Battery electric vs. hydrogen

As we said before, “Electrification of transport combines an energy efficient power train system with the opportunity of using any source of energy other than fossil fuels including those from renewable sources.”¹

For the remainder of the course, it is important to clarify on which pathway for electrification, within this wide definition, we are going to focus on.

There are currently two main pathways: battery electric applications, and fuel cell technologies that use hydrogen.

Both technologies are currently in use, but their market uptake differs significantly:

• In 2021, more than 1 million battery electric passenger cars (both pure battery electric and plug-in hybrids) have been sold as of September 2021.
• Whereas only 600 fuel-cell electric passenger cars have been put on the market during that period.²
• For buses, the situation is similar, as only 3 fuel-cell electric buses have so far been registered in 2021, and 48 in 2020.³

And both technologies have their own pros and cons:

There is currently a lot of interest in hydrogen applications, beyond the road transport sector, and there may be other applications where the storage capacity of hydrogen might be of higher importance.

Recent research indicates if hydrogen is not produced from renewable energy, using natural gas instead, its lifecycle greenhouse gas emission may be much higher than often assumed, and potentially higher than directly burning the natural gas.⁴

It might yet be too early to judge whether this situation will change for certain types of vehicles, for example heavy-duty applications.

At this stage, it is therefore clear that when we speak about the electrification of urban mobility, we almost exclusively speak of battery-electric applications (including for bikes, scooters, other small vehicles) in addition to existing technologies (e.g. catenary systems, which are mainly used for tramways and trains and, in some cities, for buses).

^References

^{1. European Commission’s Direcorate-General for Research and Innovation}

^{2. EAFO General information on Vehicles & Fleet}

^{3. EAFO Alternative fuel fleets}

^{4. How green is blue hydrogen? (Howarth, 2021)}