Wow, this is one hell of a thread! Lots of distractions.
It needs to remain #6, until it reaches the main ground bar. It can be used to ground equipment and enclosures, along the way. But, it needs to be a wired connection for the entire length. (Don't stop and start it, on two different ground lugs, in equipment or enclosures)
This quote brings up a concern I have.
My current roof mounted solar has solid, bare #6 from the roof to the MSP and ground bus bar.
Was inspected years ago and in operation currently.
I'm looking to add another roof mounted array.
I was going to join the ground for the new array onto the existing #6 ground in a box close to the arrays and just run the single #6 for both arrays back to the main panel.
Does the NEC specify the need for dedicated ground wires from the PV to the MSP/ground?
Tim, I included your quote above because you mention not starting/stoping the ground which sounds similar to my plan.
I couldn't find any NEC call-out one way or another, but I'm ot the best at finding anything in the code.
If I end up splicing the new array ground onto the original, I'd probably use something like this:
(Unless anyone has a better recommendation)