Shedding light on dark communities in the Philippines is a liter-sized plastic bottle that contains water and bleach.
One organization, Liter of Light, is organizing people to build "solar bottle bulbs."
The bottle is sealed in an iron sheet and installed into a small hole in the roof of home.
The bottles absorb sunlight and emit about 55-watts of light into a dark interior, the Discovery News reported.
This is a boon for people in Manilla, the Philippines, where About 3 million homes are in the dark and have to rely on kerosene lamps for light.
These bottles provide a cost-effective and environmentally safe way to provide light to these families during the daylight hours.