Pretty disappointed with their choice of winner. Using refrigeration to maintain a dewpoint means that this appliance is pretty impractical below 50% relative humidity.
Or in other words, this thing only makes water when you probably don't need water.
Blow some nice 90 deg F 20% humid air past those coils, and you'll be blowing out a lot of 80 deg F 25% humid air out on the other side, getting bupkis for actual produced water, but sucking down plenty of juice. Slow down your intake fan to almost zero, and now your water produced goes up from zero, but the slowest of trickles.
Gotta love all that ozone generator carbon filter garbage on the business end. It's all just bells and whistles to put lipstick on a three-legged pig.
>> this thing only makes water when you probably don't need water.
Living in California recently I constantly see the weather forecast claiming 70-90% humidity and yet the area is basically a dessert with almost no rain. I suppose there are many more areas in the world like that.
That happens because there are many hills which tend to spawn rainclouds when the humidity hits a certain threshold. So while there is moisture in the air it mostly falls in the mountains. Other places with this pattern include e.g. Morocco or the Snake River Valley in Idaho.
(This is also why people keep building houses in fire danger zones: the forests have a nice climate, but they burn. The flat areas don't burn, but they're inhospitable.)
You might think that, but the illusion will break fast if you actually move here. The inland can be supper dry, so much you could almost hear it dinning in your ears. No surprise so many water conservation efforts have been launched here!
I actually had a discussion on this subject with Phil Mason aka Thunderfoot who has a Phd in chemistry and is the creator of the video that is critical of this announcement ( https://www.youtube.com/watch?v=e3s-xI895zc )
The discussion was about how much work is actually required to condense the water vapor. The fact is that it is thermodynamically possible to MOVE more heat energy (Q) than work (W) applied. The efficiency of heat movement is dependent on temperature gradient but is more than 100% efficient. So as bizarre as this sounds it actually requires effectively zero work to condense water from the air at 100% humidity.
At 100% humidity, sure. If it's raining, it takes no work to get wet.
I have a unit in my garage that can actually produce water at less than 10% relative humidity, moves a lot more air so it has more chances to actually capture the water, and smokes these other units under price/performance, particularly when tested in a desert. It's not a dehumidifier-based system. It's also cheaper to build.
> Thanks for reaching out. Mine uses a deliquescent salt, which requires no energy to absorb water from the air. It's pretty messy, but does the job. Getting the water back out is where the energy is required, and this is non-trivial, but still far better than those dehumidifier approaches, which are unfortunately the perpetual motion machines of our era.
It’s a slightly different motivation. There is something worse than a forum troll, and that’s a forum censor.
I could post all the stuff publicly, but then I’d get more downvotes, because a lot of forum users enforce the norms they like.
I see the number of points in my posts like this one jockey up and down repeatedly, meaning equal double-digit numbers of readers approve and don’t. Being able to follow that history would prove fascinating, but it’s not a feature on HN.
I’ve even attracted a following of a couple of readers who downvote anything I post.
So it’s with the norm—enforcing downvoter in mind when I want to reach out.
Share away. I can’t even give my technology ideas away.
There is actually way more water in the air than 0.04 grams... i think this is because liters not m^3
for 1m^3 there is 30 grams at 30 degrees and 17.3 at 20 degrees. its at least ~15/10 - > 1.5 grams per Centigrade
Say we do small diff of 4 degrees, 30 to 26. We gain 1.5 * 4 = 6 grams / m^3
To do this we need to cool 1m^3 water at 30 to 20.
Now this is tricky because humidity but
https://www.engineeringtoolbox.com/heating-humid-air-d_693.h...
h = 1.01 (kJ/kg.oC) t + x [1.84 (kJ/kg.oC) t + 2502 (kJ/kg)]
x is relative weight so its actually small like 0.03 so it changes the result very little
h = 1.06 (kJ/kg.oC) t + x 2502 Kj/kg
partial diff with t gives us 4.24kJ/kg change for cooling the air (sensible)
partial diff with x gives us (0.006kg delta) 2500 - > 15kJ/kg for this 4 degree change for condensation with 6g/m^3 of water
Since the cooling of air that didnt result in water is reclaimable energy lets ignore it
Now efficiency of this heat transfer
1/ (303.15 / 299.15 - 1) = 75x heat transfer efficiency. Does this make sense? we know heat pumps are amazing :)
so per gram its like 15kJ/6g = 2.5kJ/gram -> this is really expected as 2.3MJ/kg from original video!
