Wouldn't it be cheaper in the long run, easier and more future proof to just electrify the damn track? The tracks themselves need maintenance anyways. Having overhead electrified tracks allows you to make the electricity for it anyaway you want including hydrogen. You are also able to purchase practically any electric locomotive and the costs for those are much lower as well as maintenance.
Electrifying tracks can be more difficult than it first seems. For example in the UK on certain lines you have to replace most road bridges that go over the track. The bridges are not high enough to fit electric lines underneath. Tunnels can also have the same problem.
Some bridges and tunnels are also not electrified in Austria but electric trains still pass through them on their massive inertia alone. It's really not a big issue for trains.
They're doing that more here (putting neutral sections with reduced clearance under bridges) but it doesn't save everything. A major disadvantage of being early to the railway game is that we have amongst the most restrictive structure gauge in the world.
It also turns out that we've repeatedly stopped and restarted our electrification campaign over the last hundred years, such that we have little persistent expertise and excessive costs per km. So it's not just tunnels and bridges.
This. The capital costs are huge, such that it only makes marginal sense on a financial basis alone. You get further factoring in service improvements (lighter trains without diesel engines -> faster acceleration -> shorter journey tines), the societal benefits of decarbonisation, and electric trains breaking down less often, but that only moves the viable point so far.
In the extreme case, a railway which is 200 miles long and takes 3 trains a day will never have a positive financial case for electrification. So once you've electrified all the stuff that should have been done decades ago (like main lines with 10 trains an hour) and then pushed on to the marginal stuff (hourly rural lines) there's still a small core of lines left. You could just bite the bullet and electrify them anyway, or you could go with things like battery electric trains (good for short distances off an electric mainline) or biodiesel/green hydrogen. The latter are likely to be cheaper.
Worth testing, anyway, and this looks like a good place to test them.
Hydrogen trains might make sense even if hydrogen cars don't, since the trains run on their tracks, according to a fixed timetable, and need little new infrastructure.
The issue with Hydrogen is its storage technology.
It requires a high pressure (300-bar minimum, 700-bar ideal) environment... or cryogenics to store compact liquid hydrogen.
Building a small, personal, car-tank that withstands 700-bar of pressure and survives typical car accidents is... really difficult? However, building a large train-tank that withstands a typical derailment is far easier.
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I don't think Hydrogen will ever be useful for personal cars. The pressure requirements / storage requirements look rather insane.
I know there's groups working with carbon-fiber designs and other advanced materials, but those are really expensive. Larger trains / trucks can just use standard steel to contain the Hydrogen at 700-bar of pressure (because a bigger tank is easier to scale).
I mean, Toyota and Hyundai are making personal H2 vehicles.
But they're expensive, very expensive, because those storage tanks are extremely sophisticated. Unless those storage tank costs come down by a LOT, I don't think H2 cars will compete reasonably against other technologies (Hybrid, PHEV, or EVs)
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$50,000 for an H2 vehicle with only 180 horsepower engine is really meh.
As a reference point for just how expensive, the Caltrain electrification project in SF is currently estimated at $2.44 billion dollars for 82 km of track, and still climbing. And this is for what's almost a best-case infrastructurally: flat land, few bridges or overpasses, etc. (But, admittedly, what just might the world's worst regulatory environment.)
Midland Main Line in England "cost given as £1.3 billion pounds and also included three station modifications at Leicester, Derby and Sheffield. 422 single track miles of wiring was supposed to occur and a total of 120 bridges modified."
Anecdata: as a regular commuter on the east coast main line in the UK for several years, a very common source of service interruption was blamed on overhead cable problems.
From an engineering perspective the complication of the track electrical infrastructure and pantograph seem inferior to a hydrogen tank and fuel cells. Far less actual stuff to build and maintain.
The East Coast Main Line is prone to dewirement (where the pantograph comes off the catenary and normally gets tangled and brings down the wire) at an unusually high rate. The folk wisdom is that the use of wired headspans instead of rigid portals, combined with a long distance between stanchions, makes it fragile. I don't know the extent to which that's true.
Set against that, the miles per technical incident for electric trains are about twice that for diesel, and a train breaking down on the ECML is also disruptive, if not obviously infrastructural...
cheaper maybe, easier definitely but diversifying into new tech is worth it in and of itself, this is more of an experiment if anything given that it's only about a dozen trains.
If we're learning one lesson right now in Germany it's probably that having some things not running on the electricity grid is potentially a good idea. Hydrogen is energy dense, burns clean and doesn't depend on any system infrastructure, which is pretty neat. I think it's underused still, afaik Japan is the only other place betting some money on it.
It still doesn't solve the issue when you have trains coming from countries like Switzerland which is 100% electrified and you loose tons time switching locomotives.
I agree, and for areas without active electric, we could probably use some combination of batteries and super capacitors to push the train along till it gets back into electrified rail.
For example, nuclear power continues to create energy at night, at 2am when there aren't many trains running.
In contrast, when an electric train pulls from the grid, it needs electricity immediately, no matter how loaded the grid is. Electric Trains running at 7pm (during the "Duck curve") will inevitably be powered by natural-gas peaker plants.
