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GravityLight for Remote African Villages


Provide off-grid lighting solutions for remote African villagers.


Kerosene lamps are widely used in remote areas of Africa to provide light, and to cook and read by. These lamps are costly to run and generate harmful emissions for both users and the environment, as well as presenting a fire hazard.


SolarAid, a charity, challenged – a design studio with experience designing handheld computing and communication devices – to develop an LED lantern to tackle this issue. They produced a more radical solution: GravityLight.

Making use of Koomey’s Law: “At a fixed computing load, the amount of battery you need will fall by a factor of two every year and a half.” This means that relatively simple devices progressively need less energy to run. Similar efficiencies have been seen in radio communication too, opening up the possibility of low cost, off-grid computing and communication equipment.

GravityLight uses a small current generated by a gravity-fed dynamo. The simple device is driven by a falling weight – a sack that can be filled with rocks – providing half an hour of light before being reset. The project was crowd-funded via Indiegogo to pilot the first 1,000 units.


Less than US$10 to buy, with a longer term aim to price it at US$5
No running costs
3-month payback from avoided kerosene costs
Can be used to power other items and recharge batteries

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