So, it has been a little bit since I have played off the grid, but from what I remember the water/power production is fairly simplistic. Imagine an unseen water tank and battery at play here. It takes time to make power/collect water and once it has been stockpiled it has to be used up for it to go away. Mine would do it very quickly, but I never gave them twelve generators. If you still had extra you could sell it with bill cycles from what I remember, but as I said mine would use their excess very quickly since they never had much.
So I am now going to ask just how long the power lasted.
I have indeed heard of the fuel cell problem as being a known bug, but the rest I am not so sure
