Room for two: the role of electric batteries and hydrogen in a decorbonised transport sector

By Kevin Peakman
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Hydrogen has received a lot of hype in the media and throughout the energy industry lately. For some, the talk of hydrogen offers a missing link to decoupling industrial sectors from fossil fuels and presents an opportunity for long duration energy storage and a replacement for polluting fuel sources. Others, however, are sceptical of the hydrogen hype, claiming that the cost to commercialise, and the risks of storage and transport are too great.

One area where this debate is particularly heated, is the application of hydrogen as a transport fuel.
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Despite the increasing market share of electric vehicles, the most common fuel-type for transport is oil. With net-zero targets and the threat of climate change increasingly weighing on the actions of governments, large corporations, investors and transport companies, clean fuel alternatives are the next big step in the energy transition. EV advocates will say that electric batteries are integral to the transport sector of the future – which is true to an extent. What is often overlooked, however, is the important role that hydrogen will play in doing the 'heavy lifting' for certain mobility types.

Just as petrol and diesel are both derivatives of crude oil, hydrogen and electric batteries are both produced through the conversion of electricity to stored fuel. And, just like diesel and petrol, hydrogen and electric batteries will equally play an important role for different vehicle types into the future. Per litre, diesel contains more energy than petrol. Per kilogram, hydrogen can store significantly more energy than an electric battery. This increased storage capacity means that compared to a battery-powered EV which might travel 300-500kms on one charge, hydrogen fuel cell vehicles can travel closer to 700km before refuelling.

The process of refuelling or recharging, and the infrastructure involved in this process, is also an easier feat for hydrogen vehicles. Whereas batteries take a long time to charge (usually between six and twelve hours for a Tesla), hydrogen refuelling mimics the process of filling up with petrol. Using dedicated hydrogen refuelling stations, which could potentially be repurposed petrol stations, drivers would decant gaseous or pump liquid hydrogen into their vehicle, where it is stored as a gas for usage. Many EV advocates point to fast-charging as the solution to this problem, however in reality, the practicality of fast-charging on a regular basis or simultaneously for multiple vehicles, would cause surges and a significant strain on the current electricity grid.

Bigger cars like SUVs, buses (especially those that travel hillier routes), trains, long distance haulage trucks, ships and aircraft will therefore benefit from transitioning away from oil-based fuels towards hydrogen. Already, some companies such as Riversimple, are planning to roll out lightweight hydrogen vehicles over the next two-to-five years. Within the next decade, this technology will be more widespread and used more commonly in heavy vehicles. As the cost of electrolyser manufacturing continues to decline and key players in the transport sector become serious about achieving net zero emissions, hydrogen will increasingly play an important role in decarbonising the transport sector.