The stuff (car) dreams are made of: Water

Being number one doesn’t only have benefits. Not, at least, where energy sources are concerned. These can be separated into primary and secondary categories. That our primary energy substances, such as coal, petrol and gas, are not particularly environmentally friendly, is something we are aware of at least since last year.

Hydrogen, on the other hand, is a secondary substance, which basically means that the process of generating hydrogen itself requires energy. If regenerative energies such as wind, hydro power or solar energy are used to power this process, it is possible to talk about hydrogen as a clean energy source. This is because in its application as an energy source in a fuel cell, water is the only product. Hydrogen, H2, and oxygen react to form H2O, or pure water. Thus, electricity can be generated in a fuel cell to drive an electric motor.

Integrated fuel cell in the floor of Mercedes

As the application of fuel cell technology to power cars has not yet been perfected, the direct combustion of hydrogen in a motor which is only been slightly modified offers an alternative. The exhaust emissions of such a hydrogen combustion process are made up of almost pure water vapour. They also contain some nitric oxides, which are generated at high temperatures in the combustion chamber from the nitrogen present in the air – substantially less, however, than by the combustion of other fuels.

But even the best concept can have a flaw: the general problem with hydrogen engines up to now has been the storage of the hydrogen. Despite insulating the fuel tank, the extremely elusive hydrogen leaks if the vehicle is left standing for a long period. Currently, there are two systems available: The storage of liquid hydrogen at very low temperature (minus 253 degrees), or the storage of gas hydrogen at high pressure. Both concepts are being tested. In the more distant future, storage in metal hybrid tanks should be possible. There are currently three car manufacturers – BMW, Mazda and Ford – who have taken on the challenge of utilising hydrogen in combustion engines.

More to come…..