The GravityLight gets power from the slow lowering of a weight. All it takes is enough elbow grease to hoist the bag, and you can light a room with nothing but a bag of sand.
The need is enormous: more than 1 billion people still lack electricity.
Two socialpreneurs wanted to find a replacement for the dangerous and dirty kerosene lamp–which is also relatively expensive to run, highly polluting, and comes with multiple health and fire risks.































