So he built one.
William built the first windmill when he was fifteen. He's revised and rebuilt since then. He's nineteen now, and his current windmill lights three rooms of the family house, not including the porch, charges the family's radios and the village's mobile phones.
Last November, the MTTA's deputy director visited William's library. I can imagine how that went: "Were the books we donated useful?" "Oh, yes. You should see William Kamkwamba's windmill." "... I'm sorry, WHAT?" So William got written up in the national newspaper, and then got attention from international-development types. He's now working with folks from various companies and development groups, and the publicity has raised enough money for him to go back to school; he was even a special guest at a TED conference in Tanzania.
William Kamkwamba's project is really quite cool. Powering ultra-tech homes with sustainable energy is still difficult and expensive, but if your needs are very modest, a windmill can do a hell of a lot. I think the Kamkwamba approach has a lot to recommend it, and I'm very interested to see his future efforts. His blog is updated as communications allow (he has irregular computer access, so often has a friend post for him). Check it out: it's not often you get to watch a mad scientist blossom in rural Malawi.