GREENVILLE -- The first electric bus built by a Colorado firm at a South Carolina plant is ready to roll off the assembly line and be introduced to the community, a company official said Wednesday. "It's a 12-week process, and production time will be about a third of that by the end of the year," said Proterra President and Chief Executive Officer Jeff Granato. The 35-foot, black and white vehicle that is powered by battery will be shown off Thursday morning at a ceremony at the firm's temporary plant in Greenville, Granato said in a telephone interview. "We're putting 'Made in Greenville' at the top of it," Granato said. The bus seats 37, but can handle 68 passengers with some standing. It can operate on an inner-city route for a daylong shift and can reach up to 75 mph. It can be recharged within 10 minutes, he said. "It's a real smooth ride as well," Granato said. Proterra LLC, headquartered in Golden, Colo., was founded in 2004 and makes hybrid- and battery-powered buses for mass transit. Granato said the firm expects to start work on its new South Carolina assembly plant in the spring and could make up to 1,500 buses by 2015. The 220,000 square-foot plant will be located at the International Center for Automotive Research on the Clemson University campus. Granato said the firm is working with local technical schools to help train workers and is also hiring engineers and administrators for its staff. At present, 115 people work in its temporary quarters. The firm anticipates hiring up to 400 more in 2011, Granato said. The company is making buses for the transit agency in Pomona, Calif., and has a contract with San Antonio, Texas, as well. It is working on contracts with transit agencies in four other states, he said. The new bus is headed for a testing facility in State College, Pa., for safety testing required by the Federal Transit Administration. Granato said the bus, formally known as the EcoRide BE35, is the first all-electric bus the center is testing. If approved, the company may move forward to mass produce and sell the bus commercially, he added.