Seems about a decade late. Did anyone other than toyota execs really believe hydrogen everstood a chance? Maybe if the push had started in 1984 they would have been able to effectively insert themselves into the market and properly compete with EVs before battery tech has grown to be able to be viable.
I'm genuinely baffled at the money and time that was poured into this when it seemed dead on arrival to almost everyone (as far as I know). Am I missing something? Is this some quirk of Japanese techno-optimism and simply a failed moonshot?
"Did anyone other than toyota execs really believe hydrogen everstood a chance?"
I think BMW did. They had a good prototype in the early 2000s and really went to town with it. They marketed it heavily as a finished and usable product and I guess the thinking was that no one would notice the difference because the infrastructure wasn't there.
Now, the story goes that a sheik tried to test them and actually ordered a whole fleet, which BMW could not deliver. This dealt a heavy blow to BMW's hydrogen ambitions and the program only continued at a much much smaller scale.
Of course this is all anecdotal, and I do not know how much is really true, but it is the story I heard on multiple accounts when working close to these projects.
For many years there was a hydrogen fuel station in Hamburg and I think many BMW images showcase it. Last time I heard it was decommissioned.
Hydrogen electrolyzers perhaps makes sense as a backup load: something that can be turned on when there's too much electricity production (as is increasingly the case in renewable-heavy grids). But then what to do with the hydrogen?
Fertilizer? sure. Heating? maybe.
Cars? the infrastructure still has a long way to go. See https://www.reddit.com/r/Mirai/ for the deets.
I agree that is a better use for excess power than just dumping it into a resistor, but why go through all the extra effort? Batteries are getting better and better and better, and choosing to use excess generated power to generate hydrogen seems like one step backward. Why waste so much power on a doubly inefficient process (losses from hydrogen production and then again during use) when you could just, you know....store the actual pure energy you need for everything else?
Even barring a great battery, there are dozens of other great ways to store energy. Pumped hydro is 80%+ efficient, and all you need is a pump and a hill, vs hydrogen electrolysis, which maxes at 80% efficency, and then hydrogen combustion, which is like 40%, on top of all the exotic equipment required for manufacturing.
By all appearances, it just seems like an absolute no brainer....I really dont get it
> By all appearances, it just seems like an absolute no brainer....I really dont get it
I understand the policy around hydrogen (Bipartisan Infrastructure Law allocated $8 billion to hydrogen production) as a technological pivot for the United States which leads the world in oil and gas extraction and logistics tech. The US has a lot of gas handling experience.
Optimistically, green hydrogen will diversify the energy supply, bringing "energy resilience", a key policy buzzphrase. Batteries and pumped hydro are undeniably superior in round trip efficiency, but hydrogen does have some desirable properties such as relative ease of overland transport, very long term storage, and being a chemical precursor for some industrial processes.
Pessimistically, green hydrogen is a way for oil and gas companies to siphon many taxpayer dollars while doing superficial work similar to the compliance EVs of the 90s and 00s.
I'm optimistic mainly because my PhD in electrical engineering is being funded partly with the green hydrogen taxpayer dollars. Shout-out to my fellow taxpayers and my advisor's grant writing skills! I'm working on power electronics which are fundamental in renewable energy and by extension green hydrogen electrolysis.
> Batteries are getting better and better and better
They are still too heavy. Carrying a ton of battery every time doesn't really makes sense.
hydrogen was never in the running in the first place. Toyota were just kidding themselves. Billion dollar projects still can't get handling hydrogen right. A hydrogen infrastructure is pure sci-fi
It’s not sci fi. There are small scale hydrogen generation and storage solutions that are real and cost effective.
Hydrogen is actually a really good solution for shipping and long haul trucking. Conceptually, it really could have worked for cars but Tesla did a really good job of making BEVs sexy, when consumers looked at the market they decided to head towards BEVs.
Personally, I think they could have done some quick cocktail napkin math and figured out their strategy without too much effort, but large mega corps tend to frown upon that sort of thing. I remember the Honda clarity (a retro-fitted civic) was going for $350K and saying to myself: no one thought to use a spreadsheet before building?
Why?
Hydrogen is dangerous and difficult to store, dangerous and difficult to transport, and has egregious specific energy density--all of them are deal-killers for any widespread fuel.
