The water heater is a simple design, and uses a flat panel collector connected to a plastic water tank. There is also a header tank to replace the hot water as it is used.
A lot of the material used in the project was recycled. This included both of the water tanks and the metal sheet used in the collector ...

Most solar water heating systems rely on the thermosyphon effect to cause the water to flow through the panel without the aid of a pumps. This works because as the water heats up it becomes lighter, so heavier water flows into the bottom of the panel from the bottom of the tank and pushes the hot water out of the top of the panel into the top of the tank. There are two main requirements for this system to work. Firstly, the solar collector panel must be mounted on an incline, and secondly, the tank must be mounted above the top of the panel. ...

A low cost and excellent idea!!!

There are numerous sources of renewable energy available that are inexpensive and non-polluting. A good example of a renewable resource is solar energy, which is continually provided by the sun. Solar Energy can be collected as thermal energy, and then can be converted into electricity, or used to warm a building or provide hot water for such processes as cooking or bathing ... [an interesting idea]