When I turn on a heater, it's supposed to be roughly 100% efficient. So it converts electricity to heat with great efficiency, but why can't we do the reverse: generate electricity by absorbing heat? I have been searching the internet and from what I have read it seems completely pointless because it is so inefficient, like ridiculously inefficient, as in 10% efficient. So why can't we do the reverse? I get that energy is lost when converting from one form of energy to another but how can we get such great efficiency going from one form but have horrid efficiency going back?
I also read online that one way to cool the earth down could be to radiate the heat off the planet. Anyways, sorry about my mini debate, can anyone answer how we could potentially cool the earth, because to me it would seem funny if we couldn't, and if we could then global warming wouldn't be as bad of a thing as it is now, would it?
Best Answer
"So, why can't we do the reverse?" Because of the Second Law of Thermodynamics! Very, very roughly, heat is 'thinly spread' energy and won't spontaneously organize itself into the 'concentrated' energy that we want (in the same way that a drop of ink released into a tank of water won't spontaneously gather itself up into a drop again). Advice: if you're really interested, read up about thermodynamics!