Germany Unveils a Hydrogen-Powered Passenger Train (fortune.com)

An anonymous reader writes: The world's first CO2-emission-free train powered through hydrogen was unveiled this week in Germany. The Coradia iLint, created by French company Alstom, was presented at the Berlin InnoTrans trade show on Tuesday. The train's energy comes from combining hydrogen stored in tanks on the train with oxygen in the air. The energy is then stored in lithium-ion batteries. The train's only emissions are steam and condensed water. The train also has lower noise levels than diesel trains, emitting only the sound of its wheels on the track and any sounds from air resistance at even its highest speed of 140 kilometers per hour (about 87 miles per hour). The train has the ability to travel up to 800 kilometers (497 miles) and carry up to 300 passengers; it's the worldâ(TM)s first hydrogen passenger train that can regularly operate long journeys.

Comments

Oblig.

[Anonymous Coward]

Oh the humanity!!

Re:Oblig.

[lbmouse]

Those crazy Germans, they never learn!

Re:Oblig.

[invictusvoyd]

Don't worry . Samsung is making the batteries

Re:Oblig.

[thinkwaitfast]

US did this a decade ago and no one cared. Have to wait for the Germans to do something for people to notice.

http://trainoftheweek.blogspot...

Re:Oblig.

[sittingnut]

energy comes from combining hydrogen stored in tanks on the train

Thus confirming my theory: Germans Love Hydrogen.

hope they will not name it hindenburg.

Re:Oblig.

[mjwx]

energy comes from combining hydrogen stored in tanks on the train

Thus confirming my theory: Germans Love Hydrogen.

hope they will not name it hindenburg.

If they continue the naming convention, this will be called the Gauck and is likely to be just as bad for Germany.

Re:Oblig.

[rch7]

This one was just a switcher. German one is long distance train. Although the concept certainly isn't new.

cost

[micahraleigh]

Cool! Is it cheaper than diesel?

iLint

[The-Ixian]

That can happen when you don't blink often enough.

maybe but when the batteries go bad it can

[Joe_Dragon]

maybe but when the batteries go bad it can jam up the line or maybe blowup if they cheap out on them.

Re:maybe but when the batteries go bad it can

[zlives]

because there is no way to keep tabs on battery efficiency and safety?

Re:maybe but when the batteries go bad it can

[sexconker]

This is Germany, not Korea. I doubt Samsung will be involved.

Re:maybe but when the batteries go bad it can

[micahraleigh]

Reminds me of how the Soviets kept tabs on Chernobyl, cheaped out submarines, and imposed starvations.

In glorious Soviet Union less than 60% of deaths are directly from the hands of the government.

Whether or not people prefer to live in this glorious land is arbitrary, subjective, capitalist pig, counter-revolutionary drivel.

It's missing the full picture

[PhantomHarlock]

Currently it is incredibly energy intensive to separate hydrogen from oxygen. What power plant is powering the separator? If it's anything but nuclear, hydro, solar or wind, then it's powered by whatever fossil fuel is doing the separation, and at a much lower efficiency than simply putting diesel fuel into a diesel-electric or directly powering an electric train by overhead catenary. In the end you're just centralizing the pollution.

If the separator is run by a non-fossil fuel source, then more power to them.

Re:It's missing the full picture

[Anonymous Coward]

Exactly. And if you're using electricity to separate the hydrogen, wouldn't it be more efficient to just use that energy to charge batteries and power the train directly?

Re:It's missing the full picture

[bluefoxlucid]

It's lower-efficiency anyway, thanks to separation and storage energy costs. You used clean energy? Great! You used 2,000MW of energy instead of 600MW, which means there were 1,400MW of coal energy that could have been clean energy but weren't because you wasted all that clean energy doing a bullshit hydrogen stunt!

Re:It's missing the full picture

[tomhath]

Here's a better link. As I read it, the idea is to use extra electricity from intermittent power sources such as wind and solar to produce hydrogen, which can then be stored and transported to where it's needed. That seems far better than trying to store electricity in huge batteries.

Thompson's calculations, based on a 2007 set of figures from India Rail, estimate that as much as three billion barrels of crude oil - or the equivalent of 214 million tonnes of CO2 - could be saved over one year by transitioning from diesel to hydrail.

"The two magic properties of hydrogen are the ability to store and transport it," Thompson says. "It's that utility of time and place which is unique to the hydrogen economy. And that's what you can't do with the existing power grid."

There's also an economic reason behind investing in windmills instead of diesel oil, as Busch explains: "We have fluctuations in wind and solar energy which gives us the chance to produce energy for very, very cheap."

Re:It's missing the full picture

[OpenSourced]

Surprise, surprise, the Germans had already thought about the objections that could muster the Slashdot crowd.

Re:It's missing the full picture

[Anonymous Coward]

Germany is very into solar & wind. Electricity can be generated well with these technologies so the process to produce hydrogen balances out. Many students are offered the chance to separate O2 and H from water using a 9 volt battery, even in low-level science classes. Renewable electricity makes it even more possible.

Oh and why not just use the electricity itself to power the vehicle? Battery storage, weight, metered release, is all more complex than the mere combusting of a substance such as H, which is non-polluting and produces water as its 'exhaust'. Nevertheless it is good to question what we don't know in order to learn, but believe me the Germans are good at these things and are merely presenting an example of what can be done. All the world's transportation fuels did not flip overnight.

Re:It's missing the full picture

[Anonymous Coward]

I'm german, and as such I don't want to be the nazi here, but MW is not a unit of energy, but an unit of power (or as we germans say "Leistung"). Use MWh instead.

