When something fall down, transform potential energy into kinetic one. furthermore you can attach a pulley and extract some energy (like in an aljibe) for example with a dynamo... if the object fall in a deep well, we can extract more energy, till the object reach downhole..
but what if we could have a "bottomless pit".. Endless energy?.. Well we would need an infinite earth.. or like a "black hole aljibe".. mmm that doesn't seem an option..
oh wait a minute, we already have one! satellite is like always "falling down".. then is exchanging "potential energy"(who knows from what reference system) into kinetic energy..
what about tied it to a pulley (a long rope I see) to a dynamo, or an earth winding with a magnet satellite, or a satellite winding with the earth magnet, or whatever.. the idea is to USE the "bottomless pit" energy..
where is the mistake? ( just in case there be any =P )