Had that happen to me with PG&E before, maybe 8 or 9 years ago. The numbers are a little hazy but it was something like we had a 1,200A service SWBD and did not find out until the interconnection application phase that PG&E had only given them a 300kVA pad mounted service transformer. This was a municipal design bid build project so the interconnection phase did not happen until the contractor started the build process. The PV system I was working with was something like 350kW AC. Upsizing the transformer to what was normally the next size up at 500kVA was not possible because PG&E said they were discontinuing that size so they could only provide a 750kVA and since that was way over the load they would charge a fee every month for the oversized transformer. We were using SolarEdge inverters but PG&E would not accept the export limiting system that was built in, we had to either install an expensive non-export relay or have the factory limit the output of the inverters. We went with the factory limit option. Good luck.
That one makes sense to me considering the size, we have always pre-applied for greater than 30kw to flush out any details. This is 23kw, I’d have never imagined this being possible, and I know why…
10kva overhead transformer = 13kw max
15kva overhead transformer = 19.5kw max
25kva overhead transformer = 32.5kw max
This of course applies if it’s only one customer fed from the transformer, which in this case is correct.
So the gray area only applies if you’ve got a small transformer, and your sizing is greater than 13kw or smaller than 30kw, or 19.5 depending on the transformer. It’s a narrow range.
The option for power control systems is new, I know nothing about it beyond using it for storage systems — I’ve never tried it for oversized PV systems, but I’m hoping it works! It does make sense, small transformer but high usage means offset usage and export less than max.