Ritu Narayan/Zum (Oakland, California)

Ritu Narayan is revolutionizing the largest mass transit system in the US: school busing. Her business Zum not only provides safe and reliable student transportation; it also benefits the environment, a cause near and dear to CNN Chief Climate Correspondent, Bill Weir. Last year, the nation's first fully electric fleet of school buses rolled out in the Oakland, California school district. By using groundbreaking technology, Zum also equipped the buses to feed energy back to the grid while idle, reducing strain on power plants and potentially offering vital support during blackouts. Today, the company serves more than 4,000 schools across 14 states.