When you install solar, an electric panel upgrade is sometimes required by your local building and safety department. This is to ensure your electrical panel is up-to-code and can support an added electrical load. 

This is common in older homes and may be necessary depending on the specifics of your system, structure of your home, and changing electricity needs.  

Please note that upgrading your electric panel is not the same thing as reprogramming your electric meter. When you go solar, meter reprogramming will be a part of the process and will be handled by SCE and your contractor before you can operate your system.