I've posted here about the square foot solar cooker, and here is another of the many uses for it.
This is a solar alembic, or pot still, made from square foot mirrors, which can produce between 2 and 5 ounces of distillate on a lazy sunny afternoon.
It is not that great at making distilled water (without added reflectors as above), but can make essences, perfumes, and even ethanol.
Please note: it is illegal to distill ethanol except for fuel, and you must have a federal permit to do so. However they are not that hard to get, and our government is actually encouraging the citizenry to experiment with this which is why I'm writing. I am with a group who have one.
Here is the link for a permit, which you MUST have. You need to specify that you will be making alcohol for fuel on the permit application.
You need 3 square foot mirrors, about $7 at your hardware store to build the reflectors..
Put them together with duct tape (carefully) to make a half box.
You can run a bead of silicon along the seams.
Be sure to have some backing on the mirrors (as above) as they are dangerous to carry about. You can use cardboard, or even better a good wood backing for safety. Paint your wood with a good coat of shellac or paint to help preserve it in the weather.
Your 'mash' bottle, outer cover insulating jar, and collector bottle can be had with a little scrounging in the recyclable bin, or from your local bar or casino. For the outer insulator jar, I use both glass and PET plastic gallon jars. I like the PET better because it insulates just a bit more, and is lightweight and unbreakable.
Cut a 1 inch hole in the middle of your jar lid to allow the beer bottle to poke through.