Here's the part nobody tells you at the sales table: the panels go on your roof in one or two days. Everything around those two days — design, permits, utility paperwork, inspection, and the final authorization to switch on — is what sets your real timeline, and in Texas most projects land somewhere between several weeks and a few months from signed contract to a running system. This is what each stage is for, and what actually moves the needle at each one.
The stages, in order
1. Site survey and design (days to a couple of weeks). A technician verifies your roof, electrical panel, and meter; engineers turn that into the plan set every approval downstream depends on. Accuracy here is the whole game — a mis-measured electrical panel discovered later restarts the paperwork.
2. Permitting (days to ~6 weeks, city-dependent). If you're inside city limits, your installer submits plans to the city for review. Texas law gives cities up to 45 days to act on building permits, and most are faster — but every correction cycle adds a week or more, which is why an experienced installer's clean first submittal matters more than which city you live in. Outside city limits there's often no city permit at all, which removes this stage entirely. If you're in an HOA, its architectural review runs alongside — good installers start it at contract signing.
3. Utility interconnection application (parallel with the above). Separately from the city, your utility reviews the system's grid connection. Who that is depends on your wires: Oncor or CenterPoint in most of DFW and Houston, Austin Energy or CPS in Austin and San Antonio, a co-op in much of rural Texas — each with its own clock. You'll sign utility paperwork along the way (with the big utilities, typically two documents); signing them the day they arrive is one of the few timeline levers you hold personally.
4. Installation (1–3 days). The photogenic part. Racking, panels, inverter, wiring, labels.
5. Inspection (days to a couple of weeks to schedule). The city (where applicable) inspects the finished work against approved plans; utilities do their own verification, often from photos.
6. Permission to Operate (roughly 1–4+ weeks, utility-dependent). The utility completes its review, everyone signs the interconnection agreement, and the utility issues PTO — the legal green light. The PUCT requires Oncor, for example, to provide PTO within 30 days of the interconnection submission; other utilities run their own timelines, and backlogs happen. Your system must stay off until PTO — turning it on early violates utility rules and can flag your account.
7. After PTO: the billing tail (30–60 days). The meter gets reprogrammed and export data starts flowing to your electricity provider — so your first bill or two after PTO may not show export credits yet. Normal, not broken.
What actually makes projects fast or slow
Across all of it, three factors dominate: first-pass approval quality (rejected paperwork is the biggest silent delay), signature turnaround (utility documents waiting on a homeowner's inbox stall more projects than utility queues do), and jurisdiction (a Houston SolarAPP+-eligible job and an Austin Energy job simply have different shapes). A good installer will tell you the expected range for your city and your utility — and the best ones can show you live numbers, because they track every stage of every job. That's the standard worth shopping for: installers running on TexPTO can show you exactly where your project stands at any moment, which stage it's in, and what it's waiting on — no "checking with the office."
FAQ
What's the single longest wait? Usually a paperwork stage, not the build — commonly city plan review or the utility's interconnection/PTO step, depending on your area.
Can anything skip stages? Unincorporated addresses often skip city permitting; Houston's automated review path shortens plan review for eligible systems; nothing legitimate skips utility PTO.
Can I speed it up as the homeowner? Yes: sign utility and HOA documents same-day, respond quickly to your installer's requests, and hold off on switching electricity plans until your installer advises (it affects your solar credits).
When do I start saving? The system offsets your usage from PTO onward; export credits typically appear on bills a cycle or two later once metering updates complete.
Sources
- Texas LGC §214.904 45-day framework — see The 45-Day Rule
- Oncor Renewables FAQ (PTO within 30 days of submission; operation only after PTO): https://www.oncor.com/content/oncorwww/us/en/home/faqs/faq-renewables-solar-and-more.html
- Oncor DG overview (surplus reporting 30–60 days post-PTO): https://www.oncor.com/content/oncorwww/us/en/home/smart-energy/renewables-solar-and-more/residential-small-commercial-thinking-about-solar.html
General information. Timelines vary by jurisdiction, utility, season, and project — ask your installer for current local ranges.