For a hydrogen-fuel advocate, Craig Knight, the CEO and co-founder of US hydrogen truck and bus maker Hyzon Motors, is surprisingly cynical about the zero-emissions gas.

He does not see a bright future for hydrogen cars, admits that green H2 can be considered an inefficient use of renewable electricity, believes that trucking hydrogen to filling stations is a “bad” and expensive way to move the gas around, and is also not a fan of blue H2.

Yet at the same time, he strongly believes that hydrogen is the only viable carbon-free solution to long-distance trucking.

“Doing a few battery electric trucks is easy; doing hundreds is near impossible,” Knight tells Recharge. “Doing a few fuel-cell trucks is a pain in the butt; doing hundreds is a walk in the park.”

The Australian says that those advocating against long-distance fuel-cell trucks and in favour of battery-electric versions, such as the Fraunhofer Institute for Systems and Innovation Research in Germany, are missing the following key points:

1) That grids will not be able to cope with the sheer amount of electricity required to fast-charge multiple battery trucks at the same time;

2) That longer charging times for battery trucks means that an all-electric system would require eight times as many chargepoints as a fuel-cell lorry network;

3) That long-range truck batteries would be exceedingly heavy, reducing the efficiency and adding to the cost of transporting goods over long distances;

4) That it would be easier and cheaper to increase the range of a fuel-cell truck, compared to a battery one;

5) That batteries require more hard-to-obtain raw materials than fuel cells;

6) That low-cost green hydrogen can be produced locally from waste, or made from electricity when there is excess electricity, taking pressure off the power grid and removing the need to transport the H2 across long distances.

Let’s look at each of his points in turn, as well as the arguments against using hydrogen as a road fuel:

1) Grid limitations

One of the arguments in favour of long-distance electric trucks is that a new megawatt-scale EV charging standard of up to 2MW is now under development, which would theoretically enable truck drivers to add 400km of range in about 20 minutes — comparable to the 10-15 minutes it would take to fill up a hydrogen tank with the same range.

But Knight points out that such chargers would require expensive grid upgrades.

“When you invest in that type of charger, you will need to upgrade the grid supply, [I can] absolutely guarantee it,” he tells Recharge. “And you may need even to upgrade the regional grid transmission and supply.

“After the first five or ten [battery] trucks, I guarantee you’ll have to do that.”

Knight says that several bus operators around the world, including one in Sydney, Australia, have already run into problems with the charging of multiple battery-electric buses.

[Chinese electric-bus operators] had to pay to upgrade the electricity grid — crazy amounts of money

“The guys in Sydney had to spend quite a bit of money [on upgrading their electricity supply] just to get the first four [battery buses] set up. They ran these first four buses for a little while and the manager of the depot got a call one day from the local substation operators. And they said, ‘I just wanted to talk to you about how much power is actually being used… how big is your depot? [The depot manager] said, ‘Oh, we’ve got about 140 buses. They said, ‘Oh right, no wonder you’re using so much power’. And the guy at the bus depot says, ‘but we’ve only got four battery buses’.

“And the electricity supplier guy goes, ‘You’re telling me, you’re using this much power charging four buses? In that case, I better just check how many you’ll be able to charge before you max out the grid’. And the bus operator said, ‘yeah, you better tell us how many, because we quite like these battery buses, we’re planning to get more’.

“He [the power supplier] said, ‘your maximum number of buses in that location here in Sydney with this grid is six buses. If you charge at a higher rate than that, we’ll simply turn you off… because you’ll pull down the [grid for the] whole inner west [area] of Sydney, it can’t sustain this amount of power.”

Knight continues: “I spoke to the CEO of that business and he said, that to them was the dawning of their realisation of where this crossover point between batteries and hydrogen really is. It’s a lot lower down the curve than people think. And I have heard very similar stories from truck and bus operators who’ve tried battery electrification.”

The Hyzon boss adds that heavy-vehicle fuel stops on the highway typically fill up dozens of diesel trucks at the same time. This is partly because “trucks travel in packs… so wherever you’ve got one truck wanting a fast charge, you’ll have a lot more”.

If the same number of battery electric trucks tried to simultaneously fast-charge at the same location, “that will suck down staggering megawatts of power from the grid”, he explains.

“You have to multiply 1-2MW per charger by how many trucks need to charge [simultaneously]. And these roadside locations can’t deliver that much power. So perhaps the upgrade to all that fast-charging infrastructure actually brings with it multi-billion-dollar electricity infrastructure upgrades that need to happen everywhere you’d want to charge [battery] trucks.”

Knight says that while China has something like 500,000 battery electric buses in operation today, fleet operators “know their limitations, they know what they’ve had to pay to upgrade the electricity grid — crazy amounts of money. They know how they’ve had to buy extra land to fit charging capabilities and all the rest of it. They know the headaches of trying to charge those things every single day”.

