text: have you ever made a solar powered device of your own design? did it work? how much did it cost?  why did you make it?  what material did you use? two, actually- one was a simple water heater for a cabin of mine, using a rooftop black insulated tub with a large clear cover-the sun heated the water, and i was able to take a warm shower at night- the other was a triple paned greenhouse made out of 3mm plastic- it was an experiment i did to see how long i could keep a greenhouse going in the winter here in manitoba.  the cost of either was negligible.