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.
I've done some reading on this topic and came up empty with ways to paste two pieces of PET together. The only thing I have done with soda bottles is to cut the bottom off and melt the remaining rim in a hot skillet so that it makes a reinforcing bead around the bottom. A good way to come up with a cheap cloche to protect small seedlings.
He's dead Jim. Grab his tricorder. I'll get his wallet and this tiny ad: