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UK company reveals new technology that can transform radio frequency waves into energy

By midian182 ยท 14 replies
Oct 2, 2015
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  1. A British startup company, Drayson Technologies, has unveiled a new technology that harvests electricity from unused radio frequency waves in order to charge low-power electronic devices such as sensors and beacons.

    The patented technology, called Freevolt, harvests the ambient radio frequency waves from WiFi, cellular and broadband networks and turns it into a small but usable amount of energy. It’s been suggested that Freevolt could be used to power the low-energy devices used in smart homes or certain wearable tech like the Fitbit.

    Drayson Technologies CEO and former UK science minister, Paul Drayson, said that companies have been trying to draw out energy using this method for years. "But it is difficult, because there is only a small amount of energy to harvest and achieving the right level of rectifying efficiency has been the issue," he said.

    The solution to this efficiency issue was to develop a multi-band antenna that can harvest the energy from a broad spectrum of radio bands; improve the rectifier component, which transforms the energy into an electric current; and create an optimized power management system to make sure all the spare energy is collected.

    It is the nature of broadcast transmissions that, when you broadcast, only some of the energy is received and used. The energy that is not received goes to waste. It's only nanowatts of energy, but the energy is everywhere. What we're doing is using that fact to power very small low-energy devices. The radio frequency transmissions come from wireless networks, and as our hunger for information goes up, the amount of data that we want to transmit is going up exponentially, and therefore this is growing all the time

    Drayson demonstrated the first product to use the technology, a personal air pollution monitor called the CleanSpace Tag, at the Royal Institution in London. The device is a carbon monoxide sensor that monitors personal air quality and transmits the data, via Bluetooth, to an app on a user’s smartphone. The battery in the CleanSpace Tag is continually recharged by a Freevolt energy harvester.

    One issue that has been raised is whether or not the owners of the wireless spectrum that Freevolt would be harvesting will demand a fee. Drayson says this is unlikely and he is confident it would have no legal basis.

    Freevolt is available for license globally, giving other companies the chance to find uses for the technology in their products. It’s hoped that Freevolt could one day be used in compact wearable products that require frequent charging, such as smartwatches. And while shrinking the technology would give it more applications, it could also be made larger and built into walls in order to collect more energy. "It's going to be really exciting to see what ideas people come up with," said Drayson.

    Permalink to story.

  2. stewi0001

    stewi0001 TS Evangelist Posts: 2,198   +1,625

    This sounds really neat.

    What I am wondering about though, based on what I read here, is that technically the device would act as a signal sponge and converting to energy. So let's say the device is on the wall of room A that is adjacent to room B. The Wifi router is in room A. Would the signal be weaker and possibly dead in some parts of room B?
  3. wiyosaya

    wiyosaya TS Evangelist Posts: 3,984   +2,286

    There is only so much energy in a radio wave, and given your hypothetical situation, I think there is a possibility of dead spots that would not be there if the device were not there.

    Radio works because a receiver is able to take the signal in the air and amplify it, I.e., adds more energy to it, in the receiver. If there is not enough signal so that the receiver cannot amplify it, then the receiver does not work.

    What it sounds like this device does is drain the energy from the signal in the air and doing so has to weaken the signal in some way, otherwise, the device would be breaking the laws of physics.

    Your hypothetical situation, I believe, is also the reason behind this quote from the article:
    From this quote, it seems clear that Drayson understands that the energy harvested comes from the signal's transmitter, and thus whoever is transmitting the signal is the one that is providing the energy for this device to harvest. In my opinion, it is unlikely that this device will absorb all of the energy that is being transmitted, but if you were to set up a mesh on a wall that functioned as the antenna, to me, it seems that there would be little difference between this device and a Faraday cage so that no energy would get through.

    I am speculating based on my knowledge of physics, of course, but the only way to know for sure will be when this device is in the open market and people start complaining that their normally strong WiFi signal is suddenly too weak to be usable in the presence of this device.
    Elec-Techie likes this.

    IAMTHESTIG TS Evangelist Posts: 1,720   +808

    Pretty cool. wonder if one could power a security camera with it that also uses WiFi. Could it then power itself in a way? Hmmmm.... The efficiency is probably considerably less than solar panels but this all slowly improves over time.
  5. jobeard

    jobeard TS Ambassador Posts: 12,883   +1,530

    Ouch - - clearly no experience with RF propagation. Just like photons from the Sun are scattered, RF is scattered and just because there is one or more receivers does not mean that 100% of of the transmitter energy is being consumed - - let alone being consumed by one and only one receiver.

    another analogy is baseball. hits go all over the place and only those that get intercepted by a fielder can generate outs - - all the others are untouched and generate hits.

