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> Or just sell it as salt? We use, I don’t know, billions of pounds of salt per year in food production? Are you sure the math even remotely checks out? Just l

> Or just sell it as salt? We use, I don’t know, billions of pounds of salt per year in food production? Are you sure the math even remotely checks out? Just looking up some numbers, even if we naively assume ocean "saltwater" is just H2O + NaCl (which it obviously isn't): the world consumes around 300 billion kg salt/year, whereas (say) Los Angeles alone uses 700 billion kg water/year. So even if a city like LA provides for the whole world's use of salt, what does everyone else do?

raducu 3y ago
I'm sorry, perhaps my engineering education makes me handwave at problems -- but the water we're desalinating has to return to the ocean someway, it's not like we throw it into black holes, why can't we just dump the brine 20 miles into the ocean, the water we've desalinated will return by other means.
imgabe 3y ago
You’re assuming we need to get 100% of our water from desalination when it would only need to cover any shortfall from other methods. We’re currently getting 100% of the water we need from those other methods.
- dataflow 3y ago
  Really depends who "we" is. Israel gets 75% of its water from desalination already, and that's just right now. And a lot of the other water sources right now are nonrenewable (groundwater, etc.), hence a big part of the motivation to look for new ones in the first place. The current situation is not sustainable on its own in many parts of the world, let alone the effects of dramatically increasing population sizes and global warming.
jfk13 3y ago
According to a quick Google search, > On average, about 35 g of salt is present in each 1 kg of seawater so if those 700 billion kg of water for LA all came from desalination, that would yield 24.5 billion kg of salt. That suggests we could have 12 LA-sized cities relying entirely on desalination before we'd saturate the world's demand for salt.
- dataflow 3y ago
  > That suggests we could have "Could have" is doing a lot of heavy lifting there. Assuming spherical cows, 12 is an upper limit, okay. What you could actually do is neither remotely close to that nor is that itself remotely close to what the world needs, was the point.
- BurningFrog 3y ago
  The demand for salt is already saturated. It's a mature worldwide industry. Adding your 12 cities would double the supply.
  - mxmilkiib 3y ago
    Salt filled with micro/nanoplastics.

raducu 3y ago

I'm sorry, perhaps my engineering education makes me handwave at problems -- but the water we're desalinating has to return to the ocean someway, it's not like we throw it into black holes, why can't we just dump the brine 20 miles into the ocean, the water we've desalinated will return by other means.

imgabe 3y ago

You’re assuming we need to get 100% of our water from desalination when it would only need to cover any shortfall from other methods. We’re currently getting 100% of the water we need from those other methods.

dataflow 3y ago
Really depends who "we" is. Israel gets 75% of its water from desalination already, and that's just right now. And a lot of the other water sources right now are nonrenewable (groundwater, etc.), hence a big part of the motivation to look for new ones in the first place. The current situation is not sustainable on its own in many parts of the world, let alone the effects of dramatically increasing population sizes and global warming.

jfk13 3y ago

According to a quick Google search, > On average, about 35 g of salt is present in each 1 kg of seawater so if those 700 billion kg of water for LA all came from desalination, that would yield 24.5 billion kg of salt. That suggests we could have 12 LA-sized cities relying entirely on desalination before we'd saturate the world's demand for salt.

dataflow 3y ago
> That suggests we could have "Could have" is doing a lot of heavy lifting there. Assuming spherical cows, 12 is an upper limit, okay. What you could actually do is neither remotely close to that nor is that itself remotely close to what the world needs, was the point.
BurningFrog 3y ago
The demand for salt is already saturated. It's a mature worldwide industry. Adding your 12 cities would double the supply.
- mxmilkiib 3y ago
  Salt filled with micro/nanoplastics.