The Solar Installation Process Step by Step: What to Expect

Short answer: A typical residential solar installation takes 4–12 weeks from contract signing to Permission to Operate (PTO), broken into eight stages: site assessment, system design, permitting, equipment order, physical installation (1–3 days), inspection, utility interconnection, and monitoring setup. Physical install is the shortest step — paperwork and utility review take the majority of the calendar time.

The 8 steps, in order

1. Site assessment & energy audit (week 1). Your installer sends a technician to measure your roof, inspect the main electrical panel, and pull 12 months of utility data. A satellite-derived production model is built alongside a shading analysis using a SunEye or Helioscope-style tool. The outcome is a preliminary system size (kW), expected annual production (kWh), and roof layout proposal.
2. System design & proposal (week 1–2). The installer converts the site data into a proposal document: panel count and brand, inverter choice, optional battery, estimated output, 25-year savings projection, and itemized pricing. You review, compare to other quotes, and sign.
3. Permitting & HOA approval (week 2–5). The installer submits an electrical permit and — depending on jurisdiction — a structural permit. HOA review is parallel. Turnaround varies wildly: 3 days in parts of Texas and Florida, 4–8 weeks in California counties with backlogs.
4. Equipment ordering (week 2–3). Panels, inverters, racking, and any batteries are ordered once the contract is signed. Most installers stage equipment at a local warehouse to shorten install lead time. Battery supply has loosened in 2026 — most SKUs now ship in under two weeks.
5. Physical installation (1–3 days during week 4–8). The crew arrives at 7–8 AM. Day 1 is typically mounting the racking and panels on the roof. Day 2 is electrical: inverter, conduit runs, main panel tie-in, and the production meter if required. For larger systems or battery additions, a day 3 finishes interior wiring and commissioning. Your power may be off for 2–4 hours while the crew ties into the main panel.
6. Inspection (week 5–10). The local Authority Having Jurisdiction (AHJ) inspects the work — usually a quick 30-minute visit where the inspector confirms rapid shutdown, grounding, conductor sizing, and signage. Some AHJs require a separate structural sign-off. Scheduling is the bottleneck; inspection itself rarely fails.
7. Utility interconnection (week 6–12). After inspection, the installer submits a signed inspection form to your utility and requests Permission to Operate. The utility may swap the meter for a bidirectional model, then issue PTO in writing. Timeline varies by utility: 3–10 days for most co-ops, 2–6 weeks for major IOUs.
8. Monitoring setup (day of PTO). Your installer configures the inverter's cellular or Wi-Fi module and pairs it with your monitoring app (Enphase Enlighten, SolarEdge mySolarEdge, Tesla One, etc.). You see daily, monthly, and lifetime production data, plus system alerts. This is when your system first exports electricity and begins earning net metering credits.

Timeline table

What can cause delays

• Permit backlogs. Urban California counties and Long Island NY routinely run 4–8 weeks behind. Check your installer's recent permit turnaround for your ZIP.
• HOA review. Some HOAs meet monthly, so you may wait 3–4 weeks for a single vote. Installers that know your HOA's quirks save weeks.
• Main panel upgrades. If your 100A or 125A panel needs upgrading to 200A, add 1–3 weeks and $2,500–$4,500.
• Roof condition. If the inspector flags a roof with less than 7 years of remaining life, you will need a roof replacement first.
• Interconnection queue. Utilities like PG&E and ConEd have run 6–10 week PTO queues during 2024–2025. 2026 has improved but is still utility-dependent.

What you can do to speed things up

• Pull 12 months of utility bills before your site assessment so the design can proceed immediately.
• Submit your HOA application the same day you sign the contract — it runs in parallel with permitting.
• If your electrical panel is 20+ years old, proactively order a panel upgrade at contract signing rather than waiting for the designer to flag it.
• Ask your installer to confirm current utility PTO timelines in writing — it sets expectations and reveals who has better relationships with the local utility.

Ready to start your own timeline? Browse verified installers in your state or get matched with up to five local contractors free. For budgeting, our 2026 cost breakdown covers exactly what each phase adds to the total price.