I have never seen where solar stills are anything but a waste of energy and sweat in the desert, but I think they could be feasible in more temperate climates.

Here in the Pacific Northwest, I think they could be a viable source of water where/when there is no CLEAN water to be had, and rainfall is not forthcoming.

I'll have to try it sometime and see. I'll put it on my list. (we need a Rolly Eyes smilie)

Sue