SOLAR POWER 55W LIGHT BULB FOR CENTS

Who says you can’t bottle (and distribute) genius? Developed in Brazil to address under-illuminated slums, this simple design idea has been adopted by MIT students and expanded to other developing areas where many low-income homes lack access to either daylight or electricity.

We have lightbulbs made from glowing metal filaments, fluorescent gas, and LED diodes. And now we have one made of water. There is also a virtually unlimited supply since the "bulb" is composed of nothing more than one-liter plastic bottle, water, and bleach. The simple technology can be installed in less than an hour, lasts for five years, and is equivalent to a 60-watt bulb.

It works simply: The water diffracts the light, letting it spread throughout the house instead of focusing on one point. The bleach keeps the water clear and microbe-free.

Adapted by students from the Massachusetts Institute of Technology focused on "appropriate technologies," the solar bottle bulb is illuminating poor settlements across the Philippines, where the organization Isang Litrong Liwanag ("A Liter of Light") has already installed 10,000 of them. “With the Solar Bottle Bulb project, a brighter Philippines is going to become a reality,” Illac Diaz, a social entrepreneur installing the bulbs, told a Filipino publication. You can watch a video of the bulbs in action, here: http://goo.gl/wGDfMX

In total, one of these do-it-yourself lights takes maybe an hour to install, cutting an appropriate hole, inserting a bleached-water-filled bottle, and resealing around the resulting gap. Even where clean water is rare, a little can generally be spared for a half-decade of lighting.

We take for granted our electric lights, windows and skylights to access the sun’s glow, but for those living in close-together shacks with corrugated-metal roofs, a stray ray is welcome, and something that can spread light to the darkest interior corners can be a dream come true.

~ Tom Retterbush