However this heat (Q) is moved via work (W) at 75x rate
This means to get 1kg (1L really) it only takes 30KJ
So at 15watts (J/sec) -> 2000sec -> 33 min
Perhaps this wont work because the MASSSIVE heat sink required :)
How much air needs to be moved?
we get 6 grams for each meter cubed of air. Not great thats about 166m^3 of air that needs to filter.
https://www.amazon.ca/Ultra-Strong-DC12V-Cooling-200CFM/dp/B...
200CFM -> 5.66 m^3/min 60 min/h = 339 ... this is double what we need.
its about 1.6A 12v = 15 watt... but its more than we need. Half it?
Sort of topic, but man is his presentation format tiresome.
I would never have guessed that he has a PhD in chemistry... he comes across as rather off his rocker
I think it's his rhetoric - there's some substantive argument under the surface but it gets washed out with all the aggression and rhetorical fallacies.... it's very schizophrenic...
Following up on my comment because this is driving me nuts...
His aggressive diatribe manner of speaking seems all too ubiquitous these days, as we find ourselves conducting the vast majority of our communications with the 'hivemind' on platforms where ability to attract attention wins out over quality discourse.
And it's just fucking impossible to have any real conversation in that context. There's no room to entertain subtleties, the higher-order structure of the subject, if you will.
For instance.... he makes it out like everyone involved in this prize is absolutely clueless about thermodynamics and that there are no conceivable advancements to be made for this particular scenario because thermodynamics.
Bullshit. There's plenty of innovation to be had. You can take advantage of daily temperature swings, use a ground-source heat pump... and almost certainly current humidifiers aren't operating at the thermodynamic limit; there's probably work to do in developing better materials, optimizing the design for efficiency, etc
I kind of see what you're saying in regards to leaving no room for subtleties but that argument goes both ways.
I tried to find accurate information on the technology and how they differentiate from the regular old dehumidifier spiel when I first heard about the prize, even spending a few minutes on Google scholar searches for their contributors. It was all drowned out by marketing materials and fancy graphics.
On one side we have a person with a Youtube brand that lives off of these kinds of debunkings, including their over the top tone. On the other side we have multiple companies with a product and accompanying marketing budgets. Both clearly lacking in room for discussion and subtlety. Could the youtuber get their point accross more objectively and clear? Sure. Would somebody listen or even discover their argument? I kind of doubt that. Just like the product would not gain traction from scientific papers alone.
Trying to make my point clearer, I do not feel like that the Youtube person is solely at fault for a weirdly framed discussion here. If the XPrize winners have more innovation to show than combining two technologies that they seem to have used before they should clearly communicate that, including scientific analysis that are easy to discover. They got a prize for a product that claims to be better than competition with similar tech in a space that previously saw players that absolutely were pure snake-oil. Just put facts next to your pitch decks and fancy marketing materials people.
I don't know why this is attracting so much bitterness.
If anyone is informed about water, it would be great to get a little more context, for example what other solutions like desalinization and other dehumidifiers cost in energy and dollars. (Yes, obviously nothing is going to be as cheap as putting a pipe in a river.)
For example their FAQ says they use less than half the power of their competitors. That seems like a huge advance. And is $.02/liter amazing or just slightly better?
There used to be a time when extraordinary claims required extraordinary evidence - particularly when thermodynamics is involved. The dehumidifier business is a multi-billion industry. Why would they need an X-Prize when they're extraordinarily better than the state-of-the-art?
If you remember back to the perpetual motion machine, that was supposed to produce more electricity than it consumed, you'll capture the mindset detractors like myself have.
