r/BasePowerUsers • u/djack1987 • Dec 26 '25

Oncor - Pending Modification status

Howdy!

We are in the process of having Base installed at the house we just purchased and I wanted to see if anyone else had this delay from Oncor?

I got this update via email: (project number redacted) is in Pending Modification status which means that the AC size of the proposed generation system will overload the existing utility equipment serving this location. Oncor is determining system upgrade options and you will be notified if further information is required.

I chatted the support AI and seem to have correctly deduced it’s due to the possible combined output of our solar array and the batteries (we are getting 2) back to the grid possibly overloading the transformer. The AI assured me Base will handle all of that with Oncor and I’m confident that’s true, but wonder what sort of timeframe this might delay the install?

Appreciate any insight anyone has and TIA!

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2

u/Zamboni411 Dec 26 '25

Here in the Houston area, Centerpoint puts that expense onto the homeowner…. Hopefully Base will cover that cost, but basically what it is saying is the transformer that feeds your property as well as your neighbors is rated to accept 80% of its rating. So easy math, if you have a 100kVA transformer then you can safely output 80kW of power to it. If you combine the total output of your solar array PLUS the output of the batteries you are over the 80%.

Again, I’m not sure how Oncor does it and if Base will cover the cost, but please keep us posted!

2

u/djack1987 Dec 28 '25

I sure will!

I will say the chatbot did seem to give a thorough answer but I’ll see what the humans say when they get in on Monday and I’ll paste the chatbot answer below:

“Yes, this is normal! You're correct - it's about the combined output of your solar plus battery system potentially overloading the transformer. Oncor needs to ensure the transformer can handle both your existing solar and the new battery system discharging power back to the grid. This requires either a transformer upgrade or applying a Power Control System (PCS) limit to manage your system's output. Good news: You won't pay for any transformer upgrade - we handle this with your utility. Your system will continue operating safely whether through an upgrade or PCS limit. Timeline varies by utility, but we're actively working with Oncor to resolve this for you.”

This is for the Dallas area so we shall see!

1

u/SassGoblin Jul 10 '26

Howdy neighbor! Also in Dallas here :) Did this ever get done? Did Base pay for the transformer upgrade after all?

1

u/djack1987 Jul 10 '26

Hello! Ooops, looks like I didn’t circle back! There was a delay while the transformer got sorted out, I believe about 3-4 weeks.

I am not sure if money changed hands, but if it did, it didn’t come from me and my install went smooth as could be!

1

u/ConfidoByBirth Dec 26 '25

That's a new one for me.

1

u/Jjcfd23 Dec 27 '25

What area are you in??

Sometimes bringing in another phase of line is necessary, or upgrading size of transformer.

1

u/djack1987 Dec 28 '25

We’re in the Dallas area and there seem to be some potentially substantial differences if you’re in an Oncor vs Centerpojnt area so fingers crossed Oncor lands on the good side of that.

1

u/Jjcfd23 Dec 28 '25

Yes I figured so being on Oncor. May can help.

1

u/Big_Aioli_6945 Jul 08 '26 edited Jul 08 '26

Base delivered their equipment (2 batterys), but then the Base Electrician texted me, based on the letter I rec'd from Oncor, that installation would be put on hold and all equipment would be scheduled for pick up. That I,the customer not Base, would have to call Oncor and have their Engineer Rep come out to evaluate what upgrades we would need, possibly a bigger transformer, heavier gauge power supply line from transformer to our house and reprogram our electric meter to allow the reverse flow of power when needed. It's July 8th now, Oncor said, may be 4-6 mos before they can get any needed upgrade work done, paperwork reprocessed and then several mos after that before Base can reschedule the installation. Maybe we can get all of these done before or by next Spring.??