cause the protective glass of these cells to crack, they should not be cleaned and water should not be applied to them when they are hot. The best time to clean them is early in the morning before they are exposed to sunlight and their temperature rises.
The surfaces of the solar panels must be dried after cleaning and dusting, using clean cloths, taking into account the following:
· Do not apply excessive pressure to the glass panels to avoid breaking them.
* Choose the right place to stand when cleaning the middle of the panels.
• Start the drying process from top to bottom.
* Follow safety instructions when using ladders during cleaning and drying operations.
Important tips and guidelines for cleaning solar panels:
- Please make sure to clean the panels during the early morning hours when the panel temperatures are low, and avoid cleaning during the daytime, especially at noon.
- Use clean water with a low mineral content and never use detergents. Ensure the water temperature is close to the temperature of the panels. A sudden change in the panel's temperature can cause the glass to crack.
- A soft brush or sponge can be used to avoid scratching the surface of the panels.
- Avoid using water pressure with pumps. It is recommended to use a water pressure of less than 40 bar. Ensure that the water exiting the pipe head is well-distributed and not concentrated at one point.
- Avoid standing and walking on the panels, as they are designed to withstand a certain amount of pressure from layers of snow and wind distributed over the panel's surface. Concentrating your body weight on your feet or other parts of your body can lead to small, invisible cracks in the cells.
- As a precautionary measure, you can electrically disconnect the panels from the inverter via the DC breaker during the cleaning process and turn it back on half an hour after cleaning is complete.