The only two benefits of hydrogen over other fuels are:
1. The cleanest and most efficient combustion 2. Ease of synthesis on a distributed scale
Ammonia beats hydrogen on every front aside from:
1. Less efficient/clean combustion (which we can handle with extant NoX scrubbing technologies) 2. Currently, it's only efficient to manufacture it in large-scale non-distributed industrial plants.
The great thing about ammonia is we've been manufacturing and storing it at-scale for about a century so we're really good at it. Ammonia is the best current candidate for replacing bunker oil and diesel in shipping.
Ammonia is also incredibly toxic. Hydrogen is explosive, but not toxic.
In fact, fun fact, it makes for an incredibly good dilutant for extremely deep scuba diving (you can't breathe pure oxygen underwater and most gases, including oxygen, become toxic under pressure). For some reason though, people are queasy about the idea of mixing pure hydrogen and oxygen hundreds of meters underwater.
Ammonia in a form suitable for combustion is extremely toxic and even produces chemical burns on direct skin contact.
There's been quite a few deaths from industrial ammonia tank (plant, truck, railcar), leaks but unlike hydrogen there's zero chance for a combustion explosion or incidental damage from fire.
Ammonia also almost immediately diffuses and dissipates in air at atmospheric conditions, so while it's VERY toxic it's only VERY toxic for a VERY brief period of time (a few minutes).
One of the odd "safety" benefits with ammonia is that it takes a rather special set of circumstances for it to combust in the first place. That makes it a sub-optimal fuel in many applications--notably aviation.
Thanks for that neat fact about using hydrogen in diving. I'm only familiar with trimixes or bimixes of oxygen, nitrogen, and helium.
Interesting re ammonia. But is it the same when there would be a huge spill? E.g. imagine a leak at a large storage facility, of comparable size to how we store hydrocarbons today. Wouldn't that turn into a massive toxic cloud?
Interesting read re breathing hydrogen: https://en.m.wikipedia.org/wiki/Hydreliox
I’d say that Tesla did a lot more than just make BEVs sexy, they made them practical. You don’t see Toyota out there making a nationwide network of Hydrogen fueling stations like Tesla did with Superchargers. Someone had to get the ball rolling, and Toyota didn’t do it.
Maybe not Toyota, but Japanese gvt has been doing it: https://hydrogen-navi.jp/en/station/index.html#:~:text=As%20....
Hydrocarbons are already good at that. Its the fact that the carbon comes out of the ground instead of the air that is a huge, pressing problem. Use the excess electricity to split water, and bond it with carbon in the air.
Electricity in batteries isn't great for trucking, but it's going to win anyways.
Because it's far cheaper than diesel or hydrogen.
60% of the cost of trucking is fuel. A reduction in that provides a massive competitive advantage that will push out other trucks. Trucking is a highly competitive low margin business.
Green hydrogen uses about 3X the electricity per mile as a battery powered truck, it can never be competitive on cost. It may be better in every other way, but cost is primary.
Its not that it had a big chance, its that because everyone (other auto manufacturers) was doing it and you have to keep up to make the shareholders happy
We still have to solve aviation and maritime don’t we?
I can see why you’d want a single fuel source for all vehicles.
But I know nothing about fuel production.
Sadly, aviation is looking like only hydrocarbon combustion will work for anything aside from very short-haul flights.
No battery breakthrough will get around the fact that medium and long-haul planes get the bulk of their range from the fact that they get substantially lighter as they burn fuel. Short-haul routes and trainers can be all electric ( https://byeaerospace.com/ ).
We'll probably end up with something like "green" hydrocarbon synthesis--at substantial cost increases. The vast bulk of aviation will never be de-carbonized in any foreseeable future short of something akin to "Mr. Fusion" from Back to the Future.
There's good hope for ammonia in maritime. Man in Germany has had working ammonia fueled gas turbines on a variety of vessels and routes for years with forthcoming retro-fits available this year. https://www.man-es.com/discover/two-stroke-ammonia-engine
Ammonia won't work well in aviation due, primarily, to its very short/slow combustion wave-fronts and low combustion temperatures, but also due to its lack of specific energy density with storage infrastructure that's light enough to be airworthy. It's "do-able", but a very distant "2nd fiddle" to even lite/green Jet-A (kerosene) synthesis.
It is possible to take some of the carbon out of the jet fuel equation, but there are worse forms of pollution than carbon.
