A Household Lamp Powered By A Bag Of Rocks
About a billion of people around the world still use expensive and toxic kerosene to light their homes. London-based product designer Martin Riddiford and his colleague Jim Reeves have addressed this problem and created GravityLight, a cheap and safe alternative. It is a household lamp powered by a bag of rocks. Here is how it works: a person hangs the device and fills an attached fabric bag with up to 28 pounds of rocks, dirt, or other material. Lifting and releasing the bag steadily pulls a notched belt through GravityLightâs plastic hub; the belt spins a series of gears to drive a small motor, which continuously powers an LED for about 30 minutes. 1,000 GravityLights are to be sent to developing countries for field testing, plus 6,000 more for backers. Riddiford is sure that the lamp could prove handy not only in desolate villages, but also in campsites, closets, and any dark nook far from a socket.