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In contrast, Hydrogen electrolysis could continue into the night and be powered by "otherwise unused" 2am or 3am electricity from nuclear power. Even if the train was running at 7pm, the electricity comes from the most advantageous time throughout the day.
That is to say: Hydrogen is a fuel, AND a battery, AND is compatible with electrification technologies thanks to the fuel cell.
In that case what prevents us from building energy storage facilities that produce hydrogen at night and release the electricity back into the grid during the day? Wouldn't it be more efficient than transporting the hydrogen by truck and transporting the hydrogen battery on every train?
Hydrogen is a storage technology, not really an energy source. Hydrogen competes with Li-ion batteries.
How many Li-ion batteries do you need to equal one 200-ton liquid H2 storage tank? At 120MJ per kg, 200-tons == 200,000 kg == 6GW-hrs of electricity. There's no Li-ion battery in the world that's anywhere close to that kind of storage capacity... and various researchers are aiming at 3000ton H2 storage tanks.
Erase 50% or even 80% of the energy due to inefficiency / costs of cryogenics, and you still have a bigger energy storage tank from H2 than anything possible with Li-ion. And the future of H2 is looking like 10x capacities are reasonable over the next 10 years.
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Whatever solar solution you were thinking, just do the same except instead of using big, expensive, heavy Li-ion batteries, replace the storage mechanism with H2 fuel cells.
Higher energy density = higher danger of releasing it unintentionally.
I totally understand why hydrogen is a great rocket fuel. You need this high energy content and the extreme lightness for high Isp.
On land, I suppose, the energy density of 100 tons of hydrogen in one place is unnecessarily high. The fact that hydrogen has no odor, and its flame is entirely infrared, invisible, does not help.
By the same token, I think that lithium batteries have excessive energy density for large-scale land applications, like buffer storage for solar / wind power. Even a lead-acid battery, with all its environmental downsides, weight, etc is at least not a major fire hazard. I suppose that large-scale electricity storage will take off when cheaper and safer, while less dense, alternatives to lithium batteries are commercialized.
As a power source for a car, a lithium battery at least is not cryogenic. OTOH on the scale of a train this may already be not a big problem. Same possibly for an oceangoing ship, but it would be terrible to start losing fuel and power if a bad storm damages the cryogenic system.
An ideal (fantastic) system could use methane and turn it into carbon, only oxidizing the hydrogen. Sadly, similar reactions only work so far with much more complex molecules.
> In that case what prevents us from building energy storage facilities that produce hydrogen at night and release the electricity back into the grid during the day?
Hydrogen is a newer technology than Li-ion. But yeah, its more than capable of these things. We just gotta build out pipelines and facilities to handle it.
But no. To deliver MWs of electricity to trains requires using a ton of copper on all rail-lines, as well as advanced transistors to switch that electricity around. Hydrogen storage of electricity is a good idea and is being developed, but there are innate benefits to the fuel-methodology for applications like trains.
In particular, a pipeline will likely transmit more "energy" at cheaper costs than a bundle of copper wires. Steel and concrete pipelines are just cheaper. So instead of building expensive copper wires + expensive transistors to switch electricity all around the place, why not build pipelines?
> Wouldn't it be more efficient than transporting the hydrogen by truck and transporting the hydrogen battery on every train?
Well, first off, the most efficient form of transporting Hydrogen would be a pipeline. But lets say we're dealing with a remote area so a truck is necessary.
1kg of Hydrogen has 120MJ of power, or 0.033 MW-hrs of electricity. A singular kilogram.
These trailers can store 900kg of Hydrogen. Or in other words, 30 Megawatt-hours of Hydrogen based electricity. Larger vehicles, like trains, can likely afford to carry larger containers, possibly even cryogenic liquid-hydrogen that is even more compact.
Current storage tanks from NASA can hold 270 tons of liquid Hydrogen, with plans to scale to 3000 tons of liquid hydrogen storage. That's 3000000 kg, or 100 Gigawatt-hours of energy storage per tank.
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So yeah, the amount of H2 energy storage available far exceeds what is possible with Li-ion technology.
Pipelines will be more efficient at moving Gigajoules / dozens of MW-hours at cheap costs. Trucks and trains can carry the fuel wherever they need to go. Energy storage / Hydrogen batteries will scale to far higher capacities than Li-ion could ever dream of.
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Hydrogen is an incredibly light fuel. Its difficulty in transportation is __volume__ rather than its weight. Storage technologies, such as higher pressure (700-bar or higher), and liquid cryogenics are needed for H2 storage to be effective. These technologies are just becoming possible today.
So only now can we dream of what liquid-hydrogen storage tanks can offer us. Literally 100GW-hrs of energy per liquid-hydrogen tank is feasible (while *current* prototypes from NASA are holding 9GW-hrs of energy storage).
Thanks for the article on energy storage with hydrogen to resolve peaks on the grid. Seems like a nice solution on paper, although ineficient according to this article citing someone from the MIT, round-trip efficiency of 18%-46%.
Considering that night-time energy from nuclear plants, as well as peak 12pm noon energy from Solar Power plants, are going wasted right now, 18% round-trip efficiency is better than the 0%-efficient fully wasted energy that we're doing right now.
