What to Expect During Solar Installation: The Complete Timeline from Quote to Power-On

One of the most common frustrations with going solar is the timeline. From signing the contract to actually producing electricity, the process takes 2-4 months - sometimes longer. Most of that time isn't installation (which takes 1-3 days) but rather permitting, design, utility approval, and inspection. Here's the full timeline.

Week 1-2: Site Assessment and System Design

After you sign the contract, the installer performs a detailed site assessment. This may include a physical roof inspection (condition, angle, orientation, structural integrity), shade analysis using satellite imagery and/or on-site measurement, electrical panel evaluation (capacity, condition, upgrade needs), and precise measurements for system design. Using this data, engineers design your specific system layout - which panels go where, how they're wired, and where equipment is mounted. You'll receive a final system design for approval before the next step.

Week 2-6: Permitting

This is typically the longest wait. Your installer submits plans to your local building department for a permit. Permitting timelines vary dramatically by jurisdiction: some cities approve in 3-5 days, others take 4-8 weeks. Your installer handles all permitting paperwork. You don't need to do anything during this phase, but it's the most common source of delays. Ask your installer about typical permit timelines in your jurisdiction before signing.

Week 6-8: Installation

Once permits are approved, installation is scheduled. The actual installation process takes 1-3 days for most residential systems. Day 1: Mounting hardware installed on the roof. Panels mounted on the racking system. Wiring routed from panels to the inverter location. Day 2 (if needed): Inverter and electrical connections installed. Battery system installed (if applicable). Electrical panel work and meter setup completed. Day 3 (if needed): Cleanup, system testing, and quality check. The crew should protect your home during installation, clean up completely, and leave the site as they found it (minus the new solar panels on the roof).

Week 8-10: Inspection and Utility Approval

After installation, two approvals are needed before you can turn on the system. The building inspection verifies the installation meets code requirements. Your installer schedules this with the local building department. Inspections typically happen within 1-2 weeks of installation. Then your utility interconnection must be approved. The utility reviews the installation, replaces or reconfigures your meter for net metering, and grants Permission to Operate (PTO). This can take 1-4 weeks depending on your utility.

Power On!

Once you receive PTO from your utility, your installer activates the system. You'll receive a walkthrough covering how to monitor production through the app, what the indicator lights on the inverter mean, basic maintenance (keep panels reasonably clean, keep vegetation trimmed), and warranty information and who to contact for service. From this point, your system is producing electricity and reducing your electric bill.

How to Minimize Delays

Choose a local installer familiar with your jurisdiction's permitting process. Respond quickly to any requests for information or signatures. Schedule your electrical panel upgrade (if needed) before the solar permit is submitted. Ask about the installer's current project backlog and realistic timeline before signing.