Gravity light is the revolutionary piece of technology. GravityLight will cost only $5 USD in mass production and will work without any operating cost - a lighting solution designed for developing countries. It works in such a way that it stores the energy in rechargeable battery (through solar panels) and the energy is used to lift the weight attached to it therefore providing light through gravity pull for up-to half an hour. Takes no batteries to run out, replace or dispose off. Capable of powering up the radio, other small lights or even recharging batteries, the GravityLight comes with a durable fabric bag wiz filled with sand, soil to power it up. This remarkable achievement will be the best alternative lighting system and will work for number of years because it doesn’t take any operating costs.
Available at indiegogo.com for $50