Solar Bottle Light

An amazing and simple solution for the Manila slums in the Philippines, by MyShelter Foundation in collaboration with students from Massachusetts Institute of Technology takes old plastic bottles, fills them with water and a cupful of bleach – to prevent the build-up of algae – and embeds them in a piece of corrugated metal. This device is then inserted into a carefully-cut hole in the roof and sealed to prevent leaking during heavy rainfall. The bright Philippines sun is refracted through the water and penetrates the room below, illuminating it with the equivalent of a 50 watt bulb.

See the original post at Inspire Fusion