Electricity From Air/Water

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Can I get my 8 minutes back? I watched with interest because I expend much real energy extracting "humidity" from my indoor air. The one professor growing the wires claimed that a refrigerator sized device might someday power a house. 🤔

This IMO is yet another example of over selling a technology. They have bench top devices powering LCDs... (Hint: LCDs require very little current). One explanation given in passing is that water vapor molecule impart energy (charge?) to the top electrode?

I give them an "A" for optimism, but won't be holding my breath for this one.

JR
 
Hey John. If I could give you your eight minutes back I would...lol.
It just reinforces my inclination to NOT click on videos.... No worries my bad, it would be nice if real.

I hope they don't suck too many people in with another "green" substitute for producing energy.

JR
 
I wish I could. But you certainly saved me 8 minutes of my own time.

Don't watch it if you don't want. These are actual researchers/scientists from an actual university, etc...discussing a rather new type of tech they've stumbled upon.

Just don't go around throwing extra knives. Peace out.
 
I had no intention of doing such a thing. So, if it came across that way, my apologies.

It's just that I trust John's judgment on this.
 
I trust John's judgment as well, most of the time. But I have my own mind and perspective as well.
 
Not to dismiss this out of hand I did some more research.

https://www.smithsonianmag.com/smar...enerates-electricity-from-thin-air-180982263/

smithsonian said:
-The invention involves two electrodes and a thin layer of material, which must be covered with tiny holes less than 100 nanometers in diameter—thinner than one-thousandth the width of a human hair, according to a statement from the University of Massachusetts, Amherst, where the researchers work.

-As water molecules pass through the device, from an upper chamber to a lower chamber, they knock against the tiny holes’ edges, creating an electric charge imbalance between the layered chambers. In effect, it makes the device run like a battery. The whole process resembles the way clouds make electricity, which we see in the form of lightning bolts, according to Inverse’s Molly Glick.

-“What we have invented, you can imagine it’s like a small-scale, man-made cloud,” Jun Yao, a co-author of the new paper and an electrical engineer at the University of Massachusetts, Amherst, tells the Washington Post’s Dan Rosenzweig-Ziff.

Currently, the fingernail-sized device can only create continuous electricity equivalent to a fraction of a volt, writes Vice’s Becky Ferreira. But the researchers hope it can someday become a practical, sustainable source of power.

“Hard to know what to make of this,” Donald Sadoway, a materials chemist at MIT who did not contribute to the study, tells the Boston Globe’s Sabrina Shankman. “It’s not apparent what kind of practical numbers can emerge. Investors would ask what we can expect in terms of power output in watts and the cost.”
https://www.bbc.com/future/article/...ir-could-one-day-power-our-electronic-devices
BBC said:
In 2020, Yao and his colleagues published a scientific paper that described how tiny protein nanowires, produced by a bacterium, could harvest electricity from the air. The exact mechanism is still under discussion, but the material's tiny pores appeared to be able to trap floating water molecules. As they rub against the material, the water molecules also appear to lend it a charge.
Yao explains that, in such a system, most molecules stay near the surface and deposit lots of electrical charge while a few others penetrate more deeply. This creates a difference in charge between the upper and lower parts of the material layer.

Nevertheless, it might not be realistic to imagine such technology powering entire buildings or energy-hungry machines like cars, Rao cautions. Humidity might only be enough to power internet-of things-devices, such as sensors, or small wearable electronics.

This phenomenon was first recorded in 1840, when a train driver at a coal mine north of Newcastle, in northeast England, felt a strange tingling feeling in his hand while operating the engine. Later, he noticed a tiny spark jumping between his finger and one of the vehicle's levers. Scientists who investigated the incident concluded that steam rubbing against the metal of the engine's boiler had caused a charge to accumulate.

I found other articles that were even more optimistic about predicting huge energy potentials (from thin air).

