One of the ways we can and do use power is desalination of water. Taking sea water, which we can’t use for much, and turning it into fresh water, which we need for everything.
This is a pretty energy intensive process no matter how you do it, and there are a variety of methods to do it.
In this case, it’s using the fact that black material absorbs sunlight and heats up to evaporate water, which then trickles down into a bowl, leaving the salt behind. As Treehugger says, it’s basically a solar still. Here are a few pictures from the website of the designer:
Thanks to a hundred years of pollution (give or take) there are other concerns with sea water, but none as immediate as the need for hydration, and none that are insurmountable.
On a side note – keep an eye on the so-called “developing nations” of the world. They all recognize what’s going on, and they’re working hard to find ways to deal with it. As such, there is a VAST amount of innovation going on that’s being aimed at helping folks in poverty-stricken areas.
Since the governmental policy of the United States has failed to encourage this sort of innovation here at home, it’s happening elsewhere, and a lot of this stuff still applicable to life in America. I’ll be updating on that topic in the near future.