How exactly does it work?
Above is a version of GravityLight that uses the same method as described below, except with a weight as opposed to a ballast bag. The original GravityLight uses the concept of gravitational energy. It works in a very simple and time efficient manner. The light consists of an LED bulb fixed to an adjustable lamp which the consumer must hook onto a wall or from a ceiling. There is a "ballast bag" which is filled with 9kg of rock, sand, or soil. This method is very similar to that of pendulum clocks which work with the help of weights. The potential energy is represented by the ballast material. When the consumer suspends the ballast bag from the weight hook, the potential energy is converted by Gravity with a slow descent of the bag. This converted energy generates light. The GravityLight can be operated for thirty minutes continuously before the consumer must refill the ballast bag.