Most everyone has experience with passive solar water heating. How many times have you turned on the hose in the yard and nearly burnt yourself with hot water? While you weren’t looking, old Sol was quietly working to give you hot water, even if you didn’t want it. Well if it’s that easy,
imagine what you can do if you’re actually trying to make hot water. Passive solar hot water systems are probably the oldest commercially available solar systems. At the turn of the century there were large numbers of solar water heating systems on roof tops, especially in Los Angeles and Florida. Very little has changed from the original concept. Put a water holding tank in a box, with glass on the side facing south and fill it with water. No moving parts, nothing to break down, free fuel and no pollution.
The passive solar water heater is known today by many names; PSWH, Batch Heater and Bread Box are the most common and then there is the very technical; Integrated Collector and Storage System (ICS).