But look, our PMM is producing this many volts! And it works great on paper too!
I haven't seen any data or reports to show this competition actually tested built units and measured both their water output and energy consumed, and did so in a variety of climates. In areas where the mercury has gotten below freezing, for instance, there is no water in the air, and yet, we're supposed to believe these snake oil machines are producing 2000gal/day for $0.02 each, even there.
RE "no water in the air blow freezing", that's not true. In the mountains you can hang your towel up to dry at night. It freezes, then dries through sublimation. Ever seen funny smooth ice formations?
From what I can glean online, the 150 gal/day unit costs $18k usd + $150-$300 in electricity a month if run 24/7 at $0.10Kwh. Ignoring electrical costs, it would take 1581 days to reach $0.02/liter. In that time you would use up $7.5-15k in electricity.
The best estimate I could find is that the average US household uses 240 gal a day.
A friend of mine had to drill a 980 ft well through bedrock. A well this deep requires a much stronger pump and more electricity. They are on their 2nd pump. I should ask them what that all cost.
I think the competition guidelines are around manufacturing cost, not retail cost:
> The cost per liter of water extraction will also be calculated based on a pro forma Bill of Materials and
estimated NRE and tooling costs. A more detailed description of this calculation is provided in the Rules
and Regulations. The Affordability Index must be less than $0.02 (two cents). No prize will be awarded
to a Team that does not meet that criterion.
We are four people living in a house & garden in france and I used 70m3 (70000 liters) last year. That would be about 190L/d or 50gal/day, 5 times less. Where do you dump so much water in the US?
My math says that's about 2 HCF (hundred cubic feet, which is what our water is billed as) per month? That's considerably lower than the typical water usage in drought-ridden Santa Barbara of 11HCF. It's also double the baseline usage of 4HCF (after 4HCF rates go up).
With 3 adults and 4 children in my house we used 4-6HCF per month with no garden (when we moved in the irrigation system used about 12HCF per month on its own, we landscaped the yard to eliminate the need for outside watering).
I'm going to guess that if you need to spend $18k on equipment to get your water then you probably aren't going to blow through 240 gallons a day.
150 gallons could be quite a lot of fresh water for a small remote village that otherwise lacks a good fresh water source. Useful for drinking and cooking, but not used for bathing or irrigation. I assume the system could be powered by a reasonably sized solar array.
On the other hand, given the cost of this setup it would probably be a lot easier and cheaper to install water filters.
All the pictures show the units operating in lush, green environments, which would indicate high(er) humidity where moisture extraction from the air is trivial. I'd like to see some action shots from the middle of the Atacama or Taklamakan.
It looks like the winner is a standard dehumidifier bolted to a standard biomass generator that has a condenser from a high efficiency furnace bolted on to it.
So the only "magic" they are doing is also capturing the water vapor from the generators combustion. While somewhat novel in combining it all, its all off the shelf tech.
What I don't like is the lack of good hard numbers in its performance in a range of conditions as snake oil is extremely common in the water from air industry.
The other magic is financial. My bet is that they assume free biomass. Once you assume input cost = $.00, things look easy.
And, to be fair, maybe this thing makes sense after a hurricane. There's lots of "free" biomass laying around in an area of extraordinary transportation costs.
But it's obviously not a solution to the "water problem" in rural, impoverished areas. You'd need to include the price of a renewable forest or palm plantation (for coconut shells), or the huge solar array.
I'm a bit irked that a technology of this significance has no videos or demos or actual use cases, just a PR blurb. Is it confidentiality, or is it too early stage? Otherwise X Prize becomes another congratulatory event. This feeling seems to run through the entire site as I click around.
That's cool. I hope it takes off. Water shortage is a very serious issue in Asia affecting millions and this solution seems too good to be true, so it's exciting. I wonder what the costs are like and can I buy one and donate them to communities in Asia?
Just google “water from thin air”. This has been done quite often the past 15 years. It’s an overpriced dehumidifier that is working outdoors.
1. They’re in Hawaii. It’s a little humid there. So... yea. Dehumidifiers will collect quite a bit of water in a water abundant area.
