How long does solar installation take?
The panels go up in a day or two. The paperwork around them takes months. Here are the real medians.
From signing the contract to the utility's permission to operate, the median home solar project in 2024 took 93 business days, about 4 months; the middle half of projects took 64 to 150 business days. That is from NREL's SolarTRACE data on projects up to 10 kW reported by installers (NREL SolarTRACE). The installation itself is a small part of it.
Where the time goes (US, 2024 medians)
| Step | Median business days | Middle half of projects |
|---|---|---|
| Design: contract to first permit application | 20 | 9–39 |
| Permit review by the city or county | 7 | 2–14 |
| Utility pre-install review | 5 | 1–11 |
| Installation work after approvals | 10 | 5–21 |
| Inspection | 11 | 5–24 |
| Final utility approval (permission to operate) | 7 | 3–14 |
Business days, systems up to 10 kW without a battery. Steps overlap and not every utility requires a pre-install review, so they don't add up to the total. Before installation: 63 days median; after: 28.
Permit, inspection and utility steps in the cities I cover
Median business days in the latest year with enough projects. The paperwork is quickest in San Diego and slowest in Yonkers among these cities:
| City | Permit review | Utility pre-install review | Inspection | Permission to operate | Data |
|---|---|---|---|---|---|
| Phoenix, AZ | 0 | 4 | 25 | 8 | 2024, 158 projects |
| Tucson, AZ | 0 | 5 | 11 | 6 | 2024, 204 projects |
| San Antonio, TX | 0 | 4 | 8 | 11 | 2024, 84 projects |
| Austin, TX | 4 | — | 14 | 10 | 2024, 39 projects |
| San Diego, CA | 0 | 0 | 3 | 2 | 2024, 40 projects |
| Fresno, CA | 1 | 0 | 10 | 12 | 2023, 815 projects |
| Chandler, AZ | 1 | 4 | 4 | 8 | 2024, 23 projects |
| Scottsdale, AZ | 4 | 4 | 6 | 8 | 2024, 19 projects |
| Gilbert, AZ | 0 | 6 | 3 | 9 | 2023, 83 projects |
| Glendale, AZ | 8 | 4 | 8 | 8 | 2024, 30 projects |
| Tempe, AZ | 14 | 6 | 18 | 9 | 2023, 27 projects |
| Peoria, AZ | 20 | 4 | 16 | 8 | 2024, 30 projects |
| Surprise, AZ | 12 | 4 | 7 | 8 | 2024, 36 projects |
| San Jose, CA | 0 | 0 | 10 | 4 | 2024, 51 projects |
| Bakersfield, CA | 2 | 0 | 8 | 12 | 2023, 432 projects |
| Clovis, CA | 3 | 0 | 11 | 12 | 2023, 289 projects |
| Chula Vista, CA | 9 | 0 | 12 | 7 | 2023, 430 projects |
| Oceanside, CA | 1 | 0 | 11 | 7 | 2023, 336 projects |
| Carlsbad, CA | 3 | 0 | 6 | 7 | 2023, 178 projects |
| New York, NY | 6 | — | 13 | 1 | 2024, 54 projects |
| Elizabeth, NJ | 5 | 7 | 15 | 9 | 2023, 33 projects |
| Yonkers, NY | 70 | 1 | 14 | 3 | 2022, 68 projects |
Same source, jurisdiction and utility with the most projects for each city. 0 means same-day approval was the median. "—" means no pre-install review or too few projects to report.
What you can do about it
- Ask for the installer's own timeline for your city and utility, in writing, with the date they expect permission to operate. The design phase alone ran 20 business days median in 2024.
- Don't sign the loan clock early. Ask when payments start; with a 4-month median you may be paying before the system produces.
- Roof work and main panel upgrades add their own permits. Get them on the schedule before the solar permit is filed.
- Nothing runs until permission to operate. Turning the system on before the utility approves it can void the interconnection agreement. Ask who submits the final paperwork and when.
Run your own numbers
Enter your ZIP and bill to see what the system will save once it's on.
Keep reading
- How much solar panels cost in 2026 — Average price per watt by state and city, and what a 5, 7 or 10 kW system costs before incentives.
- Is solar worth it in 2026? — Payback without the federal credit in the cities I cover, and when solar is a weak deal.
- Disadvantages of solar panels — Nine downsides to weigh before you sign, with numbers from real tariffs.
Installer records by city: solar companies in Phoenix, solar companies in Tucson, solar companies in San Antonio, solar companies in Austin, solar companies in San Diego, solar companies in Fresno, solar companies in Chandler, solar companies in Scottsdale, solar companies in Gilbert, solar companies in Glendale, solar companies in Tempe, solar companies in Peoria, solar companies in Surprise, solar companies in San Jose, solar companies in Bakersfield, solar companies in Clovis, solar companies in Chula Vista, solar companies in Oceanside, solar companies in Carlsbad, solar companies in Toms River, solar companies in New York, solar companies in Elizabeth, solar companies in Yonkers.
Updated 2026-09-21.