So it occurs to me that one might be able to obtain mass quantities of used soda bottles and then cut the top and bottom off. Then slit the remaining "cylinder" right down the middle. What you are left with is a strip of clear PET. Well PET is fairly easy to solvent together. (And FREEEEEE.)
Take the strips and glue them together and attach to a normal
greenhouse framework. PET is INCREDIBLY strong stuff and will easily take the desert environment except I don't know about UV resistance.
I am looking to make a super cheapo covering for my three season grow house, turning it into a four season
greenhouse.
Granted, this will be incredibly time consuming, but if one just did a few soda bottles a day, one could make
enough to cover a small greenhouse fairly fast.
YLE