RCA's Airenergy charger converts WiFi energy to electricity

January 13, 2010 by Lin Edwards weblog
CRA's Airenergy charger converts WiFi energy to electricity

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(PhysOrg.com) -- Airenergy is a gadget that can harvest free electricity from WiFi signals such as those from a wireless Internet connection, apparently with enough efficiency to make it practical for recharging devices such as mobile phones.

At the (CES) in Las Vegas this week a RCA spokesman said they had been able to charge a BlackBerry from 30% charge to fully charged in around 90 minutes using only ambient WiFi signals as the power source, although it was unclear on whether the Airenergy was recharged in that time. The Airenergy recharging time depends on the proximity to the WiFi signal and the number of WiFi sources in the vicinity.

The RCA Airenergy unit converts the WiFi antenna signal to DC power to recharge its own internal lithium battery, so it automatically recharges itself whenever the device is anywhere near a WiFi . If you have a wireless network at home the Airenergy would recharge overnight virtually anywhere in your home. When you need to recharge your phone or other device you plug the Airenergy battery into the phone via USB to transfer the charge.

This video is not supported by your browser at this time.

Harvesting electricity from signals in the air is not new, as anyone who ever built a crystal radio running only on the radio signals it received can testify, but until now no device has been able to harvest enough electricity to make it of practical use. In most modern cities WiFi signal hotspots abound, which might make the Airenergy device a viable option, although in rural areas WiFi sources are less widespread.

A USB charger costing around $40, and about the size of a phone, is expected to be released later this year, with a WiFi-harvesting battery around the same size and price as an OEM battery available shortly after.

© 2010 PhysOrg.com

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ThomasS
Jan 13, 2010

Rank: 4 / 5 (5)
something tells me its more efficient to hook up your phone directly, and switch off the wifi.
joefarah
Jan 13, 2010

Rank: 5 / 5 (1)
Why not build this right into the phone.
fhtmguy
Jan 13, 2010

Rank: not rated yet
You may be right Thomas but it is free if your neighbor has wifi or anywhere outside your home. Great if you forget your charger on a trip.
Smellyhat
Jan 13, 2010

Rank: 1.7 / 5 (7)
The 'RCA' famous for it's 'little dog looking into a gramophone' logo no longer exists as a company. I have read elsewhere that serious questions are being raised about whether sufficient energy exists to be harvested in this manner. The probability that the device is fraudulent should be taken into consideration pending further information.
El_Nose
Jan 13, 2010

Rank: 5 / 5 (5)
RCA never went away and they never went under -- there logo is still a dog, they just stopped trying to make TV's and stereo's and focused on technology becuase thats what they are good at.

If it is a bad idea then it will get exposed... but I wouldn;t call it fraudulent until you do the actual work to prove it false.
KBK
Jan 13, 2010

Rank: 2.1 / 5 (15)
When it comes to RF radiation from microwave ovens, no amount of leakage, it turns out..is safe. The frequencies that microwaves work at..are ones that have the best capacity to pass through air that is filled with H20 and also to excite H20. That's how they work. Same frequency ranges as your cell phone and cordless phones, I might add.

Now when it comes to WiFi, the freq ranges are of a similar nature.

Now, anything that can harvest Wi-Fi from the air and convert it to usable energy, ie, electricity ..and that the loses in conversion occur..it tells you that if you are getting enough Wi-Fi energy to charge your cell phone, then that is entirely far too much energy in the air. it is harmful.

Note that in Germany, it is illegal to have any cell phone towers within, IIRC, about 500M or 1K (I can't remember the distance) from any school for children. This is because they know and have clearly illustrated that the waves are very harmful.

I'm not anti-technology, I'm anti-stupidity.
Bob_Kob
Jan 13, 2010

Rank: 2.6 / 5 (5)
Im really trying hard to find something to counteract your clams KBK, but i cant.

I had no idea wifi was at almost the exact same frequency as a conventional microwave oven. Who gave the green light for this?
seraph321
Jan 13, 2010

Rank: 4.6 / 5 (9)
@KBK & Bob Kob
Yeah, and in other news, the heat that powers your stove is the same kind that can burn down your house and the oxygen in the air is the same thing they use to power rockets to the moon! In fact, it turns out, if you breathe really fast it can knock you out!

Come on people. We're talking massive differences in intensity and focus here. There is nothing inherently wrong with some given frequency, it's how it's used. If they can make a unit that sits there for hours and siphons off tiny bits of usable power from an extremely low-intensity signal like Wifi, then more power to them (pun intended).

