What is a hydrogen car?
Most people are starting to get clued up on the differences between an electric car, a plug-in hybrid electric vehicle (PHEV) and a hybrid car. However, there is a fourth kind of electric car that people often leave out of the equation – a hydrogen car.
Despite being called a hydrogen car, or more accurately, a hydrogen fuel cell vehicle (HFCV), a hydrogen car is just a different type of electric vehicle. This is because while electric cars get their power from a lithium-ion battery that stores electricity, the electric motors on board a hydrogen car are powered by the fuel cell that converts hydrogen into electricity.
How does a hydrogen car work?
The key behind a hydrogen car is the fuel cell. It’s used to convert hydrogen into electricity, with the only byproduct being heat and water. Most hydrogen cars use a polymer exchange membrane (PEM) fuel cells, these consist of two electrodes.
The hydrogen is stored in a gaseous form in compressed air tanks and forced into the fuel cell. There it is broken up by the catalyst, forming electrons. These electrons are harnessed and used to power the electric motor on board. The remaining hydrogen molecules, when mixed with oxygen, turn to water.
So while lithium-ion batteries in an EV store electricity, fuel cells in a hydrogen car convert hydrogen into electricity. Many hydrogen cars also feature lithium-ion batteries which then store the electricity that has been produced.
Hence, the key difference between an electric and a hydrogen car is then where the electricity comes from. For electric cars it comes from the grid. For hydrogen cars it comes from hydrogen.
A key advantage hydrogen cars have over electric vehicles is that they come with a larger driving range – often 300 miles or more, and can be refuelled in minutes rather than hours.
Why aren’t hydrogen cars more popular?
The above distinction also explains why hydrogen cars are still in their infancy. While electric cars can be plugged into the grid, hydrogen cars have to be refuelled at dedicated hydrogen fuel stations.
While hydrogen is the most abundant element on earth, it has to be harvested and processed – this is costly and currently there’s little infrastructure to do so. There are just a handful of hydrogen fuel stations in the UK – although the number is growing.
The lack of a dedicated hydrogen infrastructure currently acts as a barrier. However, the UK Government recently announced a £23 million fund to accelerate hydrogen vehicle infrastructure and uptake.
Can I purchase a hydrogen car?
There are just a few models to choose from. One is the Toyota Mirai – a hydrogen saloon car – while the other is a Hyundai ix35 Fuel Cell. The South Korean maker has also unveiled the new Nexo – a small hydrogen SUV that will be arriving in 2019.
However, do your research before purchasing – make sure there are refuelling stations near you.