Plastic waste. From plastic straws being replaced by cardboard straws to the EU banning single-use plastics, to your millennial neighbour with their impressive mason jar collection, it seems everyone is on a mission to cut down on plastic waste.

But what if this “evil” had the potential to bring light into darkness?

A litre of light

Electricity is an expensive necessity, a necessity that is even more important for the people who have no natural light seeping through windows in their home.

This need led to the creation of the Litre of Light, a simple innovation that started in the Philippines to provide indoor lighting from daylight by using… plastic bottles!

Fitted to the roof of homes, it refracts sunlight to light up a whole room. Using cheap materials easily accessible by the poorest of the poor, the Solar Bottle Bulb (as it’s also been called) produces high-quality natural lighting to those living in the slums of cities, giving them an affordable and sustainable alternative to electric light during the day.

The method

Recycled plastic bottles (yes, the very ones we keep hearing about for being evil) are filled with water and a little bit of bleach. The bottle is then pushed through a steel sheet to prevent it from slipping; the sheet is then inserted into a corrugated steel roof. The top part of the bottle is left outside, with the rest of the bottle inside the house. A sealant is used to make sure the hole is weatherproof.

The result? A  natural light that emits the same amount of light as a 40 – 60 W incandescent electric light bulb!

Litre of Light has also introduced a version of the Solar Bottle Bulb that uses solar energy to create light at night.

This innovation has spread across the globe, and through a network of global partnerships, Litre of Light teaches marginalised communities how to use recycled plastic bottles to illuminate their homes, businesses, and streets.

The organisation’s open source technology has been recognised by the UN  and adopted for use in some UNHCR camps. It won the 2016 St. Andrews Prize for the Environment, the 2015 Zayed Future Energy Prize, and is a winner of the 2014 — 2015 World Habitat Award.

And it’s all possible thanks to a plastic bottle and some bleach!