The Hydrogen Truck Problem Isn't the Truck
mikeayles.com
mikeayles.com
Batteries are just too good nowadays to expect hydrogen to receive the level of R&D and infrastructure investment to become at all competitive.
The bulk storage method of interest is dissolved salt caverns: https://news.ycombinator.com/item?id=47160599
They were built 50 years ago. (Slightly before today).
Pumped hydrogen at Walpole is a great functional little project that eases the grid edge brown out problem. ( https://news.ycombinator.com/item?id=45332157 )
Scaling that up to the energy storage potential of the right geological structures of the sizes needed to power cities and run heavy industrial isn't as economically clearcut as you may assume.
== Pumped hydroelectric / pumped water <doh>
Besides that: pumped storage is good for regulating short-term fluctuations (between day and night), not so sure about storing surplus renewable energy produced in summer to use it during winter, as the article proposes?
When it comes to long distance shipping or aviation, the energy density of liquid fuel is simply too hard to beat. Fossil fuels will stay dominant for decades, likely evolving into carbon captured or bio derived alternatives rather than being replaced by batteries.
> In 2020, nearly all new trucks in China ran on diesel. By the first half of 2025, battery-powered trucks accounted for 22% of new heavy truck sales, up from 9.2% in the same period in 2024, according to Commercial Vehicle World, a Beijing-based trucking data provider. The British research firm BMI forecasts electric trucks will reach nearly 46% of new sales this year and 60% next year.
> The share of electrics in new truck sales, from 8% in 2024 to 28% by August 2025, has more than tripled as prices have fallen. Electric trucks outsold LNG-powered vehicles in China for five consecutive months this year, according to Commercial Vehicle World.
> While electric trucks are two to three times more expensive than diesel ones and cost roughly 18% more than LNG trucks, their higher energy efficiency and lower costs can save owners an estimated 10% to 26% over the vehicle’s lifetime, according to research by Chinese scientists.
https://www.ap.org/news-highlights/spotlights/2025/chinas-di...
https://electrek.co/2026/01/24/hybrid-and-electric-semi-truc...
https://www.electrive.com/2026/01/23/year-end-surge-electric...
Probably the least convenient thing would be if you had to land and take off again somewhere without recharging.
...or... go around?
If you're up there waiting for a long time you don't have to fly in a tight circle at a high speed.
I have a problem with the current physics of this. A car requires a LOT of energy to run. The electrical requirements "at the pump" are going to be pretty hefty for 10 minute charging.
Unless:
1. Reduce capacity requirements. IE Cars evolve smaller and smaller until they are practically aerodynamically efficient go-karts. A trend opposite of current affairs....
2. Charge for longer timeframes but swap in less than 10 minutes. IE standardise and replace batteries as needed.
I suspect that the "10 minute recharge" meme will be obviated by ridiculous ranges allowing us to then charge while sleeping instead.
So not impossible, as long as the battery can handle the current. It's obvious that charging technology is not going to be the bottleneck.
(A real battery would probably have a charging curve that slows down towards the end, so more than 6C would be required in realistic conditions.)
Consider this as it scales up, though - I can get electricity from anywhere for my car, from a 120V socket in front of a building that a nice owner lets me borrow for an hour, to a 600VDC superfast charger. I can get gasoline anywhere. Heck, there are even hydrogen stations around here now.
I just don't see this kind of thing being scalable to anything other than small urban areas, which are exactly the place they're not needed, because you can charge a car with 300-400km battery range once a week or less and be fine in the city. Where I need my battery swap is more likely to be while I'm on a road trip going for distance. How could I be confident a full battery that's compatible with my car is going to be available for me, and that all the automation to replace it will be in perfect shape, and that the bottom of my car hasn't rusted to the point where this doesn't work anymore?
They also weigh an absolute ton, so specialized lift equipment is needed; they take up space and will be very difficult to move around. So, are we expecting to stock a huge pile of batteries somewhere with an automatic loader/unloader that can handle multiple people at once with a quick turnover rate that can put away a 2000 pound battery? It's just too much infra, compared to a charging station...
And then there's the matter of the vehicle design; chassis rigidity is important and batteries, being a huge weight, need to be positioned properly with enough load bearing structure around them to support this. I'm imagining a hydraulic lift raising a 2000 pound battery up into my car; some massive brace needs to be attached below it to hold it up. Talk about difficult to get right; we've got harsh conditions like road salt and rust to deal with, and we have to make a fully automatable fastening device that can work at a random gas station with any brand of car... yikes.
