Hydrogen train

In transportation, the original (2003) generic term "hydrail" includes hydrogen trains, zero-emission multiple units, or ZEMUs — generic terms describing rail vehicles, large or small, which use on-board hydrogen fuel as a source of energy to power the traction motors, or the auxiliaries, or both. Hydrail vehicles use the chemical energy of hydrogen for propulsion, either by burning hydrogen in a hydrogen internal combustion engine, or by reacting hydrogen with oxygen in a fuel cell to run electric motors, as the hydrogen fuel cell train. Widespread use of hydrogen for fueling rail transportation is a basic element of the proposed hydrogen economy. The term has been used by research scholars and technicians around the world.^{[1][2][3][4][5][6]}

Hydrail vehicles are usually hybrid vehicles with renewable energy storage, such as batteries or super capacitors, for regenerative braking, improving efficiency and lowering the amount of hydrogen storage required. Potential hydrail applications include all types of rail transport: commuter rail; passenger rail; freight rail; light rail; rail rapid transit; mine railways; industrial railway systems; trams; and special rail rides at parks and museums.

The term hydrail is believed to date back to 22 August 2003, from an invited presentation at the US Department of Transportation's Volpe Transportations Systems Center in Cambridge, MA.^[7] There, Stan Thompson, a former futurist and strategic planner at US telecoms company AT&T gave a presentation entitled the Mooresville Hydrail Initiative.^[8] However, according to authors Stan Thompson and Jim Bowman, the term first appeared in print on 17 February 2004 in the International Journal of Hydrogen Energy as a search engine target word to enable scholars and technicians around the world working in the hydrogen rail area to more easily publish and locate all work produced within the discipline.^[9]

Since 2005, annual International Hydrail Conferences have been held. Organised by Appalachian State University and the Mooresville South Iredell Chamber of Commerce in conjunction with universities and other entities, the Conferences have the aim of bringing together scientists, engineers, business leaders, industrial experts, and operators working or using the technology around the world in order to expedite deployment of the technology for environmental, climate, energy security and economic development reasons. Presenters at these conferences have included national and state/provincial agencies from the US, Austria, Canada, China, Denmark, the EU, Germany, France, Italy, Japan, Korea, Russia, Turkey, the United Kingdom and the United Nations (UNIDO-ICHET).^{[citation needed]} In its early years, these conferences were largely dominated by academic fields; however, by 2013, an increasing number of businesses and industrial figures have reportedly been in attendance.^[10]

During the 2010s, both fuel cells and hydrogen generation equipment have been taken up by several transport operators across various countries, such as China, Germany, Japan, Taiwan, the United Kingdom, and the United States. Many of the same technologies that can be applied to hydrail vehicles can be applied to other forms of transport as well, such as road vehicles.^[10][8]