Bird Mesh
Bird mesh is a wire mesh netting that goes around your solar panels outer edge, going all the way to the roof tiles so nothing gets under the solar panels, and they also go slightly above your solar panels too, making it difficult for anything to get underneath your solar panels from the top too.
Bird Spikes
Bird spikes are the other main option that is available to protect your solar panels from birds. They are designed to protrude from the roof at awkward angles in order to make birds just uncomfortable enough to choose elsewhere to land. They do not hurt the birds!
Replica Predator
A replica predator is designed to work alongside either mesh or spikes to help deter birds from landing. It seems silly, but birds have been proven to avoid areas with replica predators such as owls on them. They are a cheap way to add additional protection for your panels.