I think there may be a bit of misunderstanding. The ground output of the inverter (the ground pin of the socket) has 60 volts potential between neutral or hot. In a normal electrical system neutral and ground should be bonded, but if I do this, I will create a 60 volt short and damage the inverter.
The charge controller has some odd circuitry which causes the negative of the PV side and the negative of the battery to not be isolated from each other either and are at a different potential (I forget what) so I cannot bond those either.
I'd have to measure battery and AC output to see if those are isolated or not but I have a feeling they arn't either.
So for now I will leave the PV and battery side float, but I'm more concerned about the AC grounding, so I'm proposing to ignore the inverter's ground, and supply my own from the ground rod which will tie to the AC ground and the neutral at the main junction box that feeds everything else. This will ensure that the AC ground, wiring boxes, and neutral are all referenced to earth ground as it should be in a normal AC system.
This would be a somewhat temporary solution though as I do plan to buy a better inverter, so if I'm lucky the new inverter will have proper isolation between input/outputs so that I can bond everything correctly without causing issues. But that's not something I'll know until I pick an inverter and measure it. We are very limited here in Canada as far as PV related products so I have slim pickings.