4 ms·

You are assuming that electricity is the only cost involved. Based on the numbers in the article, the plant runs at 38-megawatts, consumes 100,000,000 gallons

You are assuming that electricity is the only cost involved. Based on the numbers in the article, the plant runs at 38-megawatts, consumes 100,000,000 gallons of sea-water a day, and produces 1 gallon of drinkable water per 2 gallons of sea-water. Assuming a cost of 15.2 cents/kwh [0] (california seems to be one of the most expensive states), this comes out to an electricity bill of $451.70/acre-foot. A non-trivial portion of the total cost, but there is plenty of room for cost savings without reducing electricity usage. Its also worth keeping in mind that Isreal exists, relies heavily on desalination plants, and is an agricultural exporter so we know the situation is solvable [1] [0] https://www.npr.org/sections/money/2011/10/27/141766341/the-price-of-electricity-in-your-state https://www.npr.org/sections/money/2011/10/27/141766341/the-... [1] Although will likely involve less wasteful agricutlure.

entee 8y ago
Fair enough! I didn't know some of those numbers, maybe there's more hope :)
mabbo 8y ago
> Isreal exists, relies heavily on desalination plants, and is an agricultural exporter so we know the situation is solvable Israel also has a lot of reclamation systems. Most of their sewage gets filtered and the fresh water reused. In most of North America, we give minimal safe treatment to sewage and then dump it back into our water sources. That is a very expensive process, but cheaper than desalination usually. We just need to get over the ick factor.
- loeg 8y ago
  "Gray water" use for irrigation is pretty common in dry areas. I don't know if it used for farms producing food for humans, though.
- atoav 8y ago
  That is interesting to hear, I grew up in the alps, where water plays an important role in my province (90% of the enery comes from water). You can drink the water from the lakes etc. The idea not to perfectly clean the sewage water you created, would sound irresponsible to anybody living here, as the water cycle becomes very apparent even to the craziest right wing nut when you live in the mountains.
  - ctdonath 8y ago
    Political slam unnecessary.
gpm 8y ago
If the primary cost is electricity and not equipment this can double as a "battery" by only running when electricity is cheap, lowering the price further.
synaesthesisx 8y ago
Would it be feasible for a desalination plant to also process and sell sea salt as a byproduct? Alternatively, could the salt be used for molten salt energy storage? Humans have come up with tons of interesting ways to generate and store energy. I think we'll see some truly innovation solutions combining these methods to solve our biggest problems.
- gpm 8y ago
  Desalination typically only raises the concentration by 2 in the non fresh water output. So it would be another process on top of the desalination. Doesn't mean it doesn't make economic sense. Just that it's not an easy win.
  - ggm 8y ago
    Your comment sorted below one saying the KSA has ruined the gulf because of intensive hypersaline solutions in the water. So.. can you help reconcile your optimistic and their pessimistic assumptions? Whats the difference? Gulf doesn't wash out well. Maybe the dumped water doesn't disperse?
    - gpm 8y ago
      There was an article on this not too long ago on HN with a good comments section, you should be able to find it by searching. From what I recall the situation is basically - Locally it doesn't disperse fast enough, 2x is a lot when talking about sealife. - They add copper (and maybe some other stuff) to prevent fouling of the pipes, which is bad for you.
- ShorsHammer 8y ago
  The brine waste from desal is full of nasty stuff you don't want concentrated even further and sold as food. Removing the long list of chemicals and heavy metals is not going to be viable costwise and even the most foolhardy consumer would think twice over regular salt. A responsible desal plant does studies on how to pump and disperse it in the ocean as best possible. Sadly in the gulf the Saudis aren't doing this and have completely ruined the local ecosystem. https://www.bloomberg.com/news/articles/2019-01-08/saudi-thirst-for-water-is-seen-creating-a-toxic-brine-problem https://www.bloomberg.com/news/articles/2019-01-08/saudi-thi...
Alex3917 8y ago
> Its also worth keeping in mind that Isreal exists, relies heavily on desalination plants, and is an agricultural exporter so we know the situation is solvable https://www.aljazeera.com/news/2016/06/israel-water-tool-dominate-palestinians-160619062531348.html https://www.aljazeera.com/news/2016/06/israel-water-tool-dom...

entee 8y ago

Fair enough! I didn't know some of those numbers, maybe there's more hope :)

mabbo 8y ago

> Isreal exists, relies heavily on desalination plants, and is an agricultural exporter so we know the situation is solvable Israel also has a lot of reclamation systems. Most of their sewage gets filtered and the fresh water reused. In most of North America, we give minimal safe treatment to sewage and then dump it back into our water sources. That is a very expensive process, but cheaper than desalination usually. We just need to get over the ick factor.

loeg 8y ago
"Gray water" use for irrigation is pretty common in dry areas. I don't know if it used for farms producing food for humans, though.
atoav 8y ago
That is interesting to hear, I grew up in the alps, where water plays an important role in my province (90% of the enery comes from water). You can drink the water from the lakes etc. The idea not to perfectly clean the sewage water you created, would sound irresponsible to anybody living here, as the water cycle becomes very apparent even to the craziest right wing nut when you live in the mountains.
- ctdonath 8y ago
  Political slam unnecessary.

gpm 8y ago

If the primary cost is electricity and not equipment this can double as a "battery" by only running when electricity is cheap, lowering the price further.

synaesthesisx 8y ago

Would it be feasible for a desalination plant to also process and sell sea salt as a byproduct? Alternatively, could the salt be used for molten salt energy storage? Humans have come up with tons of interesting ways to generate and store energy. I think we'll see some truly innovation solutions combining these methods to solve our biggest problems.

gpm 8y ago
Desalination typically only raises the concentration by 2 in the non fresh water output. So it would be another process on top of the desalination. Doesn't mean it doesn't make economic sense. Just that it's not an easy win.
- ggm 8y ago
  Your comment sorted below one saying the KSA has ruined the gulf because of intensive hypersaline solutions in the water. So.. can you help reconcile your optimistic and their pessimistic assumptions? Whats the difference? Gulf doesn't wash out well. Maybe the dumped water doesn't disperse?
  - gpm 8y ago
    There was an article on this not too long ago on HN with a good comments section, you should be able to find it by searching. From what I recall the situation is basically - Locally it doesn't disperse fast enough, 2x is a lot when talking about sealife. - They add copper (and maybe some other stuff) to prevent fouling of the pipes, which is bad for you.
ShorsHammer 8y ago
The brine waste from desal is full of nasty stuff you don't want concentrated even further and sold as food. Removing the long list of chemicals and heavy metals is not going to be viable costwise and even the most foolhardy consumer would think twice over regular salt. A responsible desal plant does studies on how to pump and disperse it in the ocean as best possible. Sadly in the gulf the Saudis aren't doing this and have completely ruined the local ecosystem. https://www.bloomberg.com/news/articles/2019-01-08/saudi-thirst-for-water-is-seen-creating-a-toxic-brine-problem https://www.bloomberg.com/news/articles/2019-01-08/saudi-thi...

Alex3917 8y ago

> Its also worth keeping in mind that Isreal exists, relies heavily on desalination plants, and is an agricultural exporter so we know the situation is solvable https://www.aljazeera.com/news/2016/06/israel-water-tool-dominate-palestinians-160619062531348.html https://www.aljazeera.com/news/2016/06/israel-water-tool-dom...