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Hydrogen vs. Battery Buses: A European Transit Reality Check

cleantechnica.com

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Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#71

Post by londons_explore »

7e wrote: post #47
londons_explore wrote: post #30

Earlier quoted context omitted.

0.7 m/s^2 is a typical acceleration for a city bus - most people won't fall over whilst standing at that acceleration. A city bus perhaps holds 50 70kg passengers = 3.5 tons of cargo, and a lightweight bus design is perhaps 6.5 tons (typical bus=10 tons). Total = 10 tons. Peak Power required to accelerate 0.7 m/s^2 up to 30 mph = 93 kilowatts. Which is car territory. The cheapest tesla model 3 has a 208 kilowatt moto…

The bus is constantly starting and stopping. Regen doesn't recapture it all. Power isn't the issue, energy is. Also, current hybrid busses with not-so-heavy batteries weigh about 15 tons without cargo. You are way off.

This math is for future busses designed for city use - so batteries will be much smaller and therefore lighter, and the bus construction itself will be much lighter because, as you point out, with a city bus pulling away ~5 million times in its lifespan, the cost of energy lost when stopping and pulling away far exceeds the cost of upgrading the frame to aluminium and other weight saving measures.

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#72

Post by rsynnott »

londons_explore wrote: post #30
maxerickson wrote: post #25

Earlier quoted context omitted.

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

0.7 m/s^2 is a typical acceleration for a city bus - most people won't fall over whilst standing at that acceleration. A city bus perhaps holds 50 70kg passengers = 3.5 tons of cargo, and a lightweight bus design is perhaps 6.5 tons (typical bus=10 tons). Total = 10 tons. Peak Power required to accelerate 0.7 m/s^2 up to 30 mph = 93 kilowatts. Which is car territory. The cheapest tesla model 3 has a 208 kilowatt moto…

That’s a small bus. Buses here take about 100 people and are 20 tonnes fully laden.

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#73

Post by rsynnott »

j_4 wrote: post #58

Often overlooked but electric buses are very heavy. Here in my small hometown they visibly started decaying the road infrastructure super fast in many places since they got introduced. Not impossible to patch up, but not a negligible cost of moving to the tech.

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

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#74

Post by jillesvangurp »

vegavis wrote: post #44

Yeah this only reveals a snapshot of the current situation. The truth is that lithium ion has a few more decades of serious R&D and successfully mass produced commercial products on the market. Hydrogen fuel cells arent as fortunate; they still have a high production cost due to low volume, the supply chain has had a fraction of the investment of ICE and EV, and the regulatory environment is even less clear than EV a…

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.

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#75

Post by londons_explore »

rsynnott wrote: post #72
londons_explore wrote: post #30

Earlier quoted context omitted.

0.7 m/s^2 is a typical acceleration for a city bus - most people won't fall over whilst standing at that acceleration. A city bus perhaps holds 50 70kg passengers = 3.5 tons of cargo, and a lightweight bus design is perhaps 6.5 tons (typical bus=10 tons). Total = 10 tons. Peak Power required to accelerate 0.7 m/s^2 up to 30 mph = 93 kilowatts. Which is car territory. The cheapest tesla model 3 has a 208 kilowatt moto…

That’s a small bus. Buses here take about 100 people and are 20 tonnes fully laden.

okay - well the motor from the cheapest Tesla will still do the job just fine.

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#76

Post by linedgolyi »

deepsun wrote: post #50
api wrote: post #13

Earlier quoted context omitted.

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.

You'll see the bus on your phone / home hub. Like ridezoom company does, you see whenever your kid checked in/out of the bus, and the bus itself on a map.

Hopefully in a way not tied to some commercial third party. People should be able to reliably go to public school without having to accept an arbitrary third party contract

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#77

Post by linedgolyi »

api wrote: post #13
rsynnott wrote: post #4

I think battery buses have comprehensively won this one, to be honest. The biggest hydrogen bus fleet seems to be 35 vehicles; there are many BEV bus fleets in the hundreds and some in the thousands. As a certified old person, I'm having trouble getting used to them. It is unnatural for a double-decker bus to pull up near-silently, and then move off smoothly when you get on. They are _supposed_ to vibrate violently a…

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.

There's a similar danger with very quiet and/or electric cars where people near the school barely hear them coming and need more attention to keep themselves safe. Avoiding an older gas or diesel car is practically automatic as you can hear their speed, acceleration and location comparatively far away. I think EV manufacturers have added some sort of noise to low speed driving, but I haven't heard anything beyond one being right behind me

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#78

Post by BlueTemplar »

7e wrote: post #48
VectorLock wrote: post #28

Earlier quoted context omitted.

Inertia that can then be recovered, which you can't with air resistance.

There is plenty of air resistance in a low speed bus, which is shaped like a brick and has huge frontal area. That is still a lot of air to push.

Sounds like there is room for improvement here too ?

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#79

Post by BlueTemplar »

amsha wrote: post #59

There is a very to-the-point diagram called the Hydrogen Ladder [0] that classifies the usefulness of hydrogen by domain. The author makes a good case that, despite its versatility, hydrogen is almost always worse than some other clean technology for any use case. It’s hard to make, store, and use in a scalable/cheap way, and even generous estimates of future progress show a cost curve that requires subsidies basical…

With some emphasis on the "almost" :

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

Re: Hydrogen vs. Battery Buses: A European Transit Reality Check

#80

Post by linedgolyi »

adgjlsfhk1 wrote: post #37
martinald wrote: post #19

Earlier quoted context omitted.

Not really. Buses need to be charged whenever, not just overnight (it creates enormous logistical problems otherwise). A typical bus route running 5am to midnight say is not going to last with one charge, depending on length. Also, if it is a cold night and everyone leaves electric heating/heat pumps on, what happens then? Noone can get to work the next day? Regardless most urban transformers are not going to have 15…

Lots of busses are split shift. i.e. they drive from ~6:30am to ~9:30am and ~4pm to 7pm. This means that a significant portion of your bus fleet will be able to charge during the middle of the day when energy demand is relatively low and there's a ton of solar power. As an aside, we have so far really dropped the ball on level 1 electric vehicle chargers at offices. As solar power and EV numbers increase, it's pretty…

>we have so far really dropped the ball on level 1 electric vehicle chargers at offices

Our govt. really did a disservice to transition to EVs by slapping on a big tax to anyone even brushing against a charger at work: 120€/year

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