In California, Installers are required to have possibly a standard contractors license or perhaps a C-46 Solar Contractors License. This license handles installations for photovoltaic systems, solar water and space heating, and solar pool heating. Other certifications you need to watch out for, none of that are legally required but https://bestsolaragencyinfresno.blogspot.com/2025/11/power-your-home-and-business-with.html