Earlier today I remembered hearing something about a cooling system that only used magnetism(turned out it also needs movement, but i digress) & after googling it, I found the one I was thinking of was called the magnetocaloric effect. Then I remembered the Peltier effect & a story(the source of which I can't remember) about a machine that would ice over as it drained heat from the environment as it generated kilowatts of electricity.
First magnetize the magnetocaloric alloy using an electromagnet, causing it warm up. Once it's radiated most of it's heat, cut the power to the electromagnet causing it to cool down. As it cools, it should take heat in from the environment, using the peltier effect plates surrounding it to generate energy to be stored in capacitor(s). That energy is then used to remagnetize the alloy. The effect could possibly be improved with multiple layers of peltiers.
I know both of these technologies are considered inefficient & unexplored, but I still figured it would be worth sharing. I also would have made a diagram, but it came out pretty bad.
http://www.science20.com/welcome_my_moon_base/new_magnetocaloric_material_will_allow_magnetic_refrigeration (http://www.science20.com/welcome_my_moon_base/new_magnetocaloric_material_will_allow_magnetic_refrigeration)
also, it's worth noting that a magnetocaloric alloy has been made that's composed of manganese, iron, phosphorus and germanium, which are cheaper & less toxic than previous gadolinium or arsenic-based ones.
What, still no replies? :(
I just found this post (rather long after original posting), but since it is basically the same concept I have been engaging in some thought experiments of late, I thought I would post. The fundamental premise of my thinking is:
1) As we (people of the world) "consume" energy, we, of course, are not really actually using it up, but rather are returning the energy we use for practically everything we do to Earth's environment as heat (with a small fraction being lost to space).
2) If we could discover a way to convert the ambient thermal energy that is always around us into electricity - i.e. create a device that would cool the environment around itself, while that thermal energy is converted to electricity - then we would have a limitless supply of energy for our needs since a recycling process for energy would be established (no need to break any laws of physic, either! :)).
3) A little Googling turns up two principals that might fit the bill for this sort of device: the magnetocaloric (MC) effect and the thermoelectric effect. With next to no energy used, you could move a magnet around a ring of MC metal. Once in motion, a heat gradient is continuously created in MC metal. A judiciously placed thermoelectric (TE) material could convert the gradient to electricity (i.e. some of the thermal energy converts to electricity). Cool, huh? :)
Of course this is just a thought experiment, and I would hazard a guess that at this point, with current MC and TE materials, that the amount of energy produced would fail to exceed the energy "overhead" for the device, but I am not sure that is the case or that better materials are not about to be discovered.
In any case it seems to me that this or any other "energy recycling" scheme is worth thinking about as a solution to our energy woes.
yes i had a discussion on this topic a while back but there is no need for a thermoelectric material as that would be excessively inefficient.the heat and cool cycle happens so fast on an electromagnet that it would be a useless endeaveour anyways.you just have to make use of the back-emf kickback for an energy gain under the ideal circumstances because the core of any electromagnet itself undergoes magnetocaloric heating and cooling.