Colleyville · Approvals and paperwork

Home battery permits and Oncor interconnection in Colleyville.

A grid-tied home battery in Colleyville normally needs three approvals, and none of them are yours to chase. The City of Colleyville reviews and permits the electrical work; a city inspector signs off on what was built; and Oncor, your distribution utility, executes an interconnection agreement before the system may run while your home is still connected to the grid. Your installer draws the plans, files the permit, meets the inspector and submits the Oncor application. You approve the design, sign the interconnection agreement as the utility customer, and give access on installation and inspection days. The order runs design, permit, install, inspection, interconnection, commissioning — and most of the calendar sits in plan review and interconnection, not in the one to two days of work at the house.

The three approvals, and who handles each.

These are three separate processes run by three separate bodies. They tend to reach homeowners as one blur of paperwork, which is how people are caught out by the third one.

The sequence, from design to commissioning.

1. 01

   Design approval.

   We assess your home’s real load, agree how many batteries it takes and which circuits sit on backup, and put it in a written scope at a fixed price. Nothing is filed with anyone until you approve it.

2. 02

   Permit filing and plan review.

   Your installer submits the plan set to the city through its permitting portal. Colleyville maintains its own contractor registration alongside that portal, and your installer handles both. Plan review is the city reading the drawings before anyone touches your service, and it usually sets the calendar.

3. 03

   Installation.

   Most installations finish in one to two days on site once the permit is issued. Main-panel work, or a long conduit run to where the batteries go, can add to that.

4. 04

   City inspection.

   Plan on an inspector at the house. The city does run a virtual-inspection program, but it is listed for a specific set of replacement work — HVAC, water heaters, reroofs, under-slab repairs and irrigation — and storage is not on that list.

5. 05

   Oncor interconnection.

   The application for interconnection and parallel operation goes in, the agreement is executed, and the utility gives written permission for the system to run in parallel. Until that is in hand, a grid-tied battery is not meant to be operating.

6. 06

   Commissioning and handover.

   The system is energized, tested against a simulated outage so you can watch it take over, and handed over with the app configured and explained.

Why a grid-tied battery needs a permit at all.

A home battery is not an appliance you plug in. It is a modification to your home’s electrical service: new conductors, a battery inverter, disconnecting means, usually a backup load subpanel holding the circuits the battery carries, and sometimes a change at the main panel. That is exactly the category of work permits exist for.

The practical value is that it puts an independent party between your installer’s drawing and your home: somebody who does not work for the installer reads the plans, and somebody who does not work for the installer looks at the finished job. It also leaves a record you can show an insurer and that a buyer’s inspector will not flag years later. The standard is a current one, too — Colleyville publishes submittal guidelines specifically for solar PV and energy storage systems, the present set effective April 2025, so your installer is measured against a document written for this equipment.

What the Oncor interconnection agreement is.

This is the step homeowners have usually never heard of, and the one that explains the timeline. A grid-tied battery spends almost all of its life electrically tied to Oncor’s system — charging from it, and depending on configuration able to push power back onto it. A battery that can export is handled under the state’s distributed-generation interconnection framework, and running it while you remain connected to the utility is what that rule calls parallel operation. No utility permits it by default. Under the Public Utility Commission of Texas rule that governs on-site distributed generation — the framework applied to export-capable home batteries — a customer must first submit an application for interconnection and parallel operation to the utility and execute an interconnection agreement on the forms prescribed by the Commission, and the utility may refuse to connect the facility if that application has not been received and approved.

The logic is easy to state. When the street loses power, your battery must stop feeding the line and isolate your house instead, so a lineman working on the conductors outside is not working on a circuit your battery is quietly energizing. That is why certified equipment matters, and why the utility wants a signed agreement on file rather than a phone call.

On timing, the rule is useful but not a promise: it sets target windows of four weeks from receipt of a completed application where the equipment is pre-certified and six weeks for other facilities, with the utility using best reasonable efforts and notifying the applicant if it cannot meet them. Note the word completed — an application missing a document never starts the clock, which is most of the argument for having the installer file it. The same rule bars a pre-interconnection study fee for pre-certified units up to 500 kW that also stay within the rule’s export and short-circuit thresholds, A house-sized battery sits far below the capacity ceiling, so a study fee is not normally part of a residential project, though the other conditions are the installer’s to confirm. We publish no fee figures here, because city fees and utility charges change; your installer confirms the current ones in your written quote.

Your role versus your installer’s.

One installer does all of that, and one point of contact reports on it. You should never be the person telephoning a permit desk.

What typically causes delay.

A main panel that has to change.

Older service equipment sometimes lacks the capacity, or the busbar rating, to take a battery inverter as designed. That changes the scope and the drawings, and occasionally brings in a separate utility service step. A proper site visit finds it before you have a permit in review, which is why we look at the panel early rather than quoting from a photograph.

HOA architectural review.

Many Colleyville neighborhoods have a homeowners association with an architectural review committee, and that review has nothing to do with the city permit: different body, different criteria, and its own meeting calendar, which is often the slowest clock in the project. It usually turns on where equipment sits and whether it is visible from the street. A side yard behind a screen is an easier conversation than a street-facing wall, and far easier to design around at the start than to relocate later. Tell us at the consultation.

Inspection scheduling, and an incomplete file.

Inspections happen in windows, and a corrected item means a second visit. On the utility side, an incomplete application has simply not started. Neither is dramatic; both are why a few weeks is a realistic expectation and a few days is not.

The terms you will hear.

Parallel operation

Running your battery while your home is still connected to Oncor’s system, which is how a grid-tied battery normally lives. It is the condition the interconnection agreement governs.

Interconnection agreement

The contract setting the conditions under which your system may be connected to the utility’s system. It is between the utility and the customer, so you sign it even though your installer prepares it.

Permission to operate

The utility’s written go-ahead, commonly shortened to PTO, that the system may begin running in parallel. It is the milestone that ends the paperwork.

Anti-islanding

The protective function that makes the system stop energizing the utility line and isolate your house when the grid goes down.

Backup load subpanel

The panel holding the circuits the battery carries during an outage. On a whole-home design the intent is that everything, central air included, sits behind it.

Where the paperwork sits in the price.

Permit filing, inspection coordination and the utility interconnection belong inside the installed price, not on a later invoice. The planning ranges we publish — roughly $25,000–$40,000+ installed for a whole-home system of two to three batteries, or about $12,000–$15,000 for an essentials-only single battery — are meant to include the approvals, and a fixed written quote replaces them either way. There is more on what drives those numbers on our Colleyville home battery cost page. The federal residential tax credit ended on December 31, 2025, so systems are quoted without it.

The approvals are also a quiet practical difference between a battery and a standby generator. A generator needs a permit and an inspection too, but most residential standby units transfer the house off the grid rather than running in parallel with it, so a utility interconnection agreement is not typically part of that job — one of several trade-offs we set out on battery versus generator in Colleyville.

Questions about permits and interconnection.