SUMI DAS, CNN CORRESPONDENT: Good morning to you, Daryn. Unique indeed. Well, some hydrogen cars have made it out of the labs and on to the road and at this Shell station, they sell both hydrogen and conventional gas; that's what makes it unique.
It's all part of company's efforts to continue research and development of hydrogen technology and introduce that technology to the public.
DAS (voice-over): Through rain, sleet and snow, Steven Yates (ph) delivers the mail, but instead of a mail truck, Yates drives a hydrogen fuel cell minivan.
STEVEN YATES (ph), MAILMAN: It's just as powerful as combustion engine.
DAS: At Fort Belvoir, Virginia, a hydrogen-powered truck helps Sergeant Antonio De La Fuente complete army missions.
SGT. ANTONIO DE LA FUENTE, TRUCK MAINTENANCE: If I was looking for the gear shifter -- well on this one, it doesn't have one. It has a push- button.
DAS: Both vehicles come from the General Motors test fleet. The car maker is one of many companies developing hydrogen technology as possible alternative to gasoline-powered vehicles.
PATRICK SERFASS, NATIONAL HYDROGEN ASSN.: The three main reason that we're developing hydrogen are to reduce our dependence on imported fuels, to improve the environment and to drive economic rifts.
DAS: Officials at Shell Hydrogen say 50 million tons of hydrogen are produced globally every year. This hydrogen pump at a publicly accessible Shell station, the country's first, shows how stations can be upgraded.
Opponents of the technology say that pressurizing hydrogen for transport and extracting it require more energy than the hydrogen produces.
SERFASS: The process by which you use the hydrogen is normally much more efficient than the combustion process with fossil fuels. With hydrogen, that process can be two to three times more efficient. Hydrogen is a long-term proposition. It's a marathon, not a sprint, but already industry is well beyond the starting line.
DAS: Officials at Shell Hydrogen say they expect the cost of hydrogen to be on par with the cost of gasoline per mile. Now that may sound discouraging, but if hydrogen becomes more widespread, as use of it becomes more widespread, the economies of scale could come into play, distribution could improve and those prices come down.