August 26, 2025, 1:02 pm | Read time: 3 minutes
Solar panels are a significant investment—and they should pay off. To ensure a photovoltaic system on the roof operates at full capacity, it must remain clean. While rain and snow handle most of the cleaning, stubborn dirt like bird droppings can challenge even natural elements. Such deposits can reduce electricity production. Additionally, if animals nest under the modules, it can lead to issues. myHOMEBOOK consulted an expert on how best to address these situations.
Overview
Can Bird Droppings Affect Solar Panel Performance?
Typically, bird droppings don’t remain long on a solar module. Rain or snow in winter naturally cleans the system. However, if the roof and solar panels are directly under a branch, the modules can be consistently covered with bird droppings. “Since the solar cell beneath the droppings is partially shaded, it can occasionally lead to performance impairments,” explains Carsten Körnig, CEO of the German Solar Industry Association, to myHOMEBOOK.
It’s often just a temporary effect and usually not critical, Körnig says. However, if birds consistently occupy the modules, it can lead to problems. “Then there’s a permanent shading of several cells, which can cause the affected cells to heat up, leading to so-called hotspots.”
How Damaging Can Bird Droppings Be to a Solar Module?
Seeing some bird droppings on the solar panels might make one wonder if they could be harmful. After all, these residues can have a corrosive effect. “If bird droppings occur persistently and in large quantities, the glass surface can be damaged,” Körnig explains.
To prevent this, the modules should be cleaned regularly. For tips on how best to proceed and whether you should clean the system yourself, read this article.
Birds Nesting Under Modules
It is not only bird or animal droppings that can cause issues with rooftop solar systems—sometimes animals nest under the PV systems. “Nests under the modules can damage the system, for instance, by damaging the backsheet,” Körnig explains. Empty nests that have clearly not been used for a long time may be removed, according to the expert.
Increasing Incidents of Spontaneous Glass Breakage in Solar Panels! Expert Explains Causes
For this reason, you should regularly clean your solar panels.
How to Prevent Nesting
To prevent birds from nesting under the solar modules, certain precautions can be taken. There are various bird protection devices, like stainless steel spikes or plastic strips. “This reduces the likelihood of damage from nests, as the animals no longer have access under the system,” Körnig says.
Martens Can Become a Problem
But not only animal droppings or birds can become problematic. “Martens can also cause damage to a PV system, as they gnaw on cable sheaths and rubber-containing materials,” Körnig explains.
If the risk of marten bites is known in an area, efforts should first be made to prevent martens from reaching the roof. Remove branches that extend to the roof, and cover cables with a special protective sheath that marten teeth cannot penetrate. “Alternatively, existing cables can be laid in plastic pipes that serve as protective covers,” the expert says.