Most homeowners are surprised by how long the solar installation process takes. The panels themselves go up in 1–3 days — but permits, inspections, and utility interconnection can stretch the total timeline to 2–4 months.
Here's a complete walkthrough of what to expect.
The Complete Solar Installation Timeline
| Step | Who Does It | Typical Duration |
|---|---|---|
| Get quotes | You | 1–2 weeks |
| Site assessment | Installer | 1–3 days |
| System design | Installer | 3–7 days |
| HOA approval (if needed) | You + Installer | 2–8 weeks |
| Permit application | Installer | 2–8 weeks |
| Equipment ordered | Installer | 1–4 weeks |
| Installation day(s) | Installer crew | 1–3 days |
| City/county inspection | Inspector | 1–3 weeks |
| Utility interconnection | Utility company | 2–8 weeks |
| Permission to operate (PTO) | Utility | Same day as approval |
Step 1–3: Quotes and Design (2–3 Weeks)
Get at least 3 quotes. Legitimate installers will want to see 12 months of electricity bills and may do a brief site visit or satellite assessment. The design phase creates a system layout optimized for your roof's orientation, tilt, and any shade obstacles.
Red flag: Any installer pressuring you to sign same-day without reviewing your bills or roof. Good installers never rush this.
Step 4–5: Permits (2–8 Weeks — The Longest Wait)
Permits are pulled from your city or county. Simple jurisdictions process permits in 1–2 weeks. Complex cities (LA, San Francisco, many Northeast cities) can take 6–8 weeks. Your installer handles this — your job is to not lose patience.
Many states are pushing for streamlined solar permitting (30-day maximum), but implementation is uneven.
Step 6: Installation Day
The actual installation is anticlimactic compared to the wait. A crew of 3–6 workers will:
- Mount racking to your roof rafters
- Install panels on the racking
- Run conduit and wiring to your electrical panel
- Install the inverter (usually on a garage wall)
- Install monitoring equipment
Your power will be off for 1–4 hours. Most installs complete in a single day (larger systems take 2–3 days).
Step 7–9: Inspections and Interconnection (4–8 Weeks)
After installation, the system sits dormant while waiting for a city inspection and then utility interconnection approval. This is the most frustrating phase — your panels are on the roof but can't be turned on.
Some utilities have backlogs of 6–10 weeks for interconnection approvals. This is a known industry problem. Your installer should give you a realistic timeline based on your specific utility.
Step 10: Permission to Operate (PTO)
When your utility approves interconnection, they issue a Permission to Operate (PTO). Your installer will flip the final switch, and your system goes live. You'll typically get access to a monitoring app (Enphase, SolarEdge, Tesla) to watch your real-time production.
📅 Pro tip: Start the solar process in spring (March–April) to get PTO before summer peak season. If you wait until June, you might miss the best generating months while your system sits in permitting.