Hydrogen can also serve as fuel for internal combustion engines, but unlike with fuel cells, will produce tailpipe emissions and is less efficient. Learn more about fuel cells. The energy in 2.2 pounds (1 kilogram) of hydrogen gas contains about the same as the energy in 1 gallon of gasoline. Because hydrogen has a low volumetric energy density, additional steps are needed to store enough hydrogen onboard fuel cell vehicles to achieve the driving range of conventional vehicles.
Wiktionary (0.00 / 0 votes) Rate this definition: zeppelin (Noun) A type of large German dirigible airship of the early 20th century designed to carry passengers or bombs. Zeppelin (ProperNoun) A German manufacturing company, famed for building the zeppelin airships. Origin: Named after Ferdinand, Count von Zeppelin.
  Answer     Zeppelins are a type of rigid airship pioneered by German Count Ferdinand von Zeppelin in the early 20th century, based in part on an earlier design â¦ by Croatian aviation pioneer David Schwarz.ount Ferdinand von Zeppelin invented the Zeppelin airship. Zeppelin arrived at the idea for his flying machine after observing dirigible balloons in use during 1870-1871.