The idea is to create a green fuel of the future, powered by Solar Panels and Nuclear energy, and wind and hydro.
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I do think that green-hydrocarbons have a potential future. Green diesel would be a biofuel. But Hydrogen can turn into a hydrocarbon through Syngas synthesis (eventually turning into Kerosene and other "green hydrocarbon" fuels).
If the chemistry works out, maybe that's the future. But experimentation with pure H2 looks promising right now.
I believe that as you say, converting the hydrogen obtained by electrolysis or photolysis into hydrocarbons via syngas is the most likely future solution for all energy storage problems where batteries are inappropriate.
Even if the energy efficiency of a storage cycle is lower than when using directly the hydrogen, the savings due to easier handling and storage are huge.
Moreover, that path will allow the reuse of all the existing infrastructure for hydrocarbons, whose replacement would require a very long time and very high costs.
Only consider the Levelised cost of Energy (LCOE) over the lifetime of systems, like solar+ electrical cables and night-time batteries versus solar generating hydrogen, storing plus transport plus burning or fuel cells in new locomotives.
If you look at LCOE over lifetime, solar photovoltaics always wins over wind, hydro and certainly over hydrogen and nuclear.
Lowest cost wins.
Hydrogen made from solar electricity is around 40% efficient, so it is more than 2.5 times more expensive (expensive storage and transport) than just solar and overhead electric cable. Cheaper still because you can put solar panels along the train tracks so land use is almost free. You would have much less losses if you convert solar panel 40-60V directly into high voltage the train use.
And instead of running electrical wires, why don't we pump that Hydrogen into a pipeline that goes to the train station? That way, our energy transport uses cheap steel-and-concrete to move our energy around, rather than expensive copper and transistors.
And instead of electrifying 3000 miles of track, why won't the Locomotive engine be a fuel cell that converts the H2 back into electricity on board?
If you calculate the LCOE, you'll find that using wind at night is cheaper than hydrogen. Maybe certain batteries storing solar can beat wind at cost?
My point remains, don't guess "why not use my favorite X" but calculate and simulate all alternative systems and the the lowest cost of energy ofve lifetime of systems is the winner you actually build.
A pipeline and a steel drum, even built to withstand 700Bar of pressure, is cheaper than 1MW circuits that you propose lining thousands of miles of rail with.
Transistors, transformers, and electric wires use an incredible amount of copper.
I think the reason why hydrogen (or derivatives such as ammonia or methanol) will become a very widespread carrier of energy in the long term is: seasonal storage of energy.
There doesn't appear to be a promising solution for seasonal storage of energy other than hydrogen.
Pumped hydro power is limited to certain areas and also doesn't scale in the same way that hydrogen does. Compressed air is sometimes mentioned but doesn't appear to make much progress.
Since the world is going to need massive amounts of seasonal storage for the sake of the stability of the energy system (which is the backbone of society), as more and more renewables are built, there just has to be a solution. And if there's only one that scales to demand, then that's what will be built.
Hydrogen (and derivatives and generally all chemical energy carriers) also have this triple synergy of huge capacity for transmission plus flexibility plus buffering.
Transmission capacity of a pipeline is massively larger than any cable.
Flexibility is given through the fact that hydrogen can spontaneously be transported to almost any location. Compare that to "spontaneously" building a new power line to an arbitrary location.
Buffering is a byproduct. As soon as the hydrogen is produced, it acts like a buffer, whether it's inside a pipeline or some tank. Compare that to electric energy transmitted via cable .. as soon as the power plant is shut down, the lights will go out.
A chemical based energy system is inherently more stable and resilient than an electrical grid, IMO.
I don't understand about trains but I imagine that doing maintenance in one electrified line would shut down or overload other parts of the network. Also, energy transported this way could be easily stolen, they just need to pull some wires and hide underground.
Also, to transport energy cheaply in long distances you need a very high voltage, that would electrify anything that gets closer to the track. That is why you see high voltage cables being only used in very high poles.
> I don't understand about trains but I imagine that doing maintenance in one electrified line would shut down or overload other parts of the network.
The track is divided into section, so you can turn off parts of it. It isn't one continous wire, there are unelectrified dividers.
> Also, energy transported this way could be easily stolen, they just need to pull some wires and hide underground.
The standard voltage used is 25000 volts. You can't 'just' use it, you need an entire electricity substation.
> Also, to transport energy cheaply in long distances you need a very high voltage, that would electrify anything that gets closer to the track. That is why you see high voltage cables being only used in very high poles.
About 3 metres clearance is needed to avoid arcing. Anything higher is mainly to stop something hitting it.
Yes and Deutsche Bahn is planning on doing it for all tracks where this is commercially and technologically feasible. The remaining tracks will mostly be battery electric trains and hydrogen.
This is still important, even if right now the hydrogen comes from natural gas. Otherwise, it's a chicken and egg problem: if there's no demand for hydrogen, people won't build plants to make green hydrogen, and if green hydrogen is not available, people won't build the trains and other vehicles to use that.
There is in fact already significant industrial use of hydrogen https://en.wikipedia.org/wiki/Hydrogen_production#Use_of_hyd... -- independently from the use case of replacing fossil fuels. So there is already significant demand for hydrogen that could be green, but the vast majority of hydrogen produced today is from fossil fuels.