Re:It's missing the full picture

[Verdatum]

Germany is pretty decent with using renewable energy sources. The sources I can find say it's over 25% and rising. Electrified rail may be a better way to go efficiency-wise, but that requires running a bunch of copper along existing railways; and mining copper and then purifying it via electrolysis takes quite a lot of energy. So at least for medium-term, hydrogen makes sense.

Re:It's missing the full picture

[Anonymous Coward]

Read post above, second paragraph beginning with "Oh and why not just use the electricity itself to power the vehicle?" Basically, it would be a physical burden and materially pollutive to bring electricity itself onboard, when renewable & free electricity can be used to create a more portable fuel.

Re:It's missing the full picture

[GuB-42]

Germany has plenty of solar and wind, which have a nasty tendency to give you plenty of power when you don't need it.
H2 production can be seen as way to store that energy, with a much better capacity than batteries.

Re:It's missing the full picture

[Sique]

Actually, it costs about the same energy to separate hydrogen from oxygen as it will release when united again. There's that nice thing called Laws of Thermodynamics. Hydrogen in this case is a way to store energy, not to generate it. So whenever you have surplus energy, you store it by generating Hydrogen, and then you release it in the fuel cells of the train to power it. The amount of energy you can store by generating Hydrogen is by far higher than Lithium-Ion or even Sulfur-Air batteries.

Re:It's missing the full picture

[Anonymous Coward]

Actually, storing hydrogen is remarkably challenging. Options include cryogenic storage, with attendant explosion risk and costs of chilling and compression. High pressure storage has a surprisingly high leak rate; hydrogen molecules are very small and transport rather quickly through metals. 2-3% loss is a big deal when you're storing energy. The third, which works very well, is to dissolve it into a platinum foam, but that's a kind of expensive and low density container.

Please, though, completely ignore that all commercial hydrogen production is done by stripping hydrogen off hydrocarbons with high temperature steam. Then it's a pretty easy PSA to separate the H2 from CO2 and HCx's and dump those to the atmosphere.

Re: It's missing the full picture

[hackwrench]

Yeah, people are a little short sighted on the fungibility of energy details and you addressit better than most.

Re:It's missing the full picture

[Sique]

Actually, it's not. That's the whole point.

Re:It's missing the full picture

[mspohr]

H2 is very inefficient compared to batteries.
This diagram explains it in detail...
http://cdn.greenoptimistic.com...
Bottom line, only about 20% efficient compared to battery 69% efficient.
More detail here:
http://www.greenoptimistic.com...

Re:It's missing the full picture

[angel'o'sphere]

Currently it is incredibly energy intensive to separate hydrogen from oxygen.
No it is not
Why come pleople always up with such nonsense?

Regardles how you get your H2, Electrolysis or from CH4: it is more energy efficient than burning Diesel!

Re:It's missing the full picture

[angel'o'sphere]

Of course we would love to electrify those remaining routes that are mot yet.
However in the last decades traffic has increased dramatically. Human transport I mean.
All main tracks are obviously electrified. But plenty of rural areas are not. Those areas often only have a single track, instead two parallel tracks. So you have to balance if you shut down that single track to work in the electrification or if you keep it running, by Diesel or now perhaps in future by H2 or natural gas.
Bottom line it is a double money issue, lost customers, sometimes even long term, those who buy a car won't come back quickly and a huge investment.

Re: It's missing the full picture

[bluefoxlucid]

It's because this new generation hasn't been properly educated. Don't any of you people know what opportunity costs are?

Re: It's missing the full picture

[Anonymous Coward]

You realize about half the railway lines in Germany already are electrified? In Switzerland, all of the electricity is carbon free (a mix of hydro and nuclear) and all the trains are electric

Re:It's missing the full picture

[Verdatum]

Yeah, the DC metro is currently getting worried about that last bit because of shutdowns related to massive repairs it's undertaking. Although that's just one of a long list of problems with that system.

Re:It's missing the full picture

[JaredOfEuropa]

If the hydrogen chain (generation, storage, burning) is very cheap, it may be a better option than battery storage which still is hideously expensive. Especially when converting surplus power, which in terms of €€€ is worth bugger all.

Re:It's missing the full picture

[mspohr]

If you'll read the references, you'll see that batteries are much cheaper. The equipment needed to convert surplus electricity to H2, compress it, store it, transport it and convert it back to electricity is much more expensive than batteries.

Re:It's missing the full picture

[Sique]

Oh, I like people who think that the Third Law of Thermodynamics is the same as all Four Laws of Thermodynamics.

I was talking about the First Law of Thermodynamics: U_system = Q - W.

One way to put it is: In the case of a thermodynamic cycle of a closed system, which returns to its original state, the heat Q_in supplied to the system in one stage of the cycle, minus the heat Q_out removed from it in another stage of the cycle, plus the work added to the system W_in equals the work that leaves the system W_out.

Another way to put it is the Law of the Conservation of Energy.

If we increase the energy of a system consisting of Hydrogen and Oxygen by separating molecules of water, we need the same amount of heat and work (Q_in + W_in), as we get when we reduce the energy of the system later by putting Hydrogen and Oxygen together (Q_out + W_out). We can do this by burning the Hydrogen, but then (as you rightly state) we only get 45% back as W_out, everything else leaves as heat Q_out.

As of today, we have fuel cells that increase W_out (as electrical output) up to 70% (SOFC, Solid Oxid Fuel Cells), so only 30% gets converted into heat.

Re:It's missing the full picture

[rubycodez]

No they haven't. This is an extremely inefficient use of "green" power, alternative storage methods would be superior to hydrogen

Re:It's missing the full picture

[Sique]

On the contrary: That's exactly how the Laws of Thermodynamics work.

There are four of them, not just the Third. And also heat (Q_in, Q_out) is a form of energy, albeit not a very usable one.

