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New Solar-Powered Device Can Pull Water Straight From the Desert Air (sciencemag.org)
sciencehabit quotes a report from Science Magazine: You can't squeeze blood from a stone, but wringing water from the desert sky is now possible, thanks to a new spongelike device that uses sunlight to suck water vapor from air, even in low humidity. The device can produce nearly 3 liters of water per day, and researchers say future versions will be even better. That means homes in the driest parts of the world could soon have a solar-powered appliance capable of delivering all the water they need, offering relief to billions of people. To find an all-purpose solution, researchers led by Omar Yaghi, a chemist at the University of California, Berkeley, turned to a family of crystalline powders called metal organic frameworks, or MOFs. Yaghi developed the first MOFs -- porous crystals that form continuous 3D networks -- more than 20 years ago. The networks assemble in a Tinkertoy-like fashion from metal atoms that act as the hubs and sticklike organic compounds that link the hubs together. By choosing different metals and organics, chemists can dial in the properties of each MOF, controlling what gases bind to them, and how strongly they hold on. The system Wang and her students designed consists of a kilogram of dust-sized MOF crystals pressed into a thin sheet of porous copper metal. That sheet is placed between a solar absorber and a condenser plate and positioned inside a chamber. At night the chamber is opened, allowing ambient air to diffuse through the porous MOF and water molecules to stick to its interior surfaces, gathering in groups of eight to form tiny cubic droplets. In the morning, the chamber is closed, and sunlight entering through a window on top of the device then heats up the MOF, which liberates the water droplets and drives them -- as vapor -- toward the cooler condenser. The temperature difference, as well as the high humidity inside the chamber, causes the vapor to condense as liquid water, which drips into a collector. The findings were published in the journal Science.
Sounds a bit like a windtrap. Can sietchs and spice-harvesting be far off?
Fog collection https://en.wikipedia.org/wiki/...
Domestic spying is now "Benign Information Gathering"
I gave TFA a cursory glance only, so sorry if ghis has been answered.
How large is this thing?
And I assume the water it produces is akin to distilled water. Isn't that bad to drink?
There have been a few, let's say, shady promises about extracting water from air, mostly coupled with crowdfunding campaigns (gee, why could that be?). Those that actually delivered a product were mostly ridiculous, provided you were not one of those duped into backing it. Then it was more a reason for anger and disappointment.
Most actually never delivered. Which reminds me, wasn't Fontus due to deliver right now in April? Any backers here, did they actually deliver? Because, let's put it careful, I'd really, really love to see that!
So don't get me wrong when I don't hold my breath. I have been promised easy water from thin air before. And what has been delivered so far, if anything, was ridiculous. Either it didn't work, didn't scale past proof-of-concept scale or only worked if the humidity was high enough that rain was more the rule than the exception, rendering a system that extracts water from the air redundant: A bucket would do.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
Who on earth is so stupid to believe that "a billion" people live in "deserts"?
How about the United Nations? Strictly speaking it isn't all desert but apparently well north of a billion people live in water stressed parts of the world or areas threatened by desertification.
Nevertheless a device like this might be useful in all warm/humid areas.
Maybe. The real question is how much does it cost per unit of water generated. To be useful it would have to generate a rather sizeable amount of water even to just cover drinking and basic cleaning needs.
What is the cost per unit of water generated? It doesn't matter if it works if it is prohibitively expensive per unit of water generated. If the economics of it don't make sense it will never be used at scale.
The heat of vaporization of water is about 2,260 kJ/kg. It's the law.
So, they hooked a solar cell to a thermoelectric cooling cell. Its the same tech as those USB refrigerators. You can build a basic a basic unit for $30-40.
You say things that offend me and I can deal with it. Can you?
...that really is VAPOR ware. ;)
If you give a man a fish- he can eat for a day. If you teach a man to fish, better hope he doesn't live in the desert.
I don't know where you're getting the cost of $1000 solar panel. For one appliance it's not going to cost that much. It's probably not going to cost anything in the same range as that. Even if it did. Yes, $1000 can buy a lot of water if you live near a water source. If you have to keep shipping water hundreds of miles then the costs are going to go up.
Wouldn't it be better to ship one time to a location rather than having to ship continuously for years? Also, if you have your own means of getting water you don't have to worry about- what if guerrillas take out the delivery man and steal my water? What if the shipment never arrives? You're more independent. In the end, we all want our fate and future as much in our own hands as possible.
"That's the way to do it" - Punch
A human only needs around 1l of water a day to survive.
You will respirate and pee away well more than 1 liter per day under normal circumstances even if you aren't in a desert and are doing nothing active. Water requirements can easily exceed that substantially if you are sweating significantly or if it is very hot.
Great, all it needs is a $1000 solar panel and you are set
Solar powered does not imply solar panels. It runs off the heat differential between a sunlit top and a shaded, air cooled condenser.
...do you need a droid that speaks the binary language of moisture vaporators (which is very similar to binary load lifters) to operate it?
In the end they will lay their freedom at our feet and say to us, Make us your slaves, but feed us. - Fyodor Dostoyevsky
I have no idea where you're getting 300L a day. A human only needs around 1l of water a day to survive.
No, active adults need about 3L not 1L. So with this device producing about 2.8L it could sustain a single person. Things get complicated with activity levels and climate, and water in food counts towards the total.
The 1L per day figure is life raft level rationing where you are sedentary and either rescued from the sea in a few days or likely to die so additional water is unlikely to change the outcome.
