One of the problems that affect the energy production of solar panels and that affects all installations, regardless of their size, is the dirt that accumulates on them.

In addition, the dangerous hotspot that can produce dirt as we explained in the article: Hotspot effect: Hot spots on solar panelsIf the system is not working properly, the accumulation of dirt can lead to a number of other problems.

When a solar panel does not have a drainage system in its corners, it is common for dirt to accumulate in these corners unless proper maintenance is performed and the photovoltaic modules are cleaned, as we explained in our blog: How to clean solar panels. This accumulated dirt causes an increase in the temperature of the cells where it is located, causing them to lose part of their efficiency and can produce hot spots.

Loss of performance due to soiling

The amount of yield loss will vary depending on various factors related to panel soiling.

The type of dirt is one of the key factors, since depending on whether it is bird or other animal droppings or atmospheric dust, the energy loss will be different due to the density or extent of the dirt. For example, droppings tend to be more opaque and dense which increases the likelihood of hot spots, while atmospheric dust reduces efficiency slightly.

The inclination of the solar panels also has an influence, since it will influence a better cleaning with the rain. The steeper the inclination, the more effective the rain will be, avoiding leaving furrows. The type of cell is another factor to take into account, since monocrystalline split-cell panels are usually less affected by dirt.

The design of the installation will affect the amount of energy loss produced by the panels. When the installation is made in string, the fouling of one of the panels will affect the rest of them, because the efficiency of the whole will be equal to the lowest of them. On the other hand, if the installation is done with microinverters, this problem disappears since the performance of each panel does not depend on the rest of them.

The yield that will be lost will vary between 5% and 15% approximately and depending on the above mentioned factors. Although it could even reach figures close to 40% in the worst cases if proper maintenance is not carried out.