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Comment by zubairq | Hacker News Reader

Amazing! Is this a game changer?

Probably not. It's more expensive than available alternatives (according to the article they use expensive materials) and the performance is poor compared to commercially available alternatives.

Might be useful for certain niche applications, but outside of that it's more of a proof of concept at this point.

Maybe. I think Atmospheric Water Generators are much More likely to change the game since they don’t need a body of water other than the atmosphere.

“Atmospheric Water Generators”

At first I thought you were just using a marketing term for dehumidifiers but I looked it up before posting.

I see that term is used for tight mesh fabric that’s hung vertically as a passive matrix to collect condensation.

While those are actually game changers, they unfortunately only work in special regions that have the needed weather and topography to make them work.

I think there’s only one place on earth that has the perfect combination for AWG: weather, drought, and humidity. It’s an awesome technology for them but that’s about the extent of it.

I’ll try to find the region and update my comment with more info.

Edit: here’s a video that talks about what I think you’re talking about.

https://youtu.be/YxRONAZoMDk

It’s providing water in the Atacama Desert near Lima Peru.

Edit 2: They’re called fog collectors and apparently Morocco uses them too. https://youtu.be/0F7CQMd6mQ4

> It’s providing water in the Atacama Desert near Lima Peru.

I think one big issue is that in winter (May-September) not every day is foggy, so sure its helpful but not a perfect solution. It does get really foggy though in June-October. Thus we get natural vegetation in otherwise arid hills around Lima, the most popular called Lomas de Lachay[0].

[0] https://en.wikipedia.org/wiki/Lachay_National_Reserve

Atmospheric water generation (AWG) uses technology to produce potable water from surrounding air.

Here's a cool example of using the sun to do just that...

https://youtu.be/VQRAtwz3Igs

https://en.m.wikipedia.org/wiki/Atmospheric_water_generator

I wonder if you could use a similar sort of device with weather balloons to harvest water from clouds.

I could totally see a Project Loon style craft which automatically surfs the crosswinds, going up above the clouds to radiate heat to the open sky at night, and descending to condense water.

Would dry regions that need water have enough cloud coverage for that to be viable?

My guess is that any place with sufficient cloud coverage is already getting enough rain water to satisfy their needs.

I think there are parts of coastal California where there are clouds more of the year than rainfall. I'd also suspect if you just raised them up with balloons to cool them off and then brought them down where it's warmer, you could condense evaporation from the ocean, without spending energy directly on cooling.

You’d have to raise them up pretty high to get them colder than the dew point.

The energy it’d take to raise and lower the material would make it cost prohibitive.

I considered that the balloons would be a balancing force but don’t forget the rope length changes as the balloons go up and down. That changing length shifts the weight around. You can’t be balance against it.

There are big thermodynamic problems with those, the phase transition requires a lot of energy... Generally the main places where they work with any kind of acceptable efficiently and decent yield (where there's high enough humidity) are also the places where it tends to rain a lot!

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