“I’ve spoken with the operations director of the largest electric bus fleet in China. He said to me ‘if your technology was where it is now ten years ago, I don’t think we would have battery buses’.”

Knight does concede that electric buses are more than capable of travelling over 100km a day, but he points out that the average daily power consumption of a city battery bus is 20kW, compared to 100-140kW for a Class 8 ultra-heavy truck.

“This is not an efficient way to use batteries and the electricity [that would be] used to charge them. Hydrogen fuel-cell electrification offers the potential for a more capital-efficient decarbonisation of commercial fleets in a way that can be free of obligations on the grid, or be used as a grid service. When you’ve got power you can’t use, put it in hydrogen.”

Knight adds that the cost of electricity varies according to how much renewable power is on the grid at any given time.

“Peak power prices in some jurisdictions are now five times the price of off peak power. Even if there is time to charge the battery [truck], it may or may not be when power is affordable.”

2) Recharging vs fuelling times

Knight says that when the US Clean Air Task Force investigated what would be required to decarbonise heavy road freight, it found that if hauliers went all-electric, eight times as many locations would be needed for fast-charging points than hydrogen filling pumps if the same number of trucks were fuelled by hydrogen — “simply because it takes so much longer to charge and the range is less”.

“And this was with no reference to how the power can actually be supplied to all those locations in the middle of nowhere, spread across the US. That power simply does not exist today from either a generation or transmission and delivery standpoint.”

He adds that a hydrogen filling station with two dispensers could fill 200 trucks a day, compared to one per hour at a future megawatt-scale fast-charger.

“I think we can safely say that heavy-vehicle fast-charging is generally an inefficient use of capital,” Knight explains.

“The utilisation of expensive assets is important and every business needs to optimise returns on invested capital. The closer an operator gets to 24/7 operation, the more competitive or profitable their business. Suggesting that a recharge of 45-60 minutes [from an 800MW charger] is in any way comparable to filling with fuel in 10 or 15 minutes is quite spurious, in my view. There are many scenarios where each and every minute is valuable.”

The same cannot be said for fuel-cell passenger cars, he adds.

“Frankly, a Toyota Mirai that someone drives 30-40 minutes in the morning and 30-40 minutes in the evening, I don’t think it’s a sweet spot for hydrogen. The heavier [the vehicle] and the higher utilisation [ie, the number of hours per day the vehicle is in use], the much more likely it will be a hydrogen use case.

“Your average commercial truck is doing two driver shifts a day, is used for 16- 20 hours a day. It’s a very different proposition and it has a very different power and energy requirement overall [than a passenger car].”

3) and 4) Range and weight

It is an immutable fact, says Knight, that “you can’t separate power from energy in batteries”.

“And the fact that you need to continue adding batteries to either increase range or carrying capacity will be self-defeating at some point [due to the additional weight].”

By contrast, to increase the range of a fuel-cell truck, you simply add much lighter hydrogen tanks.

“Any time you make a vehicle lighter, you need less energy to propel it around. So that vehicle is more efficient for every single mile you drive. So it’s interesting that those criticising round-trip efficiency of [renewable] hydrogen don’t bother to mention the inefficiency of carting [around] extra tonnes of batteries.

“So every fuel-cell truck that can either run more efficiently or carry more payload than the equivalent battery truck is delivering a real-world benefit in commercial transport, which as we all know is very competitive world.”

5) No raw material constraints

Knight believes that the demand for certain raw materials used in batteries, such as lithium, cobalt and nickel, will be so high that in the future it will be difficult to source them at an affordable price.

“With the increasing scarcity of lithium and other battery-chemistry metals, batteries will not continue declining in price. And in fact, we’re starting to see the reversal of some of the longer-term trends already based on scarcity of supply.”

In fact, Norwegian analyst Rystad Energy stated on Tuesday that lithium prices were 118% higher than at the end of September 2021.

“On the other hand, hydrogen equipment and fuel cells themselves are just starting a cost-down trajectory as production is scaled,” Knight says. “Being less dependent on the exotic metals, and with very high levels of reusability and recyclability, we think fuel cells offer a compelling set of economics over the longer term.

“In fact, we argue that the increasing adoption of battery electric heavy vehicles inevitably would suffer from an increasing marginal cost of adoption. Think about that. As you do more, it gets less economic because you have the scarcity challenge around batteries.”

By contrast, he says, there are no raw material constraints on fuel cells — the equipment that converts hydrogen into useable electricity. While PEM [proton exchange membrane] fuel cells — which benefit from a higher power density and lower weight than alkaline models — use platinum as a catalyst, there will be no shortages of this expensive metal, Knight argues.

“Since we don’t react the platinum in a way that makes it hard to recover or reuse, we are very happy to take back every single fuel cell at end of life from every single vehicle. Why don’t you ask all of the suppliers of BEVs if they will take back every dead battery?” he asks, adding that every catalytic converter in petrol and diesel vehicles also contains platinum that can be easily recycled.