Of course do not take my word for anything. Their explanations about how lightning is generated does not agree with my understanding but maybe I am wrong about that too. 🤔

JR
 

Abstract


Air humidity is a vast, sustainable reservoir of energy that, unlike solar and wind, is continuously available. However, previously described technologies for harvesting energy from air humidity are either not continuous or require unique material synthesis or processing, which has stymied scalability and broad deployment. Here, a generic effect for continuous energy harvesting from air humidity is reported, which can be applied to a broad range of inorganic, organic, and biological materials. The common feature of these materials is that they are engineered with appropriate nanopores to allow air water to pass through and undergo dynamic adsorption–desorption exchange at the porous interface, resulting in surface charging. The top exposed interface experiences this dynamic interaction more than the bottom sealed interface in a thin-film device structure, yielding a spontaneous and sustained charging gradient for continuous electric output. Analyses of material properties and electric outputs lead to a “leaky capacitor” model that can describe how electricity is harvested and predict current behaviors consistent with experiments. Predictions from the model guide the fabrication of devices made from heterogeneous junctions of different materials to further expand the device category. The work opens a wide door for the broad exploration of sustainable electricity from air.


https://onlinelibrary.wiley.com/doi/10.1002/adma.202300748

You have to pay for the whole study.

Here is a dumbed down article for people like me, similar to the Smithsonian article linked by JR.

https://www.popsci.com/technology/air-gen-electricity-film/

Of course, this is what's known as "science", a discipline which has pretty much been shown to be wrong and not to be believed over the last few years.
 
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My freshman chemistry is a little rusty after more than half a century of cobwebs. First what is "humidity"? Humidity is the gaseous state of water (H2O). The claim that it is a "vast, sustainable reservoir of energy ", ASSumes a) that is true, and b) there is a cost effective way to extract that energy. a) Yes of course there is energy all around us, high humidity is correlated with warm temperatures so those water vapor molecules are already moving around. b) A cost effective extraction mechanism stands to be proved.

The invention as I understand it is using small apertures ( less than 100 nanometers in diameter) that scrape off loosely held electrons from water vapor molecules. I don't doubt that there is measurable energy to be harvested from room temperature humid air like the example offered that can power a LCD display. Powering an entire home from a refrigerator sized apparatus is a remarkable leap.

I don't recall which thermodynamic law covers "no free lunch", but where is all this free energy coming from, "Brownian motion"? In polar water molecules the oxygen atom carries two unshared electrons that are available to create mischief with other atoms/molecules. Contributing these loose electrons to other atoms/molecules is known as oxidation.

None of this explains (to me) where the energy is coming from. Presumably from bumping against these 100 nanometer holes. The example given of a steam engine train creating shocks from voltage (surplus free electrons) through the metal controls suggests an obvious answer for where the excess energy is coming from (the boiler).

I do not doubt that this is a real phenomenon, I just question whether I will be ever be able to power my home from a refrigerator sized box of 100 nanometer holes. 🤔

I will continue to run my dehumidifiers (consuming energy) because I have a surplus of humidity.

I wish these optimistic predictions were true. ;)

JR
 
Actual science is good. But even that does not mean a practical working device at a usable scale can be made from this "discovery," much less mass manufactured. This is what differentiates engineering from science.

For example, this invention requires a very thin material with 100nm pores. How will this membrane be supported such that it can withstand the pressure per unit area for a larger scale (both area and pressure differential) device? How will the water be kept pure enough that the 100nm pores are not clogged? What is the net system loss for pumping/pressurization, filtration, etc. for a minimally viable product?

For now this is just another of thousands of scientific curiosities, few of which lead to any practical product or system.

Edit to add: For illustrative purposes 100nm is the size of typical virons (influenza, Covid, etc.). Bacteria are 10-100x larger. Pollen is 100-1000x larger than the pore size.
 
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Water is very generous with it's two unpaired electrons that will happily oxidize anything it comes into contact with.

The very small size of the electron stripper holes is bordering on biologic scales, like photosynthesis etc.

JR
 

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