A clever group of teenagers in rural Nepal, led by Milan Karki (age 18, pictured holding his invention while a friend holds a lightbulb over his head), devised this solar cell that uses human hair instead of the more expensive and less eco-friendly silicon. At a cost of about £23, the new solar cell about 1/4 less than a comparable silicon-based cell. The prototype produces about 9V, lasts several months, and is easily maintained -- just replace the worn-out hair with fresh clippings!
As a child, Karki lived in a remote village with no electricity. He decided to find a way to bring electricity to his home and his village. For a poor village, this means it must be portable and inexpensive.
Karki's invention was inspired by physicist and author Steven Hawkings, who wrote about producing static electricity using human hair. The project took three years to develop the prototype featured here. The youth is hoping to commercialize and mass-produce his solar cell, and fulfill his dream of providing inexpensive electricity to poor rural areas.