I have no idea where you're getting 300L a day. A human only needs around 1l of water a day to survive.
It sounds like total water usage in the west once you consider showers, toilets, cooking, cleaning, etc.
I would expect by making the air dryer by taking moisture out, you would probably also proportionally increase the rate at which water evaporates into it, so if enough people used these, I could totally see a consequence being a lower amount of rainfall overall. While this is not directly problematic for us, being able to extract all of the water that we need from the atmosphere, (and not a problem for the atmosphere, since it will get re-evaporated), this could be a very big problem for plant life which depends on rainfall to thrive, and so by virtue of the food chain may impact us very adversely.
File under 'M' for 'Manic ranting'
No, you have to worry about "what if the guerrillas take my water-making gadget?"
"I do not agree with what you say, but I will defend to the death your right to say it"
Where did they test this thing and what was the relative humidity during the test? 3 liters isn't enough for one person to survive on in the desert (1 gallon per person per day) so you'd really need a lot of them for normal daily use and a lot more to be able to grow crops.
I mean if drinking distilled water is bad for you, long term, without adding the minerals that your body needs, that's not really a good solution. Plus, I expect this water is going to be pretty hot since it's sitting in the desert sun, so that the solar panels can power it, so... Maybe the real application for this is that they have a really fancy way to boil a pot of water to cook their noodles? I didn't really think that my 10 cent pack of ramen needed a more cost effective cooking mechanism, but if they put it on Kickstarter, I'm totally buying one because that obviously means that I need it. /sarcasm
Dissenter
"There is no knowledge that is not power."
The s indicates plural, that means more than one billion ... actually minimum two.
Who on earth is so stupid to believe that "a billion" people live in "deserts"?
Hmmm. I live in a desert in the SW US, the Sonoran desert. I share this land with about 8M of my fellow humans. It is probably the wettest desert on the planet, but it is still, by definition, a desert, with most areas receiving only about 150mm/yr in its bimodal precipitation regime. It is also the smallest desert biome on the planet, covering only about 260,000 square km.
The generally accepted definition of a desert is less than 250mm of annual precipitation. The UN breaks this down into desert, arid, grassland, and rangeland, and it covers a whopping 61M square km, or 41 percent of the land surface of the planet. According to the same UN report, 35 percent of the planet's population live in areas that meet this definition, which gets us to 2.6 billion people. There's your billions, with an "s," if you are one of those people on earth "stupid" enough to actually do a little research.
https://www.youtube.com/watch?...
has typed the words "moisture vaporators" prior to this?
Damn, has this place gone downhill.
So, the UN breaks down "desert" into "desert, arid, grassland and rangeland".
So, when someone says "desert" are they talking about LHS or RHS of the equation ?
New Solar-Powered Device Can Pull Water Straight From the Desert Air
Yeah, it's called a sheet of plastic.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
Second-world community I knew had a condenser for night dew installed by a global charity. Two nights later, the locals had stolen the polythene sheeting on which it relied. 'Appropriate Technology' Rules OK.
Average rainfall in the Saharan desert is 25mm per year. Let's say 20mm. The Saharan desert is 9.2 million square miles. Therefore, the volume of rainfall is 184km^3 (9,200,000km^2 * .00002km), or 1.84*10^13 liters per year of rainfall. Rainfall is just excess moisture that precipitates from the air, so the actual volume of liquid is going to be much, much higher than this...and the Saharan desert is one of the driest areas on the planet. In other words, there is no way this device, or any device that pulls anything on the order of magnitude of 1, 10, or even 100 liters per day per person, is going to cause any noticeable drying of the air in aggregate. Even localized drying is not really likely due to convection mixing of the air, and the fact that the moisture is going to be expelled in roughly the same areas where it is collected.
if implemented widescale, it will screw up weather patterns globally. there's a finite amount of water on the earth.
Remember kids, if you're not paying for the service, YOU ARE THE PRODUCT THAT IS BEING SOLD.
You just have to provide the proper squeeze to the Hutts, and you're good.
His ignorance covered the whole earth like a blanket, and there was hardly a hole in it anywhere. - Mark Twain
Yeah, OP must be trolling. It doesn't even use solar cells.
His ignorance covered the whole earth like a blanket, and there was hardly a hole in it anywhere. - Mark Twain
Great, all it needs is a $1000 solar panel and you are set
Solar powered does not imply solar panels. It runs off the heat differential between a sunlit top and a shaded, air cooled condenser.
Yeah, good catch. Half the numbnuts posting on this are chattering on about solar cell efficiency and cost, etc.
Not that this is bad. I come here for the tangents as much as for the articles.
His ignorance covered the whole earth like a blanket, and there was hardly a hole in it anywhere. - Mark Twain
But . . . people fart in it.
"I believe in Karma. That means I can do bad things to people all day long and I assume they deserve it." : Dogbert
http://www.sciencemag.org/news...
It should be 30 deciliters. C'mon, get the units right. It's a windtrap.
--Shai-Hulud
Yeah, imagine how much kg of copper one would need for 1 acre of, let's say, corn.
"Trump!!", the new Godwin.
You already broke it down into 3 quite different areas.
So: there are not 2billion people living in a desert.
I would be surprised if it is more than 200million (looking ata Arabica and Gobi).
No idea why you write such a long post when you clearly don't grasp about what you are writing.
Hint: Grassland and Rangeland are not desserts.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.