Re:It's missing the full picture

[91degrees]

Very little commercial hydrogen comes from water. It's cheaper to get it from natural gas. Problem remains (You'll be better off using the methane to power a power station), but I think it's important to be aware of this if we're discussing the relative benefits. .

These trains are designed for low volume routes where catenary would be expensive. Still, I'd have thought there are more convenient fuel sources. Hydrogen has excellent energy density by mass, but it's terrible by volume. Presumably hydrogen is just best for fuel cells.

Re:It's missing the full picture

[PCM2]

I think your diagram might be misleading for the Germans' particular use case.

Presumably, the transport/transfer phase here is where the hydrogen is taken to some kind of "filling station" where fuel cell vehicles will be fitted with fuel cells. It seems to me you can cut out some of these steps/losses when the vehicle you're filling up with hydrogen is itself a train, which is more than powerful enough to transport large volume of hydrogen all by itself. Build a line out to the the electrolysis plant and the hyrdrogen never even needs to leave the railway system.

Furthermore, I haven't bothered to read TFA but the hydrogen train designs I've read about do have batteries, so they are not exempt from the efficiencies of regenerative braking.

Re:It's missing the full picture

[angel'o'sphere]

You should reread carefully the zerost law of Thermodynamics.
This is the one about energy conservation.

It basically says: The energy in a closed System is constant. [1]

In other words, it is not the same law as The law of conservation of energy[2]

1 and 2 have not many in common except the used words.

If we increase the energy of a system consisting of Hydrogen and Oxygen by separating molecules of water
Strictly speaking: we don't do that. The results end up in different systems. Hence TLoTD are unfit to describe the processes.

As of today, we have fuel cells that increase W_out (as electrical output) up to 70% (SOFC, Solid Oxid Fuel Cells), so only 30% gets converted into heat. Exactly! So you should grasp now, that TLoTD don't describe the reaction in a fuel cell. Otherwise the higher performance of fuel cells versus burning H2 would be a contradiction to those laws.

And that 30% is converted into heat is simply wrong. It often just vanishes, e.g. you bring a ion through a membrane and expect it to react so that an electron goes back via the wire (creating the current) but it simply evapours or snatches an electron from elsewhere: no heat created, no current either.

Re:It's missing the full picture

[PatientZero]

Yes, better to use the excess electricity to push the train up a hill. When you need it, just disengage the break. It might be hard to board the train when it's flying through the station at 180kph, though.

Re:It's missing the full picture

[Anonymous Coward]

You are comparing apples to oranges. A car is not a train. Scale is hugely important here - even though hydrogen's energy density isn't nearly as good as diesel, it beats batteries in a massive way. Electric cars only need to move themselves plus passengers, and are OK with limited range so a 1-ton battery that makes up half the weight of the car and holds the equivalent of two gallons of gas is just fine. But if you are moving a freight train across a country, the battery to do that would be bigger and heavier than the train itself! With a hydrogen series-hybrid you'll need bigger tanks than diesel, but at least it's doable.

Re:It's missing the full picture

[rubycodez]

nothing like the losses of sending green power to place that rips water apart and then transports/stores hydrogen

there are better ways to store wind and solar power, and you don't need to "carry" stored energy when you have electric train connected to grid

Re:It's missing the full picture

[mspohr]

They may be able to save a bit on the transport step if they can pull the train up to the H2 factory although you have to drive the train to the H2 factory. However, this only saves a few percent and still leaves a huge gap in efficiency between batteries at 70% and H2 at 20%.

Re:It's missing the full picture

[jcr]

Keep in mind that diesels, like any internal combustion engine, lose at least half of the chemical energy of their fuel as exhaust heat. A hydrogen fuel cell can deliver 70 to 80 percent of the oxidation reaction as electricity.

Also, don't assume that the current methods for producing hydrogen are the final word. I know people who are working on hydrogen-producing bacteria, for example.

-jcr

Re:It's missing the full picture

[jcr]

wouldn't it be more efficient to just use that energy to charge batteries and power the train directly?

Not necessarily Remember that batteries are heavy. An HFC car can discard as much as 2/3 of that weight.

-jcr

Re:It's missing the full picture

[jcr]

Actually, storing hydrogen is remarkably challenging.

Much less so than it was just a few years ago. Today, you can make tanks to take 10K PSI out of carbon fiber instead of steel. They're surprisingly light.

-jcr

Re:It's missing the full picture

[dunkelfalke]

Weight isn't really a bad thing for a locomotive.

Re: It's missing the full picture

[Anonymous Coward]

Only half? I expected Germany to be about the same as the Netherlands which has near to 100% electrification.

Re:It's missing the full picture

[Sique]

Somehow your definition of Energy so vastly differs from mine, that the conversation becomes meaningless. Energy according to my definition doesn't vanish. We can always tell how much energy our not-so-closed-system gives to the environment (it gives us an idea how much cooling our fuel cells need).

And the process of splitting water into Hydrogen and Oxygen is well-understood: You just take an anode and a cathode and put them into water. As soon as you connect both to an electric energy source, Hydrogen bubbles will rise at the cathode, and Oxygen bubbles will rise at the anode. This process is called electrolysis of water. The Hofman voltameter was already invented 1866 -- 150 years ago. If you catch the Hydrogen at the cathode, you can store it and later use it for a fuel cell. The amount of energy needed is also easily calculated. The potential difference between anode and cathode should be 1.23 Volts, and the amount of Hydrogen you gain is directly proportional to the amount of charge you transfer between anode and cathode.

