A Agent out of your city government inspects your system and offers acceptance for interconnection. The endorsements often come with benefits that are passed on to customers, like most popular pricing or prolonged warranties.  Though fewer than in the past, California nonetheless provides beneficial incentives, especially for batteries: Be aware: https://residentialsolarinstallationcalifornia.finance.blog/2025/09/14/california-solar-panel-system-designed-for-efficiency-and-savings/