How do hydrogen systems work?
Hydrogen-powered vehicles use
fuel cells to convert the chemical energy in the gas (stored under
pressure in cylinders) to electrical energy via an electrochemical
process - fuel cells do not combust hydrogen, but instead combine it
with oxygen in a chemical reaction that produces electricity for power.
The only tailpipe emission is water.
This process is extremely
efficient – nine litres of water can produce one kilogram of hydrogen.
And that kilogram of hydrogen contains about 33 kilowatts of energy
which, in the case of a small road vehicle, can power the electric motor
and achieve a range of around 100 kilometres.
The efficiency of
water electrolysis is between about 70-80%, with a goal set to reach
82-86% efficiency by 2030 using proton exchange membrane (PEM)
If the energy required to produce the hydrogen gas,
in the initial instance, comes from a sustainable or renewable source
then the potential is practically unlimited. Of course, in reality
hydrogen production is still quite reliant on less green methods, but
investment in wind, wave, biomass and solar power, combined with our own
internal policies on reducing our alternative fuel system manufacturing
footprint and recyclable cylinders, will make great strides towards
this. Well-to-wheel emissions of a hydrogen fuel-cell car are nonetheless
currently about 30% lower than those of a conventional diesel-powered
How does a hydrogen fuel cell work?
cell systems are a clean, efficient, reliable, quiet and scalable power
source. There are no moving parts and they do not need to be recharged
like batteries and continue to produce electricity as long as fuel is
The cell is made up of an anode, cathode, and an
electrolyte membrane. Passing hydrogen through the anode splits the
hydrogen molecules into electrons and protons. The protons pass through
the membrane, while the electrons go into a circuit, generating the
electric current. At the cathode, the hydrogen protons and oxygen
combine to produce water.
Further efficiencies are achieved in the
vehicle design using techniques such as regenerative braking, idle-stop
and onboard batteries to store excess energy.