You're actually much closer to the idea with the reduce-capacity idea. I had a Ford Focus Electric a while ago that had about 80km of range on a good day. This was more than enough for 90% of my driving; my old SUV handled the rest. Net carbon savings were huge; pity it was totaled in an accident or I'd have kept it going. Even at almost 10 years old it still kept a charge no problem and was a delight to drive compared to a normal Focus. My current EV has far more range but feels heavy and ponderous despite nearly 500 HP.
http://www.icders.org/ICDERS2007/abstracts/ICDERS2007-0255.p...
Second smallest, after monatomic Helium molecules (which have similar problems of storage, embrittlement, and leakage).
The main reason EVs are a thing is that Tesla built the supercharger network. The fact that Honda or Toyota didn't do that for Hydrogen is the reason it has not been a serious fuel alternative. And they probably didn't do that because they always knew the economics would never work out and were never serious about pursuing it.
One thing that seems wrong is in the efficiency comparison: step 1 for hydrogen should be grid transmission, not electrolyzer.
Also, how come the BEV price doesn’t adjust in response to electricity prices (not that it would impact the result).
The BEV cost not adjusting with the electricity slider is a bug, not a choice. I'll fix both. Thanks.
In the end it's only about as efficient as just using a regular diesel engine, much harder to service, more expensive to maintain, and doesn't improve your carbon footprint at all. What's the point?
Short answer, it takes more energy to generate than the energy it produces.
You can do things like only producing electrical power from the alternator when decelerating, ensuring no load comes off the engine, but that would require accumulation as you're not actually burning fuel then either.
But running the numbers on the power requirements, I reviewed one commercially available system (at 12v 14A) and calculated that the HHO they are able to produce is 0.037% by energy going into the engine vs regular fuel.
When presented with 0.037% of the fuel substituted, their 10-15% claim on fuel savings becomes a bit of a red flag.
Is there a chemical process that achieves this with a better efficiency than just using the fuel to turn the wheels?
I do think that batteries will win, but the correct argument is one that shows that capital costs of batteries are going down faster than the cost of hydrogen production.
I don't see a bright future for hydrogen in transport while we keep putting cheap solar, wind, and batteries on the grid / roads.
Gray is $8-10 for liquid delivery. This equates to a little over $1 per mile, which - compared to a CNG bus - is double the operating cost (and about 4x more than a battery electric bus per mile... just for fuel/electricity). And yeah, as I mentioned previously, capital costs will be like 1.3x of battery electric.
That said, there are lots of novel ideas out there for creating H2 fuel! Forest waste (with supposedly all carbon captured), methane pyrolysis (with carbon bricks as an output). The promises never end.
The big thing I haven't covered yet is HVO, which provides the WTT CO₂ saving at a slight fuel cost surcharge, which matters if a fleet is mandated to reduce their CO₂. The TCO assuming a £100k diesel truck and £200k lifetime fuel cost, a 10% HVO surcharge brings the TCO to £320k, versus a £250-350k BEV truck that costs maybe £80k in electricity over the same life. That's £320k with an 80-90% CO₂ reduction from a drop in fuel you can put in your existing trucks tomorrow, versus £280k for battery electric with zero tailpipe. Both of those are available now, with existing infrastructure. Hydrogen is asking you to spend £300k+ on the truck, £150k+ on fuel, and hope someone builds a station within range of your routes.
0- this is a massive upfront investment for what amounts to a small time savings (having extra batteries on hand, charging them and the equipment to remove / move / install the heavy units
1- unless manufacturers agree to share a specification, you're tied to a single brand and risk being shut out of replacements when that inevitably goes away because it didn't catch on or got deprecated
2- for individual consumers, the battery is the most expensive component of their vehicle, and trading it for a used one of unspecified origen to save a few minutes instead of charging is not appealing.
Given one and two, overcoming the expense of 0 is not at all economical for many situations. The ones that most need it can't afford it, or could be satisfied with relatively short high voltage charging.
It will work great for them because these trucks are designed to be modular and easily repairable (they are driven hard and WILL break when their owners need them). I would not be surprised at all if it develops into an impromptu standard just because so many eyes are on the system all the time.
