Panels mounted on house roof, connected to MPPT in RV, grounding?

[jameshowison]

RV with existing solar, batteries, and inverter/charger. I have an external array that I have used laid on the ground outside the RV, connected to its own MPPT (panels --> disconnect --> two wires, positive and negative --> MPPT).

I'm going to mount those panels to a metal roof nearby the driveway where the RV is located, with conduit bring wires down to connect to the disconnect (and then on into the MPPT in the RV).

I'm wondering whether and where to ground the panels/frames. Any thoughts on that?

Inverter/Charger is a Victron so that handles the neutral/ground bond when the RV is plugged into "shore power". I don't intend to regularly plug the RV in, hoping that Solar will be sufficient.