A large number of us don’t have access to electricity. Those in the know put the number at 1.5 billion. That’s more than the total population of China. Can you imagine an entire country the size of China being completely off the grid?
So how do those who don’t regularly have access to reliable electricity get by? They burn kerosene for light, charcoal and wood for heat and cooking, and often at night live in the dark. Kerosene doesn’t come cheap. And in places like Sub-Saharan Africa charcoal and wood are increasingly scarce items. Add the additional hazard of smoke and its potential for causing respiratory diseases, and the risk of an open flame causing a fire, you can see why bringing electricity and light to households currently in the dark is a worthy task.
That’s what makes the GravityLight lamp so exciting. This is technology that is easy to build, requires no batteries, uses cool LED as the light source and gravity as the energy source.
How does it work?
The GravityLight comes in a kit (see image below) that includes an LED bulb fitted into an adjustable lamp that can be hung on a wall or from a ceiling. It also includes a pulley mechanism and a ballast bag which hangs below the lamp.Hang the lamp. Fill the ballast bag with up to 9 kilograms (20 pounds) of soil, sand or rock and you are good to go.
The GravityLight works on the same principle as pendulum clocks that run using weights. The technology used by the GravityLight, therefore, has been around for four centuries or more. It works on very simple principles. The ballast material represents potential energy. When suspended the potential energy in the ballast gets converted by gravity as the bag slowly descends. That energy is then emitted as light. A GravityLight can operate for 30 minutes before it needs a “rewind.”
The goal of the inventors is to make this light available for as little as $5.00 U.S. making the lamp pay for itself in a couple of months from the savings in not having to buy kerosene. The inventors went to a crowd funding site to raise capital for manufacturing. Their goal was $55,000. To date they have raised almost $250,000.