That is true. But the vast majority of the hydrogen produced today is used for things hydrogen was used for decades (fertilizers and oil refining). As such it already has its infrastructure in place, so it's quite a change to migrate to a new way of producing this hydrogen. New uses can demand green hydrogen however.
Germany in particular has a number of green hydrogen producing projects. [1] is a very good source.
State of the art is about 93% efficiency for electrolysis of water "in the lab". It was about 80% efficient at industrial scale back in 2017 (see https://www.carboncommentary.com/blog/2017/7/5/hydrogen-made...), so we can expect that to be a few percentage points higher today.
Apart from the aforementioned hydrogen agreement with Canada, construction is underway for a wind-powered multi-GW electrolyzer plant in the Netherlands, which is pretty much next door to the German trains from TFA.
4% of current industrial hydrogen production is from electrolysis. This is 8 GW electrical for a production of about 3.5e6 tons/year, i.e. 72 MJ/kg, compared to the energy density of hydrogen of 120 MJ/kg is an efficiency of 60% in the actually deployed systems. While we know how to do better even at industrial scale, PV (in the right place) is so cheap that even 60% makes sense economically.
Technologically, hydrogen electrolysis predates batteries by nearly 50 years, and practically speaking it is so trivial today that I first did it when I was single-digit-years-old.
Not sure what you're thinking of when you suggest fusion might be used for materials instead of energy. Transmutation?
Fusion is the sun. In the future we will be able to do what the sub does which is to create the raw materials we all do.
Keep in mind fusion is not just another way to power our lightbulbs, it's a different type of energy among others with the ability to get us to 10% of the speed of light.
Electrolyses uses mostly fossil fuel and will continue to do so. It's a simple question of physics.
The sun only fuses up to carbon; bigger stars go up to iron; supernova and colliding neutron stars produce the heavier stuff we currently use.
Trying to use this process artificially for various elements in current annual demand by our economy involves more than enough energy to boil the ocean in fairly short periods — I'd have to redo the calculations to see if that period was hours or years, but it's a simple question of physics.
We might skip fusion rockets for antimatter (making that is painfully expensive, but it would get us up to 0.4c) or laser propulsion (needs massive infrastructure, but can arbitrarily approach c).
> Electrolyses uses mostly fossil fuel and will continue to do so. It's a simple question of physics.
Physics doesn't require that electrolysis uses fossil fuels, it requires only electricity. Electrolysis will use whatever electricity is cheapest. Right now, for new installations, that's PV. Ten years ago it was not. It's a simple question of economics.
How? Are you counting PV as fusion? In which case I think you used the wrong tense earlier. I still claim you're wrong about fossil fuels being necessary for hydrogen, BTW.
I would think that having a battery based train engine, that can use electricity where available and use batteries where tract electrification is not done is better than fuel based ones, no matter the source or type of fuel.
What if the Hydrogen fuel was made by electricity, and the Hydrogen was used in a Fuel Cell to generate electricity?
Then you have effectively a full electric train, powered by Hydrogen Fuel Cells.
This is superior because Hydrogen has far higher weight-density, so the train can travel further than if it had the much heavier Li-ion batteries to store and use electricity.
The locomotives are made intentionally much heavier than they could be made. The weight of batteries cannot be a problem and any energy used to accelerate a higher mass is recovered.
The energy storage cycle using hydrogen has a much lower efficiency than batteries, even when a fuel cell is used.
Using hydrogen would make much more sense as a means for energy storage in an off-road vehicle than in trains, where the weight is irrelevant and the efficiency of the energy storage cycle is much more important, due to the very high energy consumption of a train.
However, for other kinds of vehicles than trains, there are many kinds of synthetic fuels which are more difficult to make than hydrogen, but which are much easier to handle and store.
> The locomotives are made intentionally much heavier than they could be made. The weight of batteries cannot be a problem and any energy used to accelerate a higher mass is recovered.
Hydrogen storage technology can fit 30MW-hrs of electricity in a standard semi-truck today (aka: 900kg of pressurized H2), and liquid-hydrogen cryogenics are coming around that fits far, far more energy in much denser packages.
How many Li-ion batteries do you need to store 30MW-hrs?
You are right about the lower energy density of batteries, but in the same space where you can store 30 MWh of hydrogen you can store much more energy as diesel fuel.
So that is not an argument in favor of using hydrogen, that is an argument in favor of using the traditional diesel-electric locomotives.
1. Green H2 production needs to happen so that we get our fertilizers off of fossil fuels. The "greenification" of H2 / Ammonia / Fertilizer is one of the most important tasks of the near future, regardless of the energy / fuel issue.
2. Once we've stockpiled large amounts of H2, and created H2 pipelines to support the Fertilizer industry, we will gain the opportunity to use that H2 as transportation as well.
3. H2 to Syngas to Kerosene (or other hydrocarbons) are additional hits to efficiency. Electricity to H2 to electricity is some 40% efficient. But electricity to H2 to Syngas to Kerosene to ICE engine is like 1% efficient at best.
