Why do transit agencies keep falling for the hydrogen bus myth?
152 comments
·March 14, 2025fraserharris
int0x29
Only two years? They operated hydrogen buses from 2006 to 2010 and then got some more in 2011 and 2019. There are budget line items for new buses in 2023 and 2024 that I assume got bought
AtlasBarfed
I'm not going to dispute your numbers with diesel versus EV reliability, but I have to think the simplicity of an EV drivetrain will win that battle in the next version or two.
calibas
Back in 2003, President George W. Bush announced the Hydrogen Fuel Initiative. At the time, people criticized the effort as an attempt by the oil industry to shift attention away from electric cars. The oil industry knew that hydrogen power wasn't going to be viable anytime soon, while electric cars were already a direct threat to their profits, so they pushed the US government towards hydrogen power.
Not to disparage the talented scientists and engineers working on hydrogen power, but now that 20 years have passed I believe it was designed to fail.
yummypaint
It absolutely was. In the event that breakthroughs happened and it became viable faster than expected, the backup plan was to get the hydrogen from fossil fuels to make sure the industry would still get its cut.
analog31
Isn't that the only plan right now? Is commercially viable hydrogen being made from any process other than the shift reaction?
yummypaint
Back when the Bush admin was hyping this stuff they managed to get the media to talk mostly about electrolysis of water using solar power. They would talk about how only water comes out the tailpipe, and the symmetry of being able to reuse water to make more fuel was extremely appealing to the credulous minds of the public.
Nothing has really changed either, 20 years later and laypeople still don't have better information about this technology...
neves
Why? Because Oil Companies are lobbying for inefficient hydrogen to delay a green revolution:
https://adamtooze.substack.com/p/carbon-notes-5-green-hydrog...
> The members of the hydrogen coalition are all obviously incumbent fossil fuel and petrochemical interests looking for a bridge to the new era. If realized, their ambitious hydrogen projects may overload the available supply of green power, for little real benefit. By diverting badly needed clean power, green hydrogen vanity projects may even slow down the energy transition. And the subsidy regimes that are being put in place could become self-perpetuating. As Gernot Wagner and Danny Cullenward recently warned, “hydrogen could become the next corn ethanol”, a ruinously inefficient and environmentally damaging creature of subsidies that are too big to kill.
pjscott
Do you have actual knowledge of their motives? Or is this speculation, confidently stated as fact?
Another possible motive, mentioned in the the paragraph you quote, is that the oil companies see an energy transition coming and are trying to get aboard the hydrogen train to diversify their future revenue sources. And that sounds like a reasonable motive; the sort of thing that people who don't see themselves as evil villains – i.e. the supermajority of people – could embrace.
mixermachine
One can extract hydrogen from fossil fuels. So if a hydrogen break through is coming, they already have a cheap source for the material. Not really green though...
askvictor
Not just to delay, but they're hope is that they'll be able to control it when it happens. Oil companies move fluids, using pipes and tankers. Hydrogen is a fluid. They want to keep doing what they've been doing. Electricity doesn't fit into their M.O.
manchego
I'm just waiting for flywheel powered buses to make a return: https://en.m.wikipedia.org/wiki/Gyrobus
why_at
Wow I had no idea this existed
>Disadvantages
>Weight: a bus which can carry 20 persons and has a range of 2 km (1.2 mi) requires a flywheel weighing about 3 tons.
>The flywheel, which turns at 3000 revolutions per minute, requires special attachment and security—because the external speed of the disk is 900 km/h (560 mph).
It's truly a mystery why they never caught on
adamanonymous
You missed the last and most funny one
>Driving a gyrobus has the added complexity that the flywheel acts as a gyroscope that will resist changes in orientation, for example when a bus tilts while making a turn, assuming that the flywheel has a horizontal rotation axis.
So you have a giant blender than can travel one mile in a straight line before needing to be recharged
whenc
Trains in operation:
askvictor
I'm currently reading "The Windup Girl" set in a mostly-post-fossil-fuel future, where most energy storage is springs.
