4 ms·

Desalination is not economical for agriculture. Crops like pomegranates, grapes, etc requires large amounts of cheap water.

sologoub 9y ago
It’s not economical because we have not reached the scale needed to make it economical. At the other end of the spectrum, current prices are artificially deflated by aquifer use that’s unsustainable.
- dredmorbius 9y ago
  Costs, ultimately, relate to the resources (and opportunity costs) required to provide or provision something. Desalinisation costs energy, and even with advances in technology, reverse-osmosis processes require moving water across membranes that it doesn't want to move across. And that's on top of everything else, so that you have to deal with pre-filtering and straining (probably through gradations of rock, gravel, and sand filters), and the flushing of those periodically, and other effects. Technology is not some majickal bottomless bag of tricks from which you can extract endless efficiencies. There are limits, constraints within those, risks, and side-effects. And the volumes of water required for crops is large. The more so for tree crops, as mentioned in the article, as they must be watered for their entire lives. (There are orange orchards still producing in Southern California which date from Mission times -- over 200 years ago. Though most orchards have an effective life of about 15 - 40 years or so, if I recall my research on this a few years back.) Contrast alfalfa, another high-water crop, in which, in a predicted dry year, a farmer can simply forgo planting the crop (or allow it to die), without incurring a long-term liability, as the next year's crop would have to be planted afresh anyway.
  - the8472 9y ago
    > as the next year's crop would have to be planted afresh anyway. Isn't alfalfa perennial?
    - dredmorbius 9y ago
      Not my area of expertise, but it seems it's fairly frequently re-seeded: http://farminfo.org/forage/alfalfa.htm http://farminfo.org/forage/alfalfa.htm
  - sologoub 9y ago
    Article states their entire operation uses 400,000 acre-feet of water a year. That’s 645,332,372 cubic-yards. Israel today produces 785 million cubic yards of water per year, using it for agriculture, among other things. [1] From the same article: “Desalination used to be an expensive energy hog, but the kind of advanced technologies being employed at Sorek have been a game changer. Water produced by desalination costs just a third of what it did in the 1990s. Sorek can produce a thousand liters of drinking water for 58 cents. Israeli households pay about US$30 a month for their water — similar to households in most U.S. cities, and far less than Las Vegas (US$47) or Los Angeles (US$58).” At the $0.58 per 1000 liters, that farming operation would require $286 million to pay for the water needed. The article quoted profitability scratching a billion, so it seems that it is both within technological means and economically viable. For sure not as profitable as free water, but still viable. No magic required either. [1]https://www.scientificamerican.com/article/israel-proves-the-desalination-era-is-here/ https://www.scientificamerican.com/article/israel-proves-the...
    - dredmorbius 9y ago
      "...farmers in the Central California Irrigation District near Los Banos (Merced County) paid $17 per acre-foot of water used..." http://www.sfchronicle.com/opinion/article/California-drought-Charge-true-cost-of-water-6319943.php http://www.sfchronicle.com/opinion/article/California-drough... Via GNU units: You have: 17/(acrefoot) You want: /litre * 1.3782124e-05 / 72557.755 Your Israeli desal source is 42,083.499 times more expensive.
      - sologoub 9y ago
        The acre-foot in the desal prices would be $715. All you are proving is that $17 is an unsustainable price and not what non-ag consumers pay at all. California as a landmass has sunk measurably during the few years because of these unsustainable practices. If you were to buy water at real unsubsidized prices in any metro area, you would not be able to find $17/acre-foot.
        dredmorbius 9y ago
- simonh 9y ago
  Just look at pumping costs. There's a reason we generate hydroelectric power from water flowing downstream. Doing the reverse is incredibly energy costly. Also scale only gets you so far. Once you max out the limits of the technology available, increasing scale provides very little extra return.

sologoub 9y ago

It’s not economical because we have not reached the scale needed to make it economical. At the other end of the spectrum, current prices are artificially deflated by aquifer use that’s unsustainable.

dredmorbius 9y ago
Costs, ultimately, relate to the resources (and opportunity costs) required to provide or provision something. Desalinisation costs energy, and even with advances in technology, reverse-osmosis processes require moving water across membranes that it doesn't want to move across. And that's on top of everything else, so that you have to deal with pre-filtering and straining (probably through gradations of rock, gravel, and sand filters), and the flushing of those periodically, and other effects. Technology is not some majickal bottomless bag of tricks from which you can extract endless efficiencies. There are limits, constraints within those, risks, and side-effects. And the volumes of water required for crops is large. The more so for tree crops, as mentioned in the article, as they must be watered for their entire lives. (There are orange orchards still producing in Southern California which date from Mission times -- over 200 years ago. Though most orchards have an effective life of about 15 - 40 years or so, if I recall my research on this a few years back.) Contrast alfalfa, another high-water crop, in which, in a predicted dry year, a farmer can simply forgo planting the crop (or allow it to die), without incurring a long-term liability, as the next year's crop would have to be planted afresh anyway.
- the8472 9y ago
  > as the next year's crop would have to be planted afresh anyway. Isn't alfalfa perennial?
  - dredmorbius 9y ago
    Not my area of expertise, but it seems it's fairly frequently re-seeded: http://farminfo.org/forage/alfalfa.htm http://farminfo.org/forage/alfalfa.htm
- sologoub 9y ago
  Article states their entire operation uses 400,000 acre-feet of water a year. That’s 645,332,372 cubic-yards. Israel today produces 785 million cubic yards of water per year, using it for agriculture, among other things. [1] From the same article: “Desalination used to be an expensive energy hog, but the kind of advanced technologies being employed at Sorek have been a game changer. Water produced by desalination costs just a third of what it did in the 1990s. Sorek can produce a thousand liters of drinking water for 58 cents. Israeli households pay about US$30 a month for their water — similar to households in most U.S. cities, and far less than Las Vegas (US$47) or Los Angeles (US$58).” At the $0.58 per 1000 liters, that farming operation would require $286 million to pay for the water needed. The article quoted profitability scratching a billion, so it seems that it is both within technological means and economically viable. For sure not as profitable as free water, but still viable. No magic required either. [1]https://www.scientificamerican.com/article/israel-proves-the-desalination-era-is-here/ https://www.scientificamerican.com/article/israel-proves-the...
  - dredmorbius 9y ago
    "...farmers in the Central California Irrigation District near Los Banos (Merced County) paid $17 per acre-foot of water used..." http://www.sfchronicle.com/opinion/article/California-drought-Charge-true-cost-of-water-6319943.php http://www.sfchronicle.com/opinion/article/California-drough... Via GNU units: You have: 17/(acrefoot) You want: /litre * 1.3782124e-05 / 72557.755 Your Israeli desal source is 42,083.499 times more expensive.
    - sologoub 9y ago
      The acre-foot in the desal prices would be $715. All you are proving is that $17 is an unsustainable price and not what non-ag consumers pay at all. California as a landmass has sunk measurably during the few years because of these unsustainable practices. If you were to buy water at real unsubsidized prices in any metro area, you would not be able to find $17/acre-foot.
      - dredmorbius 9y ago
simonh 9y ago
Just look at pumping costs. There's a reason we generate hydroelectric power from water flowing downstream. Doing the reverse is incredibly energy costly. Also scale only gets you so far. Once you max out the limits of the technology available, increasing scale provides very little extra return.