I love solar power, but here is a solution that is brilliant yet elegant in its simplicity: a (super-efficient) LED light that can be powered by a bag filled with rocks. Kind of like an old-fashioned Grandfather Clock.

Hat tip to the folks over at the Red Ferret Journal, who wrote:

A huge part of this planet exists without access to reliable electricity, which doesn’t just mean no access to computers and other tools, but a lack of even the most basic of necessities such as cheap lighting. Most of these places still rely on kerosene lamps, which are smelly, polluting and expensive to run. There are some superb initiatives happening around the world at the moment to solve the problem, and we think this new project could be a real winner if it takes off as hoped.

The GravityLight uses a clever belt and pulley system to generate light through the force of gravity. The idea is for the user to pull a bag up to generate enough energy for short periods of light. Because it uses ultra low power LED bulbs, this could mean up to 30 minutes of light for a quick 3 second hoist. It’s much cheaper than solar (which needs batteries to store the sun’s power) and easier to maintain than other more complex devices.

The product comes in it’s own pouch, which can be used to hold stones or dirt as the weight needed to make the light work, so it’s very self-contained. The GravityLight has also been designed with sockets to charge up batteries or other devices, but we’re assuming that the efficiency of the product will need to be improved considerably before this becomes a valid option.

The project is at early crowdfunding level at the moment, as the developers need funds to distribute test units to Africa and India for testing, but the team have a good track record in design and engineering, which should help the product get the necessary support. This project reminds us of the brilliant original Watercone product, for water purification and de-salination, which also delivered a simple but effective solution to an important problem. We need more of these innovative types of projects.