One man’s trash is another man’s solar water heater! By using household junk, most of which you can get for free at the local landfill (and you’ll be doing someone else a favor, too), you can make your own thermal water heater for less than the price of a fast food meal. A highly customizable project yet super effective (water can get hot enough to scald, so be careful!), its open face also brings the neat aspect of being able to watch the solar heating process in action. Though the instructions here are for small scale heating, with a few modifications you can make this work for your home. To start, you will need to find:

  • 2 buckets
  • Drill, plus drill bits and screw bits
  • Scissors
  • Simple hand saw
  • Wood, a few pieces will do
  • A pane of glass
  • Back of a small refrigerator (here is where you’ll need to troll the landfill or your neighborhood on garbage day)
  • 12 feet of air pump hose (similar to those used in fish tanks)
  • Backing material (this can be as simple as an old doormat, leftover carpeting, etc)
  • Wood Screws
  • Aluminum Foil
  • Duct tape
  • Angle cutter/hack saw

Firstly, remove the grill from the refrigerator. For safety’s sake, ensure that all the coolant, such as freon, has been removed. There should be two tubes conspicuously sticking out – you will be attaching the water hoses to these later, so don’t cut them.

The wood will be your frame, and will really depend on the size of glass you have. Construct a simple four edged frame, slightly bigger than the fridge grill. Place the foil  on top of your backing material, and secure your frame to the back with screws. Use duct tape to seal off the gaps between the foil and the wood so that it is as watertight as can be.

Cut some notches on the side where the fridge’s grill has the two tubes for entry and exit. Thread them through these holes; the water tubes will run out of the water heater device and be attached to both ports. Use duct tape liberally as needed to make sure everything stays together, including the grill to the backing (though, if you saved the mounting brackets from the fridge these can help too).

Attach the glass pane to the top – this again can be done with duct tape, but screws would be a more long term solution. Angle your water heater to catch the most sunlight.

Fill one bucket with regular cold water and place somewhere where it will be higher than your “warm” water bucket (which is currently empty). Taking one end of the water tube, siphon the water by sucking the tube and quickly re-attach it to the grill’s entry hole. One end of the tube will drape into your empty bucket. The water will run through your collector at a slow pace, gradually heating up until it comes to the end of its journey at the exit port of the grill. If you want even hotter water, just pour your warm water into your “cold” bucket and repeat the process.  Try this project today – for something made out of garbage, it sure works surprisingly well!