Numerous studies have shown that dirt and pollution on your solar panels can have a marked effect on their performance. A study by TNO in the Netherlands has shown that the performance of solar panels dropped in a single year by between 4.4% and 7.7%.
Dirty panels can be caused by many factors. Migrating birds, industrial estates, motorways etc. increase the level of pollution. A layer of dust begins to form on the panels as soon as they are installed, which will lead to reduced performance after several months.
Hotspots
A possible problem caused by pollution is the phenomenon known as “hotspots”. These are caused by a small area of the panel heating up. If the tiles cannot produce electricity (due to dark shadows, leaves or bird excrement), they will act as resistance, and as current passes through them (coming from the tiles that are working properly) they will start to overheat. This can cause permanent damage to the panels.
Self-cleaning?
It is often claimed that solar panels are kept entirely clean by the rain. However nothing is further from the truth. The largest lumps of dirt can be washed off panels that are installed on a slant, but bird excrement, dust and other pollution are left behind on the panels. This is why it is recommended that you get your panels cleaned thoroughly at regular intervals.
