Imagine a light bulb that's cheap, easy to make, and needs no electricity to run.
It may sound too good to be true, but that's exactly what a Brazilian mechanic, Alfredo Moser, has created.
He is the inventor of a light bulb made from just a plastic bottle, water, and a tiny bit of bleach.
By next year, it's predicted his low-tech bulb will light a million homes around the world http://bbc.in/19pGft9
(Photo: Gibby Zobel)