Can I ask a very naive question? Isn't it viable to use solar energy to make the water evaporate and use the vapor as the desalined water?
I'm sure there should be some big issue, otherwise someone would use it. But I'm curious to understand what is wrong with such an approach.
down sides beginning you need to keep the mirrors cleaner than you do solar panels. Bird's that fly though the focused beam die. the sun has to be tracked, though I don't know if that's any different from a normal panel farm tracking the sun.
You could take a long and wide but short pathway of water with a tilted glass top and a black floor. The light is absorbed by the black floor, heating the floor then the water. Water evaporates to a vapor which leaves the salt behind. It then will condense on the tilted class ceiling and run down to a storage tank for consumption (You can also get a warm shower using this lowtech solar method.
I've membrane filtration at home, it consumes very little power than what you'd need to boil the water and condense it to water again.
I've tried it on my solar panels, getting even 5 liter of water on my 2x350w panel takes 3-4 hours while I get 5 liter water from RO membrane in 1 hour while using 5% of solar panel power.
