A simple, low-cost solar water purifier (SWP) for rural households, which does not require electricity or waste precious water has been developed. The SWP consists of four tubular solar water heaters attached to a manifold. Non-potable water is filled in the SWP after filtering with four-layered cotton cloth and heated in the stagnation mode by solar energy to make it potable. The cost of the SWP is around Rs 2500–3000 (~US$ 40–50) and is so simple that any small rural workshop can fabricate it. In large-scale production it is envisaged that the cost can come down to Rs 1500.