Re:It's missing the full picture

[thegarbz]

Hydrogen is a waste product from many industrial processes, e.g. Platforming. Any refinery with a reformer but only a handful of hydrofiners are likely just pumping pure hydrogen into the air via their flaring system, or putting it to fuel gas if their burners can handle it.

Many refineries have excess hydrogen. Many air separation plants which feed the refineries which don't generate their own have a heck of a lot left over. For the uninitiated, in the oil and gas industry they burn a shitton of hydrogen because they have no idea what to do with it otherwise.

It could essentially be a free product on a small enough scale. It's only if you scale it up that it start becoming an issue.

Re:It's missing the full picture

[Mr D from 63]

That seems far better than trying to store electricity in huge batteries.

It may not seem that way if you do the cost comparison.

Re:It's missing the full picture

[pipingguy]

"The two magic properties of hydrogen are the ability to store and transport it,"

Coincidentally, those two are also the two biggest magic PROBLEMS with hydrogen.

Re:It's missing the full picture

[mspohr]

Regardless of the energy density, H2 is still massively inefficient as an energy storage medium so it doesn't make sense to run anything on it.

Re:It's missing the full picture

[tomhath]

Efficiency isn't everything. Generating excess electricity when you don't have a demand for it means you need some way of storing it, or you just dump it.

So now you need to figure out how to store all that energy until you can deliver it to the train when the train needs it; liquid fuels are very good at that. Even if producing it doesn't use the excess electricity efficiently it's a reasonable trade-off. I'm sure they considered batteries and wires, apparently they decided hydrogen is worth trying instead.

Re:It's missing the full picture

[AmiMoJo]

The only advantage is that you can refuel faster than you can typically charge a battery, so it is attractive for a very small number of applications. For most transport batteries are better, and especially for trains where utility scale batteries make charge time irrelevant.

Re:It's missing the full picture

[Blaskowicz]

Transmitting power a few hundreds kilometers or a thousand kilometers away has a high enough efficiency I believe. It's the infrastructure that costs a ton.
You can electrify all train lines too, but that will cost some billions likewise. Billions that need to be spent for power delivery network upgrades elsewhere.

What I like about the idea is it's a "range extender" for trains and could be one of very few real uses for H2 as a fuel, made from useless wind power.

Re:It's missing the full picture

[jabuzz]

It's a train, the idea that you carry the fuel required to power the train around on the train is shear nonsense.

  Any modern train and track is overhead electric and if the line is not electrified the first job is *TO* electrify it. There is some third rail stuff mostly in the south east of England and even there they are looking at the costs and practicalities of changing to overhead.

The basics are carrying fuel on train is idiotic in the extreme.

Re: It's missing the full picture

[Coren22]

Where did the poster say the power plant needed to be on the train? As far as I see, that is only something being added as a strawman argument.

Re: It's missing the full picture

[Coren22]

Do we somehow need to be to understand that H2 is not available free from any source?

H2 is produced currently by cracking natural gas (Methane), so it is a process which produces lots of CO2, and it is a process that would be better just put on the train. Wouldn't it be better to use the Methane to power the train directly? It has a higher energy content than the produced Hydrogen after all.

Re:It's missing the full picture

[Coren22]

In 6 months worth of storage ALL the Hydrogen would escape....I'll take the 2-3% of batteries any day over 100% for H2.

Re:It's missing the full picture

[rch7]

Practical electrolysis is up to 70 efficient. "Currently it is incredibly energy intensive to separate hydrogen from oxygen" - it is just incredibly uninformed scary-mongering, kind of the one Musk uses to denigrate competing technologies.

Re:It's missing the full picture

[rch7]

You have no clue what are you talking about. Hydrogen can and is stored in underground caverns just like natural gas. It doesn't escape anywhere when using proper materials. Hydrogen usage in pipeline networks predates natural gas.

Re:It's missing the full picture

[rch7]

Typical 765 kV line has 1.1% to 0.5% losses per 100 miles.
345 kV - 4.2%/100 miles
https://en.wikipedia.org/wiki/...
It can be done, but it isn't that efficient over thousands of km. And as you noted, infrastructure cost becomes more important than direct losses.

Re:It's missing the full picture

[rch7]

Of course railroad is already electrified where it makes sense. Electrifying everything over thousands of km just doesn't pay off.

Re:It's missing the full picture

[Coren22]

Ok, so you are thinking you will lose less hydrogen than the equivalent charge of a battery? You sound like you don't know anything about the issues involved.

Somehow

Power source > hydrogen > storage > fuel cell > battery

is better than

Power source > battery

in your mind? Somehow using power to crack hydrogen and store it, then run it through a fuel cell to charge a battery is infinitely more efficient than just charging the same damn battery?

Re:It's missing the full picture

[rch7]

Your numbers are approximately correct, but it is way too simplistic analysis.
You need to compare with alternatives and what better ones you have? Electrify railroads? It is already done closer to metro areas, but it costs massive amounts of money, adds power losses in lines, and if electric grid is out, all trains stop.
It is not that direct losses are biggest issue. Electricity cost can vary at least couple of times depending on supply/demand. You can run electrolizers on cheapest electricity but you can't do the same with many other electricity usage, you use it when you need to use. This already may cut fuel costs in half.
Batteries alone have by order of magnitude too low specific energy, high cost to run trains over hundreds of miles and have no quick charging option that may be necessary. And charging/discharging also imply energy losses.

Re: It's missing the full picture

[Anonymous Coward]

Burma Shave.

Re:It's missing the full picture

[angel'o'sphere]

My definition of energy is the one Physicists use.

The potential difference between anode and cathode should be 1.23 Volts, and the amount of Hydrogen you gain is directly proportional to the amount of charge you transfer between anode and cathode.

