PTRA

Proterra Inc

A maker of battery-electric transit buses, Proterra also built the battery packs and charging systems that power other companies' electric trucks, delivery vans, and school buses. Founders Dale Hill and Jeff Granato started it in 2004 in Golden, Colorado, with a mission to bring zero-emission buses to American city streets. Its name blends the Latin "pro" and "terra," meaning "for the earth" — a fitting label for a firm that built its first buses to be so light they once set a record for the most efficient commercial electric vehicle.