The world's longest extension cord, huh. Someone oughtta do the math for how heavy it would need to be in order to carry the requisite current... shoot, even to support itself against high atmospheric winds.
The thing I was proposing was only for interplanetary travel, so no winds to deal with in vacuum. It would be a nuke propulsion unit trailing a tether that would drag the payload capsule along with with it, so no extension cord either. At 0.01 G, the load would not be high, but a unit that could maintain that indefinitely could build up considerable velocity