Proportional more or less yes, But not every electron moving through the apparatus is splitting a water molecule. For starters: you need to split two molecules and need up to 6 electrons for that to get 2H2 and 1O2. Plenty of electrons decide to just move through the apparatus and do nothing: hence you are far from 100% efficiency and hence the "energy" you have in the H2 and O2 later does not correspond to the total energy you used.

Then again you want at some point to revert the process somehow, with fuel cells you have at least a high enough energy conversion that it is worth it, and you get electricity ...

If you just burn it, you obviously get 100% of the energy in the chemical bounds back, BUT: in form of heat! And that heat you can only convert under normal laws of thermodynamics into work or electricity. With a loss of nearly 60%

CO2-emission-free ?

[Pascal Sartoretti]

I guess it depends on how you generate the hydrogen. If you do so by cheap electricity produced by burning coal, it might not be so CO2-emission-free...

Re:CO2-emission-free ?

[Gavagai80]

If you read the first word of the title, it says Germany. Germany is famed for their wind and solar power production.

Re:CO2-emission-free ?

[Oswald McWeany]

Even in a worse case scenario and none of the hydrogen was generated by renewables, you're still only producing pollution in one spot rather than spreading it around across the country. In one spot it is easier to scrub it to get the worst of it out of the environment, it is easier to turn the pollution into usable products, etc.

1.2units of nasty stuff at a powerplant might be preferable to 1 unit of nasty stuff pumped directly into the environment on the back of a train.

Re:CO2-emission-free ?

[CanadianMacFan]

It's also famous for shutting down its nuclear plants and starting up its coal plants again.

Only emissions are H2O?! Wrong

[Bugler412]

How was the hydrogen used in the train produced and delivered?

Re:Only emissions are H2O?! Wrong

[PatientZero]

I hope it's not Lead Zeppelin because lead is highly toxic!

How efficient is hydrogen really?

[harrkev]

OK. How efficient is hydrogen, really? Shout out to all of the chemistry majors out there who might answer this.

One of the reasons that fuels work, from my understanding, is that you start with a small number of molecule, combust them, and get a larger number of molecules with more heat. The heat increases the pressure, and the increase in the number of molecules increases the pressure.

Example: combustion of alcohol:

C2H6O +3O2 --> 3H2O + 2CO2

We start with four molecules on the left, and get five molecules on the right. Even if the reaction was not exothermic, we would still get a pressure increase good for pushing a piston.

Now, when we burn hydrogen, we get a decrease in the number of molecules (goes from three down to two):

2H2 + O2 --> 2H2O

So, yes, we get increased pressure due to heat production, but we get decreased pressure due to fewer molecules.

So, I guess that my question is: when burning a fuel, how much pressure created is due to the typical increase in molecules, and how much pressure is due to heat?

Re:How efficient is hydrogen really?

[avandesande]

I assume since it is noiseless it is using a fuel cell. As to your concern with pressure, I know that the Wankel is the preferred ICE for hydrogen. Not sure why but it is more efficient than a piston engine.

Re:How efficient is hydrogen really?

[hey!]

Conversion efficiency is not a big deal when you're using renewable sources; in those cases you're interested in capital investment efficiency (what you get out for dollar invested).

That's because wind or solar or tidal you don't capture simply goes away; the waste is 100% when you don't use it, so if you capture any of it, it's a win, so long as the money up front isn't too much.

Re:How efficient is hydrogen really?

[DigiShaman]

The problem with using hydrogen in an ICE is an issue with 'hydrogen embrittlement'. It basically causes cracks to form in steel. In the case of a Wankel, a steel based apex seal would have a short life. I'm not sure what hydrogen would do to a more expensive silicon nitride apex seal however over its life.

With regards to why hydrogen is more efficient in an ICE; I think it has to do with detonation duration and time in the chamber. With a piston, there longer travel time for the gases to detonate and expand. In a Wankel engine, only 1/3rd of rotary is traveling (rotating) during the combustion phase, so a shorter duration in the chamber is an advantage here.

Re:How efficient is hydrogen really?

[angel'o'sphere]

In such an reaction we don't really express stuff in molecules, but in 'mol mass'. https://en.wikipedia.org/wiki/...
And then comes Thermodynamics, Yay!

At same temperature, all gases with X molecules consume approximately the same volume (that is still Chemistry, .law of Avorogardo, or Avocado ... well, it is in the link above ;) ) So 2 * H2 + 1 * O2 -> 2 * H2O, we have 3 molecules on the left side and 2 on the right, so the volume is reduced by 1/3.

On the other hand, here now comes the thermodynamics, the volume or pressure increases due to the heat. For that you have to take into account the volume reduction above and then just multiply in the formulas with the temperature, you can look that up under laws of Thermodynamics ... "google for thermodynamics wiki ideal gas"

Re:How efficient is hydrogen really?

[angel'o'sphere]

Right now the H2 in question is 'waste' from big chemical plants, that would burned otherwise.
However wind plant operators plan to produce H2 and feed it as supplement into the natural gas grid.
Of course with the transformation of Germany to 100% renewable energy production, production of H2 or other synthetic gases is better than shutting down power plants or disconnecting them.

Re:How efficient is hydrogen really?

[cnaumann]

Another thing, H2O is a lousy combustion product if you are building an ICE. The problem is that H2O has a very high heat of vaporization, 44kJ/mol, and it is nearly impossible to recover this heat. When you burn hydrogen in an ICE, you are spending a lot of energy essentially boiling water. You get 286kJ from burning a mole of H2 gas, but you lose 15% of that heat because you cannot condense the water vapor.

Re:How efficient is hydrogen really?

