• Ephera
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    11 days ago

    I’ve usually heard that hydrogen is not worth it for storing energy, because the conversion is really lossy, so I thought maybe they want to export it. And then the article says that exporting isn’t worth it either. 🫠

    I’m sure, there’s niche use-cases where hydrogen really is the best solution, but I don’t know, is South Australia really that close to cracking that ‘conundrum’, just because they’ve got a lot of spare energy? You’d still want to be reasonably efficient with how you use that spare energy, to get the most value and/or money out of it…

    • Mountaineer@aussie.zone
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      11 days ago

      It’s definitely not worth using full price electricity to split hydrogen out of water, if your intention is to turn that hydrogen back into electricity through some method (fuel cell, internal combustion engine, steam turbine, whatever).

      But if the electricity was otherwise going to be discarded (as is currently the case practically daily in SA), that cost/benefit gets crazy.

      Wikipedia has 3 links indicating around 70% efficiency on the electrolysis.
      https://en.wikipedia.org/wiki/Hydrogen_production#Electrolysis_of_water_–_green,_pink_or_yellow

      Let’s flip that around and pretend it’s only 30% efficient, because we need to turn it back into electricity afterwards, and rather than quibble about exact efficiencies/losses, I’d rather exaggerate the loss for a theoretical worst case.

      That’s still X amount of electricity saved for later use, that would have otherwise have just been switched off.
      And that’s especially useful when your primary source is not available (ie, solar in the middle of the night).

      • Ephera
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        11 days ago

        Well, for storing it for the night, I typically hear that battery or saline storage is much more efficient (something like 60% efficiency for the whole cycle of storing and retrieving).

        So, unless it’s much more expensive to build this battery/saline storage, it seems like it’d only be economical to blow it on hydrogen, if you’ve got your storage filled up for the night + somewhat of a buffer.
        I guess, this theory might be void, if companies are willing to pay a lot of money for hydrogen. Some industries do strictly need hydrogen for chemical processes, so I guess, those would pay…

        • Mountaineer@aussie.zone
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          5 days ago

          I think you’re right, hydrogen is ludicrous, and bang for buck, some other tech will win out for time shifting the power, probably pumped hydro.

          edit to add: Hydrogen is ludicrous in the primary context of a battery. There’s other potential uses such as making steel, making ammonia/fertilizer etc that could change the equation again. Hell, you might even find it desirable to make it HERE and transport it THERE as a battery, but again, the maths are currently wrong.

    • Agent641@lemmy.world
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      10 days ago

      There are underground hydrogen reserves in SA, but I don’t know if this is being used in the story.