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Hydrogen Vehicle See also:
A hydrogen vehicle is a vehicle that uses hydrogen as its on-board fuel for motive power. The term may refer to a personal transportation vehicle, such as an automobile, or any other vehicle that uses hydrogen in a similar fashion, such as an aircraft. The power plants of such vehicles convert the chemical energy of hydrogen to mechanical energy (torque) in one of two methods: combustion, or electrochemical conversion in a fuel-cell:
The molecular hydrogen needed as an on-board fuel for hydrogen vehicles can be obtained through many thermochemical methods utilizing natural gas, coal (by a process known as coal gasification), liquefied petroleum gas, biomass (biomass gasification), by a process called thermolysis, or as a microbial waste product called biohydrogen or Biological hydrogen production. Hydrogen can also be produced from water by electrolysis. If the electricity used for the electrolysis is produced using renewable energy, the production of the hydrogen would (in principle) result in no net carbon dioxide emissions. Hydrogen is an energy carrier, not an energy source, so the energy the car uses would ultimately need to be provided by a conventional power plant. A suggested benefit of large-scale deployment of hydrogen vehicles is that it could lead to decreased emissions of greenhouse gases and ozone precursors.[1] Further, the conversion of fossil fuels would be moved from the vehicle, as in today's automobiles, to centralized power plants in which the byproducts of combustion or gasification can be better controlled than at the tailpipe. However, there are both technical and economic challenges to implementing wide-scale use of hydrogen vehicles, as well as better and less expensive alternatives. The timeframe in which challenges may be overcome is likely to be at least several decades, and hydrogen vehicles may never become broadly available.[2][3][4][5] The Hype about Hydrogen: Fact and Fiction in the Race to Save the Climate (see below) is a book by Joseph J. Romm, published in 2004 by Island Press and updated in 2005. Romm is "one of the world’s leading experts on clean energy, advanced vehicles, energy security, and greenhouse gas mitigation."[2] The gist of the book is that hydrogen is not economically feasible to use for transportation, nor will its use reduce global warming, because of the cost and greenhouse gases generated during production, the low energy content per volume and weight of the container, the cost of the fuel cells, and the cost of the infrastructure. The author argues that a major effort to introduce hydrogen cars before 2030 would actually undermine efforts to reduce emissions of heat-trapping greenhouse gases such as carbon dioxide.[6][7][8] [9] Research and prototypes
Hydrogen does not come as a pre-existing source of energy like fossil fuels, but rather as a carrier, much like a battery. It can be made from both renewable and non-renewable energy sources. A potential advantage of hydrogen is that it could be produced and consumed continuously, using solar, water, wind and nuclear power for electrolysis. Currently, however, hydrogen vehicles utilizing hydrogen produce more pollution than vehicles consuming gasoline, diesel, or methane in a modern internal combustion engine, and far more than plug-in hybrid electric vehicles.[6][4] This is because, although hydrogen fuel cells generate no CO2, production of the hydrogen creates additional emissions.[7] While methods of hydrogen production that do not use fossil fuel would be more sustainable,[8] currently such production is not economically feasible, and diversion of renewable energy (which represents only 2% of energy generated) to the production of hydrogen for transportation applications is inadvisable.[4] The recorded number of hydrogen-powered public vehicles in the United States was 200 as of April 2007, mostly in California,[9] and a significant amount of research is underway to try to make the technology viable. The common internal combustion engine, usually fueled with gasoline (petrol) or diesel liquids, can be converted to run on gaseous hydrogen. However, the more energy efficient use of hydrogen involves the use of fuel cells and electric motors. Hydrogen reacts with oxygen inside the fuel cells, which produces electricity to power the motors. One primary area of research is hydrogen storage, to try to increase the range of hydrogen vehicles, while reducing the weight, energy consumption, and complexity of the storage systems. Two primary methods of storage are metal hydrides and compression. The current land speed record for a hydrogen powered vehicle is 207.279 mph set by a prototype Ford Fusion Hydrogen 999 Fuel Cell Race Car at Bonneville Salt Flats in Wendover, Utah on August 16, 2007. The car was designed and built by Ford engineers in collaboration with Ohio State University, Ballard Power Systems and Roush. High-speed cars, buses, bicycles, cargo bikes, golf carts, motorcycles, wheelchairs, ships, airplanes, submarines and rockets already can run on hydrogen, in various forms at great expense. NASA uses hydrogen to launch Space Shuttles into space. There is even a working toy model car that runs on solar power, using a reversible fuel cell to store energy in the form of hydrogen and oxygen gas. It can then convert the fuel back into water to release the solar energy.[10] For more information see the following links: References
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