Is beneficial to your Solar Panels for a couple good reasons. The main reason being that Squirrels and Birds will stay under your panels to stay warm and keep themselves less exposed to predators. When this happens there is a higher likelihood of them chewing through a wire, or building a nest underneath. Having a nest under your panels can cause hot spots which might lead to decreased efficiency. Mesh around your Solar Panels will also prevent any type of debris from collecting underneath your panels.