Doug I actually do not recommend the solar sill either. What the intent of the article is to set the record straight because there are errors on both sides. No it is not a great thing to precure water in the desert but it is not completely useless either.

Where I think its best use is as a still to decontaminate bad water. While boiling and chemical means can deal with bio hazards. They do nothing for other water contamination sources such as alkaloids often found in desert water sources or salt from sea water. And as I said it is just another option.

I do not know if it is still available but years ago I ran in to a product called if I remember right was tedlar. This was 1 mil thick and textured on one side. It was a very strong plastic that looked a lot like saran wrap. The texturing helped the water to collect better and run into the container. Being so thin Carrying a one or more large pieces was easy.