It typically takes one to two months for an installer to design your solar array and secure initial permits (from your municipal government) and interconnection agreements (from your electric utility).
Depending on your exact solar permitting office and utility interconnection team, this could take anywhere from a few weeks to a few months.
Once initial permits and interconnection agreements are in hand, your installer will typically need only one to two days to physically install your array (panels, inverter, racking system, and wiring).
The installer will then need to get final approval from the municipal permitting office and secure final interconnection approval from the utility. This can take an additional one to three months depending on the jurisdiction.
Because solar permitting is handled by the local municipality, the permitting process will vary based on where you live. Most localities require installers to file for a solar permit, the stipulations of which differ by jurisdiction.
Solar permits are in place to ensure that your system is installed safely and follows local code. From a customer perspective, you should not have to file any of the local permits yourself.
Your installer should handle all permitting aspects themselves, including submitting the permit application and getting the solar system inspected