6 ms·
It is clearly not impossible, the paper clearly states that it's thermodynamically feasible, even if not practical at 1970s
by quertered 3y ago
It is clearly not impossible, the paper clearly states that it's thermodynamically feasible, even if not practical at 1970s
- waveBidder 3y agowhere are we extracting the energy from? is it effectively geothermal power?
- MarkMarine 3y agoIt’s solar powered. Ok, I’m being brief but you seem genuinely curious, so, lemme explain what I mean: In thermo, you would draw a line around a closed system, and say basically conservation of energy applies in this system. Energy in = work out + losses. In a system where one input is the ocean, you basically just consider that infinite because of the size differences. One dinky little pipe compared to the mass flow into the system from the ocean, that math would be silly to bother with. That said, to swat down the stupid “this is perpetual motion” comments from people with Reddit engineering degrees, you also have to add in the energy input into the system of the sun, which is keeping the water from freezing over the course of 1 million years as it runs someone’s sarcastic water wheel.
- lazide 3y agoYour comment is literally word salad. Mind taking another pass?
- postalrat 3y agoSalt falling though gravity? It won't work after the upper layers of the ocean are depleted of their salt.
- fbdab103 3y agoThere are 1e20 kgs of salt in the ocean. I am going to put that as a somewhat low concern.
- AnotherGoodName 3y agoSeparating salt and water releases energy. Adding salt is endothermic, it absorbs energy. Most people have this mentally backwards since it's currently so hard to separate salt and water and they don't really notice the water getting cold when they stir in salt. But... there's no reason a process couldn't separate them and give off energy from a thermodynamics point of view.
- richk449 3y agoSo salt combining with water takes energy, and separating it gives off energy. Yet combining happens spontaneously, and separation doesn’t. Because I don’t understand this, it seems like a paradox. What am I missing?
- lazide 3y agoThey’re talking about a tiny, tiny portion of the energy balance for one part of the salt in saltwater. The energy needs to actually purify it are far, far greater in practice.
- AnotherGoodName 3y agoTo move to each side of the energy states you need to overcome a hump between. Think electron tunneling. The separated side is the lower energy state. It's just that we don't know a good way to 'tunnel' to that state from the higher energy state in this particular case. The separated state has an easy way to receive energy to overcome that hump. It just needs agitation. There should be a way to reverse it and gain energy but we haven't found a good way yet.
- IshKebab 3y agoYou're forgetting about entropy. You can magically unmix a cake. http://butane.chem.uiuc.edu/pshapley/GenChem1/L20/2.html http://butane.chem.uiuc.edu/pshapley/GenChem1/L20/2.html