2. The places that need clean water typically have low humidity as well. To pull water from air, there needs to be water in it.
Think of this as all those folks that claim they can run their car on water as a fuel. The thing they fail to mention was they were using a battery to split out the hydrogen from the water to use that as fuel. Which is not more efficient than just using the straight up battery.
This is a publicity stunt scam. A real shame too. That money would have been better spent on education or better water infrastructure in places of need.
It means that it uses refrigeration to make it rain (maintain a dewpoint temperature) in a small chamber instead of just grabbing the condensation dripping off the refrigeration coils.
2 cents a liter is not close to feasible for any sort of agricultural or industrial use and is an order of magnitude more expensive than residential tap water. Seems like cool tech, but I can't see how this is a solution to any type of water shortage.
> I can't see how this is a solution to any type of water shortage.
If you don't have drinking water, five to ten cents per day is a pretty good deal! It really doesn't matter that tap water somewhere else in the world is one cent.
Perhaps he's referring to the notion that, in general, the taste of distilled water differs from mineral water?
Also, I was about to post a concern about distilled water possibly leaching nutrients from the body, but a quick google reveals the opposite may be true: https://www.nutriteam.com/distilledleach/
If it all works this would be useful. (Contary to all the negative comments about how pointless this is.)
Not a water expert, but here's where this reported price ranks from some googling:
Tap water in California: $.0005 / liter [1]
XPrize winner: $.02 / liter
Water truck delivery in CA: $.01 - $.05 / liter [2]
Desalination: $.05 - $.30 / liter [3]
Wholesale bottled water: $.30 / liter [4]
Walmart bottled water: $.68 / liter [5]
If $.02/liter is right, this is close to the water truck in pricing. Also it seems like you could ship this with solar
to disaster areas instead of flats and flats of bottled water and be up to 15 times cheaper. It could be an alternative to desalinization near the ocean where there is lots of humidity at 2 to 15 times expense. This seems useful.
Tap water is awesome, btw. It's 100 times cheaper than all these options.
For places without existing water infrastructure, however, doesn't the technology seem like it may have some appeal?
Not everywhere has tap water. Some places don't have an aquifer suitable for drilling a well. Other places don't even have a road network suitable for the delivery of water by truck in an economical manner (or at all).
Beyond that, drawing water from the air has benefit in that it does not negatively impact a local aquifer which might already be over-drawn. What is the additional economic benefit per liter of that? That could be subtracted from the $0.02 / liter cost if you care to look at more than just the immediate bottom line.
I don't get it, why don't poor communities build piping from their nearby water sources? People were able to do this 2000 years ago. Why do they need to invent a reverse-entropy machine?
When I looked into conventional dehumidifiers and air conditioners, what stopped me from systemically re-using air conditioner condensate even as gray water was finding out that it can contain trace amounts of heavy metals and industrial oils from the condensate going through less-than-ideal materials used for the coils and evaporator parts. Also, if you live in an area with air pollution, the condensate contains concentrates of the pollution, as well as allergens and biological contaminants. I'm hoping someone reading this might have looked into it more than I have, and can point me to some reading material that can help me either further work through or dismiss those concerns.
When I read through the article, I didn't see any links to potability test results. So there might be a purification step after this gasifier powered water generator to turn the output of this into truly potable water, so the cost won't really be below two cents per liter in the field. Purification itself is an energy-intensive endeavor, whether to create purification materials or straight use of energy in more active systems, and is why potable water is a rough order-of-magnitude proxy for energy.
Good video on how we see an Adiabatic Cooling process drop moisture in nature.
https://www.youtube.com/watch?v=XH_M4jItiKw
edit: I personally didn't know what "adiabatic" meant.
As I understand it, it is basically the skysource water extraction device hooked to an all-power labs gassifier, which produces electricity from gassifying organic material. Allpower's product uses the gassifier output in a conventional engine, in turn using that to power a generator. The great part here is - uses locally generated biomass, and produces a waste stream of biochar, which can be used for argiculture, essentially putting the carbon back into the soil. Pretty, it isn't, but carbon neutral it is.
