William Kamkwamba

William Kamkwamba was born in 1987 and grew up in Masitala, a village near Wimbe in central Malawi, one of seven children of a maize farmer. In 2001 the rains failed, the harvest was lost and the family ate one meal a day. There was no money for the secondary school fees, about 80 dollars a year, and he was sent home from school in his first term. For a while he sneaked back in until he was caught.

The village had a small library stocked by an aid agency, and he went there to keep up. He found a textbook called Using Energy with a picture of a windmill on the cover and read that a windmill could generate electricity and pump water. Only about two per cent of Malawians had electricity. He decided to build one.

He took a bicycle frame, a shock absorber, a tractor fan, PVC pipe melted flat for blades and a dynamo, and raised a tower of blue gum poles. Neighbours watched him picking through the scrapyard and told his mother he was mad. When the turbine finally turned, a bulb in his bedroom came on. Soon four lights, two radios and a phone charger ran off it, and villagers queued to charge phones. He built a second windmill to pump water for the fields.

A newspaper story in 2006 led to a TED talk in 2007, where his halting English moved the audience. He finished school, graduated from Dartmouth College in 2014, and wrote The Boy Who Harnessed the Wind, later a film.