Bringing light to rural regions that lack electricity is one of the greatest challenges facing developing countries. While extending the power grid will still take several decades in countries such as Rwanda and India, private entrepreneurs are delivering practical solutions. Sameer Hajee founded Nuru Lights, a company that makes LED lamps that run on rechargeable batteries.Despite that, the batteries have to be recharged far from any power supply system. Instead of solar cells, Hajee is using converted bicycles that can charge the batteries in 20 minutes. The LEDs can then be used for up to ten days - a huge step away from climate-damaging kerosene.