Let me start by saying that my knowledge of physics is almost nil (only high school level and I pretty much forgot everything) so bear with me, if I am asking naive questions the answers of which may be obvious to you.
My question is twofold:
Is it possible to use the motion of the planet or its magnetic field to extract an electric current efficiently?
If yes, how much electricity could be generated? Enough to power a toaster? A house? A city?
