Engineers invent high-yield atmospheric water capture device for arid regions | Hacker News Reader

Engineers invent high-yield atmospheric water capture device for arid regions

techxplore.com

17 pointsPaulHoule9 comments

Devil is always in the details. If solar power is all you need, are there any other maintenance or running costs and how high are they? How much does it cost to make this medium (hydrogel membrane) that is used to draw out the water?

Also, based on the paper it looks like this would be more efficient and have greater utility somewhere like the Persian Gulf states, Northern Australia or other places that are consistently sunny and have high humidity.

Makes you wonder if you could do this to stop global warming. After all, global warming is a feedback loop, almost 100% running on water vapor. Remove water vapor will do a lot more than anything else. And you don't have to actually remove the gases that are already there, which is the (energy) expensive part. You just have to make it turn back for long enough, probably only a few months, after which the feedback loop would take over.

But that also points out a big problem with doing so. Reversing global warming will dry the atmosphere, A LOT. And once it starts reversing, it will rapidly accelerate, both rapidly cooling and rapidly drying out very large areas of the globe.

> After all, global warming is a feedback loop, almost 100% running on water vapor.

The positive feedback part kicks in with water vapor and methane after thresholds are crossed - for now the preamble heavy lifting to approach thresholds has been done by a century of what has now ramped up to an addition 11 billion tonnes per annum of additional C02 added by human activity that's over and above the 'normal' (for past 200K+ years) carbon cycle of volcanoes, fires, and organic growth and decay.

We're quite away from "almost 100% running on water vapor" to date.

“Thermal Equilibrium of the Atmosphere with a Given Distribution of Relative Humidity” Manabe, Wetherald (1967) https://journals.ametsoc.org/view/journals/atsc/24/3/1520-04...

By the time we get to a majority positive feedback loop it may well be too late to reverse .. that's one of the intriguing mysteries to complex non linear dynamics.

That still means global warming should (rapidly) reverse just as soon as we get enough water vapor out of the atmosphere to reverse the effect of 11b tonnes CO2 for ~a year. If you can do that, the year after that, more water should be removed from the atmosphere without interference, and then the year after that, and so on.

I wonder how much that is.

> That still means global warming should ..

Does it? Got a paper that expands on that thinking?

> If you can do that, the year after that, more water should be removed from the atmosphere without interference

Same question really.

> I wonder how much that is.

If only you had a model, some data, some equations, etc.

s/Engineers/Fremen/

Is there a useful product I can buy to turn my excess solar electricity into water where the air isn't quite so dry? Around here, particularly in the mornings, the humidity is quite high and practically all surfaces condense water out of the air. I'd love to capture some deliberately.

There are two options: 1. purchase a 12v refrigerator and turn it on when the dewpoint is achievable by the fridge and then run air though a baffled pathway within the fridge to capture the water that condenses out. 2. Use zeolite to adsorb water from the air and then boil it off with heat produced from your solar panels and recollect the water. I believe you can purchase units that do just this from https://www.skywater.com/

Reminder that the efficiency of such a device has a hard bound given by the laws of thermodynamics which doesn't depend on implementation details.

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