Light to the Poor, One Liter at a Time

In the slums of Manila, an innovative project is shedding light on the city's dim and dreary shanties.

Plastic bottles jut from the roofs, bringing light to the dark dwellings below.

The technology is as simple as it could be. Each bottle contains water and bleach.

When placed snugly into a purpose-built hole in the roof, the home-made bulb refracts and spreads sunlight, illuminating the room beneath. 

Eco-entrepreneur Illac Diaz is behind the project.

[Illac Diaz, A Liter of Light Project]: 

"What happens is, the light goes through the bottle, basically a window on the roof, and then goes inside the water. Unlike a hole which the light will travel in a straight line, the water will refract it to go vertical, horizontal, 360 degrees of 55 watts to 60 watts of clear light, almost 10 months of the year."

The initiative, known as "A liter of light", aims to bring sustainable energy practices to poor communities, an idea originally developed by students at Massachusetts Institute of Technology.

Working with low-income communities, local governments and private partners, the project has installed more than 10,000 bottle lights across Manila and the nearby province of Laguna.

For residents, it means less money spent on electricity to power lights during the daytime, and more money on food.