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Going all in on hydrogen is a bit of a loosely defined notion. Mostly it boils down to dumping lots of money on the table for whomever wants to grab it and crea

Going all in on hydrogen is a bit of a loosely defined notion. Mostly it boils down to dumping lots of money on the table for whomever wants to grab it and creating a few photo opportunities for politicians parroting whatever their sponsors want them to parrot. And as it turns out the fossil fuel industry seems to want to claim most of that. Looking at the physics, green hydrogen has some applications but what politicians seem to be pitching ranges from delusional to physically challenging. Those pesky laws of thermodynamics get in the way. So, transporting hydrogen at scale is a problem because even chilled to near absolute zero it's still way less energy dense by volume than liquid LNG. And of course chilling it to those levels is challenging and expensive. It takes up quite a bit more space. As in, you need several ships to move the same amount of energy as a single LNG ship. And of course the way to deal with cold gases heating up is to vent some of it (you boil some off to cool the rest). So, not all of it makes it to the destination. It gets worse. Those ships need fuel. And hydrogen isn't it because of it's volume. You'd need to sacrifice most of the shipping volume to storing the fuel to move it around. Volumetric density of hydrogen is a problem for transport, shipping, planes, aviation, etc. Moving around enough of it to be interesting would require an order of magnitude more ships, trucks, etc. than we use today for moving around fossil fuels. That's expensive. And all of that is before you consider that creating hydrogen is inherently more expensive than just using renewable power directly (via batteries). None of these problems has much wiggle room for scientific breakthroughs. That perpetuum motion machine just doesn't exist. Hydrogen generation is already close to the theoretical maximum in terms of efficiency. There are not going to be any 2x or 3x improvements there. Same for volume. You can't chill it any further than absolute zero. Converting it into other fuels works but is also lossy. There's a role for green hydrogen. It's replacing the enormous amount of grey hydrogen we generate today for things like fertilizer production. Australia is not going to export hydrogen in meaningful amounts, ever. Nor is anyone else going to be able to scale that to meaningful amounts. It's physically impossible. But they'll likely produce some other things that can be shipped out using green hydrogen. Like fertilizer, steel, etc.

