First, all solar installers will have to keep a sound and active license through the Contractors State License Board (CSLB). They will keep any of the following to be Qualified for solar installations in California: a solar contractor license, an electrical contractor license or even a standard constructing contractor license. https://www.americanarraysolar.com/how-can-you-be-benefited-by-hiring-a-solar-company-visalia/