They aren't saying you can pull 5volts of DC directly from the air, they are saying you can get enough to very slowly charge a battery that will later provide 5v to a separate unit like your phone.
Temple
Jan 13, 2010

Rank: 4.5 / 5 (8)
KBK: "The frequencies that microwaves work at..are ones that have the best capacity to pass through air that is filled with H20 and also to excite H20."

That is why you fail.

Energy can either pass through a medium best, or it can excite a medium best. It cannot do both. Exciting the H20 in the air will dissipate the energy (by definition).
ThomasS
Jan 13, 2010

Rank: 4.2 / 5 (5)
microwave ovens actually do frequency sweeps (unlike Wifi), and work by alternating magnetic fields, which cause polar molecules to alternate orientation, but they do not excite h20 in the sense of moving electrons to a higher bandgap.

Besides, a microwave is 800 watts and wifi is probably no more than 0.1 watt radiated power.

About the device, anyone wants to take a bet about it appearing in consumer electronics? Im betting not.
ThomasS
Jan 13, 2010

Rank: 5 / 5 (1)
I have read elsewhere that serious questions are being raised about whether sufficient energy exists to be harvested in this manner. The probability that the device is fraudulent should be taken into consideration pending further information.


hear hear :)
xtra_chrispy
Jan 13, 2010

Rank: 5 / 5 (2)
does anyone else here see similarities between this and Tesla's ideas of wireless energy, that alot of scientists claim is impossible
LKD
Jan 13, 2010

Rank: not rated yet
Is this article related to this one: http://www.physor...477.html It's the first thing I thought of when I was reading about this technology.

It would be very nice if they can come up with a means of doing this over longer distances.
Bonkers
Jan 13, 2010

Rank: 5 / 5 (3)
- looks like bollocks to me - the permitted output of WiFi is 20dbM - 100 milliwatts, quite a lot really as far as exposure is concerned.
the charge performance was 30-90% in 90 minutes - of a blackberry - say of 0.8 Amp-hour @ 3.7Volts = 3 watt hour = 10kJoules total
this would charge in ~150 minutes = 10,000 seconds, therefore we need an input power of 1 watt, not 100mW.
not only that but the 100mW is in all directions pretty much, and we couldnt hope to intercept more than a few percent at most - and this when under a metre from the antenna.

So, there's a factor of ten by conservation of energy, and another factor of maybe twenty by geometry, to explain away.
like i say, Bolx.
saintneko
Jan 13, 2010

Rank: 4.8 / 5 (4)
No proven link between cellphone frequencies(1) and any harm. Cellphones operate well below the level of ionizing radiation.

"i read somewhere ..." a lot of things, but that doesn't make them true. Link to respected scientific endeavors, annotated Wikipedia articles.

"Non-ionizing radiation is thought to be essentially harmless below the levels that cause heating."(2)

1. "In November 2008, Turkey has auctioned four IMT 2000/UMTS standard 3G licenses with 45, 40, 35 and 25 MHz top frequencies." http://en.wikiped.../wiki/3G

2. http://en.wikiped...adiation

Radiation intensity decreases sharply with distance, according to an inverse square law.[2](3)

danman5000
Jan 13, 2010

Rank: 5 / 5 (1)
@Bonkers:
This quote from the article should explain it for you:
they had been able to charge a BlackBerry from 30% charge to fully charged in around 90 minutes using only ambient WiFi signals as the power source, although it was unclear on whether the Airenergy battery was recharged in that time. The Airenergy recharging time depends on the proximity to the WiFi signal and the number of WiFi sources in the vicinity.

In other words, the device uses WiFi energy to charge a battery very slowly, then uses that battery to charge another battery (the Blackberry) much more quickly.
NotAsleep
Jan 13, 2010

Rank: 3.5 / 5 (2)
Also @ Bonkers:
Excellent comment. I think that they're intending this to be used in areas with multiple wifi sources, though. From the article:

"In most modern cities WiFi signal hotspots abound, which might make the Airenergy device a viable option, although in rural areas WiFi sources are less widespread"

Perhaps this would be convenient for people in airports, assuming it works
El_Nose
Jan 13, 2010

Rank: 1 / 5 (1)
@xtra_chrispy google wireless energy tranmission

heck there was even a large screen tv at CES that had no wires to demonstrate as long as it was 1 meter from the radiation source it would work.
TechnoCore
Jan 13, 2010

Rank: 5 / 5 (2)
@bonkers: Yes. Here is another calculation, saying it would take about 34 years to charge a blackberry:

http://scienceblo...comments
Thex1138
Jan 13, 2010

Rank: 1 / 5 (1)
Well.. if it's all so free then why aren't the coils being built everywhere, or alternately... being placed to retrieve some of the power exuded by WiFi and other radio bands...
Still got that Bolx wiff around it though.
wshanks
Jan 13, 2010

Rank: 5 / 5 (5)
I call total and Complete Bull on this product.

