Technology sucks liquid out of the air to provide safe drinking water

November 1, 2024 10:18 PM

Technology sucks liquid out of the air to provide safe drinking water for an entire remote town. Children living in a remote, desert-like town in north-western NSW can fill their drink bottles with safe, chilled water sucked out of the air by hydropanels at their school.
posted by chariot pulled by cassowaries (13 comments total)

They add in calcium and magnesium, but I'd worry that long-term there are other minerals that are missing from the distilled water pulled out of the air .. still a really great story, and it sounds like they are serious about reducing plastic waste from bottled water which is a very good thing. We'll probably need more of these systems in more places soon, it's all very Tatooine.
posted by subdee at 12:47 AM on November 2 [1 favorite]

The 10-hydropanel system at Goodooga cost about $50,000 to purchase and install and was predicted to last at least 15 years.

So let's say 4k a year, which will cover a bit of maintenance over that time. No matter how small the school is this seems like a no brainer of an investment.

Now, I know nothing about anything, but I wonder if taking ambient moisture out of the air, even in an extremely dry climate (particularly in an extremely dry climate?), has any downstream effects that we need to be worried about.
posted by Literaryhero at 4:12 AM on November 2 [1 favorite]

"Come and have supper tonight, my friend. I'll make some vegetable stew. Let's talk about building our own condenser."
posted by xedrik at 8:48 AM on November 2 [2 favorites]

Hope they got some droids that speak moisture vaporator.
posted by dirigibleman at 10:00 AM on November 2 [4 favorites]

Why can’t Nestlé and Danone just do this instead of sucking up all the springs in all the poorest counties of the eastern United States?
posted by toodleydoodley at 11:07 AM on November 2

Because on a per litre basis this is easily an order of magnitude more expensive.
posted by Mitheral at 11:42 AM on November 2 [1 favorite]

Literaryhero, water loss by evaporation (from soil or animal tissues) or evapotranspiration (while plants photosynthesize) is faster when the atmosphere is drier. So technically yes.

If the captured water is promptly drunk and then sweated or eliminated there, so it goes back into the atmosphere, I think no net change. If it’s exported, like we export water in fresh veg or dairy, increased aridification.
posted by clew at 12:19 PM on November 2 [2 favorites]

So, water vapor is itself a greenhouse gas. I asked a climate scientist once if deploying these at scale could punch holes in the infrared opacity of the local air and have a cooling effect. He was dubious, but if you run these at night, draw enough vapor out of the air to push more infrared out, and then bring temperatures down to the dew point, you get yet more water falling to the ground and a virtuous cycle going (albeit briefly).
posted by ocschwar at 8:54 AM on November 3

And apropos LiteraryHero, we should bear in mind the Callendar Effect:

More CO2 -> more heat.
More heat -> more evaporation.
More evaporation -> more water vapor.
More water vapor -> more greenhouse effect.
More greenhouse effect -> more heat.

The Callendar Effect is the real reason you need computers for climate modeling. Otherwise you could calculate the warming effect on scratch paper (which Svante Arrhenius did in 1894).

So we've already caused the atmosphere to be more humid, and making it less so is undoing our own work.
posted by ocschwar at 9:04 AM on November 3

In these places we have not caused the atmosphere to be more humid. We expect global heating to cause desertification some places while it swamps many more.

I think the vapor-blanket effect mostly happens way up in the atmosphere, probably not reachable by this scale of thing, but “kicking it off at night” in places that aren’t deserts and don’t therefore already radiate at night is a delightful idea. Steerable balloons dragging veils of micromesh to induce condensation?
posted by clew at 9:31 AM on November 3

> Why can’t Nestlé and Danone just do this instead of sucking up all the springs in all the poorest counties of the eastern United States?

That's an easy one: This technology is going to cost an order of magnitude or two more than just slurping up "free" water from a spring or whatever.

Capitalism is all about reducing cost, so they are always going to take the lowest-cost source for their product until forced to do otherwise for some reason or other.
posted by flug at 11:58 AM on November 3

In hot humid places that would be “drinking the air conditioner drips”, right? Why is that not a dual-use energy win? I know air conditioner water is usually icky, but is it that way at condensation?
posted by clew at 1:29 PM on November 3

So this is called a passive system in the article.

That to me means it does not run at night, and probably only poorly when cloudy.

I’d be curious to see how that plays out.

Or maybe I’m misunderstanding what they mean by passive system.
posted by teece303 at 9:57 AM on November 4