“I don’t believe that the world will run out of platinum in anywhere near the same rate as it will be very challenged on some of the battery chemistry raw materials.”

A report last week by French investment bank Natixis found that “there is an abundance of metal minerals in the earth’s crust which will be more than enough to satisfy future [energy transition] demand… Nevertheless, this future mined metal won’t come cheap, resources are going to get more and more complicated to exploit because of lower ore grades, depth, and tighter regulations”.

6) Local production of hydrogen, and the arguments against H2

There are several well-known arguments against using hydrogen as a road-transport fuel, including:

  • The round-trip efficiency of using renewable energy to power a fuel-cell vehicle is just 30%. In other words, for every 100kW of power, only 30kW is actually used on the road — when taking into account the electrolysis process, hydrogen storage and transport, conversion back to electricity via a fuel cell and other energy losses. By contrast, the round-trip efficiency of a battery vehicle powered by renewable energy is 77%.
  • Renewable energy would be used more efficiently via the electricity grid, and the world needs as much green power as it can get its hands on to decarbonise the grid.
  • More than 95% of the hydrogen being produced today is derived from unabated fossil fuels, so H2 vehicles cannot be considered zero emissions. What little renewable hydrogen exists today is very expensive.
  • The fossil-fuel industry is pushing to produce large amounts of blue hydrogen from fossil gas with carbon capture and storage. This would still result in large amounts of CO2 emissions, as not all of it can be captured, and would continue our reliance on methane — a very powerful greenhouse gas that often leaks.
  • Hydrogen filling stations require H2 to be trucked in on diesel-powered tankers — an expensive and highly polluting method of transporting a gas.
  • Existing hydrogen filling pumps in places like California are notoriously unreliable, often breaking down or running out of gas, with ice-cold pump nozzles frequently freezing solid to cars.

Knight does not dispute any of these points, but he believes solutions exist to many of them.

“Hydrogen is everywhere — it’s literally the most abundant element,” he says. “To suggest it’s exotic or expensive is to ignore the fact it’s all around us all the time — we just haven’t been taking advantage of it.”

Potential H2 resources, which Knight refers to as “hydrogen reserves”, include agricultural and forestry waste, municipal solid waste and landfill gas.

“People will wake up and smell the roses that we are surrounded by hydrogen. It’s just that nobody viewed the landfill dump down the road as a hydrogen reserve.”

Multiple waste-to-hydrogen companies have told Recharge in recent years that their H2 will be cheaper to produce than renewable hydrogen from electrolysers.

“Hyzon supports local hydrogen production from locally available resources. We are pursuing many partnerships on hydrogen hub models, and these resources vary from sun, wind, landfill gas to municipal solid waste and agricultural waste. We are not proponents of large centralised production on hydrogen,” Knight explains, adding that trucking hydrogen to filling stations is “a bad way” to move it around — and very expensive.

“There’s two kinds of customers that we have in the near term. One type of customer is actively pursuing green hydrogen production or supply through a partnership. And the other type of customer, which we mostly have in places like Europe and China, say, ‘We know there’s a hydrogen station down [the road], we’re willing to use it. The hydrogen coming out of it’s not yet green, but we know it will go green one day. We want to convert to hydrogen because we need to know what this journey looks like in our fleet operation’.”

As for the existing unstable hydrogen filling pumps, Knight says: “The refilling stations on the streets in California are frankly not a commercial proposition. They are striving to make it viable over time, but they’re a showcase. They’re not designed to be particularly robust or very viable, in our view.

“On the other hand, robustly designed high-capacity heavy-vehicle stations with in-built redundancy of key elements are entirely more reliable and dependable.”

And while Knight agrees that green H2 can be considered an inefficient use of electricity, he states that it is “an effective and stable means of storing energy”, particularly if excess electricity were to be diverted to electrolysers.

However, the problem with this argument is that if electrolysers are only used occasionally, the levelised cost of the green hydrogen they produce would be very high, due to the high capital expenditure.

And while Knight that clean hydrogen is expensive today, he believes costs will come down with economies of scale.

“What’s been the scale effect on batteries? What’s been the scale effect on solar power?” he asks, pointing to the massive cost reductions seen in recent years.

“We will see an experience curve drive costs down significantly… there’s been an increasing cadence of investors, governments, energy players announcing green hydrogen production plants. It is now massive.

“So in our view… costs will fall significantly through all of the hydrogen production means.”

Knight concludes: “Given the multiplier effect that each piece of hydrogen infrastructure has and the improving marginal economics from increasing adoption of fuel-cell electric trucks, we emphasise our view that fuel-cell trucks are future proof.”

Extracted in full from: The case for hydrogen trucks | Grid limitations will make long-distance battery-electric haulage ‘near impossible’: Hyzon Motors CEO | Recharge (