I'm not so sure about that being an acceptable solution for civilian transportation… Even assuming automation can eliminate the risks and training overhead associated with in-flight refueling, there are still be some major hurdles that would need to be addressed before this could be considered a viable solution. The 3 big ones that come to mind are:

What happens if the KC-135 misses the rendezvous? What if the charging port fails to work for some reason? What about the carbon footprint of these airborne generators?

Plus, now you have the weight of the capacitors to carry around all the time, further reducing the effective payload.