Ericson2314
Cool :) but reminds me that all energy storage is scary and an accident waiting to happen.
Flows > stocks, overhead wire for the win!
NikkiA
I personally think Battery buses with SAE J3105 'docking' points at key stops (basically, the stops that are used to loiter to set timing, rather than leaving as soon as possible) is a better solution than the cost of stringing OHL through every major road in a city.
https://en.m.wikipedia.org/wiki/Battery_electric_bus#Chargin...
rsynnott
Huh. I kind of thought that batteries had comprehensively won in this market, tbh.
I still can't quite get used to the electric buses. A 20 tonne double-decker bus should sound like it might explode at any moment; it is unnatural for them to move around more or less silently.
bombcar
Batteries have won this so hard (if you ignore CNG busses, which have existed forever and are "almost as good as hydrogen could be") - because even when they hadn't won it, you just needed more busses.
Is it nice if the bus can do a driver's entire shift without a recharge? Sure! But if it can't, you just design the route so that the driver can switch busses and buy another bus. That means the technology problem is now a money problem.
Busses are also already quite heavy, so battery weight doesn't affect them as much as it might in a small car.
ZeroGravitas
The stop-start nature of city busses makes them a real low hanging fruit for battery electrification, benefiting from instant torque to start and regen to stop and, as you say, fixed known routes within larger fleets.
The only nation that seems to have capitalised on this basic fact is China which bootstrapped its EV industry on busses, pulling ahead from 2010 and hitting 90% of global market share for EV busses in 2020, and now a big exporter.
AnthonyMouse
For the same reason the electric mail trucks are a good idea. You can probably expect UPS and FedEx to start replacing their fleets over time as the existing vehicles age out, now that all electric vans are starting to become available.
busthrowaway23
(At least in King County Metro) the newer diesel-electric buses are series hybrids that use electric motors for traction, and diesel generators to power a small battery. So the low hanging fruit of electric traction was already “picked”. You can look up the bus model online - New Flyer XDE class
rsynnott
> But if it can't, you just design the route so that the driver can switch busses and buy another bus
Oof, that's a huge 'just' in many cases.
That said, current electric buses have sufficient range that this mostly isn't an issue. The unnervingly silent double-deckers I mention have a claimed range of 320km, which, at least here, is sufficient.
The big problem with Dublin's electric buses, ridiculously, was that the operator was late in applying for planning permission for the substations required to charge them. With the result that for about a year, there were about a hundred of them stored and unusable.
bobthepanda
This depends a lot on local climate and topography.
Seattle has kind of been a bust with them because the hills really reduce the amount of charge, and on top of that the existing bus depots are already full, so switching to electric only would mean having to find and locate space for more bus depots, which is quite difficult.
abdullahkhalids
Many bus routes have a 5-10ish min break at some point (usually the main station) in the route. If you can utilize those ten minutes to do a top-up, you can go a lot further on the same sized battery.
bluGill
No bus route should be more than 15 minutes between full and empty. That is you start at some station, go 15 minutes, then turn around and go back. There are many systems that attempt to do more, but there is no point: people have places to be: on the bus is not on that list. That 15 minutes means an average of 7 minutes, now they walk to some other express bus that gets them nonstop (at faster speeds) to someplace, but you still only get 15 minutes to get there before it isn't worth the bother, than 7 more minutes on some other bus. Add in 5 more minutes of walking time (and transfer time!) and we are at 45 minutes - this is unreasonably long for normal trips already, but it is the best you can do!.
In short there are plenty of places to switch buses if you need to.
zizee
> That means the technology problem is now a money problem.
This is such an odd insight. Most problems in the world can be described as a "money problem", and it's usually the problem that problem solvers are pushing up against.
xattt
CNG buses were about a 10-year experiment in Toronto. There were a number of bus terminals where CNG vehicles were prohibited, either due to clearance or because of the associated explosion risk.
A second batch of buses were converted to diesel so that the fuelling station could be decommissioned.