Thanks for that link! I've been following aviation fuels for some time, but had no idea this had ever been tried.
> We still have to solve aviation and maritime don’t we?
Hydrogen for aviation is turbocharged stupidity. Particularly when we're making solid progress on synthetic (and biomass) aviation fuels [1]. (Which wouldn't require a global aircraft and airport infrastructure overhaul.)
[1] https://www.catf.us/resource/decarbonizing-aviation-challeng...
if you want to fuel an airliner with hydrogen, it might be possible, but you'd have to kick most passengers off to make place for the hydrogen
All revolutionary technologies that end up successful surely look hopeless and too expensive at some point. Just look at the price of solar panels on 1970s.
SpaceX looked insane to me. For a very long time I was incredibly sceptical Starship will ever fly. Well...
The idea endures because produce fuel from nothing but water and sun light and left with no emissions is incredibly promising.
I would ask why nearly everyone has contentedly continued using rare earth mineral, cobalt and fossil fuel to power out vehicles when a clean renewalabl source is right here.
Hydrogen is not a source of energy, it is a carrier. You have to create hydrogen gas from water (or as is done today, from fossil gas). This takes energy. This energy can just as well be used to power the thing directly. Which is significantly more efficient.
https://pbs.twimg.com/media/D0MuwO9V4AEGbUo.jpg
Hydrogen is brought up as a potential storage method which may work, but it makes metals it touches brittle. It is not like storing fossil gas. There are ways to limit it, but it has costs.
https://en.wikipedia.org/wiki/Hydrogen_embrittlement
Hydrogen in cars also uses expensive metals, platinum in the fuel cell.
https://www.sciencedirect.com/science/article/abs/pii/S03603...
Because "rare earth minerals" aren't that rare, are pretty easy to recycle (making them renewable), and batteries have end to end efficiency of ~80% compared to ~20% for hydrogen.
> easy to recycle
Maybe. But IIRC practical reality is that no one actually does this, and there is no infrastructure setup for this. Something like <1% of rare earths in product are recycled.
Please correct me if I'm outdated.
They’re currently so cheap and plentiful that it doesn’t really make economic sense to recycle them. They’re recyclable in the sense that it would become a realistic option if supplies became limited, which isn’t true of everything.
EVs (and their resulting large battery packs) haven't been available at scale long enough, but there are already established businesses for recycling standard car batteries and it's why you pay a separate "core" deposit in the US to ensure they go back into the system.
People are starting these businesses already, it's yet another logistics problem to solve. Right now there is more money in pulling apart the packs the using the cells as salvage than there is recycling, but as more and more EVs reach end of life you can bet it will be a sizable market.
Everyone compares Li-ion recycling to starter battery recycling, but starter battery recycling is extracting a single element that makes up almost all of the mass of the battery. There are many different cathode chemistries all in use for lithium ion cells, so the logistics problem is significantly more complicated.
Presumably a specific chemistry will end up winning out for chars, but, IMO, most of the cars on the road now will never have their cells recycled.
basically all batteries now are 1 of 2 types, and the differences within those types largely relate to manufacturing methods and trace elements that probably aren't worth recycling anyway.
Pretty sure this is what Redwood does: https://www.redwoodmaterials.com/
Also, Li-ion batteries don't really use rare earth metals (there's a little yttrium in some varieties of LFP cells). The idea that REs are needed for batteries dates back to nickel metal hydride batteries, which Li-ion batteries supplanted.
The difficulty with getting LPG fueled vehicles off the ground should have demonstrated the foolishness of pursuing a fuel even more difficult to handle and with no large scale delivery mechanism already in place.
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Drive a Toyota Mirai while you can–this might be the only time in history to experience the hilarious quirks of a hydrogen car. Including the "dump h2o" button, which causes the car to, um, eject its h2o waste on command. Oh and if you're in San Francisco, take a ride on the free hydrogen powered ferry "Sea Change" (its waste comes out of the drinking fountain).
Another fun quirk: The hydrogen dispenser frosts up pretty fiercely during fueling. There's a station near SFO that I stumbled across where the dispenser was too cold to dare touch.
I wonder if that depends on the pressure of the car? I vaguely recall they sold at two pressures when I looked long ago. Could stepping down from the stored pressure to much lower car pressure cause the icing?
oh, and I remember one other thing. Even though the mirai drivers were getting free fuel (at the beginning), I think H2 was like the equivalent of $17/gallon marked on the pump.