Maybe in the future, the H2 + CO2 Syngas -> Hydrocarbon chemistries can be made more efficient? But its not looking good for modern technology.
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"Green" energy is going to be harder than just slurping up pre-made hydrocarbons in the ground. But we've got like, climate-change issues, pollution, and other such issues we're trying to deal with?
Diesel does work, and trains are rather efficient. But still, they're a good use case (large enough for H2 tanks), that H2 is likely a good fit. Might as well cut out the carbon emissions where it is easiest.
It probably will be easier to convert trains to H2 Fuel cells rather than Cars to EV / Li-ion.
Hydrogen cost is going to be decisive. Right now most hydrogen is produced using natural gas (so called grey hydrogen). Green hydrogen production with renewables is only happening on a small scale and is typically still more expensive than grey hydrogen. Long term (decades) this might become the cheapest and dominant way to produce hydrogen though. But for now, it's not an option for most hydrogen consumers.
Blue hydrogen (grey with carbon capture) is something oil and gas companies love talking about but otherwise is not something that seems to be implemented at scale in the real world by anyone. And that too is going to be more expensive than grey hydrogen as it is basically the same process plus cost for capturing carbon.
So, as gas prices are high right now and there's a shortage. Hydrogen prices are going to be higher and using it for transport is not going to have a high priority. And when it comes to efficiency, you are actually better off just burning natural gas as fuel than using it to produce hydrogen. You release less CO2, the emissions aren't that bad, and it's a much more efficient way to use the gas. So, these hydrogen trains are anything but green or affordable right now. They would be nice if we had cheap green hydrogen. But we don't just yet. And we probably won't have that for quite some time.
So, yes, battery electric trains are the obvious move from a cost point of view. The charging infrastructure is already there. Just ride the train onto any rail segment that is electrified and take some juice in. It's probably not a whole lot more complicated than that. And you could electrify rails around e.g. stations so trains can charge while they stop there.
That was a bit terse: the reason this isn't a serious answer is because Germany is burning large amounts of coal to make electricity, because of the natural gas shortage.
Turning electricity into hydrogen at around an 80% loss by the time it hits the fuel cell doesn't even begin to pencil out.
Some people plan more than a few years ahead. These technologies are an attempt at electrifying activities which cannot be powered directly from the grid in a future where all electricity comes from sustainable sources.
An 80% loss is a perfectly reasonable thing to accept if that's what it takes to make your energy supply portable and you produce your hydrogen using cheap power generated during peak sunlight hours by solar panels that could not otherwise be stored.
Use of hydrogen on a train is a bit stupid though - trains are the the one mobile power use where there's no real benefit to being able to dump the ash into the environment. You may as well just supply good primary battery reactants, such as zinc, or sodium and sulfur, which can be efficiently be recharged somewhere away from the train.
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[ 2.3 ms ] story [ 156 ms ] threadIt also turns out that we've repeatedly stopped and restarted our electrification campaign over the last hundred years, such that we have little persistent expertise and excessive costs per km. So it's not just tunnels and bridges.
In the extreme case, a railway which is 200 miles long and takes 3 trains a day will never have a positive financial case for electrification. So once you've electrified all the stuff that should have been done decades ago (like main lines with 10 trains an hour) and then pushed on to the marginal stuff (hourly rural lines) there's still a small core of lines left. You could just bite the bullet and electrify them anyway, or you could go with things like battery electric trains (good for short distances off an electric mainline) or biodiesel/green hydrogen. The latter are likely to be cheaper.
Hydrogen trains might make sense even if hydrogen cars don't, since the trains run on their tracks, according to a fixed timetable, and need little new infrastructure.
It requires a high pressure (300-bar minimum, 700-bar ideal) environment... or cryogenics to store compact liquid hydrogen.
Building a small, personal, car-tank that withstands 700-bar of pressure and survives typical car accidents is... really difficult? However, building a large train-tank that withstands a typical derailment is far easier.
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I don't think Hydrogen will ever be useful for personal cars. The pressure requirements / storage requirements look rather insane.
I know there's groups working with carbon-fiber designs and other advanced materials, but those are really expensive. Larger trains / trucks can just use standard steel to contain the Hydrogen at 700-bar of pressure (because a bigger tank is easier to scale).
But they're expensive, very expensive, because those storage tanks are extremely sophisticated. Unless those storage tank costs come down by a LOT, I don't think H2 cars will compete reasonably against other technologies (Hybrid, PHEV, or EVs)
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$50,000 for an H2 vehicle with only 180 horsepower engine is really meh.
So roughly 340km of double-track for $1.5bn.
https://en.wikipedia.org/wiki/Midland_Main_Line_railway_upgr...
With the numbers US planners are spewing out, we'd never have fast train network in Switzerland or high-speed rail across Italy, France or Spain.
The UK government estimates £600k/track-km, so even in the US with high wages it should be doable at $2 million/km per track if budgeted carefully...
Source: https://www.tagesschau.de/wirtschaft/deutsche-bahn-siemens-w...
From an engineering perspective the complication of the track electrical infrastructure and pantograph seem inferior to a hydrogen tank and fuel cells. Far less actual stuff to build and maintain.