defrost 4y ago
> So, transporting hydrogen at scale is a problem because even chilled to near absolute zero it's still way less energy dense by volume than liquid LNG. What about transporting Ammonia .. that's three H and and an N .. different beast.
- c54 4y ago
  Better still is synthesizing methane from the hydrogen and transporting that. Three H and a C
  - defrost 4y ago
    'Better' is always subjective - methane spills from a 1 km long shipping vessel is a lot of potent greenhouse gas back in the air, with an end point issue of using the methane without the C binding and creating CO2 - versus the ammonia with just Nitrogen as waste (or going into ag soils). Mind you ammonia is an irritating gas and no fun spilled in water at sea .. so, yeah. The main take home point is that the argument against hydrogen because it's a tiny slippery hard to teansport molecule is a complete furphy - there are other options.
  - jillesvangurp 4y ago
    Of course those inefficiencies multiply. You generate hydrogen at 30/40% efficiency. You generate methane from that at a similar efficiency. Then you compress it ... which takes energy. You ship it around. Which takes energy. Then you burn it at 40% efficiency. Numbers rounded up here. Real world efficiencies are worse. Multiply all of that and you end up with efficiencies of a few percent. Nice that it can be done at great cost but there are a lot of things that are probably more efficient and cheaper.
- jillesvangurp 4y ago
  It works, but you loose some more energy. Better still is to make fertilizer with that and ship that out. Shipping ammonia half way around the world with the intention of using it as a fuel doesn't make sense from an efficiency point of view. You loose so much energy creating the hydrogen, transforming it into ammonia, shipping it around, and then turning it back into mechanical or electrical energy, which again is not super efficient. By the time that is done, you are looking at maybe 10% efficient (possibly way less). So, it's a very costly way to move stuff around using ammonia as a fuel. Nice that it works but unlikely to be a preferred solution aside from some niche use cases. And while ammonia is better then hydrogen in terms of volumetric density. It's still about half of what lng gives. So, you need two ammonia ships for every lng ship to deliver the same amount of energy. That same property also is an issue with bio kerosene vs. ammonia in planes.
usrusr 4y ago
You don't transport hydrogen, you transport some other fuel made in a hydrogen-driven chemical process close to where the hydrogen is made. The hydrogen serves as an initial step (that is true for just about any power-to-something) and as an input buffer to allow running downstream processes 24/7 and not just whenever the sun is shining.
- vineyardmike 4y ago
  Why not just use existing water and electricity to produce hydrogen? Green electricity is produced and stored as hydrogen locally.
  - theteapot 4y ago
    Because different natural endowments of renewable energy. There is a lot more sun and square meters in Australia than Germany or ... just about anywhere in Europe or Asia.
splittingTimes 4y ago
I just wanted to add other storage challenges to your list, but upon googling for it, I had to learn that something called liquid organic hydrogen carrier exists: "Hydrogen oil – LOHC – has two great advantages compared to compressed and liquid hydrogen: The hydrogen is stored in oil, LOHC, and there is substantially less free hydrogen on board the ship, which reduces the risk. The hydrogen oil can be transported in conventional tanks, about the same way as for diesel today, and therefore has substantially lower transport costs than compressed and liquid hydrogen." https://greenshippingprogramme.com/pilot/infrastructure-for-liquid-organic-hydrogen-carrier-lohc/ https://greenshippingprogramme.com/pilot/infrastructure-for-...
- JumpCrisscross 4y ago
  > hydrogen is stored in oil, LOHC This sounds like a parody of hydrocarbons.
  - fbdab103 4y ago
    I too am missing the punchline. Sounds like synthesizing hydrocarbons directly would probably be simpler and would not require changing any existing infrastructure.
    - LargoLasskhyfv 4y ago
      The idea seems to be to not burn the 'oil', instead to just use it as a 'carrier' for the hydrogen, which then is released from the oil when needed. While the 'used' oil is being stored, to be 'reloaded' with hydrogen by whichever means. So the 'carrier-oil-component' is the reusable thing here. All while being able to be handled, stored, transported similar to diesel. Supposedly. shrug
    - mac01021 4y ago
      I don't know what this LOHC stuff really is, but it's easy to imagine that dissolving H2 in in an existing liquid would be much less of an undertaking than inducing it to become C8H18 or whatever.
runarberg 4y ago
> And all of that is before you consider that creating hydrogen is inherently more expensive than just using renewable power directly (via batteries). This may be nit-picky of me, but how is using a chemical battery to store energy using electricity directly, but not using a chemical (hydrogen) to store energy not using electricity directly? A standard definition of a battery is anything that store energy and outputs electricity. To that extent hydrogen is just the chemical element of a battery (fuel cell). You don’t recharge it by inputting electricity (like you do a lithium ion battery), but you replace the active chemical element of it by using electricity to generate more hydrogen and inserting it into your empty fuel cells (recycling your battery basically). I think if you define direct electricity usage to exclude hydrogen (which is kind of silly) then you’d also need to exclude all other forms of battery. And you are left with basically just overhead wires. Also nobody is proposing a mass transport of hydrogen to be a viable future. Most proposals have them generated via electrolysis on site.
- jillesvangurp 4y ago
  Solar panel to battery to electrical engine is pretty efficient. We're talking ~80% efficiencies here. Solar panel to hydrogen you are down to 30-40% right away before you do anything with the hydrogen. You still need to transport it. Once it gets to a fuel cell, you hit maybe 70-80% efficiencies. That's pretty good but these inefficiencies multiply. So, now you are down to 20%. That's a 4x difference. And of course there are losses along the way, etc. So it's more like 10 to 15%. Burning it is worse.
  - defrost 4y ago
    You're correct that the current state of the art isn't great and may in fact be worse than you imagine [1]. An important fact, though, is that there has been little serious sustained effort to push for hydrogen production until now. Just recently we have seen papers on new techniques [2] some of which are already being tested at trial industrial scales [3] What is happening now is similar to vaccine development during COVID - accelerated parallel development of stages; the heavy industry side of hydrogen development is being pushed and built on the assumption that key stages will be improved in both incremental and hopefully radical ways. The message from the climate side of these developments is there's little to no time to waste. [1] https://pubs.rsc.org/en/content/articlelanding/2021/se/d0se01761b https://pubs.rsc.org/en/content/articlelanding/2021/se/d0se0... [2] https://www.chemistryworld.com/news/seawater-splitting-system-could-scale-up-renewable-hydrogen-production/4013332.article https://www.chemistryworld.com/news/seawater-splitting-syste... [3] https://www.chemistryworld.com/news/water-splitting-device-solves-puzzle-of-producing-hydrogen-direct-from-seawater/4016645.article https://www.chemistryworld.com/news/water-splitting-device-s...
jvanderbot 4y ago
If energy density is what you care about, electrify everything and ship Uranium around for fission.
LargoLasskhyfv 4y ago
https://en.wikipedia.org/wiki/Slush_hydrogen https://en.wikipedia.org/wiki/Slush_hydrogen

