re: "challenges"
I don't know how long it would take, but at some point the orbital rings and the planet would be rotating at exactly the same speed. A generator works because part of it is tied to the ground.
The electricity in our atmosphere (lightning) is generated by solar energy interacting with the atmosphere and moisture in the air, and has absolutely nothing to do with the Earth's planetary magnetic or electrical field. It's the sun rubbing its feet on the carpet.
