While electric vehicles (EVs) are all the rage these days, globally, the overwhelming majority of interest lies in the battery-powered variety. But did you know that there is another way out there currently to power an EV, with the use of a hydrogen fuel cell? But is viable, and is the infrastructure ready?
What is a Hydrogen Fuel Cell EV?
Very simply here, the propulsion part of a Hydrogen Fuel Cell Vehicle (HFCV) is as much the same as in a regular battery-powered EV (BEV), as an electric motor still drives the wheels of an HFCV. The difference between a BEV and an HFCV starts from how the energy vis-à-vis electricity for BEV and hydrogen (HFCV) are pumped to how the motors are powered; with electricity to be generated onboard an HFCV from a hydrogen fuel cell stack instead of coming from stored electricity in a battery with a BEV.
How does a Hydrogen Fuel Cell Work?
Without going too technical into the chemistry of it, a hydrogen fuel cell essentially initiates a redox chemical reaction between hydrogen and oxygen to generate energy. The full chemical equation of this reaction for the chemistry nerds is as follows: 2H₂ + O₂ ➔ 2H₂O + energy. Hydrogen in an HFCV is obtained from the onboard high-pressure storage tank, while oxygen comes from the ambient air. To propel the car, this electrical energy directly powers the motor to the transmission that drives the wheels. Excess energy is stored in the battery to recapture braking energy, used during short accelerations.
Who Currently Produces Hydrogen Fuel Cell EVs?
Current makers of HFCVs are mainly of the Asian persuasion, with Toyota being the strongest proponent of this alternative fuel option, and its Mirai sedan (incidentally the world’s first mass-produced HFCV back in 2014) likely being the most well-known example of production HFCVs around.
What are the Benefits of Hydrogen Fuel Cell EVs?
As the chemical equation for electricity generation using a hydrogen fuel cell shows, an HFCV emits zero tailpipe emissions. Or at least no toxic emissions anyway, because the only byproduct of the electricity generation process from hydrogen fuel cell is H₂O, also known as water! This therefore makes HFCVs a greener alternative to the current carbon-polluting internal combustion engine cars around.
What are the Pitfalls Of Hydrogen Fuel Cell EVs?
One of the biggest current societal barriers to wider HFCV adoption is the lack of infrastructural support for hydrogen refuelling, with this technically being a Catch-22 scenario from the lack of HFCVs available. It should go without saying also that (most non-plug-in hybrid electric vehicle) HFCVs also do not have the possibility of charging at home, with the current rising fuel cost for hydrogen (due to rising operation costs and inflation) further hampering the attractiveness of HFCVs as a commercially viable product.
Comparing to BEVs, the loss of energy in overall efficiency is greater for HFCVs (65-75%) than BEVs (10-30%), making the cost of charging BEVs much lower.
Another danger is the vehicle catching fire. As the vehicle runs on electricity, electric fires are very difficult to put out, and can only wait for it to burn out. During burning, the heat is intense; surrounding things and people are susceptible to hurt.
Alternative Applications of Hydrogen in Cars
In ending this brief explainer on HFCVs here on a slight tangent, the use of hydrogen in cars is not limited to feeding a fuel cell that powers an EV. As Toyota has long been demonstrating with its experimental Corolla race car, hydrogen can also be burnt in an internal combustion engine as a form of fuel with zero-carbon emissions. Hydrogen combustion is currently seen as a way for the internal combustion engine to remain relevant in the eco-conscious future. Alas, the infrastructure for HCFVs is still limited, potentially making HCFVs not a strong option for private transport in the near future.
