In southern Brazil, retired mechanic José Alano invented this ingenious method of turning plastic bottles and milk cartons into solar water heaters. Since winning the Superecoligia prize for renewable projects with this system, it has become popular across Brazil, saving people money while keeping bottles and cartons out of the landfill.
The system is based on the principle of thermosiphon. As the cold water in the bottles is heated by the sun, it becomes less dense and rises upwards toward the storage tank. The more dense, cold water remains near the bottom and the cycle repeats itself. Because these systems use thermosiphon, no electricity is needed to pump the water into the tank.
This type of water heater takes time to construct, but is a simple concept using free or inexpensive materials – plastic bottles, milk cartons painted black, PVC pipes, and a storage tank. This particular system uses 200 bottles, and stores 200 liters of water in the tank.
Alano now spends much of his time teaching others how to construct this type of water heater, and they are being widely encouraged and implemented all over Brazil, now found on thousands of homes and commercial buildings.
The recycled solar water heater is only the result of persistence over frustration. I don’t consider myself an inventor. I am just a citizen trying to find solutions to problems.
Source: The Ecologist