I've just read this article on a new - albeit very small scale ATM - way of generating electricity directly from water vapour:
There's also a link to the paper in the article.
To think of the evaporated water vapour in the atomsphere as a giant energy store driven by the sun smoothing out daily and yearly cycles is very compelling.
Somehow they've mananged to generate an electric field by differentially binding water vapour within the material and then have a current run along that field - again fed by water vapour as fuel. What I don't understand, however, is the conservation of energy side, here. We have water vapour going in and electricity and what going out? Liquid water?
Has anyone seen articles on that paper or the paper itself too and can elighten me?