Hydrogen
Hydrogen is an energy carrier rather than a fuel and needs to be extracted from water or from a fossil fuel. The most common way to do this is through steam methane reformation, but it can also be extracted from water by electrolysis. It can then be used in a fuel cell, an electro-chemical process, to generate electricity which drives an electric motor, with water vapour the only emission.
Some vehicles use a combustion engine to burn hydrogen but this less efficient than a fuel cell and tends to produce nitrogen oxide as a result of the high combustion temperatures.
Australia has an abundant supply of natural gas which can be used in the short term as a hydrogen source to reduce the amount of imported fuel. Clean vehicle emissions (the only emission from a hydrogen-powered vehicle is water) can help to reduce smog levels in the city, as there are no particulates, ozone or VOCs being emitted as there are in hydrocarbon-based combustion engine vehicles.
Barriers
At present there is no hydrogen piping or transport infrastructure - either one would have to be created, or hydrogen would need to be generated on-site. Using natural gas to create hydrogen also creates carbon dioxide on a comparable level to burning petrol, reducing much of its environmental benefit. The other option, electrolysis of water, is less efficient than the equivalent energy path for battery-electric vehicles, essentially using more power for the same driving distance.
Infrastructure
Probably the largest single barrier to hydrogen as a transport fuel lies in provision of the refueling infrastructure. To provide adequate range hydrogen must be carried on board the vehicle either compressed to 350 or 700 bar, or in liquefied form at -256˚C. Both of these technologies are complex, expensive and very energy intensive.
Probably the largest single barrier to hydrogen as a transport fuel lies in provision of the refueling infrastructure. To provide adequate range hydrogen must be carried on board the vehicle either compressed to 350 or 700 bar, or in liquefied form at -256˚C. Both of these technologies are complex, expensive and very energy intensive.
The refueling bowsers to provide either of these services would be extremely expensive.
For this reason it is likely that any hydrogen powered vehicle usage in the near future would be a ‘back to base’ operation such as bus, transit truck or taxi.
For this reason it is likely that any hydrogen powered vehicle usage in the near future would be a ‘back to base’ operation such as bus, transit truck or taxi.
Honda is experimenting with a home refueling station where the natural gas supply provides the feedstock to refill your vehicle overnight.
