Milan Karki, an 18 year-old from a rural village in Nepal, has invented a type of solar panel that replaces expensive silicon with cheap, easily replenished human hair. Melanin, the pigment in human hair acts as a conductor for solar energy, and hair, unlike silicon, can be easily replaced, giving the panels a longer lifespan. The devices are also considerably cheaper than commercially available solar panels, costing £23 to make (and considerably less if mass-produced). Karki hopes his hairy invention will help bring electricity to remote populations. [Times Online via Slashdot]