Lighting Up Homes With A Plastic Bottle and Some Chlorine

If you live in a home without electricity and few or no windows, it’s always incredibly dark inside, even at high noon a Liter of Light is a sustainable lighting project that is trying to help people overcome that problem with extremely simple technology


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. 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.

This project and its success is a great example of the ‘market-based’ solutions that should be pursued for socio-economic problems worldwide, strategies that are smart, effective & resourceful