I have a Toyota Mirai. The cheapest hydrogen available to me is $30/kg, and many stations (those owned by True Zero) charge $36/kg. When I bought my Mirai, it was $19.70/kg.
The reason I bought a Mirai is because I wanted to go zero-emissions but I’m an apartment dweller with no EV charging options. The Mirai is the best vehicle I’ve driven in terms of its features and comfort. However, once my fuel card ran low, I ended up getting a gas-powered car since $36/kg is prohibitively expensive for me to pay out of pocket.
I hope the hydrogen situation improves, since not everybody has convenient access to an EV charger, not to mention the cost of electricity in PG&E territory.
> Could stepping down from the stored pressure to much lower car pressure cause the icing?
A drop in temperature will be (more or less) proportional to a drop in pressure. See https://en.wikipedia.org/wiki/Ideal_gas_law
Careful, the ideal gas law doesn’t really tell you this at all.
The nice case is adiabatic expansion, and at least the sign of the temperature change has the decency to behave the way one would expect:
https://en.m.wikipedia.org/wiki/Adiabatic_process
The more realistic case for a gas station is Joule-Thomson expansion, and it thoroughly defies basic intuition: https://en.m.wikipedia.org/wiki/Joule%E2%80%93Thomson_effect
A good friend had one (leased) and loved it ... until lessor broke the lease and said she had to give it back.
I think hydrogen does still have potential, just not for regular consumer vehicles. In cases where weight matters like flight, batteries just aren't near good enough now or anytime in the near future due to weight. In cases where you need monstrous amounts of energy between fueling/charging like ocean going cargo ships, batteries are again not anywhere near now or in the near future even close to sufficient. And in scenarios where there aren't safety concerns because consumers simply have no access to it and crashes/accidents are extremely rare, like with trains or large energy storage, hydrogen doesn't really have any real downsides compared to batteries but has plenty of upsides.
I still have hope for hydrogen fuel usage, but to me it has never made sense to try and push for consumer level hydrogen powered devices and cars. You can't just ignore an old hydrogen fuel tank in like an old junker car even if it is 99% empty, eventually that tank will pop and is a safety hazard. Where someone might accidentally damage or crash a vehicle with a hydrogen storage tank, it won't be just a localized fire, it is just a straight up massive bomb. And the extremely high pressures and/or cryogenic temperatures are not and never will be fool-proof enough for just the regular joe blow to have control over or easy access to it for refueling.
The deal-killer with hydrogen in flight is specific energy storage.
At the moment, we have no hydrogen fuel storage technology that can even get a single-digit-percentage of a hydrocarbon fuel storage specific energy density.
Additionally, none of the current hydrogen storage tech is flight-worthy from an aviation systems management (weight, balance, on-boarding, jettisoning) and safety perspective.
I'm not an expert, but from what I can find it looks to me like hydrogen has a higher specific energy (energy/mass) than gasoline, but a lower volumetric energy density (energy/volume).
https://en.wikipedia.org/wiki/Energy_density#Table_of_materi...
You're correct. The sentence, specifically ;) was referring to "specific energy storage".
We don't have ANY suitable hydrogen storage tech that's even envisioned, let alone prototyped or practical, that can compete with liquid hydrocarbons for flight.
The closest alternative is ammonia, but for reasons mentioned later in the discussion, ammonia combustion is a very poor match for aviation engines.
> [...] hydrogen doesn't really have any real downsides compared to batteries but has plenty of upsides.
How about inefficiency? Conversion from electricity to hydrogen and back will get you only about 35% of the original energy. When using a hydrogen combustion engine instead of a fuel cell, comparison gets a little trickier, but at least the hydrogen generation will cost you about 35%.
In such high-energy situations, the green alternative is most likely air-to-diesel, fuels derived from captured CO2 recombined with H into hydrocarbons. Compressed/liquified H2 can theoretically power an airliner, but for all that effort they could just use "green" manufactured hydrocarbons running though normal turbofan engines.
