The City of Burbank, Calif., has been selected as a national test market for a new zero-emissions, ultra-quiet prototype bus that uses a hydrogen fuel cell instead of a diesel or gasoline engine.

The breakthrough vehicle will be unveiled in a spring 2009 Downtown Burbank ceremony and then go into immediate service on various routes within the City's Burbank Bus network.

Designed and fabricated by Colorado-based Proterra, the vehicle can travel 250 miles before needing to be recharged. It runs at double the fuel economy of a diesel bus and releases nothing but water from the engine exhaust.

In addition to being U.S. built, the vehicle relies on power that is 100 percent derived from U.S. sources, thereby reducing dependence on foreign energy.

The technology is very similar to that used in 2010 next-generation plug-in hybrid vehicles, such as the Chevy Volt. On-board computers regulate the electrical needs of the engine by alternating between power fed by Proterra's TerraVolt energy storage system, and power derived from the hydrogen fuel cells developed by Hydrogenics Corp. These cells are fed by pressure tanks located on the vehicle's roof, and transform hydrogen and oxygen into water vapor and electricity to charge the batteries. The vehicle may also be recharged by plugging into readily available wall outlets, like many of the new hybrid cars.

Other agencies involved in this pioneering project include the California Air Resource Board (CARB), the California Energy Commission and the Federal Transit Administration (FTA).