People talk about a flash of inspiration. But Xavier Helgesen's eureka moment came in the dark.
A few years ago, the American entrepreneur was traveling through Malawi to meet with clients for his book-selling company, Better World Books. He stopped in Monkey Bay, a town of about 30,000 people, to spend the night. What made this place unforgettable, he says, was that it was "100 percent off-grid."