hrmn. if it exports energy, it must be acquiring it from somewhere.
nothing wrong with magnetic field induction yielding electricity - hell, that's basically a radio receiver.
speculation:
conceivably, something could convert passage through magnetic field of the earth into electricity.
barely conceivably, a mechanism could convert more of the earth's magnetism into electricity than is used in its propulsion.
of course, it would have some (immeasurably small) impact on the magma current which produces the magnetic field to begin with.
not "creation of" energy, but on its face looks like "free" energy.
Check out using a tether in orbit for power generation.
I think you've re-invented the Aurora Borealis.