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Harvesting Energy From Humidity
rtoz writes: Last year, MIT researchers discovered that when water droplets spontaneously jump away from superhydrophobic surfaces during condensation, they can gain electric charge in the process. Now, the same team has demonstrated that this process can generate small amounts of electricity that might be used to power electronic devices. This approach could lead to devices that can charge cellphones or other electronics using just the humidity in the air. As a side benefit, the system could also produce clean water. The device itself could be simple, consisting of a series of interleaved flat metal plates. A cube measuring about 50 centimeters on a side — about the size of a typical camping cooler — could be sufficient to fully charge a cellphone in about 12 hours. While that may seem slow, people in remote areas may have few alternatives.
Could we place banks of these along the US / Mexico border at aid stations so that incoming immigrants can stop and hydrate and recharge their cell phones?
Power and water to produce... more power and water? Hmm... I wonder how much this could scale up
its called a solar panel. it'll charge your phone in about an hour
"What I really need is a droid who understands the binary language of moisture vaporators."
Authority questions you. Return the favor. -- d474
I'm from Florida and I'll take 30.
Are these modeled after the moisture vaporators used on the moisture farms of Tatooine
the amount of power produced was vanishingly small â" just 15 picowatts, or trillionths of a watt, per square centimeter of metal plate. But Miljkovic says the process could easily be tuned to achieve at least 1 microwatt ... per square centimeter.
This is another "5 years away" technology. I'll believe it when I see it.
Also, how did they calculate that? My phone's battery contains about 1000mAh at about 3.5V, or 3 joules. To charge that in 12 hours, you'll need 250000 square centimeters, or 50000 square centimeters per cube side, which comes out to larger than 2 meters cube.
They talk about making it smaller by having a large internal surface area, but I do not believe their fins-on-a-radiator strategy will work, since the moisture would condense near the edges of the fins that are exposed to open air, and the air reaching the middle wouldn't have any moisture left to condense.
"While that may seem slow, people in remote areas may have few alternatives."
''few' as in this device but no bug spray or cookstove, or few as in near death, out of water and food with only one magic wish left?
certainly not fandroid or Yphone
At ~1pW/cm^2, a 50x50cm verision of this will provide about 30mWh in 12 hours. Tiny cell phone battery. Heck, a tiny lithium coin cell will provide ~150mWh.
For contrast, a typical solar cell will give 130W/m^2 (-ish), so a 0.25m^2 solar cell will provide ~33W, while the sun shines, obviously.
I'm not sure where exactly on Earth is sufficiently "remote", dark, moist, and unreachable that this makes sense. (Yes, I though of that, but it's really uncomfortable to fit a camping cooler there...)
#include "standard_disclaimer.h"
As in, you need some cooling to get the condensation happening.
Still, pretty neat to get electricity from it.
The sales droid at the local Verizon store will state that your humidity powered phone has a no warranty coverage because it was subjected to humidity.
Didn't Frank Herbert write of something similar to this in Dune? I recall small objects which collected water, but I don't recall whether they provided any sort of power generation in the process.
What else can happen when an unstoppable force collides with an immovable object?
Now my fat sweaty body will actually be good for something... Eat It Mom!
Would this work with snow? Sounds useful for Canada and other places that have snowy winters that aren't so solar-friendly. Won't help on an overcast-but-not-wet day though.
It's interesting, but practically speaking is it worth building a large, passive electricity and water generator in a cave system?
Not really.
OTOH, it would generate electricity forever, or at least until dust caked all the plates.
You're not going to be carrying this thing in a backpack, so it's not like you won't have a car to charge your cellphone.
On the other hand, you might be far enough out in the boonies that you can't get a car to where you are. Of course, the question then becomes "how are you using a cellphone when the nearest cell tower is 40 miles away"?
That aside, if my choice reduced to carrying a cube 20 inches on a side to charge my cellphone or eight extra cellphone batteries, I know which I'd pick.
"I do not agree with what you say, but I will defend to the death your right to say it"
Given that a low end cell phone charger is about 2 watts, 1 watt would be a fair performance assumption for that 50cm unit. That gives us an approximate 8 watts per mÂ. Scaling up, this means that a cube 5 metres on a side will generate a kilowatt of electricity.
under the same conditions? That's what would really be interesting.
This new device needs a temperature differential and humidity to operate. A thermocouple only needs a temperature differential. The new device won't work anywhere where there isn't a humidity high enough to provide condensation (such as space).
It's a curiosity, but I'm not investing any money in it in the short term...
Quick, someone call Kickstarter and get iFind up and running again.
