“The gap will widen”, says prof. David Cebon on electric vs hydrogen

University of Cambridge professor David Cebon is straightforward when it comes to the use of hydrogen-fueled vehicles as a low-emission alternative for road freight. According to him, who’s dedicated decades to transport research, the numbers are hard to fight.

“Three times more on running costs, two times more on capital costs, you'd have to be insane to buy a hydrogen-powered truck, right?”, he asks midway through an explanation on why electric heavy goods vehicles have become the best option for decarbonised road freight. His research shows that the car industry is driving the learning curve for electric lorries, which means that, with batteries becoming cheaper and cheaper, the gap will only widen.

As director of the Centre for Sustainable Road Freight and the Cambridge Vehicle Dynamics Consortium, prof. Cebon works closely with innovators and solutions to tackle transport challenges, particularly those that can optimize charging and enable clean and safe freight. 

Below, he dives into some of the findings and shares his views on the future of freight, particularly in the United Kingdom. Read the full interview:

HGV and domestic shipping freight are responsible for over 20% of the United Kingdom’s domestic transport carbon emissions. What solutions does the Centre for Sustainable Road Freight (SRF) see in the shorter and longer term?

David Cebon: In the short term, it's important to focus on things that improve efficiency and reduce energy and fuel consumption. And there are quite a lot of things that you can do both on the vehicle technology side and the logistics side. On the vehicle technology side, some are easier than others, like having better drivers, making sure your tires are well inflated, using low rolling resistance tires and lighter vehicles with better aerodynamics. These are all things that can make a significant difference. There are also things around hybrid and alternative fuels, where you can save emissions. The problem with gas-engine vehicles is that to really save emissions you need to go to biogas, and there's not enough of that around. The other thing is obviously a rapid move to electric vehicles, which are pretty easy to use for all kinds of different urban applications: small vans, home delivery vans, bigger trucks doing deliveries to city center stores, rubbish trucks and all kinds of buses. 

Then, there are logistics things that you can do. They almost all revolve around getting more stuff in your vehicle so that you have to do fewer trips in order to move the same amount of stuff. That can be simply the way you package freight: if you could remove 10% of the packaging on every parcel, you could get 10% more parcels in for the same amount of fuel. And then there’s avoiding empty running with all kinds of logistics methods. For example, co-loading, which is having several smaller vehicles coming together in one place and having one big full truck driving instead of a bunch of smaller ones. Or arranging back hauls so that you bring somebody else's freight home to make sure you are always full. Sometimes it can be as simple as relaxing the time constraints so that you have a completely full truck instead of two half-full trucks.

What about hydrogen as an alternative to fossil fuels?

The capital cost of a hydrogen-powered vehicle is about double the capital cost of a battery electric vehicle. And I know that because I've tried buying them for research project purposes. There's a good reason why it's more expensive: a hydrogen fuel cell truck is a battery electric truck with the hydrogen fuel cell added on. They both have an electric motor, an electric drivetrain, a battery, inverter and so on. The electric truck just has a bigger battery, that's all. So instead of having bigger batteries, a hydrogen-powered truck has hydrogen fuel cells, hydrogen tanks and hydrogen delivery equipment. And those things are all very complicated and very expensive. 

We're all very fond of learning curves, of how technology is going to get cheaper with time. If you think about it, the most expensive part of a battery electric truck is the battery. And batteries are going to get cheaper. But it won't be because of the trucking industry, it will be because of the car industry, which uses at least five times more batteries. The technology and learning curves are being driven by the car industry, not by the truck industry. If you look at the same problem with the hydrogen fuel cell vehicle. Well, there are a thousand times more electric cars being made every year now than hydrogen fuel cars. Hydrogen fuel cells are not going to be getting cheaper, because hydrogen cars are not going to be a thing. 

"So, if hydrogen-powered trucks are currently twice as expensive as battery electric trucks, that gap is probably going to widen." 

The other side of it is the energy that they use. Hydrogen is very inefficient. Battery electric vehicles are very efficient – the opposite. In fact, if you do these rather simple calculations, you can work out that to run a truck on green hydrogen, you need about three times more electricity than you need to power a battery electric vehicle. Three times more electricity means you need three times more wind turbines, three times more solar panels or nuclear power stations. And, with that, you need three times more maintenance, three times more spare parts. Whatever you have, it's going to cost three times more to run hydrogen-powered vehicles than to run electric vehicles. So three times more on running costs, two times more on capital costs, you'd have to be insane to buy a hydrogen-powered truck, right? The only reason you would buy one would be if your electric truck could not do the work you needed it to do. 

