A cheap new light that could provide an alternative to kerosene and solar lamps in rural areas will enter field testing in Africa and Asia this year, after four years of development.

 

The device, a gravity-powered LED lamp called 'GravityLight', works by attaching a weighted bag below it from a cord. As the bag slowly descends, gears convert the weight into energy — providing users with up to 30 minutes of light, depending on the weight of the bag. There are also settings to provide brighter light for a shorter period.

 

Each device comes with an empty bag, which can be filled with up to 12 kilograms of material such as rocks and sand. It needs no battery.

 

The idea behind GravityLight was to overcome the limitations of options such as solar lamps, and kerosene lamps.

 

The field tests will examine the performance of the device over time, including the effects of varying weather conditions on its internal components. Once the tests have been conducted, production will be scaled-up early next year. Each device is expected to cost between US$5 and US$10.