Ma, a 42 years old farmer in China recently build a simply solar water heater from beer bottles as a gift to his mother. This heater only cost about twenty dollars and three days labor. Now this simply water heater is expanding within the village and more rural elderly people are benefiting from it. Ma's long goal is to promote this device into more rural areas in China.
I need to build something like that with all the beer bottles we have here in America
It would be truly useful if you could post a simple schematic or even just a closeup photo, showing a basic detail or two about the water heater's construction. How does water circulate between the bottles?