Battery swaps are not practical, but the guy you're replying to is making the point that an electric vehicle could be built with a modular, removable power source, and converted between gas/hybrid/battery/hydrogen/natural gas/whatever later in life depending on the needs. That's just not possible with a vehicle which directly connects the powerplant with the wheels - there's too much nonsense like transmissions and differentials to deal with when you do that.
I think it makes a ton of sense for trucks, much less sense for cars.
There are truck pantographs being tested out. It seems like an idea that could have potential in major shopping routes.
With the added advantage of fuel cell swaps [0] and reload giving the trucks a quicker turnaround time per charge (i think similar op is used for electric trucks as well as some consumer car models)
It certainly solves the problem of recharge points as the infra can be rolled out piecemeal, and since it would be for heavy trucks less disruptive of the rest of the cityscape (can have the outside metroplitan areas etc with maybe emergency stops within)
e-fuels are just low quality gasoline, IIUC, made by (waves hands) ethical means from thin air using electricity. They still generate NOx gases, but ICEs just take them as is, and they're much more energy dense compared to long range batteries.
The only real problem is that there don't seem to be many green and scalable means to produce them, but if we could, I think it can be an overall better alternative to seemingly unworkable hydrogen based EVs and/or unrecyclable battery based EVs.
Add a battery car and you only have to electrify a minority of the lines to be off diesel a majority of the time.
Extra points for electrifying steep grades.
To be clear, I'm fully behind decarbonising freight. It's one of the hardest sectors to clean up and it needs serious attention. But hydrogen for road transport requires jumping in with both feet (due to infrastructure requirements) when there are dozens of smaller, commercially proven steps that get you equivalent results. Better route planning, driver training, aerodynamic retrofits, hybrid and battery electric for shorter routes, even just reducing empty running.
These aren't exciting and they don't get press releases, but they compound. The industry could cut emissions meaningfully with changes that pay for themselves today, without waiting for a national hydrogen infrastructure that doesn't exist yet.
On surplus offshore wind: the economics only work if you assume the electricity is genuinely surplus, meaning there's literally no other use for it. In practice, the UK grid still runs gas plants for roughly 40% of generation. Every MWh of offshore wind that goes into an electrolyser instead of displacing gas is a missed decarbonisation opportunity. "Surplus" renewable electricity is a future state, not a current one, and even when we get there, interconnectors, grid storage, and demand response will compete for those MWh. The electrolyser only makes sense after all of those higher value uses are saturated.
On £1.50/kg: that would genuinely change the fuel cost picture, getting you to roughly 12-15p per mile which is competitive with diesel. But the distribution problem doesn't go away at any price point. You still need compression or liquefaction, transport, and a national network of dispensing stations. The UK has 11 public hydrogen stations. Even free hydrogen doesn't help if there's nowhere to fill up. The grid is already everywhere. Adding a charger to a depot is a transformer upgrade. Adding a hydrogen station is a £2-5M civil engineering project.
The place where cheap green hydrogen gets really exciting is exactly the applications where you can't just plug in: steel, ammonia, seasonal storage, maritime. Those don't need a distributed national refuelling network, they need point to point bulk delivery to industrial sites and ports, which is a much more tractable logistics problem.
So the right way to handle the carbon accounting isn't to assume that all the CO2 produced by the refinery processes count against the hydrogen produced, but rather that the energy that refineries get from burning the hydrogen would be replaced by them burning natural gas instead.
The per-kg energy value of burning H2 is ~2.5x the value of natural gas (refineries generally use LHV for this accounting). But each kg of natural gas that gets burned produces ~2.8 kg of CO2 (because burning replaces the puny hydrogen with relatively larger oxygen atoms).
2.5*2.8 = 7kg of CO2 per kg of H2 taken out of the refinery. Which isn't as big a difference from the 10kg reported in the article as I expected when I set about writing this comment.
Why does nobody want it? If it is being burned off because nobody wants it, then it effectively has less value after compressing and delivering it than the natural gas itself (or as you say, they'd be selling it and burning the natural gas instead).
The truth is, you can burn it off and save the cost and trouble of purifying and storing it (which also uses energy and produces carbon), especially when using it in fuel cells requires 99.99% purity. You couldn't just pipe it over to a data center or power plant.
It's worth considering also that not only is the hydrogen that would come out dirtier (because it's being replaced by natural gas), it's also making the natural gas dirtier, because you're burning methane instead of hydrogen to refine it.
And no, that's not an accurate hot take ankle deep summary of the hydrogen industries arc.
* https://www.mckinsey.com/industries/oil-and-gas/our-insights...