Student-Designed Electromagnetic Harvester Pulls Power From Thin Air

What if recharging the battery in your favorite mobile device was as easy as holding it up to the sky? No solar charger, USB port, or wall outlet required. German design student Dennis Siegel is winning awards with just such a miracle gadget–an electromagnetic harvester that captures and repurposes the electromagnetism that’s all around us.

Lights, power lines, even the gadgets in your pocket: all of these machines emits a very small amount of electromagnetism into the environment. Siegel’s device takes advantage of this wasted energy, using it to generate new electricity that could be used to charge a battery.

Dennis Siegel, electromagnetic harvester

Image via Dennis Siegel

Since the amount of electricity floating around in the air is relatively small, Siegel’s biggest challenge has been to harvest enough of it in a relatively short amount of time. So far, the device he built takes about a day to fully charge a AA battery. But even that feat was impressive enough to earn him a 2nd place award in the HfK Bremen Hochschulpreis 2013 competition for Digitale Medien.

Siegel imagines a world where we’ll be able to “gain redundant energy from the power supply of a coffee machine, a cell phone or an overhead wire by holding the harvester directly into the electromagnetic field whose strength is indicated by a LED on the top of the harvester.”

Siegel has now added electronics to give the device the capability of capturing electromagnetism in two ranges—one below 100Hz (electrical mains, etc.) and another for capturing those above 100Hz (Blue tooth frequencies etc.), reports PhysOrg.

Beth Buczynski is a freelancer writer and editor currently living in the Rocky Mountain West. Her articles appear on Care2, Ecosalon and Inhabitat, just to name a few. So far, Beth has lived in or near three major U.S. mountain ranges, and is passionate about protecting the important ecosystems they represent. Follow Beth on Twitter as @ecosphericblog

1 Comment

  • Reply May 27, 2013



    This is easy to do. The heart is in the antenna and the brains
    are in a fast full-wave bridge rectifier. Basically, it’s a rectenna.

    Make a fast full-wave bridge rectifier using four fast diodes, like
    FD700 diodes. Connect a low-leakage capacitor, like a Mylar, across the
    outputs of the rectifier, to store the direct current. This capacitor
    can then be discharged across a light-emitting-diode, LED, causing it to
    flash, or a rechargeable battery, causing it to slowly recharge.

    The antenna input to the rectifier is the key. Larger antennas
    will gather more electrical energy. Antennas can also be placed in
    parallel making them larger. You’ll want to make a long, flat antenna,
    in order to collect long-wave and short-wave electrical energy. Use a
    wide ribbon, made conductive by soaking in silver or graphite ink. Real
    India ink should be made of graphite. The ribbon antennas can be raised
    by using helium filled balloons. Again, the ribbons can be in parallel,
    to make them wider. DO NOT let the conductive ribbons contact any
    overhead power wires!

    Please experiment carefully!

    Try this too.

    How Our World Can Use 50% Less Watt-hours of Electricity:

    Here’s a new concept of reducing the Watt-hours used by 50%, by doubling the
    electricity’s frequency, using a variable frequency drive in series
    with a diode, to power various devices.

    If an electric clock is powered at twice its frequency, then
    it will run
    twice as fast. If the power is half-wave rectified, then it will run on
    time using half of the Watt-hours.

    This works! It electronically quickly turns the power ON and OFF. The
    power is switched OFF 50% of the time. The Watt-hours used are reduced
    by 50%. The frequency must be doubled to make the ON and OFF cycle quick
    enough. For example: 60 Hertz power has 120 ON pulses (or half-cycles)
    per second. Therefore 120 Hertz, half-wave rectified, is needed to have
    120 ON pulses and 120 OFF pulses per second. This results in a 50%
    reduction of the Watt-hours used. Please try it using an incandescent light

    It can be easily empirically tested by obtaining an appropriate variable frequency drive and diodes.

    The ON and OFF cycle will not be visually perceived in lighting for the same reason that flicker is not perceived in animation.

    If 50 or 60 Hertz is half-wave rectified, the light will glow brown,
    but you will be using 50% less Watt-hours of electricity. As you
    increase the frequency, the light will get brighter and brighter, still
    using 50% less Watt-hours of electricity. Eventually you will not see
    any difference in the light’s brightness and you will still be using 50%
    less Watt-hours of electricity.

    A light pulsed quickly enough will not seem to be pulsed, but it will use 50% less Watt-hours of electricity.

    It will not be cheap, but it can be done slowly, over time, by the utility.

    Double the electricity’s frequency after the neighborhood’s step-down
    transformer and then half-wave rectify it in the drop wires to the
    consumer. You will be using 50% less Watt-hours of electricity, much
    less fossil fuels and pollution.

    It’s a win/win solution for everyone!

    Let’s make this concept happen!



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