Yup, that's what I got from it. But also the engine is producing CO2 and Water from the biomass. Which can in turn be fed into the water extractor. I think that is the novel step.
It's using 'current carbon' which is basically the same thing. Plants grow using CO2 in the air, we burn the plants and that CO2 is released again. If we just left the biomass to rot on the ground it'd produce CO2 and / or Methane depending on the type of decomposition it underwent.
Verses plants and animals lived millennia ago, died, got compressed by huge geological forces and finally we come along and extract it and burn it.
Need to is a bit of a stretch. Manure, urine, nitrogen fixing legumes are all potential fertiliser.
In addition growing deciduous crops rather than annuals and good soil management practices and can help reduce or eliminate additional fertiliser requirement.
Is this another one of those dehumidifier machines that promises it can deliver gallons when using a tarp, rope, and a bucket to catch rain water collects more water per year?
RTFA, especially before snarky dismissals: "meeting the competition parameters of extracting a minimum of 2,000 liters of water per day from the atmosphere using 100 percent renewable energy, at a cost of no more than two cents per liter"
They have commercial models for sale that produce half the competition amounts, and have pretty detailed specs online: http://www.skysource.org/products/
Those specs mention producing half the competition's amount in optimal conditions, which I assume means 99% humidity. They don't actually say at what humidity level and temperature their product can deliver that much. They don't give any specific numbers at any specific temperature, only the machine's operating conditions and the upper limit on what it can produce.
where was the machine tested? If it was tested in somewhere more humid then the test data is invalid for use in arid areas where you'd actually need them. Also, that renewable energy is wood chips, so yeah it's renewable but in reality it's just fossil fuels without the "bury for millions of years" step. I'm not sure how that's meant to be an improvement, except perhaps that they can use local trees instead of bringing in other fuels.
That's a pretty apples-and-oranges comparison. That's a company making ridiculous promises (look ma, no external power input!) and without any third-party verification. This is a company that makes realistic claims (i.e. has actual numbers for power input per liter of water) and whose performance has been verified by the prize-awarding organization.
> has actual numbers for power input per liter of water
Where did you find that? All I could find is "0.8-1.8kW/hr" for a machine with capacity with a capacity of "30gal/day". This is complete nonsense, "kW/hr" is neither energy nor power nor energy per volume of product. And if it's power, why does it vary?
I'm going to read it as 1.8kW, with a capacity of 30 US gallons (113l) per day. My dehumidifier from the hardware store consumes 0.2kW at a capacity of 10l per day. They are 15% more productive... hardly a quantum leap.
Generally a lot of electrical appliances are advertised with kW or W actually meaning kW-hour and W-hour (and yes, this is awful, but it's pretty standard). So your interpretation as 1.8kW is about right.
It varies, as does output, because (as the numbers mention) this all varies wildly by atmospheric temperature and humidity.
(By the way, running the numbers I'm seeing it as 62.77L/kW vs. 50L/kW, which is a 25% improvement, though at much larger scale.)
It’s an overpriced dehumidifier. Pulling humidity out of the air. It’s not magic. It’s not new. There is water vapor in the air, every middle schooler knows this.
They are in Hawaii. An outdoor dehumidifier will work great in a water abundant area. How well do you think a dehumidifier will work in a low humidity area? The places that need water the most. It’s not making water, it’s pulling out the humidity.
This is such a scam.
I feel like I’m taking crazy pills. All these “smart” folks gave up 1.5mil and there are tech folks here nodding their heads because it’s xprize. Y’all turned off your thinking just because it’s xprize.
Say you want to help 3rd world poor and it gives you magic armor from logic apparently.
I think you are wrong. This gives more details about how it works. They are using gasification both as power and as an additional source of water. I think that's pretty clever and I'm confident that the x-price people wouldn't have awarded the prize if it didn't meet the requirements.
