GravityLight is a revolutionary new approach to storing energy and creating illumination. It takes only 3 seconds to lift the weight which powers GravityLight, creating 30 minutes of light on its descent. For free.

Following the initial inspiration of using gravity, and years of perspiration, we have refined the design and it is now ready for production. We need your help to fund the tooling, manufacture and distribution of at least 1000 gravity powered lights. We will gift them to villagers in both Africa and India to use regularly. The follow-up research will tell us how well the lights met their needs, and enable us to refine the design for a more efficient MK2 version. Once we have proved the design, we will be looking to link with NGOs and partners to distribute it as widely as possible. When mass produced the target cost for this light is less than $5.
Why GravityLight?

Did you know that there are currently over 1.5 billion people in the World who have no reliable access to mains electricity? These people rely, instead, on biomass fuels (mostly kerosene) for lighting once the sun goes down...

...A commonly held view is that solar powered lighting is the answer to these problems in the developing world. However a number of conflicting factors combine to complicate matters. Solar panels produce electricity only when the sun shines, so the energy needs to be stored in a battery to produce the light when it becomes dark. The amount of energy stored is dependant on the size of the panel, the size of the battery, and how much (if any) sun has shone.  However batteries, panels and lights are expensive, and beyond the reach of people with no savings. Solar lighting projects continue to provide lighting for thousands of people in the developing world, but the spread is slow because the cost is too high for individuals, so they need to be bought and installed by communities instead.

Hat tip: Good