Author Options:

Building a low cost (within $ 100) a home solar water heater Answered

 I am from India and want to build a Solar Water Heater for use in the bathroom for having bath for only two of us (me and my wife). 

The capacity of the tank need be only 5 litres. The battery backup is not needed since this will add to the cost of the gadget.

An open terrace is available on top of my house where the solar panels can be fitted and sunlight is available uninterrupted for nearly 8 hours..
My budget is within $ 100. 

Request members to provide the details for this DIY gadget.

Waiting for the replies 

A. S. Bhasker Raj


As per Raving, but who needs the tank ? Just get as much tube as you can afford, put it on the terrace, and connect the other end to your cold feed. The total volume of your pipe is Length X 3.1 X  diameter2 / 4

22metres of 12mm diameter tube holds about 5 litres of water.

Black polyethylene pipe should be absolutely ideal.

Post a picture when you've done it.


True, the tank is more of a "nice to have" than a necessity, as is any additional pipe length over the minimum required to hold 5L.

Get several hundred feet of black garden hose or sprinkler tubing. Coil it into a big flat circular coil and attach it to your roof in a sunny location.
Attach one end of the coil to a black 55-gallon drum which is placed in a location that is slightly higher than the coil.
Attach the other end of the coil to your bathroom spigot (which is lower than the coil).
Run a water hose to the roof and fill the drum. Open the spigot in the bathroom to make sure that the coil fills with water too. Close the spigot, top off the water drum, and wait for the water to heat in the sun.
The water in the coiled hose will heat quickly, the water in the drum will heat more slowly, but will provide water pressure as well as some warmth.
Take a bath.
When done, refill the drum with water to ready it for the next use.

Or... this.

Seconded - "Start with about 99 dollars worth of black rubber hose"...

"coil hose in the sun"

"pump water through the hose".