San Antonio is a municipal-utility town, which changes the shape of the job: instead of a city permit plus a hands-off TDU, you're running a dual-approval process — the City of San Antonio's Development Services permit and CPS Energy's own interconnection review — and CPS is a full participant with its own documentation standards, its own review, and its own program rules. Neither track waits politely for the other; run them in parallel or eat the delay.
Track 1: the city permit
City of San Antonio Development Services handles the building/electrical permitting through its BuildSA customer portal, with electrical permits pulled by state-licensed master electricians registered with the city. Plan sets follow the standard Texas package — site plan, one-line, equipment specs, structural documentation where required — with one local emphasis worth designing for: San Antonio applies International Fire Code access-pathway provisions to roof-mounted arrays (the IFC 1205-series requirements), so large contiguous arrays need the pathway and setback layout drawn, not implied. Outside city limits, Bexar County Development Services takes over with a lighter county process — same boundary-checking discipline as every Texas metro.
Track 2: CPS Energy
CPS Energy is San Antonio's municipal utility — wires, meter, billing, and solar program in one — and its interconnection is its own animal, not a PUCT-tariff clone:
- Its own application and agreement. CPS requires an interconnection agreement submitted by the homeowner or contractor with a detailed one-line diagram, a site plan, and manufacturer specifications for the equipment.
- Its own equipment expectations. CPS maintains equipment standards independent of the generic listings — build your CPS design library from its current published requirements rather than assuming a UL 1741 listing settles it.
- Its own review clock. Reported review times vary — roughly one to two weeks for clean electrical/interconnection reviews by some accounts, several weeks in others' experience, with extra documentation for systems above 25 kW. Quote homeowners from your live numbers, not folklore.
- Its own compensation program. CPS has historically credited solar under net-billing-style structures (retail-rate crediting up to usage with a lower rate for true excess, per third-party reporting) and has run rebate programs whose paperwork often starts the project sequence — because the incentive application captures much of the same system data as the interconnection. Program terms shift; check every sales quote's bill-impact math against CPS's current published program.
Running the dual track without dropping it
The failure mode in muni territory is sequencing drift: the city permit sails, install finishes, and then someone discovers the CPS application was never submitted — or was submitted and kicked back three weeks ago into an inbox nobody sweeps. Because CPS review can involve rebate reservations, equipment checks, and inspection coordination, its clock deserves equal billing with the city's. Practical rules: file the CPS application at contract signing, not at inspection; keep a CPS-specific submittal checklist distinct from your city checklist; and track both approvals as separate gates on the same job. That two-gate-per-job structure is native to TexPTO — each San Antonio job shows its BuildSA stage and its CPS stage side by side, each with its own aging alarm, so "approved" always answers "approved by whom?"
FAQ
Do I need both a city permit and CPS approval? Yes — they're independent. The city permits the construction; CPS approves the interconnection and controls energization on its grid.
Does the PUCT interconnection rule apply to CPS? CPS is a municipal utility, so the PUCT's TDU interconnection framework doesn't govern it the way it does Oncor or CenterPoint — CPS's own standards and agreement control. Background on the three Texas regimes: our interconnection guide.
What about unincorporated Bexar County? County development services handles permitting with lighter requirements, but CPS's interconnection process applies wherever CPS owns the wires.
When can the system turn on? After CPS completes its process and authorizes operation — the city's final inspection alone doesn't energize anything. See PTO in Texas.
Sources
- DOE/OSTI, Best Practices Guide for Streamlining Solar Permitting (San Antonio region process; CPS requirements and rebate-first sequencing): https://www.osti.gov/servlets/purl/1079472
- Third-party San Antonio permitting overviews (BuildSA portal; IFC pathway provisions; Bexar County; CPS review windows): https://www.solarpermitsolutions.com/solar-permitting-in-san-antonio-tx and https://energyscaperenewables.com/post/texas-solar-permitting-county-ahj-guide-epcs/
- Reported CPS solar crediting structure: https://www.solarreviews.com/blog/going-solar-with-cps-energy
General information, not legal advice. CPS program terms and city requirements change — verify current rules before quoting or submitting.