Permission to Operate is the utility's written green light to turn the system on. It comes after the interconnection agreement is fully signed and the utility has finished its review — and in Texas, flipping the switch before that letter arrives is a tariff violation, not a shortcut.
Where PTO sits in the sequence
For a typical residential job in TDU territory (Oncor, CenterPoint, AEP Texas, TNMP):
install → city inspection passed → interconnection application complete → utility review → interconnection agreement signed by all parties → PTO issued → meter reprogrammed/swapped → exports begin flowing to the REP.
Two documents need the homeowner's signature along the way. Oncor is explicit about this: the tariff application starts the review, and PTO is released only after the interconnection agreement is signed by the customer and the utility. The single most common "the utility is slow" complaint traces back to an agreement sitting unsigned in someone's inbox.
How long PTO takes
- Oncor: the PUCT requires Oncor to provide permission to operate within 30 days of the interconnection submission date. In practice, complete residential applications often clear faster; the 30 days is the backstop.
- CenterPoint: typical residential approvals run a few weeks, but CenterPoint has publicly acknowledged backlogs during volume spikes, with waits stretching well beyond norms in peak periods.
- Munis and co-ops: their own timelines entirely — Austin Energy and CPS Energy run separate processes, and co-op turnaround varies by co-op.
The honest way to set homeowner expectations: quote the range for their utility, and update it from your own live data rather than from the utility's published number.
What happens if you energize before PTO
Both major TDUs are unambiguous:
- Oncor: operating without a signed interconnection agreement and PTO violates the Oncor tariff and PUCT rules, and may bring fines and disconnection.
- CenterPoint: an early-energized system throws an error on the meter, triggers an investigation, delays surplus reporting to the REP, and puts the account in violation status — CenterPoint also frames it as a safety risk to the home, line workers, and nearby grid equipment.
Backfeeding a line that crews believe is de-energized is the underlying safety issue, which is why certified inverters must drop offline during outages (the IEEE 1547 / UL 1741 anti-islanding requirement). Train crews and sales teams alike: commissioning tests that require utility approval wait for the letter.
After PTO: the last mile people forget
PTO isn't the end of the paper trail. The utility still has to reprogram or swap the meter for export measurement — Oncor says to allow up to 30 days for the meter order — and surplus generation data typically starts reaching the homeowner's REP within 30–60 days of PTO, often after the first full billing cycle. If a homeowner calls two weeks post-PTO asking why their bill shows no export credits, that's usually the answer. Details in Meter Reprogramming and Surplus Reporting.
Protecting the PTO date
The utility's clock only runs when the ball is in the utility's court. The days that quietly pile up are yours:
- Submit the interconnection application in parallel with permitting where the utility allows it, not after final inspection.
- Get homeowner signatures on utility documents the same day they're issued — e-signature turnaround is a controllable metric.
- Sweep utility portals daily for deficiencies; a kicked-back application ages silently.
- Log the submission date and count against the utility's committed timeline so escalation is fact-based.
Teams do this with discipline or with tooling. TexPTO timestamps every interconnection milestone per job and flags applications that have aged past the utility's own standard, so "waiting on the utility" is a verified state instead of an assumption.
FAQ
Can the homeowner use their solar before PTO? No. In TDU territory it violates the tariff and PUCT rules; with CenterPoint it also flags the meter and puts the account in violation status.
Does passing city inspection mean PTO is close? It means the utility's prerequisites are nearly met. PTO still requires the completed application, utility review, and a fully signed interconnection agreement.
Who gets the PTO letter? Oncor sends it to both the customer and the installer once the agreement is executed.
Why is the homeowner not getting export credits after PTO? Meter reprogramming and REP reporting lag PTO — commonly 30–60 days before surplus shows up with the REP.
Sources
- Oncor, Renewables/Solar FAQ (two-signature process; 30-day PUCT PTO requirement; penalties for early operation): https://www.oncor.com/content/oncorwww/us/en/home/faqs/faq-renewables-solar-and-more.html
- Oncor, residential/small-commercial DG overview (meter programming; surplus to REP in 30–60 days): https://www.oncor.com/content/oncorwww/us/en/home/smart-energy/renewables-solar-and-more/residential-small-commercial-thinking-about-solar.html
- Oncor Interconnection Application for Certified Systems (meter reprogram up to 30 days; REP reporting after first full billing cycle): https://www.oncor.com/content/dam/oncorwww/documents/smart-energy/energy-system-developers/Oncor%20Interconnection%20Application%20for%20Certified%20Systems.pdf.coredownload.pdf
- CenterPoint Energy, DG Application Process FAQs (ICA before PTO; consequences of early energization): https://www.centerpointenergy.com/en-us/Services/Pages/DGAP-FAQs.aspx?sa=ho&au=res
General information, not legal advice. Confirm current process with the serving utility.