solar bottle bulb

Illac Diaz, of non-profit My Shelter Foundation, brought the simple, cheap and innovative technology to the Philippines.

The slums in Manila are being transformed by a new twist on recycling.  Plastic bottles are now being viewed as a cheap and sustainable way to light homes instead of trash. 


Shanty town homes in Manila are often built so close to each other that they have no windows or natural light. With electricity unaffordable or unavailable for many slum-inhabitants, many families often have to work, do chores, and eat in near darkness.

Now a simple innovation called the “Solar Bottle Bulb” is popping out of roofs and illuminating the lives of many.

Fixed into holes in a corrugated iron roof, the “bulb” is a recycled plastic bottle that contains bleached water. Bringing more light than a traditional window that can crack or leak during typhoon season, the bottle bulbs refract the sun’s rays to create 55-watts worth of light.

Illac Diaz, of non-profit My Shelter Foundation, brought the simple, cheap and innovative technology to the Philippines through his project, “A Liter of Light.”

“You can imagine how big the effect of this light is in these homes,” said Diaz.

The bottle bulb was inspired by engineer Amy Smith, from the D-Lab in MIT. Diaz started experimenting with the “Solar Bottle Bulb” technology after watching YouTube videos of her work in Haiti.

Aiming to create a green market for sustainable lighting, “A Liter of Light” has donated over 100 solar bottle bulbs to others across the Philippines to replicate the project.

Diaz’s team of eight trains and shares tools and technology with others across Manila’s slums as well as with locals from towns like Cebu and Visayas. The bottle bulbs are sold and installed for around $1 per piece.

With the help of many local governments, “A Liter of Light” and its collaborators have installed 12,000 solar bottle bulbs, lighting 10,000 homes in five Filipino provinces.

Using bottle bulbs instead of electricity or generators families can save $6 per month, according to Diaz. The Philippines is reported to have the most expensive electricity in Asia and slum homes do not have electricity meters with illegal connections costing more than standard rates.

Providing a constant light during daylight hours the bottle bulbs are promoted as a better choice than candles and electric lighting that may have dangerous or faulty wiring and could cause fires.

Diaz has high hopes for the future of his plastic bottles and is planning to expand his project to 36 towns across the country.

His idea was recently picked up by Civil Military Operations group of the Armed Forces of the Philippines that is set to distribute 10,000 bottle bulbs to different parts of Metro Manila’s slums.

“Once people see the benefits to the community, they will grab the technology,” Diaz said. “It will spread like a drop of ink.”

Photo credit: Nanyang Narratives