Its much more than that. Here are the requirements they met (listen in the second paragraph)
"easily deployable high-volume water generator that can be used in any climate, meeting the competition parameters of extracting a minimum of 2,000 liters of water per day from the atmosphere using 100 percent renewable energy, at a cost of no more than two cents per liter."
I think the key difference is that "Skywater machines use a patented Adiabatic Distillation Process, where water vapor is reduced to liquid without a gain or loss of heat." so it's a little different than just a regular dehumidifier.
It also seems to be able to pull a lot more water than a normal dehumifiier? "Skywater machines are ranging from Skywater 30 (up to 30 gallons of water each day) to Skywater 300 (up to 300 gallons of water a day)."
You are right we should be more skeptical though. Like how much energy does this thing use?
"Because the process uses a large amount of electricity, designers paired it with a biomass gassifier, a low-cost source of energy. When the gassifier is filled with wood chips, coconut shells, or whatever biomass is locally available, a process calls pyrolysis vaporizes that material. That makes the system hot and humid, the ideal environment to run the air-to-water machine.
Because the process uses a large amount of electricity, designers paired it with a biomass gassifier, a low-cost source of energy. When the gassifier is filled with wood chips, coconut shells, or whatever biomass is locally available, a process calls pyrolysis vaporizes that material. That makes the system hot and humid, the ideal environment to run the air-to-water machine. "
I think the approach is a bit more novel than normal dehumidifiers. Instead of just collecting water dripping of the condenser coils, they use the cooler air to make a "rain chamber". The website talks about "maintaining a dew point within a condensation chamber".
There's a similar type of building which uses temperature difference to generate condensation within a building, creating a pool of water. The name escapes me at the moment.
By posting this comment, you're saying "I'm a genius, and you're all idiots, because I've figured out this obvious thing that has gone over all of your heads."
Now, you might actually mean that, but it might be more useful to explicitly spell it out in that case.
I was going to say, I have a dehumidifier in my basement that I empty a gallon of water out of/day during the summer in Pennsylvania. I can't believe this kind of shit wins the xprize.
Remove moisture from the air on any significant scale, and you're depriving someone else of rain, downwind. It's another finite resource. Unforeseen consequences abound.
You know, there are places where water falls out of the air on its own, and if you don't spoil the hell out of the landscape you can even drink it. Give it a rest, humans.
Oh so we really believe the solution to all problems, including those directly caused by human technology, is going to end up being more technology? That the solution to human-caused complexity is more complexity? (With no diminishment whatsoever in returns?) That the solution to human actions that change the climate is more human changes to the climate? Because Progress? No skepticism at all huh?
Nobody subscribes to any quaint notions anymore such as "Extracting water from air is known as rain, and it's free," or "There are already too many humans, living in too many inhospitable places, enabled by technology," or even something as simple as "Hey I can keep two contradictory ideas in my head at the same time like 'I work on technology' yet 'Technology always has a downside'?"
There's an old apocryphal saying along the lines of (please say this in the stereotyped voice of Tonto or any Native American portrayed by Hollywood):
Red man build small fire, keep warm.
White man build big fire, keep warm by chopping wood.
Just thought I'd throw that in, since it's roughly analogous.
The human population needs to be cut back to within a sensible ecological planetary carrying-capacity, not be further propped up by ever-more exotic tech. The cutback will happen regardless, when these technologies inevitably fail or lead to worse problems that feed back on each other. But it's still frustrating that everybody wants to just rush headlong into the brick wall instead of hitting the brakes, and that anybody who has any foresight is automatically some Luddite or old-timer. Like people fresh-out-the-womb are the smartest ones, and the unquestioning belief in tech is anything but gullibility! Give me your money then!
Or in other words, this thing only makes water when you probably don't need water.
Blow some nice 90 deg F 20% humid air past those coils, and you'll be blowing out a lot of 80 deg F 25% humid air out on the other side, getting bupkis for actual produced water, but sucking down plenty of juice. Slow down your intake fan to almost zero, and now your water produced goes up from zero, but the slowest of trickles.
Gotta love all that ozone generator carbon filter garbage on the business end. It's all just bells and whistles to put lipstick on a three-legged pig.