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Summary for those who didn't click on the link to the actual article [1]: - a car may need 5 kg of hydrogen for a range of 500km (bbc's claim, I'll take it at

Summary for those who didn't click on the link to the actual article [1]: - a car may need 5 kg of hydrogen for a range of 500km (bbc's claim, I'll take it at face value) - the new "sponge" material can offer "deliverable hydrogen capacities (14.0 weight %, 46.2 g liter−1) under a combined temperature and pressure swing (77 K/100 bar → 160 K/5 bar)." - so for 5kg of H2 you need about 100 l of this material, at a weight of about 35 kg. Not too shabby. - however, note the conditions: you store the H2 at 77k and 100bar. So you need liquid nitrogen and quite high pressure to hold this. That might add substantial weight to the 35kg of sponge By the way, about one year ago, there was quite some big noise on HN about a different breakthrough from Australia, where some researchers showed economic ways to store H2 in ammonia. Not sure if that got anywhere. [1] https://science.sciencemag.org/content/368/6488/297 https://science.sciencemag.org/content/368/6488/297

greglindahl 7y ago
The main utility for ammonia is to transport energy long distances at industrial scale, not for individual vehicles. So, for example, you'd build a huge solar farm where it's very sunny, or a huge wind farm where it's windy. And instead of running power lines, you'd ship ammonia.
- jessaustin 7y ago
  Power lines are cheaper and more efficient than pipelines, and they always will be. Ammonia will be a storage medium.
  - greglindahl 7y ago
    So, for example, a power line from Algeria to Europe is cheaper than a ship-based ammonia scheme? Or northern Australia to China or Japan? Power lines are a winner for short distances. Pipelines some longer distances. And ships for the longest distances.
    - brownbat 7y ago
      You're right that there's a reason we constantly transport so much liquid fuel around the world. But the Europe and North Africa connection is already a relatively serious proposal precisely because of the efficiency gains. It's definitely an ambitious project, but more from the politics than from the technology. Electrons are just easier than atoms, even underwater. HVDC has made long distances realistic for cables. China's Anhui to Xinjiang HVDC link will be around 2000 miles. There's a planned HVDC submarine cable from Lincolnshire to Denmark that will be 472 miles. So for Australia to China, we might be able to pull off Darwin to Jakarta, then Jakarta to Hong Kong within 10-20 years, if you really wanted to. Would break some records, but it's not crazy impractical. Though with the most efficient transfers you're taking some percentage hit per mile. Closer generation is generally going to be smarter, especially if you're running cables through what would be really viable offshore wind fields. https://en.wikipedia.org/wiki/European_super_grid https://en.wikipedia.org/wiki/European_super_grid https://www.power-technology.com/features/chinas-mega-transmission-lines/ https://www.power-technology.com/features/chinas-mega-transm...
      - greglindahl 7y ago
        I totally agree that power lines have improved recently. That fiddles with the details, and doesn't change the fact that even if these advances pan out, there will be (very long) distances that you'll want to ship energy that will be more efficient with ships than power lines.
        brownbat 7y ago
        You're right to point out that tankers are phenomenally efficient, but that's _for oil_. Just as LNG is much more expensive to ship than oil, because of the increased handling complexity, any shipping of hydrogen is going to lose that advantage completely to electrification.