The Pop Can Solar Heater: An incredibly simple, safe, and affordable solar heating project that can be completed in a day after you have saved up the cans. You can also use corrugated aluminum siding. This is genius!
Instructables user, TheNaib, has written a tutorial on how to create a solar thermal water heater for under five dollars. It will involve a fair amount of DIY, but nothing too complicated. designed as a fun project, but with some tweaking it could