This is precisely the approach that Terraform is taking with their fuels: https://www.terraformindustries.com/
I think it is a good idea to slow down on hydrogen as a fuel for cars for a while, because, unfortunately, it does not work well within our modern civilization. Even tiny amounts of elemental hydrogen can cause serious corrosion on certain alloys and induce steel based buildings to become brittle and possibly fall into pieces. Because of hydrogen’s near quantum nature, it is mostly a matter of when, rather than if such a gas would ever escape and create troubles. So if the tech ever took off we’d need to rebuild huge chunks of our major cities in the world very quickly; certainly doable, but much more complicated than simply adding the missing fuel stations.
Hydrogen is absolutely essential for our modern civilization. The world could not feed 8 billion people without artificial nitrogen fertilizer, which is produced with hydrogen (currently derived from fossil fuels). If the world annual hydrogen production were collected as a gas at atmospheric pressure and room temperature, it would occupy a volume of about 700 cubic kilometers. About 6% of world natural gas consumption is for making hydrogen.
The issue the top level comment was pointing out was the use of hydrogen in its form as an elemental gas (H2). Not the use of hydrogen in chemical compounds. Already chemical production plants that use elemental hydrogen as part of their processes have to take into account its issues with causing metal embrittlement and that it can escape pressure containers through diffusion.
If you have a hydrogen energy supply chain and are storing hydrogen in vehicles, service stations and a lot of other infrastructure, escaped hydrogen may start causing structural issues in structures that were never designed with hydrogen storage in mind. If we transition to hydrogen powered cars, parking garages may have to be redesigned to handle metal embrittlement caused by accumulated hydrogen leaks from vehicles.
Ammonia is synthesized using hydrogen gas. Yes, the final product is not hydrogen, but hydrogen is an essential feedstock.
All this pearl clutching about hydrogen embrittlement ignores that industry solved this problem a century or more ago. It's a consideration that must be taken into account when selecting materials, not some sort of all powerful showstopper.
To be clear, none of what I'm saying should be taken as an endorsement of hydrogen as a fuel for automobiles.
I worked in materials science in the past. Although I dont recall all details, I have seen seen convincing presentations from researchers at the Weizman institute claiming strongly we are far from ready for a transition to a hydrogen economy, and I have seen no evidence or supporting studies since then arguing that we know how to introduce hydrogen cars to steel cities. We wont have ammonia synthesizers in every street of Manhattan, yet we have plenty of buildings that might start failing fast if people replaced their parked cars with hydrogen cars. I do think it would be cool if the structural part of the world was different and would allow for such cars to roam the streets, but the US is not loving rebuilding physical structures for the purpose of a new technology, so I think it will take a while, and a couple accidents to get things right at a slower pace. We might never need H-cars in the end.
Sure. But this isn't because of embrittlement, it's because of other issues: lower round trip efficiency than batteries, difficulty of storing hydrogen in a vehicle, and the cost of fuel cells.
The basic question for the next years is if hydrogen from fossil fuels makes sense. There's no other way to make enough hydrogen in the short term. In the long term I think that batteries will be better suited to use renewable electricity until we have a really huge surplus of it for most of the year to produce hydrogen. And then chemical processes that require hydrogen will be better consumers than transportation. Then gas turbines to stabilize the power grid. And if we still have lots of hydrogen left over we can think about using it for transportation. Not sure if we even reach that point.
What about hydrogen for freight transportation? Or will battery tech eventually make sense here as well?
Depends on the freight type. Trains are already electric, planes probably need hydrogen, boats are really tough either way (but hydrogen is probably better) and trucks probably prefer batteries.
Trains are only electric if there's a network of "electrified" rail. Not a thing in North America for instance.
That doesn't exist for trucks at least not end to end. Maybe something like [1] for the busiest parts of the network and then smaller, lighter batteries for the last mile.
Anyway, I'm not convinced there won't be a need for Hydrogen powered transportation unless we make big leaps in battery energy density (to reduce weight) or change our lifestyle.
[1] https://www.power-technology.com/news/germany-launches-first...
US railroads really need to be nationalized. The past 70 years or so have had absolutely minimal investment. The fact that so much cargo in the US is taken by truck instead of train is kind of crazy given how much more efficient trains are (especially when electrified, but even if not).
Not clear yet. Battery powered heavy trucks lose much payload to battery weight. Still, Scania and Volvo have been shipping electric heavy trucks for several years now.
There's also experiments like [1] which might be feasible in dense environments so the battery could be smaller for the last mile.