Set against that, the miles per technical incident for electric trains are about twice that for diesel, and a train breaking down on the ECML is also disruptive, if not obviously infrastructural...
http://www.rail.co.uk/rail-news/ecml-suffers-another-failure...
The two techs are complementary.
You see this on tram systems where bridges or junctions conplicate the overhead wires.
[1] https://www.swr.de/swraktuell/baden-wuerttemberg/friedrichsh...
If we're learning one lesson right now in Germany it's probably that having some things not running on the electricity grid is potentially a good idea. Hydrogen is energy dense, burns clean and doesn't depend on any system infrastructure, which is pretty neat. I think it's underused still, afaik Japan is the only other place betting some money on it.
For example, nuclear power continues to create energy at night, at 2am when there aren't many trains running.
In contrast, when an electric train pulls from the grid, it needs electricity immediately, no matter how loaded the grid is. Electric Trains running at 7pm (during the "Duck curve") will inevitably be powered by natural-gas peaker plants.
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In contrast, Hydrogen electrolysis could continue into the night and be powered by "otherwise unused" 2am or 3am electricity from nuclear power. Even if the train was running at 7pm, the electricity comes from the most advantageous time throughout the day.
That is to say: Hydrogen is a fuel, AND a battery, AND is compatible with electrification technologies thanks to the fuel cell.
Hydrogen is a storage technology, not really an energy source. Hydrogen competes with Li-ion batteries.
How many Li-ion batteries do you need to equal one 200-ton liquid H2 storage tank? At 120MJ per kg, 200-tons == 200,000 kg == 6GW-hrs of electricity. There's no Li-ion battery in the world that's anywhere close to that kind of storage capacity... and various researchers are aiming at 3000ton H2 storage tanks.
Erase 50% or even 80% of the energy due to inefficiency / costs of cryogenics, and you still have a bigger energy storage tank from H2 than anything possible with Li-ion. And the future of H2 is looking like 10x capacities are reasonable over the next 10 years.
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Whatever solar solution you were thinking, just do the same except instead of using big, expensive, heavy Li-ion batteries, replace the storage mechanism with H2 fuel cells.
I totally understand why hydrogen is a great rocket fuel. You need this high energy content and the extreme lightness for high Isp.
On land, I suppose, the energy density of 100 tons of hydrogen in one place is unnecessarily high. The fact that hydrogen has no odor, and its flame is entirely infrared, invisible, does not help.
By the same token, I think that lithium batteries have excessive energy density for large-scale land applications, like buffer storage for solar / wind power. Even a lead-acid battery, with all its environmental downsides, weight, etc is at least not a major fire hazard. I suppose that large-scale electricity storage will take off when cheaper and safer, while less dense, alternatives to lithium batteries are commercialized.
As a power source for a car, a lithium battery at least is not cryogenic. OTOH on the scale of a train this may already be not a big problem. Same possibly for an oceangoing ship, but it would be terrible to start losing fuel and power if a bad storm damages the cryogenic system.
An ideal (fantastic) system could use methane and turn it into carbon, only oxidizing the hydrogen. Sadly, similar reactions only work so far with much more complex molecules.
I thought it was UV? (Which, if anything, is even worse).
Converting methane into hydrogen is known as steam reformation. We can easily due this, but we don't want to because it is a fossil fuel.
That's literally the plan?
https://www.nrel.gov/news/program/2020/answer-to-energy-stor...
Hydrogen is a newer technology than Li-ion. But yeah, its more than capable of these things. We just gotta build out pipelines and facilities to handle it.
But no. To deliver MWs of electricity to trains requires using a ton of copper on all rail-lines, as well as advanced transistors to switch that electricity around. Hydrogen storage of electricity is a good idea and is being developed, but there are innate benefits to the fuel-methodology for applications like trains.
In particular, a pipeline will likely transmit more "energy" at cheaper costs than a bundle of copper wires. Steel and concrete pipelines are just cheaper. So instead of building expensive copper wires + expensive transistors to switch electricity all around the place, why not build pipelines?
> Wouldn't it be more efficient than transporting the hydrogen by truck and transporting the hydrogen battery on every train?
Well, first off, the most efficient form of transporting Hydrogen would be a pipeline. But lets say we're dealing with a remote area so a truck is necessary.
1kg of Hydrogen has 120MJ of power, or 0.033 MW-hrs of electricity. A singular kilogram.
https://www.energy.gov/eere/fuelcells/hydrogen-tube-trailers
These trailers can store 900kg of Hydrogen. Or in other words, 30 Megawatt-hours of Hydrogen based electricity. Larger vehicles, like trains, can likely afford to carry larger containers, possibly even cryogenic liquid-hydrogen that is even more compact.
https://demaco-cryogenics.com/blog/liquid-hydrogen-storage/
Current storage tanks from NASA can hold 270 tons of liquid Hydrogen, with plans to scale to 3000 tons of liquid hydrogen storage. That's 3000000 kg, or 100 Gigawatt-hours of energy storage per tank.
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So yeah, the amount of H2 energy storage available far exceeds what is possible with Li-ion technology.
Pipelines will be more efficient at moving Gigajoules / dozens of MW-hours at cheap costs. Trucks and trains can carry the fuel wherever they need to go. Energy storage / Hydrogen batteries will scale to far higher capacities than Li-ion could ever dream of.
