How to generate electricity from Earth's motion & EM field?

Being that generators essentially work from motion + a magnetic field how could we use the rotation of the earth and it’s magnetic field to generate green electricity?

2 Responses to “How to generate electricity from Earth's motion & EM field?”

mental_absence Says:
3. August 2010 at 6:23 pm

hang a wire from a satellite to the ground.
but thats not exactly feasible.

planck6626 Says:
3. August 2010 at 6:23 pm

This experiment was performed in space. A long wire was released from the space shuttle. Indeed an electrical potential was created and electricity could be harnessed from the process, but the energy came from a loss of gravitational potential energy. In essence, you can’t get that electricity for free because you need to spend fuel to get to the apparatus into position again, and there’s an inherent inefficiency associated with that.