Then, the important question is: is it possible to run logistics with an electric truck? The answer is yes, it is. In the UK, we've analysed lots and lots of operations, and they can all be done with electric trucks with charging in rest breaks and particularly at warehouses. 

The other possibility, which is worth looking at, is the battery-swapping technology being used in China and promoted in Australia at the moment. A truck drives up to the station, you take one of the batteries out, add one in, and you're off on the way again in a few minutes. There is a cost issue there because batteries are the most expensive part of the vehicle, and if you do that kind of battery swapping, you definitely have to have more than one battery per vehicle. The other way to go is the Pony Express route, where essentially you swap tractor units. You take one tractor unit off, put it on the charger, and run another one. That has the same sort of problem, though, because you've got an additional asset. A third option, which I think is really important, is to charge on the move with overhead wires. It means you don't have to stop at all, like a train. That’s a technology we're interested in, and I think it's got great promise.

Electrification gives us almost an inherent need and opportunity to rethink the whole industry. What does rethinking freight entail in your opinion?

Well, now you put fuel in a diesel truck, run it for a couple of days, and then you put in some more. It's not part of your thinking. Once you have electric logistics, the charging becomes an intimate part of the whole operation, it has to be planned along with the logistics. You're routing matters, where the charging is, and the state of charge of the vehicle. All of these things were not considered before. The other thing about rethinking logistics is that you have to have electricity available at the locations where you need it. For electric trucking, it's going to be very important to have grid connections. In many cases, I think it will be cheaper to move the warehouse to the electricity than to move the electricity to the warehouse. It's a scale type of problem. 

You mentioned the UK, whose government has recently published a Future of Freight plan. How do you see their vision for the industry and how does it relate to what we have been discussing today?

At the moment, the UK government is still trying to decide what it wants to do. It's about to run some trials of battery electric and hydrogen trucking. We hope that they're going to run a trial of overhead contact lines as well. They have legislated that by 2035 there should be no internal combustion engines for new trucks up to 26 tons – essentially, urban freight and small delivery vehicles. Then, by 2040, there will be no more internal combustion engines on the bigger trucks. So they've been clear about that which is a good thing. I think they're mistaken to rule out hybrid vehicles, and we will need to go back around that again, particularly during a transition phase. 

I think they're hoping that they will get away with it without having to spend a lot of money on infrastructure. If they really want everybody to go electric, a lot of money will have to be spent on infrastructure, and it takes a lot of time to do that. To make that decision around 2030 is, in my view, five years too late.

What solutions can we find? Is it a matter of investing in public-private collaboration? 

It's easy to think we've got to get to the end. But in reality, there's a progressive thing that is happening. One first part is urban vehicles becoming electrified and charging stations in cities and depots and so on, which builds a starting system. You don't start with the most difficult journeys but with the easiest, short distances, where you can have charging arrangements that are acceptably low cost. There is an element of this that is about building out piece by piece, which means that it's not quite as scary as it might seem. 

For the really big infrastructure, you need to have public-private partnerships and privately funded projects. The work we've done on the electric road system, which is probably one of the bigger infrastructure projects, indicates that it can be done with private financing and that it will be sufficiently profitable to sell electricity to trucks. You can use those sales to pay for the infrastructure over a significant period of 15 or 20 years. 

In order for that to happen, the government needs not to provide the money, but the direction and some sort of guarantee that the market will exist. If the government is willing to do that, then it's perfectly possible. There's plenty of money out there ready to be spent on these things. One of the biggest risks is the fact that this is being lobbied very heavily by fossil-fuel interests, which is probably not the right direction for the country or the planet. 

At the same time, we had Russia putting pressure on energy and countries going back to coal. Is there a connection to these scenarios and how can it boost diverse energy sources?

Yes, there is. The real lesson here is to try and generate your own energy. We can do that with electricity, we don't have to import it. We can have offshore wind, onshore wind, solar and so on. The great thing about electrification is that in many cases, it can be done using the country's resources without having to import anything. It's much better to electrify and use that to power the economy, an efficient economy, than it is to burn a lot of stuff which you have to import and it makes you dependent on foreign countries. 

This interview has been edited and condensed for clarity.

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