In many parts of the world, people live in windowless shacks or thatch huts that provide shelter but aren’t very useful during the day. They usually do chores outside their homes. If they need to be inside for some reason, they often resort to kerosene lamps, which can be a safety hazard and, if used four hours a day, can emit about 100 kilograms of carbon dioxide a year.
Alfredo Moser came up with a better idea. The Brazilian mechanic found himself in an extended blackout about a decade ago. He experimented with a simple device – a clear, one-liter bottle filled with water and some bleach to prevent algae growth. By inserting the bottle through his roof, he was able to create a light source (daytime only, of course) that gives off 40 to 60 watts of light. That’s enough to see comfortably.
An organization called MyShelter Foundation wants to install a million of these lights around the world by 2015. If you’d like to help with a donation, go here.