[1] https://www.power-technology.com/news/germany-launches-first...
Hydrogen as done by Toyota was a sales an lobbying tactic. By setting an undoable target (or a target too far in the future), they could push for more gasoline cars and less strict emission regulations in the meantime.
Now this tactic has run its course and they are considering of what to do next.
> they could push for more gasoline cars
Didnt Prius start the whole hybrid revolution, the logical next step would have been to go full electric.
Seems like Toyota is still mired in sunk cost fallacy and isn't even considering switching to BEVs. Not very much rethinking actually going on in the article after the headline.
> Despite the setbacks, Toyota insiders said they had not given up on hydrogen for passenger cars, with Toyoda discussing a partnership last October with his counterpart at traditional rival Hyundai to advance fuel cell vehicles.
They've been sitting on the Prius line for over twenty years and feels like not done much with it
It astounds me that people ask about gas vs BEV when great hybrids have been possible for years. And completely decent ones have been sold for decades
It seems like Toyota is going big on hybrids lately using the powertrains they developed through the Prius line. Every new Camry, Crown, and Sienna is a hybrid. The Corolla can be upgraded to a hybrid for only $1,500. Both of Toyota's trucks can be a hybrid and all of Toyota's Crossover/SUVs has a hybrid version, with the Crown Signia, Land Cruiser, Sequoia, and Venza only coming as a hybrid. Toyota even offers plug-in hybrids of its popular RAV4 SUV and Prius, offering 42 or 44 mile all-electric range respectively.
Basically every major vehicle Toyota makes comes as a hybrid. The GR86, GR Supra, and GR Corolla (Gazoo Racing) don't come as a hybrid, but they're niche performance-tuned gas vehicles. Oh, and the hydrogen Mirai and battery-electric bZ4X aren't hybrid. But Toyota is nearly all-in on Hybrids now.
And they're also pushing hybrids through other brands. Subaru is integrating Toyota's Hybrid Synergy Drive into upcoming Crosstrek, Forester, and Legacy models. The Mazda CX-50 hybrid doesn't just borrow Toyota's hybrid system, but even Toyota's engine.
Oh, and like Toyota, their Lexus division has hybrids for most of their models. 5 of their 6 SUV lines and 2 of their 3 sedan lines.
Plus, the Prius line itself is finally a car that gets accolades for more than just its fuel economy with Car and Driver saying, "Long the butt of jokes about tree huggers and science projects gone awry, the Prius has become swan-like in appearance and unexpectedly enjoyable to drive." They even ranked the Prius #2 in compact cars, ahead of the enthusiast-liked Mazda 3.
It can always be argued that companies could do more, but at least recently Toyota seems to be making a huge push for hybrid vehicles and even making some of their biggest vehicle lines (like the Camry) hybrid-only.
They make a bunch of good hybrids but, like hydrogen fuel cells, that isn’t a viable long-term strategy for getting off burning hydrocarbons.
In hindsight Toyota still made the right move. The Japanese government has heavily pushed hydrogen for a while now, and Toyota was wise to follow suit.
Was it the right move for Japan? Probably not.
Ya, the hydrogen attempt was a Japanese government geopolitical push. It's not a coincidence that both Toyota and Honda were the only co's to come out with almost an identical model hydrogen car. Raw inputs, fossil fuels and the metals needed for batteries, are weak points of Japan's position. They wanted an automotive solution that was purely technology-based so they weren't at the mercy of who holds metals for batteries. Unfortunately, as practically everyone on HN knew for a decade, this was never going to be viable and it's a shame so much resources were wasted in the attempt.
Their is still the Hindenburg. Fear and loathing
I saw quite a few hydrogen buses when I was in China. Idk what the Chinese think of their longer term viability, but they're there, and they work, at least in China. Maybe Japan (and the rest of the world) simply lacks the infrastructure needed to support them?
https://en.wikipedia.org/wiki/Low_emission_buses_in_London
London has had small numbers of hydrogen buses since 2004, although it's remained a small number since then. Currently 20 vs over 1400 BEVs.
I've been to London a couple of times over the past few years, and haven't seen anything "hydrogen" there. Maybe they just aren't marked. In China they're very easy find, and they're rather obviously hydrogen - usually green in color and say "H2" on the side. Cursory search also suggests that it's not just Beijing and Shanghai that have them.
