TEDTalks : William Kamkwamba: How I harnessed the wind - William Kamkwamba (2009)

At age 14, in poverty and famine, a Malawian boy built a windmill to power his family's home. Now at 22, William Kamkwamba, who speaks at TED, here, for the second time, shares in his own words the moving tale of invention that changed his life.