Google open sources solar atmospheric water generator • Hacker News Board

Re: Google open sources solar atmospheric water generator

#191

Post by jodrellblank » Fri, Mar 18, 2022, 5:15 AM UTC

vesinisa wrote: post #118

jodrellblank wrote: post #107

Check out Thunderf00t's videos cricising solar water collectors, e.g.: - https://www.youtube.com/watch?v=vc7WqVMCABg - Zero Mass Water: BUSTED! "Honestly, it drives me crazy how many people have reinvented the dehumidifier, put a solar panel on it, and the media has danced around like theyve just saved the world!" - https://www.youtube.com/watch?v=aPvXnmBIO7o - Self-filling water bottle: BUSTED! " The fact that its t…

Their paper is open access: https://www.nature.com/articles/s41586-021-03900-w They claim that this device with 1m² footprint could "well within thermodynamic limits" alleviate thirst for a billion people living in "tropical regions" (daytime relative humidity 30%-90%). I already look forward to the debunk. It all seems very high-level. My money is on that these regions where the device would be viable do not actuall…

> "I already look forward to the debunk."

How about: Google found a way to alleviate thirst for a billion people and then decided it wasn't worth bothering with, stopped it being a project, and dumped the plans on Github? Norman Borlaug[1] won a Nobel Prize for his contribution to food production which is said to have fed a billion people, so I guess these authors had better things to do at Google than save a billion thirsty people and do Nobel level work?

From the paper: "Our assessment introduces a hypothetical 1-metre-square device with a SY profile of 0.2 to 2.5 litres per kilowatt-hour".

From the Thunderf00t video, checks out with a Google: it takes about 2,200,000 Joules of energy to evaporate 1 litre of water at 100C into steam at 100C, and so at least that much to condense 1 Litre of water from steam. There's 3.6MJ in 1KWh which is enough for 1.5 Litres. So already in the first paragraph of the abstract their upper estimate of 2.5 litres per KWh seems to be beyond thermodynamic limits (I could be very wrong, I'm no scientist; am I wrong?).

I'm not claiming any expertise or more knowledge than watching two videos just now, but their paper describes more than just solar powered condensing, with absorbent gels and materials involved as well (but still, wouldn't those have to take the same amount of energy out of the air to condense the water?). Their paper also shows desalination as being >100x more water per KWh than getting water from air.

[1] https://en.wikipedia.org/wiki/Norman_Borlaug

Re: Google open sources solar atmospheric water generator

#192

Post by jodrellblank » Fri, Mar 18, 2022, 5:17 AM UTC

WheelsAtLarge wrote: post #143

jodrellblank wrote: post #107

Check out Thunderf00t's videos cricising solar water collectors, e.g.: - https://www.youtube.com/watch?v=vc7WqVMCABg - Zero Mass Water: BUSTED! "Honestly, it drives me crazy how many people have reinvented the dehumidifier, put a solar panel on it, and the media has danced around like theyve just saved the world!" - https://www.youtube.com/watch?v=aPvXnmBIO7o - Self-filling water bottle: BUSTED! " The fact that its t…

" It's a dehumidifier; in places where the air is wet, it rains, and you don't need it. In places where you need it, you need it because there's not much water, so it doesn't work well." I wonder how well it would work as a stand in for a desalination solution. Where there's all the water you want but it has salt (or other contaminant) that makes it impossible to drink. Seems to me that a beach would be the perfect p…

Desalination produces a lot more water-per-KWh-energy than unboiling water from the atmosphere. Elsewhere in this thread someone linked a paper which estimates up to 100 litres per KWh for desalination, vs ~1 litre per KWh for condensing.

Saving on machinery, or chemicals, might be important but $150 of materials for a device will buy you ~25,000 litres of water in bulk (in the USA).

