Cleaning off a newly installed solar bottle light bulb
Photo: A Liter of Light Mumbai

Tool 76 in the #countdown is solar bottle light bulbs. Invented in Brazil, they take advantage of free daylight. This simple innovation – a bottle filled with water & some bleach added to prevent bacteria build-up – gives out the equivalent of 55 watts of light. They”re fabricated out of local, cheap materials and inserted into a hole in the roof. They provide local jobs & zero carbon, free light. A Liter of Light has popularized them in the Philippines. Photo: A Liter of Light Mumbai