So other people have talked about the fact that it's just..expensive. But I want to focus on this statement here.

>Seems like Solar could play a significant role here...

I assume you mean solar power, right? That isn't exactly a solution even if we sidestep all the other issues like building the infrastructure that would be needed.

That solar power used for desalinating water would just be solar power we can't use for something else. Even in a world that is 100% renewable* there's a discussion that needs to be had about where the limited amount of power we have should go and with desalination, you are talking about something that was virtually free for the majority of human history and turning it into something that...isn't.

It's tantamount to saying "I bet spending money on it is the solution" I mean...yeah, but now that money can't be spent somewhere else.

*I mention this specifically because anytime you hear about a new thing that uses 100% renewable energy is still worse than replacing something that didn't use renewables. So like building a new water desalination plant that's 100% solar-powered is a lot worse for the environment than using all that solar power to shut down a few coal plants and not need the desalination plant in the first place.