[0] > there will be (very long) distances that you'll want to ship energy This is probably the real crux driving the difference in how we see this. The main reason we have to ship hydrocarbons long distances is because those resources are so concentrated. Wind and solar aren't perfectly distributed, but they are so much more distributed that local generation would be much more efficient than transporting anything much beyond what current HVDC projects can easily handle. So, sure, we're not going to stretch a cable for 12,000 miles. But we're also not going to build a solar farm in Saudi Arabia to generate hydrogen to ship to Canberra. We're just going to put a solar farm in the outback instead. [0] "Relative costs of transporting electrical and chemical energy" by Saadi, Lewis, and MacFarland, studies this very question. Even in that report, you could quibble with a lot of their assumptions that I think bias it against HVDC, project lifespans, ignoring loading and unloading costs for tankers, etc. But it's not a crazy starting place, and HVDC still beats hydrogen on $ per mile per Joule. My takeaway from it was that if we're stuck with a carbon economy, sure, we'll keep using tankers. If we're talking about going carbon neutral, the difficulties of working with hydrogen relative to oil and LNG will probably tip us back towards electrification and local generation, except in the most highly specialized of situations (fueling Antarctica or something). The report was a good reminder why we have an oil-based economy though. It is so obnoxiously practical and well suited to everything we want to use it for. Ditching carbon will be hard.
  - simonebrunozzi 7y ago
    Sometimes you don't have the luxury of a power line, e.g. in developing countries. Similar thing (larger scale though) happened with oil: there are still tons of oil tanks sailing around the world because a stable pipeline network is hard to build.
  - Hypx 7y ago
    Only for short distances. At long distances, they lose power due to resistance in the wires. Underwater power lines across oceans are also extreme expensive.
- rstuart4133 7y ago
  > The main utility for ammonia is to transport energy long distances at industrial scale, not for individual vehicles. Which is exactly how it was pitched in Australia, by the government agency responsible for developing it. It was the reason it was funded. As I recall, it was "it solar continues current downward trajectory, it will be cheaper make than it is to frack natural gas". They seemed pretty convinced of it.
jessaustin 7y ago
Liquid anhydrous ammonia is already the obvious way to store and use hydrogen. It contains lots of hydrogen but doesn't have the embrittlement issues that elemental hydrogen does. Agricultural regions have extensive storage and distribution capacity due to its use as fertilizer, so no new technology is needed for handling ammonia. Common internal combustion engines can burn ammonia as fuel with minimal modification. The only thing holding back the use of ammonia as energy storage is the fact that fossil fuels are still the most efficient feedstock. Once solar is more efficient, ammonia will see widespread production and use.
- m463 7y ago
  Also it's a dangerous material to spill.
  - entee 7y ago
    Very much so. Would be hard to breathe at any accident site with a leak.
    - rstuart4133 7y ago
      But not quiet as hard to breath as 60 litres of petrol, going up in a ball of flames.
      - entee 7y ago
        Perhaps, though I once broke a 1L bottle of ammonium hydroxide (a strong solution of ammonia) in the lab. We literally couldn’t go in the room for 15 min. That was just 1L of not 100% ammonia, and we had a door where we could get out. Even if the ammonia isn’t flammable, you might kill occupants of a car with what is effectively a poison gas.
      - CamperBob2 7y ago
        Which doesn't happen in the real world because of the way fuel tanks are constructed. Meanwhile, anhydrous ammonia is one of those things that give experienced hazmat workers nightmares.
rstuart4133 7y ago
Grrrr. It's efficiency is based on using a fuel cell. There seems to be a few ways around of storing Hydrogen in clever ways - this just adds to the list. But until we discover unobtainium that's as efficient as platinum in fuel cells but common and a fraction of the price, it's all a pipe dream. Had they burnt it in an ICE, and come up with those figures then OK. As it is, when using technology that exists now it won't be 5 kg per 500km, it will 25 kg at best, and 500l of this material will be required.
clouddrover 7y ago
> a car may need 5 kg of hydrogen for a range of 500km (bbc's claim, I'll take it at face value) It is about 1kg for 100km range. The Hyundai Nexo Blue has better than 600km range on 6.5kg of hydrogen: https://www.drivingelectric.com/hyundai/nexo/1005/hyundai-nexo-range-battery-charging https://www.drivingelectric.com/hyundai/nexo/1005/hyundai-ne... https://en.wikipedia.org/wiki/Hyundai_Nexo https://en.wikipedia.org/wiki/Hyundai_Nexo

