Can I add panels to my existing solar system? IT Support January 11, 2021 06:14 Updated You can include panels to your existing system, as long as they are compatible with the current system. Related articles How long does it take to get a permit approval? Do you work with systems installed by other companies? Can I Install a Battery to Already Existing Solar Panels? Can I Install a Battery to Already Existing Solar Panels? Can you install a solar system on an old roof? Comments 0 comments Please sign in to leave a comment.