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.
The creation of Count von Zeppelin, a retired German army officer, the flying weapon was lighter than air, filled with hydrogen, and held together by a steel framework. When the war started in 1914, the German armed forces had several Zeppelins, each capable of travelling at about 85mph and carrying up to two tonnes of bombs.