Re: Google open sources solar atmospheric water generator

#193

Post by jodrellblank » Fri, Mar 18, 2022, 5:30 AM UTC

kragen wrote: post #124

jodrellblank wrote: post #107

Check out Thunderf00t's videos cricising solar water collectors, e.g.: - https://www.youtube.com/watch?v=vc7WqVMCABg - Zero Mass Water: BUSTED! "Honestly, it drives me crazy how many people have reinvented the dehumidifier, put a solar panel on it, and the media has danced around like theyve just saved the world!" - https://www.youtube.com/watch?v=aPvXnmBIO7o - Self-filling water bottle: BUSTED! " The fact that its t…

Dehumidifiers aren't what's thermodynamically impossible, of course; Fontus was just making quantitative performance claims that were thermodynamically impossible about how small their system would be and how little energy it would use. You don't need to sink to citing YouTubers to figure out how much water air contains. You can just consult a standard psychrometric chart: https://commons.wikimedia.org/wiki/File:Psyc…

> "You don't need to sink to citing YouTubers"

You say, whiloe going through the same calculations as Thunderf00t makes, to make the same points he makes. Including: how it is possible to do it, how dehumidifiers exist, what humidity means, how far out the Fontus design sizes were from being practically workable. 49cfm assuming you get solar power 24/7. Double or triple that to get it through while the sun is shining. I happened to see this[2] video of someone who put solar water generators on his house and reviewed it after a year. Check out from time 2:06 we can hear the fans running and see how "barely noticable" they are. (Insignificant power compared to refrigeration, I agree with). Said review video also includes a complaint about the water being unpleasantly warm to drink, because the whole system is on the roof of their house in the sun and the pipes all get warm.

> "Around here supply chains are so unreliable that I'd hate to rely on a weekly delivery from a water tanker in order to not die of thirst in 48 hours."

This comment is weird because I imagine you don't actually right now have a solar-water-dehumidifier providing water for your family so that you don't die in 48 hours when your water supply fails? If not, why not?

[2] https://youtu.be/VQRAtwz3Igs?t=126*

Re: Google open sources solar atmospheric water generator

#194

Post by csense » Fri, Mar 18, 2022, 5:41 AM UTC

jimmydorry wrote: post #165

jeffbee wrote: post #152

Earlier quoted context omitted.

I think I see what you are saying, and I haven't read the book or anything on this topic. I can absolutely imagine how people would have better lives with more and cleaner water. But billions of people is an extraordinary equilibrium population already, and it makes me wonder if access to water will improve the lives in question, or raise the equilibrium population to a higher level at the same amount of misery and s…

At a high level, considering the population growth rates of developed nations, almost all of them are in decline. One could posit that at some point of improvement in life for a given population, the growth rate will plateu and then begin to fall, rather than increase in perpetuity. Looking closer at the developed nations that still have increasing population growth reveals a significant portion of it coming from imm…

I was just thinking about this earlier.

I've read a lot of stuff that says we should panic because population growth is bad, the world has too many people, it's already at or exceeding its carrying capacity, there's no way the whole world can live at Western levels, people in the West are super greedy and borderline evil for living like kings while everybody else starves. You and I need to get a lot poorer to free up resources for Asians and Africans to get out of extreme poverty, and if we object to becoming a whole lot poorer for the benefit of strangers halfway around the world, we're terrible evil racists.

I've also read a lot of stuff that says we should panic because populations are shrinking and aging. Economic growth is fueled by population growth, Social Security in the US and really the whole world's economic system is a Ponzi scheme based on an exponentially increasing population, we're headed for a ton of turmoil and collapse. If America wants to avoid a complete economic collapse, or having to replace its population with a super high immigration level that really ignites political tensions (think Trump presidency but 10 times worse), everyone needs to start having tons of babies like right now.

Is it really the case that positive growth and negative growth are both catastrophes? How does it even make logical sense that there are too many and too few people at the same time? Or is somebody lying? If so, who, and how can we tell?

