With the current state of technic we can reuse several materials of the solar panels.
Other materials will be seperated and disposed in a safe way; technic develops quickly. In the future, we expect to find more and better ways for reuse.In that way is on the long run recycling of a solar panel possible for over 95%.
To be able to do this it's important that old solar panels are collected correctly. Here you can read how you can easily recycle your old solar panels.