German student builds electromagnetic harvester to recharge a battery

You would think that phys.org would know their physics. He's adding an inductive load to wherever the energy is coming from. In some cases that will simply replace other loads, but in many cases it will add to the load, increasing energy wastage.

Come on, this is silly, the article makes it seem like it's creating energy from thin air, while of course it's adding a load to the EM field, which results in an increased energy drain from the source. Obviously no one is going to notice if you recharge an AA battery using this system, but it's not any different than just plugging a charger straight into your (or your neighbour's) power socket.

What's interesting about this article is that after reading it you might get the idea that the student created this device to recharge batteries and produce electricity.<p>However when you read the announcement[1] of the university itself you learn that he was awarded the price in <i>digital media</i> because:<p>&#62; "Dennis Siegel thematisiert die sich überall befindenden elektromagnetischen Felder[...]" &#62; TRANS: Dennis Siegel thematizes the everywhere occuring electromagnetic fields)<p>and further<p>&#62; "Die Jury hat an dieser Arbeit den feinen Humor der Arbeit, den gedanklichen Kurzschluss, die Fähigkeit zum konzeptuellen Brückenschlag, die sensible einfache Gestaltung sowie die Zukunftsorientierung des Projektes hervorgehoben und überzeugt"<p>&#62; TRANS: The jury has emphasized and was convinced by the fine humor of the project, the mental short circuit [it's not clear what this refers to in the announcement], the ability to create conceptual bridges, the sensible simple design and future-orientation.)<p>After reading this announcement one might actually come to the conclusion that this an art project and that the fact that a student created a device that charges batteries using electromagnetic fields by itself is rather boring and irrelevant. The fact that any high school student should have the necessary theoretical knowledge to built such a device could also be a give away.<p>[1]: <a href="http://www.hfk-bremen.de/t/auszeichnungen/n/hochschule-f%C3%BCr-k%C3%BCnste-bremen-verleiht-hochschulpreise-2013" rel="nofollow">http://www.hfk-bremen.de/t/auszeichnungen/n/hochschule-f%C3%...</a>

Physorg? Ugh.<p>Didn't even bother click, came here to read comments instead.<p>Can HN please ban Physorg like everyone else?

It's also quite illegal to take power from mains lines even inductively. If this kind of thing catches on I imagine the manufacturer would have a lot of lawsuits on their hands.

&#62;<i>But that clearly isn't the point of his device. Instead, it highlights not only the fact that we live our lives in a constant state of bombardment of electromagnetism, but also that all of the energy from all of the collective devices in use in the world today, is currently going to waste.</i><p>I prefer the "fluorescent tubes under transmission tower lines" demonstrations. Here's one link (<a href="http://hacknmod.com/hack/field-of-fluorescent-tubes-powered-by-ambient-current/" rel="nofollow">http://hacknmod.com/hack/field-of-fluorescent-tubes-powered-...</a>) but there are others.<p>It's neat to be able to do. I'm pretty sure the energy harvested comes nowhere near the energy used to create the parts, or assemble the device.<p>If you want to make a really simple demonstration that "there's power in the air" you could try this experiment - light an LED from cell phone frequencies (<a href="http://www.creative-science.org.uk/mobile_LED.html" rel="nofollow">http://www.creative-science.org.uk/mobile_LED.html</a>). (Good Luck getting an OA91 diode, though.)

Didn't Tesla at one point envision giant coils that would basically give you "wireless electricity" through the use of changing magnetic fields?<p>This is cool but I'd be worried if it caught on in any sort of scale.

<i>The particulars of the electronics inside his device haven't been detailed (likely to prevent copycats)</i><p>More likely because this is hardly a new idea and people have been doing this for decades. I remember reading in an <i>elementary school science book</i> how some farmers used to run fences under power lines going through their fields to get some "free" energy out of the electrical grid. This did not go over well with the electricity utility.

as others have said, you're either absorbing a wave (and blocking someone's signal) or acting as an extra coil (and making the source do extra work).<p>It's perpetual motion nonsense to suggest mounting these on roofs to power buildings.. Apparently phys.org is as bad as new scientist!

This reminds me enormously of the simplest electronics project I ever put together: A Crystal Radio back in the '70s. If you're not familiar with them, they're not much more than a coil and a "cat's-whisker" (diode) and they are powered by the radio-waves themselves.

Since this increases the load on the source, isn't this more like stealing than harvesting?

This is AWESOME!<p>&#62; He's won a 2nd place award in the HfK Bremen Hochschulpreis 2013 competition for Digitale Medien, for his efforts.<p>Who on Earth won <i>first</i> place?

I'm not convinced that the device actually does what it is advertised to do. Considering that the student is associated with a "University of the Arts", the non-disclosure of the layout becomes even more suspicious, as is the implied claim of being able to harvest useful amounts of energy from Bluetooth transmitters.<p>It would be quite in line with German culture for somebody to have no qualms about lying for the purpose of calling public attention to some perceived environmental threat or health risk (think the Green party scaremongering against genetically modified crops using flourescent dyes) and then saying it was all art for a good cause if called out on it.