In California, installers are necessary to have both a standard contractors license or possibly a C-46 Solar Contractors License. This license addresses installations for photovoltaic systems, solar water and Area heating, and solar pool heating. Other certifications you need to look out for, none of that are lawfully expected but https://californiasolarservices.fashion.blog/2025/09/14/commercial-solar-installation-dublin-power-your-business-sustainably/