[bzbarsky]

Nothing, since they are disconnected, so there's a voltage across the gap but not enough to spark. And you don't care precisely what the voltage is, because there's nothing happening with it.

But if you don't disconnect them, now you are maintaining a voltage across whatever your load is, but that voltage depends, for solar panels, on the current being pulled from them, as I understand. And you need to maintain the voltage in some nominal range. Maybe it all works out, but I'd have to do a lot of digging to be sure...