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Hydrogen is an incredibly light fuel. Its difficulty in transportation is __volume__ rather than its weight. Storage technologies, such as higher pressure (700-bar or higher), and liquid cryogenics are needed for H2 storage to be effective. These technologies are just becoming possible today.
So only now can we dream of what liquid-hydrogen storage tanks can offer us. Literally 100GW-hrs of energy per liquid-hydrogen tank is feasible (while *current* prototypes from NASA are holding 9GW-hrs of energy storage).
https://www.spglobal.com/marketintelligence/en/news-insights...
For a locomotive of a train, the volume of storage is a much more important limitation than the mass.
Moreover, after adding the mass of the fuel containers, it is likely that diesel fuel has also a greater energy per mass than hydrogen.
Hydrocarbon fuel can also be transported by pipelines.
So none of these arguments show any advantage of hydrogen versus the traditional diesel fuel.
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I do think that green-hydrocarbons have a potential future. Green diesel would be a biofuel. But Hydrogen can turn into a hydrocarbon through Syngas synthesis (eventually turning into Kerosene and other "green hydrocarbon" fuels).
If the chemistry works out, maybe that's the future. But experimentation with pure H2 looks promising right now.
Even if the energy efficiency of a storage cycle is lower than when using directly the hydrogen, the savings due to easier handling and storage are huge.
Moreover, that path will allow the reuse of all the existing infrastructure for hydrocarbons, whose replacement would require a very long time and very high costs.
Maybe that's not enough for the long term, but that mix/ratio should be sufficient to bootstrap the fledgling H2 industry.
If Syngas / synthetic diesel becomes more efficient in the future, we switch to that. I'm not against experimentation or tests.
Hydrogen made from solar electricity is around 40% efficient, so it is more than 2.5 times more expensive (expensive storage and transport) than just solar and overhead electric cable. Cheaper still because you can put solar panels along the train tracks so land use is almost free. You would have much less losses if you convert solar panel 40-60V directly into high voltage the train use.
Why can't those night-time batteries be Hydrogen?
And instead of running electrical wires, why don't we pump that Hydrogen into a pipeline that goes to the train station? That way, our energy transport uses cheap steel-and-concrete to move our energy around, rather than expensive copper and transistors.
And instead of electrifying 3000 miles of track, why won't the Locomotive engine be a fuel cell that converts the H2 back into electricity on board?
If you calculate the LCOE, you'll find that using wind at night is cheaper than hydrogen. Maybe certain batteries storing solar can beat wind at cost? My point remains, don't guess "why not use my favorite X" but calculate and simulate all alternative systems and the the lowest cost of energy ofve lifetime of systems is the winner you actually build.
Transistors, transformers, and electric wires use an incredible amount of copper.
There doesn't appear to be a promising solution for seasonal storage of energy other than hydrogen.
Pumped hydro power is limited to certain areas and also doesn't scale in the same way that hydrogen does. Compressed air is sometimes mentioned but doesn't appear to make much progress.
Since the world is going to need massive amounts of seasonal storage for the sake of the stability of the energy system (which is the backbone of society), as more and more renewables are built, there just has to be a solution. And if there's only one that scales to demand, then that's what will be built.
Hydrogen (and derivatives and generally all chemical energy carriers) also have this triple synergy of huge capacity for transmission plus flexibility plus buffering.
Transmission capacity of a pipeline is massively larger than any cable.
Flexibility is given through the fact that hydrogen can spontaneously be transported to almost any location. Compare that to "spontaneously" building a new power line to an arbitrary location.
Buffering is a byproduct. As soon as the hydrogen is produced, it acts like a buffer, whether it's inside a pipeline or some tank. Compare that to electric energy transmitted via cable .. as soon as the power plant is shut down, the lights will go out.
A chemical based energy system is inherently more stable and resilient than an electrical grid, IMO.
I don't understand about trains but I imagine that doing maintenance in one electrified line would shut down or overload other parts of the network. Also, energy transported this way could be easily stolen, they just need to pull some wires and hide underground. Also, to transport energy cheaply in long distances you need a very high voltage, that would electrify anything that gets closer to the track. That is why you see high voltage cables being only used in very high poles.
The track is divided into section, so you can turn off parts of it. It isn't one continous wire, there are unelectrified dividers.
> Also, energy transported this way could be easily stolen, they just need to pull some wires and hide underground.
The standard voltage used is 25000 volts. You can't 'just' use it, you need an entire electricity substation.
> Also, to transport energy cheaply in long distances you need a very high voltage, that would electrify anything that gets closer to the track. That is why you see high voltage cables being only used in very high poles.
About 3 metres clearance is needed to avoid arcing. Anything higher is mainly to stop something hitting it.
Source: https://www.tagesschau.de/wirtschaft/deutsche-bahn-siemens-w...
What's the state of the art on producing hydrogen from electricity without incredibly expensive catalysts again?
Germany in particular has a number of green hydrogen producing projects. [1] is a very good source.
[1] https://www.iea.org/reports/hydrogen
Apart from the aforementioned hydrogen agreement with Canada, construction is underway for a wind-powered multi-GW electrolyzer plant in the Netherlands, which is pretty much next door to the German trains from TFA.