    Your WiFi router is a transmitter and our devices are receivers, but any device like that described in the article is totally independent of all the other wifi connections and DO NOT reduce the signal strength NOR interfere. WHY? Because the raw RF being received is not being 'used' and the encoded content is not even attempted to be read. The picture is a basic RF detector and by choosing the values of L1 & C1, the frequency being detected can be chosen (aka tuned). The outputs between A & B will be DC voltage directly proportional to the strength of the RF being received.

  6. wiyosaya

    wiyosaya TS Evangelist Posts: 3,984   +2,286

  7. jobeard

    jobeard TS Ambassador Posts: 12,883   +1,530

    Well, the CIA uses a grounded "metallic grid" across the windows to stop EFI from radiating out of secure facilities. The old IBM 3270 monitors pushed enough energy to be read easily down the block with simple equipment.

    The Radio Telescope grid antennas North of Las Vegas catch minute energy and allow amplification of signal - - but still never consume even 1/10^6 of the radiation being emitted.

    The problem with the technology suggested is getting meaningful power to be useful.
    As P = VA and the simple detector shown above only generates millivolts, you do the math to collect just one Watt.
  8. tonylukac

    tonylukac TS Evangelist Posts: 1,376   +72

    No wonder those 3270 ibm monitors gave me such a headache. As to the article, what you're talking about is tesla electricity transmission. Google it.
  9. wiyosaya

    wiyosaya TS Evangelist Posts: 3,984   +2,286

    Indeed - Radio Telescopes pick up faint signals from vast distances. The key is the amplification.

    And I agree about how much power will be useful from this device. They are selling a device in the UK. Though there are many reasons to not sell elsewhere, I have to wonder whether part of the reason that they are not pursing selling devices themselves instead of "patent rights" elsewhere is because of the fact that such a miniscule amount of energy is available. They are probably counting on RF being always available everywhere, but the fact is that it depends on location. In cities, maybe there will be enough signal to harvest. In the suburbs or rural areas maybe not. On top of all this, though, are basic well-known issues of propagation.

    Time will tell, but as far as the current state of the technology goes, I cannot help but think of free-energy devices that people claim to produce and yet they have never panned out.
  10. jobeard

    jobeard TS Ambassador Posts: 12,883   +1,530

    Correction: The diagram above is not a tuning circuit - - it's a lowpass filter :sigh:

    Here's the tunable frequency detector and/or rf strength monitor:
    (it's been only 3 decades since I did this kind of stuff)
  11. Joe 5mith

    Joe 5mith TS Rookie Posts: 16   +11

    This is great! I'm going to get one and plug in my cell phone - viola! - no more battery!
    Then I think I'm going for the XL Freevolt - enough to power the house!
    And that car battery has always been trouble. Ha! It's gone!

    C'mon people - even Freevolt says it's "nanowatts". (That's billionths (!) of a Watt). That's not enough to power anything very useful, including your cell phone or flashlight. Not even close!
  12. deemon

    deemon TS Addict Posts: 294   +89

    Why only unused? I would gladly harvest my neighbours WIFI signal into energy with my wall panel harvester-device and not even feel bad about it, because he is invading my space with this ... it's more like a countermeasure.
  13. jobeard

    jobeard TS Ambassador Posts: 12,883   +1,530

    source is (of course) the wiki here
  14. cliffordcooley

    cliffordcooley TS Guardian Fighter Posts: 11,389   +5,016

    Why would you feel bad about it? Think of it as a light source. You only need light in specific locations through out the room. All other locations are unused lighting. Now if you could harvest the unused lighting, why would you think the lighting can't still be used where needed.

    And if you think about it the same concept applies to the reflective lens behind a flash light or satellite dish. The reflective surface reflects potentially unused lighting/signal and projects it to where it can be used.

    This would be no different than harvesting solar emissions from the opposite side of the sun to earth. They are unused emissions and harvesting them would not prevent the solar emissions we need and use through out our day. So why would you feel bad about harvesting the unused emissions?
  15. deemon

    deemon TS Addict Posts: 294   +89

    I would not. That's what I wrote in the first place that you are quoting on.
    cliffordcooley likes this.

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