Ken Peavey wrote:
55 gallon drums are handy. I had one in the old greenhouse, put an 8 watt pump in it, moved the water through some tubing left in the sun then back to the barrel. Heated the barrel to 120-140, gave up the heat overnight. Cost to run the pump 6 hours/day is about 12 cents/month. Run a section of hose through the tank to the hot water side of a faucet (or just a 2nd hose nozzle) and you get warm/hot water.