[Poingggg]

If you read carefully, you might notice that these trains are electric, and that they use fuel cells to produce electricity that is stored in batteries and distributed from there. So no business with pressure etc. (But this is /., R'ing TFA is too much trouble....)

Re:How efficient is hydrogen really?

[avandesande]

This goes back to the OPs original post. You can have two pressure 'sources'. Pressure from heat and pressure from molecules. With pressure from heat you need to transfer the pressure as quickly as possible because your efficiency losses to the walls of the chamber are greater. In a wankle engine that expansion period is much shorter. I think this is the way you get greater efficiency with water injection in a piston engine, you convert a portion of that combustion temperature to gas.

Re:How efficient is hydrogen really?

[excelsior_gr]

You need an equation of state. Let's assume that we're dealind with ideal gas mixture so we get: P*V=n*R*T. R is a constant and since you ask about the pressure, I'll assume that you keep the volume constant, so V is also a constant. Now you need to write the equation down for the before/after case, say with subscript 1 for the reactants and with subscript 2 for the products:
P1*V=n1*R*T1 and P2*V=n2*R*T2. Now you divide them, cancel off the constants and you get: P2/P1=n2*T2/(n1*T1). Wikipedia tells me that if I burn hydrogen at the stoichiometric ratio with pure oxygen starting at 20 C and a pressure of P1=1 bar I'll, get a flame at 3200 C (look for adiabatic flame temperature). So this is an increase in temperature by 3180 K. Also, you go from 3 moles down to two so there's: T2=3180*T1 and n2=2*n1/3. BTW, we usually talk about moles, not molecules but they are essentially the same thing since a single mol of a substance contains an amount of molecules equal to the Avogadro number, which is a constant. So now by substitution we have: P2/P1=3180*2/3.

So you see that the rise in temperature incresed the pressure by a factor of 3180 whereas the fewer amoumt of molecules in our theoretical non-expandable perfectly isolated box only led to a pressure drop by a factor of rougly 0.67.

However, at the resulting pressure of about 2120 bar (!) it's not correct to use the ideal gas equation, but you see where this is going. The temperature increase wins by a longshot in this case, and I would expect this to be so for any reasonable fuel combustion.

Re:How efficient is hydrogen really?

[Prien715]

The gas is not at Standard Temperature and Pressure (STP) -- so your volumetric calculations would have to depend on that. A mole of air takes up 22.4 liters while a mole of water is about 18 mL at STP -- since it's in liquid form. Now, if we take 1 mole of H2 and 1/2 mole of O2, we'd have ~32 liters of gas which would become 18 mL of water -- which is essentially a massive vacuum. ...but then again, no one stores H2 at STP.

Re:How efficient is hydrogen really?

[excelsior_gr]

OMG, I made a terrible mistake. That'll teach me to post such things late at night with a low blood sugar...

For the temperature, of course, you need the increase factor, not the difference! So there is T1=20 C=293 K and T2=3200 C=3473 K. So now properly we get T2=3473*T1/293=>T2=12*T1 (approximately).

So there you have it: Factor 12 pressure increase from the temperature and factor 0.67 pressure decrease from the molecule change. The temperature still wins.

Sorry about the confusion.

That's awesome..

[fred911]

Until you figure out that 95% of the hydrogen is produced from carbon fuels.

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

Re:That's awesome..

[rch7]

No they don't. They just bury it leaving problem for future generations. Just think how silly it is, you run reactor for some 40 years and leave radioactive waste for thousands of years for somebody to deal with it later.
Nuclear reprocessing is still expensive and experimental, and involves extraction of plutonium that means proliferation of nuclear weapons and risk of nuclear terrorism. That is why it was banned in the US.

Re:That's awesome..

[vandamme]

Unless it's generated at night, from windmills that can't give away electricity.

two problems

[wbr1]

One as mentioned, hydrogen production is probably just moving the emissions, and adding more due to efficiency losses.

Two, They are using Note 7 recall batteries for storage!

Weird article

[sjbe]

The world's first CO2-emission-free train powered through hydrogen was unveiled this week in Germany.

Note that they haven't built or sold any production units yet. Just some prototypes.

The train's energy comes from combining hydrogen stored in tanks on the train with oxygen in the air.

It's a fuel cell system so yeah, that's kind of how it works.

The energy is then stored in lithium-ion batteries.

The company that makes this train says nothing about Li-Ion batteries being involved.

The train's only emissions are steam and condensed water.

Correct but misleading. The real emissions depend on how the hydrogen was produced. If they got it by cracking hydrocarbons then the real emissions are considerably nastier than just water.

Re:Weird article

[rch7]

Reforming of methane is efficient process and certainly produces less emissions than burning diesel or even the same methane.

Fun Train to be on

[avandesande]

It was a gas!

Didn't the Twin Towers teach America...

[Anonymous Coward]

to stop building obscenely tall buildings?

No?

Germany lost a lot fewer people via airship than the US has via skyscrapers.

Even hydrogen filled airships have a lower chance of flaming death than many common vehicles people take for granted today (motorcycles, cars, boats, and airplanes. And if you're unlucky canadians, flaming train cars.)

Re:No noise = problem !

[Anonymous Coward]

When the Prius first came out, I figured there'd be a market for car "ringtones" to address this silent killer feature. Still hasn't happened, which surprises me a bit.

I've always thought that the Jetsons flying car sound should be the only (mandatory) option.

I rode in it

[110010001000]

I took a ride in it. What a blast!

Re:No noise = problem !

[Grishnakh]

This sounds like BS to me. Most modern cars have engines that are so quiet that at higher speeds, you'll only hear the wind noise and tire noise if you're outside the vehicle. The tire noise is the biggest factor these days, not the engine, unless you have some big diesel engine or you've modified the exhaust.

