The gap between signing a solar contract and actually turning the system on took me 74 days. I expected maybe three weeks. The panels sat on my roof for 11 of those days before the city inspector could schedule a visit. Then the utility needed another 19 days after passing inspection to grant permission to operate.
Nobody told me any of this upfront. The installer’s sales rep said “six to eight weeks from contract to system on.” Technically accurate — but framed in a way that made it sound like panels would be on and working in six to eight weeks. What they meant was that the whole permitting and interconnection process might take that long on the optimistic end.
Here’s what actually happens, step by step.
Step 1: Design and Engineering (Week 1–2 After Signing)
Before any permit application goes to the city, your installer creates a system design — panel layout, electrical diagrams, equipment specifications. This package is prepared by a licensed engineer (often remotely, using satellite imagery and your utility data) and submitted with the permit application.
Quality varies significantly here. A thorough design package gets approved faster because it anticipates what the inspector will look for. A slapped-together package gets sent back for revisions, adding 1–3 weeks to the timeline. This is one of the things I check when evaluating installers — ask how they handle permit revisions and how often they get sent back.
Step 2: Building Permit Application (Week 2–3)
Your installer submits the design package to your local building department. Every jurisdiction is different. Austin’s permit office took 9 business days for my application. Some California counties can take 4–6 weeks. Some jurisdictions have moved to online instant permits for solar — Texas HB 1560 streamlined solar permitting statewide, which helped.
What the building department reviews: structural load calculations (can your roof handle the panel weight?), electrical diagrams (does the system meet NEC code?), equipment specifications (are the panels and inverter on the approved equipment list?).
The permit fee typically runs $150–$500 depending on jurisdiction and system size. This is included in your installer’s quote — or should be.
Step 3: HOA Approval (If Applicable, Parallel to Permit)
If you have an HOA, their approval often runs parallel to the permit process. Most states have laws limiting HOA authority to prohibit solar outright, but they can regulate aesthetics and placement. HOA approval timelines range from 2 days (a rubber stamp) to 6 weeks (a board that meets monthly and wants multiple revisions).
If you’re in an HOA, initiate their process the moment you sign your contract — don’t wait for the permit to come back first. The two processes can run simultaneously.
Step 4: Installation Day (1–2 Days)
Once the permit is approved, installation is typically scheduled within 1–3 weeks depending on installer backlog. The physical installation — mounting the racking, setting panels, running conduit, installing the inverter and meter — takes 1–2 days for a standard residential system.
My installation crew arrived at 7am and finished by 4pm. The system was physically complete that day. It was not, however, on.
Step 5: City Inspection (1–3 Weeks After Installation)
After installation, the installer schedules a building inspection. An inspector from the city comes to the property, checks the physical installation against the permitted design, verifies code compliance, and either passes it or issues correction notices.
My inspector came 11 days after installation. He was thorough — spent about 35 minutes on-site. Passed it without issues. If there are corrections, the installer fixes them and re-schedules. Each re-inspection adds time.
Step 6: Utility Interconnection and PTO (2–6 Weeks After Inspection)
This is the step most homeowners don’t know about until they’re in it. After passing inspection, your installer submits the inspection results to your utility and applies for Permission to Operate (PTO) — the utility’s formal authorization to connect your system to the grid and begin exporting power.
The utility review process is entirely separate from the city permit. They’re checking their own standards: meter configuration, export capacity, interconnection agreement compliance. Austin Energy took 19 days after my passed inspection to grant PTO. Some utilities take 4–6 weeks. Until PTO arrives, your panels produce nothing — the inverter stays locked out.
The moment PTO comes through, your installer remotely enables the system (or sends someone to flip the interconnection switch) and your panels go live.
The Timeline Reality Check
| Phase | Best Case | Realistic | Slow |
|---|---|---|---|
| Design & permit app | 1 week | 2 weeks | 3 weeks |
| Permit review | 1 week | 2–3 weeks | 4–6 weeks |
| Installation scheduling | 1 week | 2 weeks | 3 weeks |
| Installation | 1–2 days | 1–2 days | 1–2 days |
| Inspection scheduling | 1 week | 2 weeks | 3 weeks |
| Utility PTO | 2 weeks | 3–4 weeks | 6–8 weeks |
| Total | 7–8 weeks | 11–14 weeks | 20+ weeks |
My 74 days — roughly 10.5 weeks — was on the normal end of realistic. Not the horror story some people experience, not the “six weeks” the salesperson implied.
The practical takeaway: when you sign a solar contract, assume 10–14 weeks to system-on. Build that into your financial planning. Your first utility bill savings won’t appear until after PTO.
— Allen
