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> The biggest hydrogen bus fleet seems to be 35 vehicles

From the OP:

Cologne is one of the few relatively good news stories for hydrogen bus fleets. Regionalverkehr Köln (RVK) has become the largest operator of hydrogen fuel cell buses in Europe, with a fleet that reached 101 vehicles by late 2024 and is expected to grow to 160 by the end of 2025.

Where I live in the US my kids still take “cheese buses” to school that haven’t changed a bit. They’re diesel and you can hear them blocks away. When they pull up with their air brakes going off and their diesel shifting to idle it sounds like one of those spice miner things from Dune going to work.

If they ever go electric I’m not sure how we’ll know it’s time to take the kids out. Won’t be able to hear them coming.

>Regionalverkehr Köln (RVK) has become the largest operator of hydrogen fuel cell buses in Europe, with a fleet that reached 101 vehicles by late 2024 and is expected to grow to 160 by the end of 2025.

I mean, right from the second section of the article.

I'm surprised hybrids are so under-represented in this considerations.

Maybe I'm missing something but I would think at the scale of a bus, a hybrid is even more appealing than at the scale of a sedan.

Even locomotives and one or two earthmoving off-highway trucks have electric transmissions, making them series hybrids (With very small batteries not used for traction)

While I agree with you; just to be clear it's not "slightly" beef up the local transformer. If you imagine a medium sized depot with 50 buses stabled at any one time, and 300kW chargers (I believe you could go higher), that's 15MW peak which is not trivial to add in many cities overnight. You really need some sort of HV connection for that kind of load, the existing local LV distribution grid isn't going to handle it.

I do definitely think green hydrogen has a big future ahead of itself though. We still use an absolutely ridiculous about of H2 in industrial processes (especially fertilizers).

Europe could produce huge amounts of fertilizers in the summer in the future with all the excess solar and wind it has via this method.

It seems to me hydrogen skipped a step - focus on replacing hydrogen feedstocks in industrial processes directly with green hydrogen, instead of replacing stuff up the chain that can be done with batteries directly anyway.

> you would need a whole new infrastructure for hydrogen powered buses, while keeping a lot of the downsides of fossil fueled air breathing vehicles (eq. air filters filters regardless of if you burn the hydrogen or use it in fuel cells)

Australia kind-of already had 'hydrogen' infrastructure and supply chains already, in LPG or 'autogas'. LPG (or dual petrol/LPG) used to be a popular option for small vehicle fuel in Australia in the 2000s though has slowly declined due to petrol/electric hybrids coming along.

https://www.abc.net.au/news/2023-04-19/lpg-cars-disappearing...

That said, it's possible to convert diesel engines to burn a 90% hydrogen/10% diesel mix, which could dramatically alter those numbers: https://www.unsw.edu.au/news/2024/08/converting-diesel-engin...

It shouldn't be too difficult to bring back 'autogas' infrastructure in Australia. And if we can, I don't see why others couldn't deploy it made sense to do so. Liquid/gas fuels make much more sense in very-low to moderate density areas with long distances between populated centres. Batteries make much more sense in high population density areas with relatively short trips.

Whilst I agree it's not as ideal as a true zero-emissions thing, it's certainly a stepping stone to greatly accelerate the decarbonisation of our fuels, by allowing many to convert internal combustion engines to use much cleaner fuels, without having to buy brand new vehicles.

Given that petrol and diesel these days are usually almost double the cost per litre of LPG in Australia, and that a lot of decently sized long range EVs are still very expensive in Australia, especially considering cost-of-living pressures and the distances many Aussies have to drive in rural and remote areas where EVs just aren't practical, I'm a little surprised LPG hasn't made a comeback.

Australia has since kicked off a project to construct a large green hydrogen generation plant in Western Australia, due to be producing by 2029 and fully operational by the end of 2031, so hydrogen could become a pretty big deal in by 2030.

https://research.csiro.au/hyresource/murchison-hydrogen-rene...

Are those new in Brno? Can't remember them from the last time I was there, but sure sounds interesting

> you would need a whole new infrastructure for hydrogen powered buses, while keeping a lot of the downsides of fossil fueled air breathing vehicles (eq. air filters filters regardless of if you burn the hydrogen or use it in fuel cells).

Unless you burn the hydrogen, you aren't producing any emissions... unless you count water as an emission. Fuel cells don't produce any emissions.

Burning hydrogen though, does produce some emissions, however it's pretty minimal. I believe it's only NOx, and even then at far lower rates compared to gas vehicles. No CO2, CO, or any other stuff from gas or not-fully-burnt gas.

That said, I agree hydrogen has seemingly no place in something like buses. Frankly, the only places that I see hydrogen has any future is either going to be for planes and boats, or potentially for intermediate storage akin to batteries (i.e., create hydrogen with excess solar/wind power).

https://sschueller.github.io/posts/74-eletric-bus-charging-s...

did the picture die or smth?

edit: no, even internet archive from a year ago shows no picture

With some emphasis on the "almost" :

https://cleantechnica.com/2025/04/07/green-hydrogen-for-ener...

As an example, most of Dublin Bus’s electric fleet have 450kWh batteries for a range of 320km. So, bigger than a car, but not as much as you’d expect given that the buses are 20 tonne fully laden and take a hundred passengers.

The low speed means they are using the power to accelerate against inertia, not to maintain speed against air resistance.

I'm not sure how important double glazing is when you're opening the inner air volume to ambient air every few minutes, but maybe?

