The NEC, like all codes, can only react. Technology will ALWAYS be ahead of our rulebooks. Why do you think I keep advocating for good design, rather than 'code complaince?'
It seems obvious: everything should have an 'off' switch. With solar panels, IMO this switch needs to be as close to the source of the power as possible. If your only disconnect is at the panel, a fault in the supply line will never be shut off - at least, as long as the sun shines.
Getting back to our 'six throws' rule: I don't want to have to flip more than six switches to kill power to every branch circuit in the building. Whether that means I flip six branch circuit breakers, six supply disconnects, or some combination of the two doesn't matter: I want no more than six switches.
Can we count on the inverter as a disconnect, simply because it disconnects the solar feed in the absence of utility power? IMO, no. Make that "Hell No." Microchips and relays fail, or 'leak.' I want a real switch.
Since I want my six disconnects grouped together, I guess that means I want a disconnect on both ends of the solar feeder. Redundant? I don't see it as such. Rather, I see them as serving different purposes. One is there to contain a fault, while the other is there to remove the supply.
