SCE - over or under 10KW interconnection agreement?

I'm having an 8.2kW system with a Tesla Powerwall installed. The company doing the installation submitted an over 10kW Interconnection request to SCE. When I asked why over 10kW when the panels are only 8.2 they replied that it's because I also have a battery. Today I received an email from SCE saying that the request has the following error:

Total ESD Rated Discharge is over 10kW. One of the options below must be selected. If there is an existing ESD, PCS MUST be entered.
Will you be installing 1) a non-export relay on the storage device(s) or 2) a NGOM Directly to the NBT or NEM REGF(s)? Or 3) Utilizing a Certified Power Control System

Does this sound correct or should they be requesting an under 10kW agreement?

Will you have PV panels? Will they have a separate inverter and if so how many watts?
I think Powerwall can deliver its watts to the grid and GT PV inverter can also at the same time, so sum of the two.

Maybe this will be a Certified Power Control System, with Powerwall using CT at the meter, and avoiding exporting too much.

This talks about Tesla and PCS.


Surely too technical for the customer to have to deal with. Only the manufacturer could certify. I would think the installer is supposed to select the type of compliance. I saw that in some IREC training couple of days ago but haven't had to use it.

Yes, I have (20) REC panels at 410 watts each for a total of 8.2kW and a Powerwall 3 that has a built in inverter, and a Tesla backup gateway.

power wall rated 11.5 kW AC of continuous power per unit

I thought we were allowed up to 30kW under the "simple" process.
11.4kW would be suitable for 225A busbar and 200A main breaker in a panel.
7.7kW for 200A busbar and 200A main breaker.
Those are from the "120% rule".
The installer or manufacturer may be able to lock a 10kW max export if required.

Is there any downside to an over 10kW agreement? If not, I'll just let the installer deal with the error message. It just seemed odd to me that it was over 10kW when my panels could only produce 8.2kW but there's clearly a lot more to the equation.

Some or all POCOs in CA are enforcing additional regulations on systems that contain batteries and can output over 10kW back to the grid.

The reason is to prevent homeowners from buying large amounts of power, storing it, and then selling it back to them. Up to 10kW of inverter power is simply small enough that they aren't worried about the extra strain on the grid (at least at the PTO stage). Sure, you are allowed to sell/credit some power back, but your system is supposed to be sized to your usage so it should be minimal overall.

For systems over 10kW, you need an approved system such as a PCS that has been tested and approved with your inverter to analyze your system and prevent selling the POCO's own power back to it. You can also, in theory, have the manufacturer lock the output of your inverter via software, and then certify that you can't change it in writing. I am trying to do that with an EG4 18kPV application, but I'm being blocked by the web form, which is why I say "theoretically".

As jjww said, the battery inverter has an 11.5kW rating, so that exceeds the limit regardless of the solar output. @dpowell , were you able to get approved? Did you need to make any changes?