Last week I posted this solar water heater using glow plugs video and, while an interesting idea, it’s not very useful when it comes to making the best use of a precious resource: off-grid electricity. With that in mind, I thought it would be useful to show a different idea of how to heat water more effectively and without batteries.
In this case, the following video is about using an old double-pane window and some 1/2″ irrigation hose to heat pool water. Add in a few other items like hose clamps, caulking, and some spray paint and that’s about it.
Although it’s not shown, I’m sure this guy had to use some sort of pump to actively most water from the pool through the solar heater, but if you understand the concept of passively heating water in this fashion then you can also use this idea to heat water passively when off-grid too. You can even upscale the project to heat more water. Just let your imagination go!