In the vast majority of developing countries without electricity, kerosene lamps are the go-to for seeing in the dark. But kerosene doesn’t burn cleanly and an accidentally knocked-over open flame can quickly set a house ablaze.
The GravityLight team have created something special—a lamp that only needs gravity to work. No harmful energy sources, and it's safe and reusable.
The mechanics are quite simple. The lamp works on a pulley system: A maximum 11 kilogram (24 pound) weight is hoisted up with a beaded cord. Once the weight reaches the top of the pulley, the user can let go, allowing the weight to slowly descend. As it drops, the bead cord passes through a connected train that lights a bright LED. And once the weight hits the floor, the process can be repeated. The entire cycle lasts 20-30 minutes.
This is actually version 2.0 of the GravityLight. The project released a trial batch last year, which was tested in almost 30 countries worldwide. That particular version unfortunately didn’t last as long and didn’t have as bright a light.
The Indiegogo campaign for the device is just over halfway funded to its $199,000 goal, and it has a month to go to get completely funded.