I am a RFID Engineer. I design energy harvesting circuitry. These claims are completely, out of Ball Park, unreasonable.

Lets us look at the basic physics. A BalckBerry battery has a capacity of roughly 1 A hr. With a terminal voltage of 3.3 V, to go from 30% charged to 100% represents an energy of about 8 kJoules. For the charger to supply this in 90 min the charging power would have to be over 1.5 Watts. The radiated power at a WiFi transmitter is 0.1 watts.
FCC part 15 regulations allow 1 watt of average radiated power, but this is out of the 802.11 spec. Normal wifi router and laptop access points radiate some where between .01 and .1 watt.

The fraction of energy that you can capture a few feed away from the such a transmitting antenna is at most a few milliwatts. Perhaps a few tens of milliwatts if their antenna was a few inches form the transmitting antenna. This would necessarily impair the operation of the wifi transmitter.
Mayday
Jan 13, 2010

Rank: 1 / 5 (3)
Why not build a house out of these things and go off-grid forever?
danman5000
Jan 13, 2010

Rank: 4 / 5 (3)
@wshanks and most other commenters: See my comment above to Bonkers. The energy in the air was not what charged the Blackberry. The WiFi radiation charged a battery on the Airenergy device. Then, this stored charge was transferred to the Blackberry's battery. It's the same as if they charged their Blackberry from a pair of AA batteries. The difference is where the initial energy came from.
Admittedly, this was pretty well hidden in the text.
DozerIAm
Jan 13, 2010

Rank: 5 / 5 (2)
Note that in Germany, it is illegal to have any cell phone towers within, IIRC, about 500M or 1K (I can't remember the distance) from any school for children. This is because they know and have clearly illustrated that the waves are very harmful.

I'm not anti-technology, I'm anti-stupidity.
Perhaps you should stop reading your own posts then. The fact that a country enacted a law is merely proof that laws can be enacted. The presence of the law doesn't prove the theory.

Here are 2 studies that are both recent, both from reputable publications, and both contrary to your opinion:

http://www.physor...604.html
No change in brain tumor incidence during a time when cell phone usage increased. (Journal of the National Cancer Institute)

http://www.myfitb...heimers/
Cell phones may be good for Alzheimer's. (Journal of Alzheimer's Disease)
fixer
Jan 13, 2010

Rank: 2.8 / 5 (5)
All true, But...
Consider the number of RF emmiters in your neighbourhood.
Start with WIFI, but add radar from speed cameras, aircraft and fixed installations, then add TV and radio antennas, Cell phone installations and the millions of phones that go with them.
Add to that GPS signals and lets not forget the massive gusts of RF from overhead power cables too.
Then there's the sun and interstellar RF sources...

I may have missed a few, but the air is so thick with RF over a range of frequencies that you could harvest power just by walking through it.
I think this is the start of a new wave of energy harvesting.
wshanks
Jan 13, 2010

Rank: 5 / 5 (5)
Quote from "fixer"
"All true, But... Consider the number of RF emitters in your neighborhood."

Radio works because we can easily detect RF energy in the billionth of a watt. The energy density in radio waves across the entire radio and microwave spectrum is on average in the microwatts at best. There is no abundance of energy floating around in the air. The key piece of technology for long range UHF RFID is the fact that modern ICs are able to operate on a few microwatts, and we power them with the equivalent of an RF flood lamp. Ok, it was stated that the device has internal batteries, but to charge those batteries after one "Blackberry Recharge" would take some where between 9 and 90 days unless this box is sitting directly in-front of a transmitter. I can go and get batteries before that. There is more energy in ambient light, so put a solar cell on the thing.

Wayne S
Bonkers
Jan 14, 2010

Rank: 1 / 5 (1)
Sorry Danman5000 -but i do not share your interpretation of the article. ...
@Bonkers:
This quote from the article should explain it for you:
they had been able to charge a BlackBerry from 30% charge to fully charged in around 90 minutes using only ambient WiFi signals as the power source, although it was unclear on whether the Airenergy battery was recharged in that time. The Airenergy recharging time depends on the proximity to the WiFi signal and the number of WiFi sources in the vicinity.


It mentions that the charging was performed with WiFi as the ONLY energy source - to my mind excluding use of stored energy in its battery.

