There’s almost nothing better than seeing someone come up with a simple design solution for a big problem. There are billions of people in the world without reliable access to electricity; at night, those folks light their homes the old fashioned way—with kerosene lamps. Unfortunately, the fuel is dangerous and expensive.
Fortunately, low-power LEDs are making new lighting alternatives possible. The GravityLight project, for instance, is raising funds via Indiegogo to mass produce a gravity-based light that uses a descending weight to power an LED bulb. The light comes in a fabric bag that can be filled with rocks or dirt and used as ballast to provide up to 30 minutes of light. (The unit can also power a radio or be used to recharge batteries.)
GravityLight would be less expensive to purchase and maintain than solar alternatives, which require costly hardware and rechargeable batteries for energy storage.
UK-based designers Martin Riddiford and Jim Reeves have been working on the project for four years. GravityLight is a product of the deciwatt.org research initiative launched by their employer, therefore.com.
The light would cost $10 to purchase, with no ongoing operational costs. If the project reaches its funding goal, the developers claim they can get the price on the Version 2 model below $5.