Hydrogen is not feasible anytime soon. Maybe when we get Fusion but then it's most likely going to be used for materials not energy.
Technologically, hydrogen electrolysis predates batteries by nearly 50 years, and practically speaking it is so trivial today that I first did it when I was single-digit-years-old.
Not sure what you're thinking of when you suggest fusion might be used for materials instead of energy. Transmutation?
Keep in mind fusion is not just another way to power our lightbulbs, it's a different type of energy among others with the ability to get us to 10% of the speed of light.
Electrolyses uses mostly fossil fuel and will continue to do so. It's a simple question of physics.
Trying to use this process artificially for various elements in current annual demand by our economy involves more than enough energy to boil the ocean in fairly short periods — I'd have to redo the calculations to see if that period was hours or years, but it's a simple question of physics.
We might skip fusion rockets for antimatter (making that is painfully expensive, but it would get us up to 0.4c) or laser propulsion (needs massive infrastructure, but can arbitrarily approach c).
> Electrolyses uses mostly fossil fuel and will continue to do so. It's a simple question of physics.
Physics doesn't require that electrolysis uses fossil fuels, it requires only electricity. Electrolysis will use whatever electricity is cheapest. Right now, for new installations, that's PV. Ten years ago it was not. It's a simple question of economics.
Then you have effectively a full electric train, powered by Hydrogen Fuel Cells.
This is superior because Hydrogen has far higher weight-density, so the train can travel further than if it had the much heavier Li-ion batteries to store and use electricity.
The energy storage cycle using hydrogen has a much lower efficiency than batteries, even when a fuel cell is used.
Using hydrogen would make much more sense as a means for energy storage in an off-road vehicle than in trains, where the weight is irrelevant and the efficiency of the energy storage cycle is much more important, due to the very high energy consumption of a train.
However, for other kinds of vehicles than trains, there are many kinds of synthetic fuels which are more difficult to make than hydrogen, but which are much easier to handle and store.
Hydrogen storage technology can fit 30MW-hrs of electricity in a standard semi-truck today (aka: 900kg of pressurized H2), and liquid-hydrogen cryogenics are coming around that fits far, far more energy in much denser packages.
How many Li-ion batteries do you need to store 30MW-hrs?
1/10th of this won't fit on a train ya know: https://www.teslarati.com/tesla-megapacks-300mw-victoria-bat...
So that is not an argument in favor of using hydrogen, that is an argument in favor of using the traditional diesel-electric locomotives.
2. Once we've stockpiled large amounts of H2, and created H2 pipelines to support the Fertilizer industry, we will gain the opportunity to use that H2 as transportation as well.
3. H2 to Syngas to Kerosene (or other hydrocarbons) are additional hits to efficiency. Electricity to H2 to electricity is some 40% efficient. But electricity to H2 to Syngas to Kerosene to ICE engine is like 1% efficient at best.
Maybe in the future, the H2 + CO2 Syngas -> Hydrocarbon chemistries can be made more efficient? But its not looking good for modern technology.
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"Green" energy is going to be harder than just slurping up pre-made hydrocarbons in the ground. But we've got like, climate-change issues, pollution, and other such issues we're trying to deal with?
Diesel does work, and trains are rather efficient. But still, they're a good use case (large enough for H2 tanks), that H2 is likely a good fit. Might as well cut out the carbon emissions where it is easiest.
It probably will be easier to convert trains to H2 Fuel cells rather than Cars to EV / Li-ion.
Hydrogen cost is going to be decisive. Right now most hydrogen is produced using natural gas (so called grey hydrogen). Green hydrogen production with renewables is only happening on a small scale and is typically still more expensive than grey hydrogen. Long term (decades) this might become the cheapest and dominant way to produce hydrogen though. But for now, it's not an option for most hydrogen consumers.
Blue hydrogen (grey with carbon capture) is something oil and gas companies love talking about but otherwise is not something that seems to be implemented at scale in the real world by anyone. And that too is going to be more expensive than grey hydrogen as it is basically the same process plus cost for capturing carbon.
So, as gas prices are high right now and there's a shortage. Hydrogen prices are going to be higher and using it for transport is not going to have a high priority. And when it comes to efficiency, you are actually better off just burning natural gas as fuel than using it to produce hydrogen. You release less CO2, the emissions aren't that bad, and it's a much more efficient way to use the gas. So, these hydrogen trains are anything but green or affordable right now. They would be nice if we had cheap green hydrogen. But we don't just yet. And we probably won't have that for quite some time.
So, yes, battery electric trains are the obvious move from a cost point of view. The charging infrastructure is already there. Just ride the train onto any rail segment that is electrified and take some juice in. It's probably not a whole lot more complicated than that. And you could electrify rails around e.g. stations so trains can charge while they stop there.
That was a bit terse: the reason this isn't a serious answer is because Germany is burning large amounts of coal to make electricity, because of the natural gas shortage.
Turning electricity into hydrogen at around an 80% loss by the time it hits the fuel cell doesn't even begin to pencil out.
Is there an optimal solution of mag-lev and sail assisted trains ?