RCA's Airenergy charger converts WiFi energy to electricity
January 13, 2010 by Lin Edwards
(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 Consumer Electronics Show (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 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.
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 hotspot. 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.
You need Flash installed to watch this ideo
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
13 hours ago
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.
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.
I had no idea wifi was at almost the exact same frequency as a conventional microwave oven. Who gave the green light for this?
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.
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).
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.
hear hear :)
It would be very nice if they can come up with a means of doing this over longer distances.
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.
"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)
This quote from the article should explain it for you:
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.
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
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.
http://scienceblo...comments
Still got that Bolx wiff around it though.
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.
Admittedly, this was pretty well hidden in the text.
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)
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.
"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
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.
The fact that we disagree on this shows how poorly worded this article is. I wish I could find some better info.
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.
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.
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.
(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.
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
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.