Desalination in general is expensive, and requires (obviously) that you've got coastline handy. I don't think solar desalination is a general answer, simply bec

Desalination in general is expensive, and requires (obviously) that you've got coastline handy. I don't think solar desalination is a general answer, simply because of the energy densities involved. The physics behind solar desalination means that you need at least 10m^2 of solar collection per household, just to heat the water if you're hoping to sustain people in this way alone, so while it might be part of a bigger solution in some parts of the world, it'll never be a solution in its own right.