GravityLight: power from the lift of a weight.

1. Sustainability Problem: Kerosene lamps

2.3 billion people across the world have unreliable or no access to electricity. Consequently, many african countries rely on kerosene lamps, which pose economic, health and environmental hazards.


2. Technology solution: Gravity Light

The set-up is pretty simple, the whole thing works a bit like a pulley – all you need to do is add 12 kg of weight to one end of the bead cord (this can be a bag of sand, rocks, whatever you like), and then lift that weight up by pulling down on the lamp attached to the other end.

Thanks to gravity, the weight slowly descends back down to the floor, transforming potential energy into kinetic energy as it drops. This kinetic energy then powers a drive sprocket and polymer gear train that lights up the LED as it goes. Once the weight gets to the floor, the light goes out and you need to repeat the process, but each pull provides you around 20 to 30 minutes of light, depending on how high you lift the weight up in the first place.



The stakeholders

  • Potential users and crowdfunding donors
  • The company (The GravityLight Foundation)
  • Retailers
  • Local governments / NGOs to foster usage of this product



  • The GravityLight Foundation has successfully gathered
    $400,927 USD (128% of the original goal) on July 18, 2015.  This enabled the plans to set up an assembly line in Kenya. First units should be available in 2016.
  • Support from NGOs, retailers and local governments is key to allow distribution of the GravityLight in areas with excess usage of kerosene lamps and/or limited access to electricity.




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