There are a number of hydrogen powered vehicles that are being researched, developed and trialled including cars, aircrafts, buses, bicycles and motorcycles. Hydrogen powered vehicles have the potential to reduce harmful greenhouse gas emissions but there are a number of challenges to overcome before they are able to be produced on a large scale.
The definition of a hydrogen powered vehicle is a vehicle that uses hydrogen as power. There are two ways of doing this, through combustion and through fuel cell conversion. In the combustion process, hydrogen is burned in the engine much the same as the traditional method used in petrol cars.
In fuel cell conversion a chemical reaction is made between hydrogen and oxygen that produces water and electricity. The electricity is then used to power an electric traction motor. At the moment, one of the hindrances to large-scale production of hydrogen powered vehicles is the inability to produce a fuel cell that can consume hydrogen, produce electricity and fit in a car.
Hydrogen powered vehicles are attractive as hydrogen has the potential to have no carbon dioxide emissions in its production or usage. One of the ways that hydrogen can be produced is through electrolysis.
If the electricity for the electrolysis is produced using renewable energy then the net carbon dioxide emissions would be zero. Potential renewable energy sources for the electrolysis could be solar power or wind power and these are able to be used on a domestic as well as a large-scale.
Unfortunately, the current methods of producing hydrogen can often still involve using fossil fuels therefore negating the positive effects of the lack of harmful emissions by using hydrogen. An example of a method using fossil fuel for hydrogen production is coal gasification.
In coal gasification, the coal is broken down by using the high temperature and pressure usually from steam, with oxygen. When the coal is broken down it produces hydrogen, but it also produces carbon dioxide which is harmful for the environment. Other sources of hydrogen production are through biomass gasification or by utilizing a microbial waste product, which is called biohydrogen.
Research is still being carried out into hydrogen powered vehicles and a number of high speed cars have been developed that run on hydrogen. Buses are being trialled that run on hydrogen fuel cells and a hydrogen bicycle has also been launched in China.
Small aircrafts are being trialled that run on hydrogen, and although it seems unlikely that large passenger planes would be run on hydrogen they are looking into ways of utilizing hydrogen energy.
If the technology is developed to produce hydrogen powered vehicles on a large scale then there would be a significant reduction in the emissions of harmful greenhouse gases. However at the moment there are still some challenges to overcome to make it economically viable on a large-scale.