> same electricity is being used to do electrolysis

Nowhere in the world is electrolysis done at scale. Industrial hydrogen almost exclusively comes from steam methane reforming (SMR).

Batteries are cheap. Installing lots of copper lines for trolley buses isn't. That's why trolley buses are pretty rare. Old idea, didn't really take that well. There are a handful of cities that have them. And they've had them for decades. Most of those cities now also have battery electrical buses to service all the areas where the cables don't go. Expanding the network of cables doesn't seem to have a very high priority. Installing chargers (in depots mostly) is much easier and cheaper. And it's not like batteries are that expensive.

With battery prices trending to 50$ per kwh, a decent size bus battery of 250kwh would cost about 12.5K. That's manufacturing cost, not purchase cost. But it drives the point home: long term batteries are going to dip even further. Far below 50$/kwh. It will drive down the cost of battery electric drive trains for everything with wheels to far below that of the traditional setup with ICE engines. And they don't need expensive fuel to run. Or a lot of engine maintenance and servicing.

Currently tens of thousands of electrical buses are produced per year. Most of them in China. Which is of course where they have lots of battery factories. It's a rapidly growing industry.

The US Government did a study in the 1950s and discovered that the damage done to a roadway by a car is proportional to the fourth power of its axle weight.

https://en.wikipedia.org/wiki/Fourth_power_law

Hrm. Dublin bus has been replacing its fleet of diesel buses with electric. Both old and new are around 20 tonnes fully laden.

I think this "debate" is largely irrelevant: China has decided that locomotion will be (battery) electric. That is the largest scale you can get, so any effects of scale for an alternative will at best be as large as the battery electric one.

And then there are the variety of other disadvantages that come with hydrogen: - significant leakage and high greenhouse factor - heavy support equipment need (both for storage and for usage)

About the only advantage of hydrogen (vs. lithium-ion batteries) is gravimetric energy density (where it's about a factor of 300). But even volumetric energy density differs only be a factor of 5-10. (Both numbers ignore that the storage thing will add significant weight). And those are _already_ not limiting for locomotion needs.

- how sure are we that we are solving a co2 climate crisis with the actions we are taking?

The thing here is yes: Even if we would generate the energy for the locomotion completely with fossil fuel! Large plants are significantly more efficient (10-35% vs up to 60%) and it would be _much_ simpler to, e.g. think about carbon capture if we had tens of thousand CO2 emitters rather than a billion. But we are not doing that!

Actually all the vehicles you mention are already available in battery electric form and typically already far more common than their hydrogen equivalents. Everything from mining trucks to scooters. Batteries are cheaper than fuel cells. And electricity is cheaper than hydrogen. You are right that there's a lot of potential for further cost reductions with battery electric through innovation and numerous paths for doing so.

With hydrogen there simply isn't any obvious path forward. Hydrolyzers are inching closer to their theoretical maximum efficiency. Same for fuel cells. A few percent improvements here a few percent there. End to end battery electric wastes far less electricity. So it's inherently cheaper to charge a battery than it is to fuel a hydrogen vehicle. This is a gap that cannot be bridged.

With batteries we're looking at steep increases in energy density by multiple factors, new chemistries based on commonly available materials, cost reductions, etc. They are already competitive now. But it's going to get far worse for hydrogen very quickly.

Simply put, hydrogen is dead as a door nail for anything with wheels. There's a lot of subsidized inertia in the market. But without subsidized hydrogen, there is no business case to use hydrogen. None whatsoever.

> Hydrogen is a quicker refuel

Only slightly. It's not that fast actually. The naive notion that you just slosh some hydrogen in a tank like you would with diesel is not based in reality. Pumping compressed gas through narrow hoses takes time and hydrogen has a lot of volume. 10-15 minutes to refuel a truck is pretty normal. Charging can take a bit longer; depending on the size of the charger. And there is a path to making that quite a bit faster.

Why so much waste?

Why would a factory invest in hydrogen fueled forklifts and their associated refueling infrastructure if they can get electric ones that just plug into a wall socket?

Unless research on hydrogen manages to upturn our foundational understanding of thermodynamics, hydrogen will be a waste of useful energy in most applications.

For further reference, check the "clean hydrogen ladder"

By your own calculation EROI of Battery buses should be about 15-30 (taking diesel EROI as given as it has no source) if you actually apply the vehicle's efficiency; ~85% efficiency for E2E diesel-generator-to-EV. While diesel bus would be around ~21% effiency.

Source/explainer: https://youtu.be/6c94vRmbM6Y?si=WmCvyB6uKJT7TWZ7&t=444

Is that hydrogen EROI number assuming lowest energy hydrogen? Or something like electrolysis?

Hydrogen makes sense as a chemical feedstock for methanol and ammonia. It also scales well to grid energy storage, because you can add hundreds of GWhs at a time, and the technology is mature (Moss Bluff opened in 1983). You wouldn't use hydrogen in vehicles, because methanol is easy to make, and is a much better fuel for non-aero applications. Shipping is moving to methanol for that reason.

The hydrogen economy never had anything to do with academics. It's a fallback plan by the oil industry.

The hydrogen economy has had a lot of not very subtle backing from the gas industry, which is fully aware that they would have no problem selling hydrogen cracked out of natural gas if it ever took off.

There's a few companies and labs in Germany who still manage to somehow sell hydrogen as a "local innovation" to government grants every now and then... Hydrogen busses, hydrogen trams, hydrogen trains. It never sticks, unsurprisingly.