The SALt lamp -- short for 'Sustainable Alternative Lighting' lamp -- is an incredible contraption that is capable of burning for up to eight hours at a time whilst powered by little more than a glass of water and a couple of tablespoons of salt.
The lamp relies on a galvanic cell battery whose electrolyte solution consists of salty water into which a pair of electrodes are placed. The lamp can be used for eight hours a day for around six months before the anode needs replacing. The lamp can generate enough power to charge smartphones via its USB port.
The SALt lamp was conceived by Greenpeace engineer Aisa Mijeno, who was looking for a way to replace the dangerous kerosene lamps used by many tribal peoples in the Philippines to perform tasks after dark. This lamp could indeed help bring light to deprived people around the world.