Shelton Nyakundi, an 18-year-old student at the Menengai boarding school in Nakuru, Kenya, believes one simple thing could make the difference between the academic success and failure of many pupils: light.  Nyakundi says to save money, his school switches off its inefficient incandescent lights at 10 p.m. depriving students of valuable studying time. “Right now, lack of light is a limiting factor, both in the evenings and in the mornings,” says Nyakundi, who wants to work in healthcare when he graduates. The United Nations Environment Programme (UNEP) C…