https://sites.google.com/site/haiticholeraoutbreak/solar-distiller
I haz a solar cooker made by the Solar Oven Society and they ship them to places like Haiti where women spend all day looking for firewood for cooking.
The solar cooker comes with a small wax tube thingie that will tell you when it melts that water you have cooking inside is cooked enough to kill things (instead of boiling). The only expensive/weird part of the cooker is the layer of stuff on the plastic top… something that lets in more light but protects the plastic or something. There are two layers of clear plastic so a layer of trapped heated air can act as a way to keep heat in.
Sounds cool 