defrost 4y ago

> So, transporting hydrogen at scale is a problem because even chilled to near absolute zero it's still way less energy dense by volume than liquid LNG. What about transporting Ammonia .. that's three H and and an N .. different beast.

c54 4y ago
Better still is synthesizing methane from the hydrogen and transporting that. Three H and a C
- defrost 4y ago
  'Better' is always subjective - methane spills from a 1 km long shipping vessel is a lot of potent greenhouse gas back in the air, with an end point issue of using the methane without the C binding and creating CO2 - versus the ammonia with just Nitrogen as waste (or going into ag soils). Mind you ammonia is an irritating gas and no fun spilled in water at sea .. so, yeah. The main take home point is that the argument against hydrogen because it's a tiny slippery hard to teansport molecule is a complete furphy - there are other options.
- jillesvangurp 4y ago
  Of course those inefficiencies multiply. You generate hydrogen at 30/40% efficiency. You generate methane from that at a similar efficiency. Then you compress it ... which takes energy. You ship it around. Which takes energy. Then you burn it at 40% efficiency. Numbers rounded up here. Real world efficiencies are worse. Multiply all of that and you end up with efficiencies of a few percent. Nice that it can be done at great cost but there are a lot of things that are probably more efficient and cheaper.
jillesvangurp 4y ago
It works, but you loose some more energy. Better still is to make fertilizer with that and ship that out. Shipping ammonia half way around the world with the intention of using it as a fuel doesn't make sense from an efficiency point of view. You loose so much energy creating the hydrogen, transforming it into ammonia, shipping it around, and then turning it back into mechanical or electrical energy, which again is not super efficient. By the time that is done, you are looking at maybe 10% efficient (possibly way less). So, it's a very costly way to move stuff around using ammonia as a fuel. Nice that it works but unlikely to be a preferred solution aside from some niche use cases. And while ammonia is better then hydrogen in terms of volumetric density. It's still about half of what lng gives. So, you need two ammonia ships for every lng ship to deliver the same amount of energy. That same property also is an issue with bio kerosene vs. ammonia in planes.

usrusr 4y ago

You don't transport hydrogen, you transport some other fuel made in a hydrogen-driven chemical process close to where the hydrogen is made. The hydrogen serves as an initial step (that is true for just about any power-to-something) and as an input buffer to allow running downstream processes 24/7 and not just whenever the sun is shining.

vineyardmike 4y ago
Why not just use existing water and electricity to produce hydrogen? Green electricity is produced and stored as hydrogen locally.
- theteapot 4y ago
  Because different natural endowments of renewable energy. There is a lot more sun and square meters in Australia than Germany or ... just about anywhere in Europe or Asia.

splittingTimes 4y ago

I just wanted to add other storage challenges to your list, but upon googling for it, I had to learn that something called liquid organic hydrogen carrier exists: "Hydrogen oil – LOHC – has two great advantages compared to compressed and liquid hydrogen: The hydrogen is stored in oil, LOHC, and there is substantially less free hydrogen on board the ship, which reduces the risk. The hydrogen oil can be transported in conventional tanks, about the same way as for diesel today, and therefore has substantially lower transport costs than compressed and liquid hydrogen." https://greenshippingprogramme.com/pilot/infrastructure-for-liquid-organic-hydrogen-carrier-lohc/ https://greenshippingprogramme.com/pilot/infrastructure-for-...