So you're telling me that when I'm outside pouring sweat in the oppressive Floridian humidity, I can look down at my phone to see it's charging and for a brief moment not hate where I live? TAKE MY MONEY!
and you can create X-rays by rapidly unrolling scotch tape in a vaccuum. I don't see conventional X-Ray machines, let alone CT scanners, leaving the scene to make way for "Scotch Tape" X-Rays. I also don't see me getting rid of my USB charging cord to make way for dehumidifier chargers. It is interesting that people have found these things out though. It gives me hope that there is still enough inquisitive nature left for true innovation.
I would have a sig but I am too busy updating programs and restarting my computer
did not know that water vapor has much energy to power small electrical devices. Thanks for sharing.
This will not only trigger Global Drying, but Republicans will deny it's happening, making it hard to do anything about it, and Koch bro's will buy up moisturizer lotion companies to profit from it.
Table-ized A.I.
While that may seem slow, people in remote areas may have few alternatives.
Try this or this as alternatives.
How much energy does it take to create a super hydrophobic surface?
Way too high tech for remote areas.
Bringing clean water to remote areas in Africa means using parts that can be sourced from those remote areas using skills taught in those remote areas or else it's back to dirty water in a few years.
Think about aliens crashing a ship on Earth. Where would we get the parts to fix it? Alien technology is worse than useless when it fails.
dam! I wish I had thought of that
Scientists have conducted simulations using super computers and whole bunch of formulas to test the impact that these devices might have on climate. Their research was inconclusive due to lack of funding but they say that it could lead to devastating planetary dryness and eventually global catastrophe. They are requesting another $10bn annually to continue the important research and have begun to lobby for Al Gore to become their fund raising spokesperson. Meanwhile a base of deniers is building who deny that these devices will cause any harm. They are all funded by big oil though and their opinions do not count.
While the "water droplets spontaneously jumping off superhydrophobic surfaces" effect is interesting in itself, the mechanism of stripping charge from those droplets as they leave the apparatus sounds like a variation of the Kelvin water-drop energy harvester from 1867. In this case, rather than charge separation via the cross-connected cups, electric-double-layer charge-separation occurs between the droplet and the hydrophobic surface, causing the two to come away similarly unbalanced when the droplet jumps away.
Caveat Emptor is not a business model.
I gather that "remote areas" somehow excludes deserts? Amazing ...
This is news? Any good RF engineer or ham radio operators know that water droplets moving through the air develop static charges that cause interference. Every see the arc jump across an antenna connector when humidity builds up on the surface of a 60 foot vertical antenna and the droplets run down? Transfers all the electrical charge to antenna and then arc across the connection at the radio. Many a radio has been destroyed due to this effect. What about the high school science experiment where you take two soup cans, attach wires to them and bring the wires to within an 1/8 of an inch of touching and then drip water through both cans? Watch the spark you get out of that!
Some scientific discovery.
Other than:
Solar power, at roughly $1/watt (and then "free" for 10-20 years), price falling on a nearly Moore's Law trajectory.
Wind power -- expensive, unreliable but simple technology and humidity isn't reliable either.
The entire panoply of standard sources -- coal, oil, gasoline, nuclear, hydroelectric, alcohol, diesel, methane... which we can deliver a variety of ways including simply delivering a small generator and fuel.
I would truly be amazed if a new, patented technology of this sort was within an order of magnitude -- or even two -- of the cost of a solar source superior in nearly every way, and there are very few places where the humidity is high, temperatures are reasonable, and the sun does not produce enough light to make this work. This is truly an edge technology unless they make it astoundingly cheap.
rgb
Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
Really MIT? Stooping to ripping off the University of Dayton?!
http://books.google.ca/books?id=ZgEAAAAAMBAJ&pg=PA75
Seriously, something like that would enable a transmitter and a camera to be set up. Where this could be useful is for fire, weather, geological monitoring. Heck, this could even be used to put simple digital telescopes up on 14K' tops and broadcast back.
I prefer the "u" in honour as it seems to be missing these days.
With electrolisis and a fuel cell, only the gas carried contaminates could possibly contaminate the drinking water. For quanity and qualityproduced, I'll take the solar solution. The distances traveled and the amount produced are both quite small. In the solar solution, the volume would be much greater and due to the recombining of gasses, much less likely to transport pathagens.
The truth shall set you free!
I live in an area with high humidity (~80% / 25C) and am wondering how well this would work as a dehumifier that uses no electricity. The one we own is rated at 400 Wh. We often run in daily for 2+hrs. Also, if this is effective I can see other uses, like drying clothes. Or a small set up that can provide 2-3 liters of potable water/day.
Perl Programmer for hire