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> If desalination was cost effective it would be being done today at scale. It is being done at scale in places like Israel. It doesn't even need base load pow

> If desalination was cost effective it would be being done today at scale. It is being done at scale in places like Israel. It doesn't even need base load power, you could run it with the infinite amount of cheap solar energy available in the Southwest. The only reason it isn't being done is places like California is entirely regulatory. In fact Arizona might get there first, there has been recent progress between them and Mexico to do desalination in the Sea of Cortez, which is only 60 miles from the Arizona boarder.

anon84873628 2y ago
Sounds like a great way to destroy one of the most diverse and unique marine ecosystems on the planet, thanks to the brine waste.
- kylebenzle 2y ago
  It's a funny problem. Too expensive to pump it WAY out to sea, but too salty to be of any use?
- linotype 2y ago
  Couldn’t you pump the brine waste into evaporation ponds and extract lithium and other materials from it?
  - cpeterso 2y ago
    Could we convert the brine waste to building materials? Truck it out to the desert and build a giant salt pyramid.
- BurningFrog 2y ago
  I'd have to see some real math to be convinced extracting fresh water from the ocean could raise salt levels enough to destroy the Sea of Cortez ecosystems.
  - alistairSH 2y ago
    Reasonable summary… https://www.wired.com/story/desalination-is-booming-but-what-about-all-that-toxic-brine/ https://www.wired.com/story/desalination-is-booming-but-what... Hard numbers aren’t readily available because we don’t track discharge consistently (or at least didn’t). And it’s not just the salt in the brine, but remnants of the chemicals used to defoul the RO systems. The brine waste is nasty stuff and absolutely deadly to the local environment where it’s discharged.
- mlsu 2y ago
  No no no, you don't understand. We'll remove it from the environment. So the environment will be safe -- the byproducts will be disposed of outside of the environment!
  - burnte 2y ago
    Well what's out there?
    - xp84 2y ago
      Nothing’s out there. All there is out there is sea, and birds and fish. And 20,000 tons of waste brine.
  - teractiveodular 2y ago
    Downvoters clearly haven't seen the legendary "the front fell off" video: https://youtu.be/3m5qxZm_JqM?feature=shared https://youtu.be/3m5qxZm_JqM?feature=shared
- credit_guy 2y ago
  I heard this concern many times. But with so many desalination plants already built, there must have been some environmental impact studies. I googled around and found one for the Carlsbad desalination plant in San Diego [1]. On page 66 you find this: > Concerns over marine life are also associated with increased salinity levels and exposure to high-saline water (brine). The proposed CDP modifications have been designed through an extensive process to minimize the impacts of mortality of fish species and larvae as part of the submittal to and requirements of the RWQCB. On page 85 you find that the average salinity prior to dilution is between 64 and 67 ppt (parts per thousand). Once it's diluted, it becomes 42 ppt and discharged in the sea. The average salinity of the sea in that region is 33.5 ppt with a natural variability of 4 ppt. On page 150 you find out that the salinity of the discharge drops from the 42 ppt to withint 2ppt of the ambient within a circle of 200 meters radius from the discharge point. That zone is called the Brine Mixing Zone, and it has area of 15.5 acres. [1] https://www.sdcwa.org/wp-content/uploads/2020/11/Final-SEIR-Carlsbad-Desalination-Plant_SDCWA_Certified.pdf https://www.sdcwa.org/wp-content/uploads/2020/11/Final-SEIR-...
skybrian 2y ago
According to the article, intermittent operation is assuming new desalinization technology that needs to be invented: > Current RO plants cost more like $2000/kW, so they’re both financially and technically unsuited to intermittent operation, which fatigues their membranes. Thermal desalination could achieve radically lower cost, albeit at lower energy efficiencies, so there’s work to be done here designing new, low cost desalination machines that fully exploit the upside of cheap solar PV. And that’s largely the point of the article. It’s not being done yet, but he thinks it’s technically feasible and could be a game-changer. Big if true. It’s not something we should plan on until the technology is further developed, but seems like worthwhile R&D to fund.

anon84873628 2y ago

Sounds like a great way to destroy one of the most diverse and unique marine ecosystems on the planet, thanks to the brine waste.

kylebenzle 2y ago
It's a funny problem. Too expensive to pump it WAY out to sea, but too salty to be of any use?
linotype 2y ago
Couldn’t you pump the brine waste into evaporation ponds and extract lithium and other materials from it?
- cpeterso 2y ago
  Could we convert the brine waste to building materials? Truck it out to the desert and build a giant salt pyramid.
BurningFrog 2y ago
I'd have to see some real math to be convinced extracting fresh water from the ocean could raise salt levels enough to destroy the Sea of Cortez ecosystems.
- alistairSH 2y ago
  Reasonable summary… https://www.wired.com/story/desalination-is-booming-but-what-about-all-that-toxic-brine/ https://www.wired.com/story/desalination-is-booming-but-what... Hard numbers aren’t readily available because we don’t track discharge consistently (or at least didn’t). And it’s not just the salt in the brine, but remnants of the chemicals used to defoul the RO systems. The brine waste is nasty stuff and absolutely deadly to the local environment where it’s discharged.
mlsu 2y ago
No no no, you don't understand. We'll remove it from the environment. So the environment will be safe -- the byproducts will be disposed of outside of the environment!
- burnte 2y ago
  Well what's out there?
  - xp84 2y ago
    Nothing’s out there. All there is out there is sea, and birds and fish. And 20,000 tons of waste brine.
- teractiveodular 2y ago
  Downvoters clearly haven't seen the legendary "the front fell off" video: https://youtu.be/3m5qxZm_JqM?feature=shared https://youtu.be/3m5qxZm_JqM?feature=shared
credit_guy 2y ago
I heard this concern many times. But with so many desalination plants already built, there must have been some environmental impact studies. I googled around and found one for the Carlsbad desalination plant in San Diego [1]. On page 66 you find this: > Concerns over marine life are also associated with increased salinity levels and exposure to high-saline water (brine). The proposed CDP modifications have been designed through an extensive process to minimize the impacts of mortality of fish species and larvae as part of the submittal to and requirements of the RWQCB. On page 85 you find that the average salinity prior to dilution is between 64 and 67 ppt (parts per thousand). Once it's diluted, it becomes 42 ppt and discharged in the sea. The average salinity of the sea in that region is 33.5 ppt with a natural variability of 4 ppt. On page 150 you find out that the salinity of the discharge drops from the 42 ppt to withint 2ppt of the ambient within a circle of 200 meters radius from the discharge point. That zone is called the Brine Mixing Zone, and it has area of 15.5 acres. [1] https://www.sdcwa.org/wp-content/uploads/2020/11/Final-SEIR-Carlsbad-Desalination-Plant_SDCWA_Certified.pdf https://www.sdcwa.org/wp-content/uploads/2020/11/Final-SEIR-...

skybrian 2y ago

According to the article, intermittent operation is assuming new desalinization technology that needs to be invented: > Current RO plants cost more like $2000/kW, so they’re both financially and technically unsuited to intermittent operation, which fatigues their membranes. Thermal desalination could achieve radically lower cost, albeit at lower energy efficiencies, so there’s work to be done here designing new, low cost desalination machines that fully exploit the upside of cheap solar PV. And that’s largely the point of the article. It’s not being done yet, but he thinks it’s technically feasible and could be a game-changer. Big if true. It’s not something we should plan on until the technology is further developed, but seems like worthwhile R&D to fund.