A new solar desalination system takes in saltwater and heats it with natural sunlight. The system flushes out accumulated salt, so replacement parts aren’t needed often, meaning the system could potentially produce drinking water that is cheaper than tap water.
It’s not nice and neat table salt. It usually comes to the form of an extremely toxic saline sludge. With who knows what other ingredients inside of it. It’s a major problem with this kind of thing. If you use it on an industrial scale a scale large enough to provide water for a city for instance, then you’re going to have enough output that will probably destroy whatever water source you’re extracting water from. Better hope no one fishes in that ocean, cuz they all going to die.