Let there be light! That's Sam Goldman's motto, and he's taking it around the world. The founder of d.light design talks with Stanford Center for Social Innovation correspondent Sheela Sethuraman about how he is bringing affordable, ecologically sustainable electricity and lighting to billions who are now operating in the dark. In this audio interview, he details aspects of the design, function, marketing, and distribution of the organization's products, as well as the kind of impact the social enterprise is having in some of the most remote, poor areas.