It's only at low speeds (like in residential areas, 30mph and below) where you'll really notice the missing engine note on an EV.

Bullshit

[frovingslosh]

CO2-emission-free train

This is a total crock. You have to also look at how the Hydrogen is being produced. And not some theoretical but not real theory of how it could be made by electrolysis, but the real truth of how it is being made by a very dirty and wasteful process that breaks down natural gas and captures some hydrogen in the process. The truth of the matter is it would be much cleaner overall to just run the train on liquid natural gas. This Hydrogen bullshit is all smoke and mirrors with even more carbon being released into the atmosphere.

Re:Bullshit

[angel'o'sphere]

Why don't you read the summary and the linked article or just google for the topic and find better articles than making an complete idiot out of yourself? (*facepalm*)

Re:Bullshit

[belthize]

I used to think Slashdot was a tech news aggregating site, now I think it's just an overly complex idiot honey pot. I'm not entirely clear on the long term plan.

Re:Bullshit

[frovingslosh]

Yea, it will all be produced by windmills, the week after we all have personal jetpacks. But if you look at the reality it is that people keep making things like hydrogen powered trains and cars and all of that hydrogen is being produced by a dirty, wasteful process of breaking down natural gas by partial burning. The net effect is more carbon in the air and supposedly more global worming (not a typo). The train and the windmills will be underwater long before hydrogen is mass produced cleanly. Not that I'm saying that is a bad thing .....

Re:Bullshit

[rch7]

What a BS of "partial burning"! It is called steam reforming and is 70% efficient process used in chemical industry like ammonia production. Natural gas power plants are only some 40%-60% efficient and are really burning everything, and emitting much more various burning pollutants comparing with methane reforming.

And it is not how hydrogen fuel is produced. PEM fuel cell fuel requires higher purity and is typically produced from excess electricity. E.g. wind electricity that otherwise would be discarded.

Canada tested similar H2O trains

[WillAffleckUW]

(scientific papers are online, no I won't do the search for you)

They found that fuel cell split water trains, using the stored hydrogen, could be easily refilled along routes by solar and wind accumulators, similar to coal and water stops, and that they were highly efficient and very safe.

Glad Germany is joining the 21st Century at last.

The main problem with split water is the economy of scale. Car sized power plants don't have sufficient efficiency, but large tractor trailers and trains do.

Re:Pointless

[MonoSynth]

A lot of secondary railroads all over Europe are not electrified, and that's where these diesel-powered Lint-trains show up. So that's the target market for these trains, not the main railroads.

And as said by others, there's a big problem with the fluctuations in energy output from wind and solar, especially in Germany. Instead of just throwing the energy away (like they do now), they could just as well use it to create hydrogen, even if it only has 50% efficiency.

That's why they're targeting the German market with this train.

You know what they say

[kilodelta]

Go gas, go boom!

Hydrogen is a stupid fuel to use

[bradley13]

Ok, my chemistry is a long time in the past, but AFAIK hydrogen is a really stupid fuel to choose. It is the smallest atom possible; even H2, the usual form of hydrogen gas, is tiny. That makes it incredibly hard to contain. Also, none of our existing infrastructure can handle it.

If you are going to manufacture fuel, you are better off producing methane (natural gas, CH4). It does require a second reaction: After electrolizing water to produce H2, you then catalyze the H2 with CO2 to produce methane and water. So the overall process is more complex, but the result is not only much easier to store, we already have the infrastructure for transporting and storing methane.

This line from TFA is also a laugh: "operating costs will be similar to the operating costs of diesel units." Sure, except for the cost of building a completely new infrastructure to produce, transport and store hydrogen. Which doesn't count as "operating costs".

Re:Hydrogen is a stupid fuel to use

[91degrees]

It does strike me as inconvenient. Per MJ, methane at 250 bar takes up as much space as hydrogen at 700 bar, and many other hydrocarbons are liquid at room temperature. Plus natural gas already has a distribution network installed. Plus it already exists as a chemical in nature; so that's zero reactions.

I guess the inherent efficiency of hydrogen fuel cells makes up for all the other costs. Fuel cells do have excellent efficiency.

Re:Hydrogen is a stupid fuel to use

[PCM2]

Sure, except for the cost of building a completely new infrastructure to produce, transport and store hydrogen.

You mean something like a ... railroad? With trains bearing big tanks of hydrogen fuel on the tracks?

Hydrogen might make sense for rockets

[matthollingsworth]

Almost all hydrogen is generated from natural gas today, which means hiding CO2 emissions and supporting the old dirty extractive industries which we must kill as quickly as possible. Windmills and solar are intermittent, but there are plenty of smart long term smart grid solutions that show promise alleviating those concerns. I suspect that hydrogen has a role to play in rocket and airplane applications since they are sensitive to weight and current battery designs are heavy. That may change too though.

Re:No noise = problem !

[Oswald McWeany]

I know of one developer who was working on such a thing. Didn't call it ringtone- but it was a customizable sound that played in correspondence with the #of rpm of the car.

Re:No noise = problem !

[Wargames]

I live near train tracks. Most of the noise comes from the whistle!!!

Re:Steam and condensed water?

[91degrees]

Diesel trains are diesel electric. There's the added inefficiency of diesel-electricity conversion. Fuel cells convert directly to electricity. Energy to wheel efficiency with power cells is pretty good.

Missing the excess factor

[SuperKendall]

Now we compress it. the compressors suitable for it have 70-85% efficiency (adiabatic). Which means that of the energy used to compress it, 15-30% is lost

Which doesn't matter because remember how we are using excess electrical capacity anyway?

Then we store and transport it.

This is the part the battery people really miss on, because they basically assuming the cost of transporting giant batteries is free it would seem.

