Recipe: Solar Bottle Bulb (55-60W)

Ingredients: Used plastic bottle (50cl-1l), water, bleach, a sheet of currogated iron.

Instructions: 1) Open the bottle, fill it with water and a pinch of bleach. 2) Cut a small hole in the metallic roof of an unlit home, just wide enough for the bottle to fit.  3) Line and seal the bottle with currogated iron to prevent leakage.  4) Insert bottle in hole.

Preparation time / cost: 1 hour.  $1.

Servings: 5 years of light  (55-60W) widely spread through an unlit room.

Meet the "solar bottle bulb".  The simplest lightbulb ever.  Originally invented at MIT's D-Lab and now adapted and widely distributed to thousands in the Philippines by the MyShelter Foundation, an organization started by Illac Diaz spreading the Isang Litrong Liwanag (A Liter of Light) project.

You're probably thinking, what's so great about a lightbulb that provides light during the day???  Well, a lot of homes do not have windows for leakage reasons and depend instead on expensive electricity or kerosene to light their houses.

The magic of the water bottle bulb as compared to just a hole in the ceiling is - refraction.  Where a simple hole in the ceiling will allow sunlight to travel in a straight line and concentrate to a specific spot, the water in the water bulb will refract and disperse the sun's rays in all directions in order to illuminate the whole room.  It's cheap.  It's durable.  It's safer than candles or kerosene or electric wiring.  It's effective.

The MyShelter Foundation aims to provide 1 million homes with light by 2012.

See this video for a better idea of the project: <a href=""Bringing light to the poor, one liter at a time"">"Bringing light to the poor, one liter at a time"</a>.

The water light bulb takes the word "simple" to a whole new level.  I'm beaming.

Thanks Charlie!