Re: Google open sources solar atmospheric water generator

#195

Post by oofbey » Fri, Mar 18, 2022, 5:55 AM UTC

zaptrem wrote: post #190

nostrademons wrote: post #185

This could be great for a prepper's toolbox. If it actually hits the $150 price point, it's easily affordable for someone in the developed world who just wants to be prepared if the developed world un-develops, and drinking water's a critical survival need that many properties won't have available without municipal utilities or transportation. And in most apocalypse scenarios that you'd prepare for, you can't count o…

This seems relevant: > The prototype described here is a purely experimental device. While substitutions and modifications are reasonably straightforward, water harvested with this experimental device is not intended to be ingested. Among other design choices, adhesives were selected for experimental performance and would need to be substitued with ones meeting food grade standards.

So typically Google. Patting themselves on the back for being smart and proving to themselves they could figure it out. But not actually accomplishing anything useful. Getting it to actually work - that’s too easy and boring for a googler to waste their time on.

Re: Google open sources solar atmospheric water generator

#196

Post by discordance » Fri, Mar 18, 2022, 6:03 AM UTC

celdon25 wrote: post #136

Dean Kamen claimed on the Colbert Report in 2008 to have invented a machine that can produce 1000 liters per day. https://www.youtube.com/watch?v=Eqg1Hu0PMG0

The Slingshot. Purifies via vapor distillation. Last I heard Dean Kamen made an agreement with Coke where they would help Coke build a water soda fountain in return for Cokes distribution network. Not sure what has happened since.

Hope it still works out, but I feel another sad Segway story coming up.

https://en.wikipedia.org/wiki/Slingshot_(water_vapor_distill...

Re: Google open sources solar atmospheric water generator

#197

Post by Semaphor » Fri, Mar 18, 2022, 6:12 AM UTC

oofbey wrote: post #195

zaptrem wrote: post #190

Earlier quoted context omitted.

This seems relevant: > The prototype described here is a purely experimental device. While substitutions and modifications are reasonably straightforward, water harvested with this experimental device is not intended to be ingested. Among other design choices, adhesives were selected for experimental performance and would need to be substitued with ones meeting food grade standards.

So typically Google. Patting themselves on the back for being smart and proving to themselves they could figure it out. But not actually accomplishing anything useful. Getting it to actually work - that’s too easy and boring for a googler to waste their time on.

They did the groundwork. Now it’s open source and anyone can improve/finish it.

What would you prefer, them never releasing it, so interested people have nothing to start from? I’m not a Google fan, but I see this as a positive.

Re: Google open sources solar atmospheric water generator

#198

Post by eloeffler » Fri, Mar 18, 2022, 7:37 AM UTC

MIT made a similar device as well. I looked it up after hearing about people in Ukrainian cities being in need of water now.

https://news.mit.edu/2020/solar-extracts-drinkable-water-101...

There was a HN post 7 months ago, too:

https://news.ycombinator.com/item?id=28265067

The commenters didn't seem to see much use in it ^^

Re: Google open sources solar atmospheric water generator

#199

Post by holografix » Fri, Mar 18, 2022, 7:44 AM UTC

Not to disparage the open sourcing of this tech, it clearly contributes some knowledge to humaninity. But…

Has Google Moonshot produced _anything_ that’s commercially a big success? Seems to me that giving Astro Teller and a bunch of smart people blank cheques helps them have tones of fun without the pressure of actually succeeding?

Re: Google open sources solar atmospheric water generator

#200

Post by stephen_g » Fri, Mar 18, 2022, 7:45 AM UTC

colechristensen wrote: post #121

Ansil849 wrote: post #57

Are there any consumer-grade atmospheric solar water generators on the market right now? I did a very quick search and didn't find anything. Is there anything like this that people can buy right now?

You could buy a few solar panels, an inverter, a dehumidifier, and a water filter and be fine. The problem is sizing the power generation and dehumidifier to match and generate an amount of water meaningful to you. Regardless you need quite a bit of solar to get a decent amount of water.

Given that a dehumidifier is prime bacteria habitat, I'd recommend probably also putting it through UV sterilisation (or ozone or chlorine) before a decent filter cartridge before drinking. But yeah, the energy required is so high that it's usually one of the least useful ways of getting water in most places.