- Birds, which could build nests beneath the solar system and cause damage.
- Voles/Squirrels, which could damage the cables.
- Bird droppings.
- Oily stains (e.g. in the near of airports or under a flight path).
- Pollen (sticky and oily).
Thanks to the water-repellent effect (lotus effect) of the photovoltaic panels, a proper cleaning is often necessary only once or twice a year. The smooth surface of the solar panels is being cleaned regularly and automatically by the rain. However, in particularly dry areas or at places where the panels’ tilt is minimal, dust and dirt can deposit on the panels and influence the energy generation.