JumpCrisscross 4y ago
> hydrogen is stored in oil, LOHC This sounds like a parody of hydrocarbons.
- fbdab103 4y ago
  I too am missing the punchline. Sounds like synthesizing hydrocarbons directly would probably be simpler and would not require changing any existing infrastructure.
  - LargoLasskhyfv 4y ago
    The idea seems to be to not burn the 'oil', instead to just use it as a 'carrier' for the hydrogen, which then is released from the oil when needed. While the 'used' oil is being stored, to be 'reloaded' with hydrogen by whichever means. So the 'carrier-oil-component' is the reusable thing here. All while being able to be handled, stored, transported similar to diesel. Supposedly. shrug
  - mac01021 4y ago
    I don't know what this LOHC stuff really is, but it's easy to imagine that dissolving H2 in in an existing liquid would be much less of an undertaking than inducing it to become C8H18 or whatever.

runarberg 4y ago

> And all of that is before you consider that creating hydrogen is inherently more expensive than just using renewable power directly (via batteries). This may be nit-picky of me, but how is using a chemical battery to store energy using electricity directly, but not using a chemical (hydrogen) to store energy not using electricity directly? A standard definition of a battery is anything that store energy and outputs electricity. To that extent hydrogen is just the chemical element of a battery (fuel cell). You don’t recharge it by inputting electricity (like you do a lithium ion battery), but you replace the active chemical element of it by using electricity to generate more hydrogen and inserting it into your empty fuel cells (recycling your battery basically). I think if you define direct electricity usage to exclude hydrogen (which is kind of silly) then you’d also need to exclude all other forms of battery. And you are left with basically just overhead wires. Also nobody is proposing a mass transport of hydrogen to be a viable future. Most proposals have them generated via electrolysis on site.

jillesvangurp 4y ago
Solar panel to battery to electrical engine is pretty efficient. We're talking ~80% efficiencies here. Solar panel to hydrogen you are down to 30-40% right away before you do anything with the hydrogen. You still need to transport it. Once it gets to a fuel cell, you hit maybe 70-80% efficiencies. That's pretty good but these inefficiencies multiply. So, now you are down to 20%. That's a 4x difference. And of course there are losses along the way, etc. So it's more like 10 to 15%. Burning it is worse.
- defrost 4y ago
  You're correct that the current state of the art isn't great and may in fact be worse than you imagine [1]. An important fact, though, is that there has been little serious sustained effort to push for hydrogen production until now. Just recently we have seen papers on new techniques [2] some of which are already being tested at trial industrial scales [3] What is happening now is similar to vaccine development during COVID - accelerated parallel development of stages; the heavy industry side of hydrogen development is being pushed and built on the assumption that key stages will be improved in both incremental and hopefully radical ways. The message from the climate side of these developments is there's little to no time to waste. [1] https://pubs.rsc.org/en/content/articlelanding/2021/se/d0se01761b https://pubs.rsc.org/en/content/articlelanding/2021/se/d0se0... [2] https://www.chemistryworld.com/news/seawater-splitting-system-could-scale-up-renewable-hydrogen-production/4013332.article https://www.chemistryworld.com/news/seawater-splitting-syste... [3] https://www.chemistryworld.com/news/water-splitting-device-solves-puzzle-of-producing-hydrogen-direct-from-seawater/4016645.article https://www.chemistryworld.com/news/water-splitting-device-s...

jvanderbot 4y ago

If energy density is what you care about, electrify everything and ship Uranium around for fission.

LargoLasskhyfv 4y ago

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