When done correctly, solar panel pigeon proofing will last for many years. At ApcUK we guarantee ours for 6. Unfortunately, though, proofing is not always carried out by a specialist and when the works are carried out by a local roofer or builder, for example, they don't tend to stand the test of time. We've been in the business for a number of years and in our experience it’s only a few days before the pigeons are back in. Work is probably carried out in good faith, but without knowing the behaviour of pigeons and how they will react to changes in their environment you cannot know how to change their habits. We often find ourselves having to remove materials such as pigeon spikes, chicken wire and damp proof membrane (to name just a few) as pigeons have managed to re-enter under the solar panels.
Not only does this type of pigeon proofing not work on solar arrays, it can also lead to problems. Furthermore, the panel’s warranty could well become null and void. Some of the materials we have seen used restrict air flow under the panels and have even been screwed into the solar panels. This invalidates any warranty straight away.