J. de la Torre.
A solar water heater prototype was constructed using polyethylene terephthalate bottles to determine its feasibility as a component of the average household in rural areas in Guatemala. The cost of the prototype (with materials acquired in Guatemala) is USD 220 and can easily be reduced to USD 127. Additional cost reductions can be expected if the water heating system is mass produced. It is clear, regardless, that such a water heating system needs the support of international programs to become available to low income families in rural areas. Its performance, on the other hand, was found to be acceptable, it heats up water at ambient temperature (varying from 22 °C to 26 C°) up to 38°C to 45 °C, respectively.