The solar bottle bulb, (also covered here by Sustainablog, our sister site) an innovation developed by students of the Massachusetts Institute of Technology, inspired by the Appropriate Technologies Collaborative, is helping poor communities in developing countries like Brazil and Philippines through simple and appropriate innovation.
What is the Solar Bottle Bulb?
It is a simple bottle bulb, usually a 1 liter soda bottle that is filled with a solution of purified water and bleach. The bottle is inserted halfway through a hole drilled in the metal roof and its sides are sealed. The whole deal looks like a bulb through a sunroof and provides a good amount of light by deflecting sunlight into gloomy interiors.
The chlorine and bleach “poisons” the water to keep molds from developing so the solution can last up to five years. The clear and purified water helps disperse the light through refraction, so the light is not concentrated. It only costs $2-3 to make a solar bottle bulb that is bringing light to dark homes.
What are the Advantages and Disadvantages of the Solar Bottle Bulb?
This simple innovation is not perfect- the water needs to be replaced every five years and obviously without any provision for energy storage, the bulb will not work at night. But the advantages are overwhelming for communities that are deprived of daylight. It is surprisingly effective, using cheap and locally available materials that allows the poor in these settlements to use their homes more effectively. The bulb does not produce any harmful pollutants and also reduces the dangers from faulty and temporary electrical connections that cause devastating fires.