You simply are not factoring in the reality of the system at a whole at various stages for battery compared to hydrogen.

Not to mention the horrific aspects of making the batteries to begin with, they always seem to just magically appear in all of these kinds of calculations.

Re:Pointless

[91degrees]

I can't see a wire here. Electrifying a line is expensive. Unless the line gets enough use it's cheaper for trains to carry their own fuel.

Long term plan clear to me

[SuperKendall]

now I think it's just an overly complex idiot honey pot. I'm not entirely clear on the long term plan.

If you can't make money from rich technical people who are also idiots, you can't make money from anyone!

Re:No noise = problem !

[dunkelfalke]

I wonder how we Germans have survived, given the shitload of electric trains running here.

Re:What happens when the train craches?

[91degrees]

Why would they add an oxygen tank? There's oxygen in the air!

A hydrogen fuel tank exploding will be quite a fireball, for sure, but hydrogen tanks are pretty tough. And even if they do explode, there's only so much energy stored. Not enough to affect anything that hasn't already been affected by a train barelling into it.

Them titles

[kangsterizer]

So if I use a Tesla in France, then France introduced a new electric car right?

Re:No noise = problem !

[PatientZero]

Same here. I've never been awoken by the engine or car noise, but I've definitely been roused by the whistle on several occasions.

A clear case of not needed

[ukoda]

Trains are in the unique situation that supplying external electricity is relatively easy, you string up a cable above the track. It is the form of EV that has been practical for decades and is widely deployed so why would you create such a complicated alternative? Yes, you could argue the less used or longer remote tracks would be expensive to electrify but do wonder if a hydrogen hybrid stacks up economically for those cases anyway.

Full disclosure: I thought hydrogen vehicles where dumb when I first read about how they where going to change the world "real soon now", in the 1980s, and nothing in the years since has change my view. If I subscribed to conspiracy theories then I would believe hydrogen vehicles were backed by oil industry to slow the development of EVs. It has annoyed me how long it has taken EVs to reach market but now they are here I think it is time stop giving press coverage to impractical hydrogen demo vehicles and focus on the real issue, the transition from ICEs to EVs.

Re: A clear case of not needed

[rch7]

These demo vehicles can refuel in 3-5 minutes and travel across whole Europe from Norway to Italy using existing hydrogen fuel stations at sustained unlimited Autobahn speeds. Half usable as a car Model S or X costs more and can't do even that without spending half of the time cooling down and charging.
For your interest, residential electricity in Germany is around 0.30EUR/kWh as it started transition to renewable energy for real and it reflects in rates. That is around $11 (0.30EUR*$1.1/EUR*33kWh/g.e.) per gallon equivalent in US terminology. Many people park on street and don't have access to any outlets at night. Try explain how "practical" pure battery cars are :/ With ICE or fuel cell range extenders, maybe, but not without.

Re: A clear case of not needed

[ukoda]

I can charge an EV at home or work. There is not an EV I know of that could not handle the daily commute of myself or any of friends, family or co-workers. The rate at which battery range is improving means within about 5 years the range will be more than I can handle in a single days drive. On the other hand there is, as far as I know, not a single hydrogen charging station in New Zealand. If I was rich I could buy a new EV today and I assume my next new car, about 4 years from now, will be within my price range. Hydrogen cars have been demos for 30+ years and I see no technology on the horizon that will change that, whereas some of the battery hype over years has become reality. Look at the battery price and performance curves over the last few decades and you will see the trend is clear.

Tell you what, I will invest my money in EVs and you can invest yours in hydrogen cars. I bet I get to retire before you do...

That's the wrong way to think of it

[Solandri]

Conversion efficiency is a big deal when you're using a mix of renewable and fossil fuel energy sources. It makes little sense to send renewable energy to a train at (say) 20% efficiency causing a shortage in the electrical grid which needs to be made up by a fossil fuel plant operating at 50% efficiency (overall average 35% efficiency), if you can instead use the renewable energy directly on the grid at 70% efficiency and power the train with fossil fuel at 40% efficiency (overall average 55% efficiency).

This is a very common error I see made by people advocating renewables. They like to compare to a nonexistant zero state. You need to compare to the next best (or better) alternative. Or in other words, you can't think of this in terms of where the energy for the train (and only for the train) is coming from. You need to think of it as having x MWh of renewable energy, and where is the best place to send it to maximize the reduction in fossil fuel burn. In that respect, it is deceptive describing vehicles as "zero emissions" - all they do is shift the emissions elsewhere. The act of charging up their batteries or hydrogen tanks requires energy, and implemented poorly it can actually end up requiring more energy than just burning diesel.

Re:That's the wrong way to think of it

[hey!]

We were talking about the conversion efficiency of hydrogen.

I mentioned it once, think I got away with it.

[Hognoxious]

The Germans certainly didn't.

Cool, so when will they give this to China?

[WindBourne]

Afterall, they gave all their trans rapid tech to China.

If only...

[Roger W Moore]

maybe but when the batteries go bad it can jam up the line or maybe blowup if they cheap out on them.

If only there were some technology where we could have a train powered by electricity without the need for large batteries or hydrogen...

Re:If only...

[rch7]

Yes, it is called overhead wires :) Short distance trains use this technology for many decades. It gets too expensive over long distances.

Re:But how do they get the hydrogen?

[Coren22]

Usually it comes from cracking Methane (natural gas), so yes, it produces copious amounts of CO2. The only way it wouldn't involve CO2 is nuclear powered hydrolysis.

Hindenburg

[DarthVain]

Did they call it the Hindenburg?

Also title is a bit misleading (as per standard Slashdot practice these days). While true Germany may have "unveiled" it, it was created by France...