Originally posted by Geomancer
OK, so we're talking about taking mass that's high up, and lowering it. Since gravity's such a weak force, in order to have any
usefulness, you need to lower an enormous mass (since the vertical distance available is limited). About the only waely to easily handle such a large
mass is for it to be a liquid, and the only liquid common enough to be worth considering is water. In terms of effeciency, room for improvement is
limited in large systems: effeciency (I believe) is already well over 90% in state of the art devices. The only radical approach I can think of is
MHD, but I'd be impressed if you could get reasonable effeciencies (>20%) there. For low flow rates you could try using pistons as opposed to
turbines. I believe this has been propesed for tidal plants. |