I think the inverters (unless of course they are designed for off-grid use) will know they don’t have a grid and refuse to start up.
Many PV system owners have tried this only to find it’s an excercise in futility.
Search the 'Net. You’ll find it’s been tried more than one would think.
I don’t know about string inverters as I have Enphase micros.
The line freq spec for the M250 inverter (the ones I have) is 57 to 61 Hz.
In addition to the frequency, the amount of deviation from spec, as well as the speed of the deviation in both frequency and voltage is monitored. Bottom line, unless a generator has very stable frequency and voltage outputs, the inverters shut down with a Grid Instability error.
Bottom line is it doesn’t make any difference. Either way, the results are the same.
Oh, I expected many have considered it!
Nice to have some figures on the stability requirements.
Mine are also Enphase microinverters.
Thanks for the input!