Solar Bottle Bulb

The Solar Bulb is both simple and life-changing. In 2002, Alfredo Moser, a Brazilian mechanic, invented a light bulb powered solely by refraction (the bending of light) of sunlight. The light bulb is composed of an empty two liter PET (plastic) bottle (“the cleaner the bottle, the better”) fi lled with fi ltered water and “…two capfuls of bleach to protect the water so it doesn’t turn green [with algae].”1 A hole is then drilled into the roof tile, the bottle is inserted into the hole, and polyester resin is applied as a sealant to prevent the roof from leaking. A fi lm case or black cap is used to cap the bottle. Moser had an engineer measure the light produced by each bulb: “It depends on how strong the sun is but it’s more or less 40 to 60 watts.”1 The bulb can work for up to 5 years depending on its installation.2 Moser got the idea while thinking with his friends how they would create an alarm during an electricity blackout. His boss suggested fi lling a plastic bottle with water and focusing the sunlight on grass to start a fire.1 In June of 2011, Illac Angelo Diaz, executive director of the MyShelter Foundation in the Philippines, started producing the bottles. Known as the Liter of Light project, the foundation began in San Pedro, Laguna (starting at 10,000 homes with installed light bulbs) and moving outward to 20 cities in the Philippines.3 Because the houses are built so close to one another, there is little to no natural daylight entering the spaces, leaving them completely dark even during the day. Obviously, the solar bulb provides a solution, but more importantly, it is a solution that lowers electric bills. Since then, MyShelter has established bases in Colombia, Peru, and Switzerland. Their goal: “Using the Philippines as our home base, we want one million bottle lights installed around the world in 2015.”3


1. Zobel, Gibby. “Alredo Moser: Bottle Light Inventor Proud to be Poor.” BBC World Service. 12 Aug. 2013. Accessed 11 Sept. 2013.
2. Kemp-Griffi n, Christian. “Bringing Light to the Poor, One Liter at a Time.” Reuters. Accessed 11 Sept. 2013.
3. “How Did a Plastic Bottle Change the World?” MyShelter Foundation. 2012. Accessed 11 Sept. 2013. <http://aliterofl>.