Comment on Japan Just Switched on Asia’s First Osmotic Power Plant, Which Runs 24/7 on Nothing But Fresh Water and Seawater

sbv@sh.itjust.works ⁨3⁩ ⁨weeks⁩ ago

• treadful@lemmy.zip ⁨3⁩ ⁨weeks⁩ ago

  Using it to run desalination is confusing.

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  • thann@lemmy.dbzer0.com ⁨3⁩ ⁨weeks⁩ ago

    I created fresh water using nothing but sea water, a membrane, and fresh water.

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    • cmnybo@discuss.tchncs.de ⁨3⁩ ⁨weeks⁩ ago

      Fresh water doesn’t mean drinkable water, it just means not salt water. The desalination plant produces drinkable water.

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    • frongt@lemmy.zip ⁨3⁩ ⁨weeks⁩ ago

      It sounds like they’re not quite using fresh water, but waste water. I presume it’s been treated, but even if it’s not 100% back to potable, if this also helps solve the problem of what to do with the brine after desalination, I think it’s a win all around.

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• AmidFuror@fedia.io ⁨3⁩ ⁨weeks⁩ ago

  This seems like a terrible use, since these plants work by mixing fresh water with seawater (or in this case the brine leftover from desalination). I guess the catch is they can use treated wastewater instead of potable water.

  This method gains very little net energy compared to other renewables.

  “While energy is released when the salt water is mixed with fresh water, a lot of energy is lost in pumping the two streams into the power plant and from the frictional loss across the membranes. This means that the net energy that can be gained is small,” said Kentish.

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  • underline960@sh.itjust.works ⁨3⁩ ⁨weeks⁩ ago

    Why do it, then?

    Is this a proof of concept/MVP build, so they can iterate more efficient versions? A vanity project? A mistake?

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    • thebestaquaman@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

      Because osmotic power has enormous potential in the sense that millions of cubic meters of fresh water is running into oceans all over the world every minute. If we’re able to get even a low-efficiency method of using the salinity gradient to generate power working then every place a river meets the sea is essentially an unlimited (albeit low-yield) power source.

      This is tech that doesn’t rely on elevation (like hydropower) or weather conditions (like wind/solar) it’s stable and possible to set up at pretty much any river outlet, which is great!

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      • tyler@programming.dev ⁨3⁩ ⁨weeks⁩ ago

        Gotta be careful about ecosystems though. River deltas are incredibly important and fragile areas.

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    • GreyEyedGhost@lemmy.ca ⁨3⁩ ⁨weeks⁩ ago

      Turning unpotable water into potable water with little or no additional cost, while not harming the environment, isn’t exactly a loss.

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  • AmidFuror@fedia.io ⁨3⁩ ⁨weeks⁩ ago

    Returning to this thread long after everyone has moved on.

    How do you get enough net energy out of mixing brine from desalination with fresh water to use to separate saltwater into brine and fresh water? Especially when the energy producing method is already known to have poor efficiency?

    This seems like this is just terrible at converting treated wastewater into drinking water. Must have something to do with government subsidies instead.

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• sexy_peach@feddit.org ⁨3⁩ ⁨weeks⁩ ago

  Finally, power at night, when everyone’s asleep and we always have had excess.

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  • Kolanaki@pawb.social ⁨3⁩ ⁨weeks⁩ ago

    Me who is up all night using up the excess power

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  • frank@sopuli.xyz ⁨3⁩ ⁨weeks⁩ ago

    This is a very old school and outdated mentality.

    In my part of the EU this year, we had very very many days of negative sale prices and having to curtail wind parks because just solar and wind were making up more than demand during the day. Afaik we only curtailed at night one time.

    Source: wrote curtailment algorithms for wind turbines

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    • sexy_peach@feddit.org ⁨3⁩ ⁨weeks⁩ ago

      Do you mean my mentality or the one of the new technology?

      It’s not necessary to produce power 24/7 since demand isn’t 24/7 either. Strong peaks and valleys.

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      • frank@sopuli.xyz ⁨3⁩ ⁨weeks⁩ ago

        Your mentality is old school. We have often more need at night than during the day for non renewable electricity right now

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  • hark@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

    That’s when my electric car is plugged in and taking up quite a bit of power.

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    • sexy_peach@feddit.org ⁨3⁩ ⁨weeks⁩ ago

      That’s when it should be plugged in.

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      • nulluser@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

        So, then why are you confused about what’s using power at night?

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  • shplane@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

    The energy can be stored for use for later during the day

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