Solar-powered electricity systems have often been touted as a solution for those living without reliable access to electricity, but another Earthly force is also readily available (and doesn't surrender to inclement weather or nightfall): Gravity.
That's the idea behind the GravityLight—a lamp that only requires the weight of a bag of sand or rocks to provide light. And for the 1.3 billion people in the world who live in "energy poverty," this simple yet genius idea could be a game changer.
For the majority of people without reliable access to electricity,dangerous and polluting kerosene is the primary source for light. But as designers Martin Riddiford and Jim Reeves said in their Indiegogo campaign, the GravityLight is "a low-cost [less than $10], safe and reliable alternative to the kerosene lamp, one that costs nothing to run, doesn't need batteries and pays for itself within weeks switching from kerosene."