PaulHoule
In Tompkins County we were early adopters of the electric bus, at least for the American market. We bought them from a startup which had trouble with the structural aspects and eventually they fell apart
https://www.ithaca.com/news/ithaca/tcat-pulls-all-electric-b...
Established bus manufacturers make good electric buses now but we don't have the money to buy replacements.
ttttannenbaum
Five months before the company filed for bankruptcy, Proterra's CEO was appointed to the President’s Export Council (PEC), "the principal national advisory committee on international trade."
Tijdreiziger
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jrussino
> A 20 tonne double-decker bus should sound like it might explode at any moment
I hope you're using "should" as in "that's what I'm accustomed to" rather than "that's how it ought to be"... right? :-D
Personally I feel like quieting buses would be a huge step toward making day-to-day city life more pleasant.
rsynnott
Yup, wasn’t being entirely serious. They’ve gotten progressively quieter over the last few decades; when I was a kid, they really did sound like they were within seconds of complete failure when going up a hill. The electric ones are a shock the first time you get on one, though - very futuristic.
KeplerBoy
Busses are not going to be quiet. Around here we have pretty cool "Van Hool ExquiCity" trolley busses and they can glide gracefully at slow speeds, but when they are hurtling down patched up streets they are not much quieter than the traditional busses.
comte7092
Why do transit agencies keep falling for hydrogen busses? From the perspective of the US, it’s pretty simple:
1. Transit agencies have no way to reasonably validate what the future holds. From the standpoint of today, a hydrogen bus can be expected to replace a diesel bus 1 to 1, while battery electric is a 2 to 1 replacement. This might not be a huge issue except:
2. FTA regulations have strict requirements on how many spare busses may be kept at any time (defined by the ratio of peak vehicle usage vs the size of the overall fleet), doubling the size of the fleet blows this ratio out of the water.
3. It doesn’t matter what BYD offers or what’s possible in China, US transit agencies are required (FTA regs again!) to buy busses made in the US. American manufacturers do have somewhat decent battery electric products, but they are clearly not at the leading edge. With the proterra banktrupcy, there are limited competent suppliers in the market. To a large degree, gillig et al do get to decide what gets pushed into the market.
xnx
> US transit agencies are required (FTA regs again!) to buy busses made in the US
BYD makes electric buses in California: https://en.wikipedia.org/wiki/BYD_K_series
londons_explore
If hydrogen busses really were going to have a lower operational cost per mile in 2050, then some company would be offering to lease busses for $X per mile to transit operators, fuel included, for a 25 year lease. They'd make a loss initially, but big profits later.
That approach turns this technology maturation and cost risk into a market, and those with most expertise can then put their own money on the line to help everyone make the right decision.
jpm_sd
Transit agencies don't have the technical expertise to distinguish truth from lies in cleantech marketing. They aren't the only ones, see the over-inflated valuations of both Nikola and Tesla as two (very different) stories of companies successfully lying to investors and the general public about the magical capabilities of their novel transportation platforms.
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andix
Answer to the question: political reasons and lobbying.
Hydrogen is produced by the big oil and gas companies. By pushing hydrogen vehicle instead of battery electric vehicles they stay in business.
They market hydrogen as a green alternative to oil, although most hydrogen is currently produced from fossil sources, and this won't change soon (next 10 years).
01HNNWZ0MV43FF
Because people are allergic to hybrids and I don't know why
"Electric is short range, fuel is expensive, guess I have to pick one"
The ideal drivetrain was invented over 20 years ago by Toyota and apparently nobody but me and Honda noticed it!
AnthonyMouse
The drivetrain was actually invented several decades before that. It wasn't until around 20 years ago that the batteries got to the point to make it practical to use.
They're also made by more than Toyota and Honda. The American automakers have been offering vehicles with a similar hybrid powertrain for around two decades and the German automakers for only a little less than that. But they're generally not a separate model like the Prius is, so the only exterior difference is a hybrid badge on what is otherwise visually identical to the non-hybrid car/truck of the same model.
