We built solar water heater from an old hot water tank that Jon got free from a plumber. We cleaned out the old deposits, then painted it black and surrounded it with reflective panels, like a solar oven. It faces south of course and on a smaller lot, it could be placed vertically. I put it on the ground right above my plumbing and insulated it with straw bales. There is a release valve in case the water boils in our hot summers, too. Over the front is a recycled sliding glass door panel and then a thick insulated flap I can put up on cold nights. I removed my hot water tank and used only this for awhile. I was having some pretty lukewarm showers on cold wintry mornings, so I purchased a small tankless water heater as backup for about $200. This has done the trick and I don't see that its using much electricity at all. I think these pictures will explain this better than words: