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.
Zeppelins, named after their creator, Count Ferdinand von Zeppelin, were first used for reconnaissance purposes, but within months of the warâs outbreak they were being used as weapons. In 1915, Germany started using them to bomb British cities, and hit London for the first time in May 1915.