Tade0
I've ridden both hybrid and electric buses and I prefer the latter, as those huge engines still produce a lot of vibration.
I drive a Toyota hybrid and while it's a step up from a purely combustion propelled car, I still have to do oil changes and its fumes still smell bad when it's running rich for whatever reason.
busthrowaway23
(At least in King County Metro) their newer diesel-electric buses are series hybrids that use electric motors for traction, and diesel generators to power a small battery. The drivetrain seems smart but maybe other agencies use it less? You can look up the bus model online - New Flyer XDE class
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bell-cot
Here in SE Michigan, one local transit authority ditched its new hybrid busses and returned to diesel ~15 years ago - because the TCO for the hybrid busses was so much higher that fixing the hole in their budget proved impossible.
mschuster91
> The ideal drivetrain was invented over 20 years ago by Toyota and apparently nobody but me and Honda noticed it!
The problem is hybrid drivetrains are complex. You don't save anything on the complexity of a combustion engine and exhaust train (over 1000 individual parts that have to be machined at extremely low tolerances), but add a more complex transmission (it needs to be able to work with two distinct inputs) and an electric drivetrain on top of that.
It is worth it in terms of energy efficiency and acceleration stats since even a small electric motor can supply a lot of torque at low speeds until the high-horsepower combustion engine catches up (virtually all modern cars have a turbocharger that needs time to spin up), but it's technically challenging to actually build into a modern car design - unlike 90s cars with ample space available to stuff components in, in a modern car every cubic centimeter is accounted for due to crash resistance.
jshier
As a simple driver of cars, I've never understood why no one has mass produced an EV with a built-in generator. That would avoid the complexity of the hybrid drive train, allow easy plugin and short range electric-only travel, and could even be offered as an optional attachment. So what am I missing? Is the efficiency gained by the generator offset by losses through the EV system?
AnthonyMouse
That is called a series hybrid and the reason they're not popular is that the power split device in common hybrids is simply better.
The power split device isn't an ordinary transmission, it's a set of planetary gears with a fixed gear ratio between three shafts. One goes to the wheels, the other two to the engine and the electric motor respectively. The ratio of the engine speed to the wheel speed is then set by the speed of the electric motor connected to the third shaft, which gives you a CVT with no belts, clutches, torque converters or even synchros.
The transmission is "more complicated" only in the sense that it contains electric motors. In every other respect it's simpler, more efficient and more reliable than an ordinary transmission. Meanwhile those electric motors mean you don't need a starter motor or an alternator because the engine can be started by the electric motor through the transmission and an electric motor is a generator when operated in reverse.
A series hybrid still requires you to have a gas engine with all that entails, but now the gas engine needs its own dedicated electric generator/motor and you can't deliver power from the gas engine directly to the wheels, so the traction motors have to be bigger in order to supply 100% of the torque used in acceleration instead of the gas engine and electric motors both contributing. That makes series hybrids heavier, slower and more expensive, so they're basically useless. Probably the main advantage would be that you could offer the generator as an option on what would otherwise be a full electric vehicle and then only people who need the extra range would pay for it.
wahern
This was the GM Volt, predecessor to the Bolt: https://en.wikipedia.org/wiki/Chevrolet_Volt GM ceased production in 2019. The answer to your question can probably be found there, but IIRC [from GM's perspective] the consumer market preferred ICE + battery over electric + generator, especially after the all-electric options came to market and siphoned demand from the latter.
BerislavLopac
BMW i3 and Chevrolet Volt both had that option: https://en.wikipedia.org/wiki/Range_extender
And of course, there are plug-in hybrids: https://en.wikipedia.org/wiki/Plug-in_hybrid
jfengel
It just turns out not to be worth it. The generator is a lot of weight to add, and a whole bunch of new parts to maintain.
It's a lot easier to add enough batteries to match the range of an ICE car. Range anxiety is largely manufactured at this point. The cars know how far they can go and where the chargers are. A gasoline powered generator would be a huge extra cost with no real upside other than averting a non-problem.