greglindahl 7y ago

The main utility for ammonia is to transport energy long distances at industrial scale, not for individual vehicles. So, for example, you'd build a huge solar farm where it's very sunny, or a huge wind farm where it's windy. And instead of running power lines, you'd ship ammonia.

jessaustin 7y ago
Power lines are cheaper and more efficient than pipelines, and they always will be. Ammonia will be a storage medium.
- greglindahl 7y ago
  So, for example, a power line from Algeria to Europe is cheaper than a ship-based ammonia scheme? Or northern Australia to China or Japan? Power lines are a winner for short distances. Pipelines some longer distances. And ships for the longest distances.
  - brownbat 7y ago
    You're right that there's a reason we constantly transport so much liquid fuel around the world. But the Europe and North Africa connection is already a relatively serious proposal precisely because of the efficiency gains. It's definitely an ambitious project, but more from the politics than from the technology. Electrons are just easier than atoms, even underwater. HVDC has made long distances realistic for cables. China's Anhui to Xinjiang HVDC link will be around 2000 miles. There's a planned HVDC submarine cable from Lincolnshire to Denmark that will be 472 miles. So for Australia to China, we might be able to pull off Darwin to Jakarta, then Jakarta to Hong Kong within 10-20 years, if you really wanted to. Would break some records, but it's not crazy impractical. Though with the most efficient transfers you're taking some percentage hit per mile. Closer generation is generally going to be smarter, especially if you're running cables through what would be really viable offshore wind fields. https://en.wikipedia.org/wiki/European_super_grid https://en.wikipedia.org/wiki/European_super_grid https://www.power-technology.com/features/chinas-mega-transmission-lines/ https://www.power-technology.com/features/chinas-mega-transm...
    - greglindahl 7y ago
      I totally agree that power lines have improved recently. That fiddles with the details, and doesn't change the fact that even if these advances pan out, there will be (very long) distances that you'll want to ship energy that will be more efficient with ships than power lines.
      - brownbat 7y ago
        You're right to point out that tankers are phenomenally efficient, but that's _for oil_. Just as LNG is much more expensive to ship than oil, because of the increased handling complexity, any shipping of hydrogen is going to lose that advantage completely to electrification.[0] > there will be (very long) distances that you'll want to ship energy This is probably the real crux driving the difference in how we see this. The main reason we have to ship hydrocarbons long distances is because those resources are so concentrated. Wind and solar aren't perfectly distributed, but they are so much more distributed that local generation would be much more efficient than transporting anything much beyond what current HVDC projects can easily handle. So, sure, we're not going to stretch a cable for 12,000 miles. But we're also not going to build a solar farm in Saudi Arabia to generate hydrogen to ship to Canberra. We're just going to put a solar farm in the outback instead. [0] "Relative costs of transporting electrical and chemical energy" by Saadi, Lewis, and MacFarland, studies this very question. Even in that report, you could quibble with a lot of their assumptions that I think bias it against HVDC, project lifespans, ignoring loading and unloading costs for tankers, etc. But it's not a crazy starting place, and HVDC still beats hydrogen on $ per mile per Joule. My takeaway from it was that if we're stuck with a carbon economy, sure, we'll keep using tankers. If we're talking about going carbon neutral, the difficulties of working with hydrogen relative to oil and LNG will probably tip us back towards electrification and local generation, except in the most highly specialized of situations (fueling Antarctica or something). The report was a good reminder why we have an oil-based economy though. It is so obnoxiously practical and well suited to everything we want to use it for. Ditching carbon will be hard.
- simonebrunozzi 7y ago
  Sometimes you don't have the luxury of a power line, e.g. in developing countries. Similar thing (larger scale though) happened with oil: there are still tons of oil tanks sailing around the world because a stable pipeline network is hard to build.
- Hypx 7y ago
  Only for short distances. At long distances, they lose power due to resistance in the wires. Underwater power lines across oceans are also extreme expensive.
rstuart4133 7y ago
> The main utility for ammonia is to transport energy long distances at industrial scale, not for individual vehicles. Which is exactly how it was pitched in Australia, by the government agency responsible for developing it. It was the reason it was funded. As I recall, it was "it solar continues current downward trajectory, it will be cheaper make than it is to frack natural gas". They seemed pretty convinced of it.

jessaustin 7y ago

Liquid anhydrous ammonia is already the obvious way to store and use hydrogen. It contains lots of hydrogen but doesn't have the embrittlement issues that elemental hydrogen does. Agricultural regions have extensive storage and distribution capacity due to its use as fertilizer, so no new technology is needed for handling ammonia. Common internal combustion engines can burn ammonia as fuel with minimal modification. The only thing holding back the use of ammonia as energy storage is the fact that fossil fuels are still the most efficient feedstock. Once solar is more efficient, ammonia will see widespread production and use.

m463 7y ago
Also it's a dangerous material to spill.
- entee 7y ago
  Very much so. Would be hard to breathe at any accident site with a leak.
  - rstuart4133 7y ago
    But not quiet as hard to breath as 60 litres of petrol, going up in a ball of flames.
    - entee 7y ago
      Perhaps, though I once broke a 1L bottle of ammonium hydroxide (a strong solution of ammonia) in the lab. We literally couldn’t go in the room for 15 min. That was just 1L of not 100% ammonia, and we had a door where we could get out. Even if the ammonia isn’t flammable, you might kill occupants of a car with what is effectively a poison gas.
    - CamperBob2 7y ago
      Which doesn't happen in the real world because of the way fuel tanks are constructed. Meanwhile, anhydrous ammonia is one of those things that give experienced hazmat workers nightmares.

rstuart4133 7y ago

Grrrr. It's efficiency is based on using a fuel cell. There seems to be a few ways around of storing Hydrogen in clever ways - this just adds to the list. But until we discover unobtainium that's as efficient as platinum in fuel cells but common and a fraction of the price, it's all a pipe dream. Had they burnt it in an ICE, and come up with those figures then OK. As it is, when using technology that exists now it won't be 5 kg per 500km, it will 25 kg at best, and 500l of this material will be required.

clouddrover 7y ago

> a car may need 5 kg of hydrogen for a range of 500km (bbc's claim, I'll take it at face value) It is about 1kg for 100km range. The Hyundai Nexo Blue has better than 600km range on 6.5kg of hydrogen: https://www.drivingelectric.com/hyundai/nexo/1005/hyundai-nexo-range-battery-charging https://www.drivingelectric.com/hyundai/nexo/1005/hyundai-ne... https://en.wikipedia.org/wiki/Hyundai_Nexo https://en.wikipedia.org/wiki/Hyundai_Nexo