It also mentions that the airenergy battery was probably not given any charge during this time - giving me the impression that the argument is between no-nett-recharge and some-nett-recharge, i.e. excluding a-whopping-discharge.
danman5000
Jan 14, 2010

Rank: not rated yet
@Bonkers: WiFi is indeed the only energy source - that's where the stored energy in its battery comes from. You made me doubt myself, so I looked around on google for some more information. Surprisingly, there isn't any. Nearly all other links lead back to this article. The only different one I found was http://techieloba...-within/ It's just some guy saying a few sentences about it (basically could have been another comment here), but at least he agrees with me :)
The fact that we disagree on this shows how poorly worded this article is. I wish I could find some better info.
antialias_physorg
Jan 15, 2010

Rank: 1.7 / 5 (3)
The article reminds me of people putting up coils in their back yard to 'harvest' radio tower transmissions for usable energy. It works, but you get thrown into jail for it (because by pulling the energy out of the air you are creating a huge radio shadow in which no transmission can be received)

So yeah, it works. But if you use his gadget in a public space be prepared to face a lot of people who are pissed off because their WiFi connection just dropped.
KBK
Jan 16, 2010

Rank: 1.2 / 5 (6)
The human body is a very subtle and sensitive electrochemical device. We are no-where near understanding how such radio waves disturb it's operation. What is safe for one is not safe for another. This much should be obvious.

For the record, I'm completely against wi-fi, period. Or other RF pollution.

IMO, we are still in the monkey based 'I can't see it therefore it's not real' aspects of understanding how dangerous RF can be for the human body's correct operation, ie how much it can interfere.

Cellphone health data was collected WELL after Celphones had been around for along time and most of the corporations selling them were the primary sources of that info, so they have a very potent vested interest in a 'negative/null health affect outcome', so bias is inherent in the data.

If we are getting to the point that some are trying to harvest an expected high level of RF in such environments..well..I, for one, am not going to be anywhere near it.
MVV
Jan 17, 2010

Rank: not rated yet
Sounds like to old Tesla dream of free wireless electricity for everyone is near.
sender
Jan 17, 2010

Rank: not rated yet
piezoceramics doped polymers will revolutionize wireless energy systems from LIR to HUV
ThomasS
Jan 18, 2010

Rank: 5 / 5 (2)
KBK, danman, your monitor is emitting more radiation to your faces in the second you read this than will all the RF power in your neighbourhood for a month. Also, I suggest you get out of the sun immediately.
ableclic
Jan 18, 2010

Rank: not rated yet
The device captures WIFI signals from multiple sources at the same time and last time I searched my "Available Wireless Networks" there were about 20 available from my living room. The device probably works as they say, but I will be looking to try for myself. Microwaves and Cell phones ... what a riot. Do people actually read what they write?
danman5000
Jan 19, 2010

Rank: not rated yet
KBK, danman, your monitor is emitting more radiation to your faces in the second you read this than will all the RF power in your neighbourhood for a month. Also, I suggest you get out of the sun immediately.

What post of mine does this reference? My only comments on this article were to clarify the battery charging aspect of this device. Nowhere did I say anything about types or strengths of radiation.
LKD
Jan 19, 2010

Rank: not rated yet
..well..I, for one, am not going to be anywhere near it.


(Completely serious and respectful)
Considering your view. I would think you would prefer to wear a couple to avoid the harmful effects? After all, if they absorb the radiation, that means you can avoid the cancer or cell mutation that you feel they might cause.

I will not argue your overall view, but I disagree to an extent your view of RF potency, and state that if this does what it says, you should relish the absorption potential.

I do disbelieve those that say they are 100% harmless, as it doesn't take much to start cancer in a human being, but I do feel that a reasonable amount in the background will be negligible worst case, and look forward to the Terahertz future with welcome arms.
Objectivist
Feb 15, 2010

Rank: not rated yet
KBK, let me ask you this. You seem to be fairly confident that EM-waves passing through your body are harmful, thus: how does EM-waves harm human tissue? Oh, and you can skip the MW spectrum, it's not relevant to my point and I think (at least I hope) you know what happens when human tissue is exposed to MW radiation.

To the others: please let him answer this. Naturally I am asking him since the answer will cure his delusions.

If you don't know the answer then before guessing, please take a look here: http://en.wikiped...d_health
AlienSteve
Feb 23, 2010

Rank: not rated yet
I'm seeing a lot of hand-waving arguments going on here.

Putting one of these in a room will -not- knock out someone's WiFi. It will only absorb the radiation that it intercepts, it doesn't suck energy out of the room. It should not affect the signal in a measurable way, unless you have it laying on top of your WiFi antenna.

In a similar way that putting a small solar panel in a room isn't going to make the room go dark by sucking all the light from the bulb.

At school, I got my connection from a WiFi router that was on the other side of two rows of 7 foot metal lockers. Scatter and diffraction provides enough signal. So I doubt a small object is going to block my signal when a dual row of 7ft by 50ft lockers can't.
Rank 3.8 /5 (29 votes)
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