00N8
Edison Motors is working on a system like this. They're looking to sell kits for retrofitting it onto pickup trucks, & a larger scale semi truck cab version for use with logging trucks. It looks great in their videos, although I'm not sure if they're selling to the public yet - probably a ways to go before it's really mass produced.
torginus
Most BYD PHEVs work like that - with the additional option of connecting the engine directly to the wheels via a clutch at highway speeds. I think Honda has a similar system.
busthrowaway23
[dead]
xnx
Some hybrid drivetrains have fewer moving parts than a traditional ICE and are more reliable.
wahern
That undersells it. The data on hybrid drivetrains is pretty clear--it's definitely more reliable. Even mechanics will tell you that; certainly mine did, and he's not a masochist. Start+stop is hell on mechanical drivetrains. It's a no-brainer when purchasing a new car except that there's still a premium for hybrid, so the RoI might not be there given baseline reliability and depending on your preferences. Though the premium gap is closing, at least for non-plugin hybrids. Plugin hybrids are the new premium option in model lineups, so traditional hybrids are moving down market.
vardump
Sounds counterintuitive.
Any references?
jillesvangurp
That goes for anything hydrogen and wheels pretty much.
It's actually pretty simple to figure out. Making hydrogen takes energy. You lose some of the energy making the hydrogen. This is not a fixable problem. At least not unless you break the laws of thermodynamics.
When you have created hydrogen, you lose more energy compressing the energy. Then you have to transport it to wherever it's going to be pumped into the vehicle ... both of which take more energy. Then it goes into a fuel cell, which loses more energy. All these losses multiply. And if you know your maths, you know that multiplying numbers smaller than 1 means the result gets smaller and smaller. These losses are significant.
And we're comparing it with putting the energy into a battery directly. It has inherently better round trip energy. Even if hydrolyzers, and the infrastructure to store, compress, and transport hydrogen were free (which they are not), using hydrogen would still be more expensive than that. Because it wastes more of the energy that goes in. So, in addition to the energy losses, you also need to deal with infrastructure cost. On top of regular energy infrastructure.
Anyway, that's all theory. For practice, just look at market price of hydrogen. Most of that stuff is of the dirty grey hydrogen variety creating that wastes a lot of methane. So much, that it would be cleaner to just use the hydrogen in a combustion engine in the bus and you'd have less CO2 emissions. Expending more methane to make hydrogen to have less emissions makes no logical sense.
If you are using grey hydrogen, it is more expensive per mile than methane. Nothing can change that. If you are using green hydrogen, it is more expensive per mile than battery electric. Nothing can change that either. That's just physics and simple economics. Yes there are some innovations in this space happening that reduce the gap a little. But it's never going to be enough.
Right now it's not even close. Unless somebody is subsidizing the hydrogen fuel, you'd be paying way more per mile than with diesel. And not just a little bit. And a common reason to switch from diesel to BEV is that it actually costs way less per mile than diesel. So, instead of saving money, you are spending more money.
Subsidies are hiding the true cost of hydrogen. That's the only reason there are some vehicles on the road. As soon as the subsidies dry up, hydrogen transport use cases evaporate. There are of course plenty of other use cases where hydrogen is needed that make much more economical sense. Using scarce and expensive hydrogen for transport is a poor use of resources. The utopian world where we have vast amounts of hydrogen surpluses does not exist.
ninalanyon
Because the US is in thrall to the oil companies.
AC Transit (eg: East San Francisco Bay) performed a detailed 2 year study (July 2020 - June 2022) comparing newer Hydrogen Fuel Cell & Battery -powered buses to existing Diesel, Fuel Cell, & Hybrid -powered buses, 5 of each type. The key results are the Hydrogen Fuel Cells have significantly more expensive infrastructure, fuel, and maintenance costs than Battery. However, both technologies are still less reliable than Diesel.
The results are broken down into 4 volumes, each covering 6 months. You can read them here: https://www.actransit.org/zebta