In this series exploring the complexity of the transition to zero emission transport, Richard addresses the point raised by many energy analysts and researchers that hydrogen is less efficient and therefore a bad thing (he paraphrases).
Efficiency is not the point
The first problem with using efficiency as the lens through which to view everything is this: In the real world nobody cares.
Let’s take the car. It is parked more than 90% of the time and spends 25% of its time looking for parking. The average occupancy is 1.5 people, 85% of the energy doesn’t reach the wheels and most of this energy is spent moving the car. Never mind the road infrastructure impacts.
It’s not efficient, but that's because efficiency isn’t the reason people have a car. It’s all the other factors about convenience, practicality, status that influence decisions. Yes, blokes will brag down the pub (what’s a pub? Ed.) about the mpg they can do, but only to justify the fact they have bought an SUV. Recent evidence shows that the improved efficiency of diesel engines has in fact led to increased carbon emissions as car size and mass across the European fleet have increased as a result. A focus on efficiency doesn’t necessarily deliver desired policy outcomes either.
Let me digress...
Having said all this, my next car will be an EV. For personal use EV’s are great; now with a good range of models becoming available can do pretty much everything I need. There are short-term issues with the charging network for long distance but there is no reason this won’t be solved over time. A peak bank holiday journey will be a bit more of a lottery, when everyone is doing the same, as infrastructure is only ever sized for average not peak. But then you’re probably in a queue anyway so take a picnic and games for the kids.
But it's still nigh-on 2 tonnes of steel and lithium sitting on the drive most of the time. It's not efficient, we'd be better off without a car. It's our personal circumstances that drive the choice; all the other things that matter. Energy efficiency of EV drive and charging is just one factor that means low running costs and a salved conscience.
The case for fleets
The case for hydrogen vehicles is stronger for fleets of larger, high capacity and heavy duty vehicles such as double-deck buses and HGVs, where current battery technology struggles. This is almost a policy mantra now, but similarly the rationale is too simplistic. The means that in the comparison between hydrogen and BEV trucks energy efficiency trumps all and the assumption is made that, as batteries improve, these vehicles will all become battery-only too. Efficiency is the only factor we can measure so it's the only relevant one. In the land of the blind the one-eyed man is king.
But fleet managers are not physicists. Fleet managers care much more about practical operations.
The practicality of refuelling in 5 minutes versus arranging for recharging of a fleet of vehicles. The flexibility of vehicles to do multiple jobs versus assigning vehicles to the jobs they are capable of. The convenience of a fleet that can do the job that current vehicles do versus changing operations. Let’s add asset and staff utilisation, payload, range, vehicle performance, warranty, lifetime, service and support, logistics network reliability and resilience. Like our family choice to have a car it's all of these other things that are what fleet managers care about, and in many operations most of them point towards hydrogen vehicles.
Putting this another way, what matters for commercial vehicles is optimising the efficiency of the business, and that's much richer and more complex than either the "heavy means hydrogen" or "efficiency means battery" mantras allow. It's a dynamic question of balancing the cost of operations with the operational costs of vehicles and the revenue or business benefits generated, to which there is no one simple answer and which will vary fleet by fleet and business by business. And in that dynamic there is space for different approaches and different vehicles; both BEV and hydrogen FCEV trucks will have a role. I can't give you an answer of exactly where I'm afraid, but in future posts I hope to lay out the questions you'll need to think about.
In both cars and commercial vehicles, nobody cares about energy efficiency, although everyone talks about it. When people say efficiency, they mean fuel cost. And at first glance, based on efficiency alone, hydrogen has a case to answer. But guess what, it's more complex than you might think. See you next time.