5 ms·

>Indoor farming would not have to worry about things like drought. As a water feeding system can be led all the way to the ocean and the salt removed using pure

by xxpor 6y ago

>Indoor farming would not have to worry about things like drought. As a water feeding system can be led all the way to the ocean and the salt removed using pure sunlight as power. Are you aware of how much water it takes to produce the output of the Midwest or Central Valley? We'd be talking about the largest desalination project in human history by orders of magnitude. As of 2013, Israel had a desalination capacity of 500 million cubic meters per year. https://en.wikipedia.org/wiki/Water_supply_and_sanitation_in_Israel#Seawater_desalination https://en.wikipedia.org/wiki/Water_supply_and_sanitation_in... As of 2015, the US used ~450 million (edit: fixed from billion) cubic meters PER DAY for irrigation. https://www.usgs.gov/mission-areas/water-resources/science/irrigation-water-use?qt-science_center_objects=0#qt-science_center_objects https://www.usgs.gov/mission-areas/water-resources/science/i... Obviously not exactly a fair comparison for numerous reasons, but it gives a sense of the scale we're talking about here.

credit_guy 6y ago
> As of 2015, the US used ~450 billion cubic meters PER DAY for irrigation I think you mean to say 450 billion liters, which would be 450 million cubic meters. Your source says this: "For 2015, total irrigation withdrawals were 118,000 Mgal/d" So roughly speaking Israel desalinates in a year how much the US uses for irrigation in one day. That doesn't sound so outrageous. Israel is a small country.
- xxpor 6y ago
  Ah you're right, I read the wrong line in the wolfram alpha output. That does make it seem less crazy. It would still be a crazy project but not "entire GDP of the US" crazy.
jedberg 6y ago
Israel coastline: 171 miles US coastline (not including Alaska): 5,800 miles So the US has 33 times the coastline. It sounds like we're only one order of magnitude off to meet those desal needs. ps. If we include Alaska, which is another 6,600 miles of coastline, we could again halve that need.
- Retric 6y ago
  Coastline distance is irrelevant, you could use a single mile of coastline to extract this much water. The issue is infrastructure and energy costs. Traditional irrigation is about 3 orders of magnitude cheaper than desalination. All those rivers dumping into the ocean demonstrate how rarely it’s needed. Long term pumping water from the eastern US to the Midwest is vastly cheaper than the kind of massive and effectively pointless desalination effort required.
tomatotomato37 6y ago
You know if we are already going through the effort of transporting & stacking dirt vertically for these things we might as well go all the way and integrate them into the pylons of offshore wind turbines, which'll guarantee them a viable support structure, an infinite amount of available seawater & more than enough power to desalinate it locally. Heck, the harvest logistics means it'll give fishing boats something to do off-season too.
newyankee 6y ago
If your nos are correct and if desalination was done at the scale of Israel in US, it would mean it would be able to provide 10% of the irrigation needs via desalination. This is off course not a big deal in USA and desalination and economics of certain agri crops if reassigned can lead to better outcomes. However i am sure India can do with the level of desalination Israel has (scaled up to its population size) as can other middle Eastern countries. If not today, then may be a decade or 2 in the future. This can enable habitation in many areas in land and water scarce countries.
pas 6y ago
So with indoor farming let's say you'd only need 5-10% of that, right? That suddenly makes it basically the same magnitude.
- xxpor 6y ago
  We'd only need 5-10% of the water? That might be possible, I don't know enough about it to say for sure. I could see us needing somewhat less just due to evaporation differences, but I'd think plants need basically the same amount of water to do what they do regardless. How do we get down to 5-10%?
  - pas 6y ago
    I don't know how, but a different post claimed that indoor farming needs 97% less water. I imagine it has something to do with using a closed loop. (And the remaining percents are obviously due to imperfections, and the actual water content lost due to the removal of the produce from the loop.)

by xxpor 6y ago

credit_guy 6y ago

> As of 2015, the US used ~450 billion cubic meters PER DAY for irrigation I think you mean to say 450 billion liters, which would be 450 million cubic meters. Your source says this: "For 2015, total irrigation withdrawals were 118,000 Mgal/d" So roughly speaking Israel desalinates in a year how much the US uses for irrigation in one day. That doesn't sound so outrageous. Israel is a small country.

xxpor 6y ago
Ah you're right, I read the wrong line in the wolfram alpha output. That does make it seem less crazy. It would still be a crazy project but not "entire GDP of the US" crazy.

jedberg 6y ago

Israel coastline: 171 miles US coastline (not including Alaska): 5,800 miles So the US has 33 times the coastline. It sounds like we're only one order of magnitude off to meet those desal needs. ps. If we include Alaska, which is another 6,600 miles of coastline, we could again halve that need.

Retric 6y ago
Coastline distance is irrelevant, you could use a single mile of coastline to extract this much water. The issue is infrastructure and energy costs. Traditional irrigation is about 3 orders of magnitude cheaper than desalination. All those rivers dumping into the ocean demonstrate how rarely it’s needed. Long term pumping water from the eastern US to the Midwest is vastly cheaper than the kind of massive and effectively pointless desalination effort required.

tomatotomato37 6y ago

You know if we are already going through the effort of transporting & stacking dirt vertically for these things we might as well go all the way and integrate them into the pylons of offshore wind turbines, which'll guarantee them a viable support structure, an infinite amount of available seawater & more than enough power to desalinate it locally. Heck, the harvest logistics means it'll give fishing boats something to do off-season too.

newyankee 6y ago

If your nos are correct and if desalination was done at the scale of Israel in US, it would mean it would be able to provide 10% of the irrigation needs via desalination. This is off course not a big deal in USA and desalination and economics of certain agri crops if reassigned can lead to better outcomes. However i am sure India can do with the level of desalination Israel has (scaled up to its population size) as can other middle Eastern countries. If not today, then may be a decade or 2 in the future. This can enable habitation in many areas in land and water scarce countries.

pas 6y ago

So with indoor farming let's say you'd only need 5-10% of that, right? That suddenly makes it basically the same magnitude.

xxpor 6y ago
We'd only need 5-10% of the water? That might be possible, I don't know enough about it to say for sure. I could see us needing somewhat less just due to evaporation differences, but I'd think plants need basically the same amount of water to do what they do regardless. How do we get down to 5-10%?
- pas 6y ago
  I don't know how, but a different post claimed that indoor farming needs 97% less water. I imagine it has something to do with using a closed loop. (And the remaining percents are obviously due to imperfections, and the actual water content lost due to the removal of the produce from the loop.)