In drought-stricken California, a giant billion-dollar desalination plant is now under construction, and 15 others are proposed along the coast. While the plants could help provide desperately needed water, the current technology has at least two major problems: it uses a lot of energy, and it’s very expensive. An alternative now in the early stages of development at MIT might help.
The new technology looks a little like a sponge. A black material, made from graphite and filled with tiny holes, floats on top of water, soaking up sunlight. As the material heats up, it heats up a small area of water around it, and a layer of foam at the bottom keeps everything hot. The water starts to turn into steam that could be used for everything from drinking water to sterilization in places off the grid.[SOURCE](http://www.fastcoexist.com/3033786/this-black-sponge-isnt-dirty-its-making-cheap-solar-powered-drinking-water)