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Wind-powered Wi-Fi Sensors
Glenn Fleishman writes "According to an article at Indolink a 10-centimeter diameter windmill can produce the 7.5 milliwatts needed for a wireless sensor. The paper was published earlier (available as a PDF), but Nature magazine has apparently picked up the tidbit. The process flexes piezoelectric crystals to create a current. Although flywheels aren't mentioned in this article, it seems like a windmill, a flywheel, and a solar cell could in combination produce effective power in a range of conditions for remote wireless devices, including network relays obviating batteries entirely."
802.11 cards typically consume around 1 or 2 watts. They are probably targeting much simpler radios, like those used in motes.
Enron could have been around if these were invented back in the day. Imagine this: Where are your records? Sorry, they fell through the windmill on my PDA.
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7.5 milliwatts?
What sort of Wi-FI are we talking about there? Something that output about 2 milliwats? pffft..
Something's not right in this article.
George
In Soviet Russia, the power generating windmills come to you!
Visit Tevlog
"Dr. Priya foresees piezoelectric bimorphs being utilized to power a variety of small devices" but I foresee nothing practical unless the efficiency is as high as enviromentally unfriendly stuff known as batteries. People just aren't going to go for this sort of thing anymore than other alternate energies unless it's going to work just as well sitting alone with no vibrations ... I mean he mentions a discman but is it still going to be fine if your lying down with it on a table playing for hours on end lacking vibrations , indoors with no wind in sight... if not it's not ready to be commercialized.
That's the problem with alternate energies, they're cool and great for the environment but lack of efficiency means you usually have to suffer to be a good citizen.
Flywheels? The simplest way to store power would be an electric double layer capacitor. No moving parts. They can come in up to 70F at 2.1V - that's 140 C of charge. At 10 mW of power, 2.1V is 5mA of current; that means that it can stay above 1.5V for 2 hours. If a higher voltage is needed, put the capacitors in series. And these are not huge devices. Here's a datasheet for one
So... what exactly are you reversing? "In America, you come to the windmills?" And do the Soviets come out looking evil/goofy here, or just like regular guys who are besieged by tiny windmills?
I'm not sure you understand the formula for "In Soviet Russia" jokes.
How about bring them back with a geeky Wi-Fi vengeance?
Possibly even attach an LED headband to it to tell others how close to a hotspot they're in. C'mon, I see profits galore!
Propeller Beanie hats :)
First, these aren't wind powered sensors that transmit over wi-fi -- they're wind-powered sensors that detect a wi-fi node nearby. There's a big difference in power levels there. The first sounds really nifty, and with lower-power radio systems would be really cool. The second sounds like something ThinkGeek will have on clearance in about two years.
I have no concept of electrical quantities. What I see here is "tiny windmills make electricity."
So, for someone with more of a clue: does this sound like something that could be scaled up? Like, could you put them all over your roof and generate green power, or would there not be enough juice?
What is the advantage of his piezoelectric device over a simple electromagnetic generator?
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
Will people stop applying this term to everything? Wi-Fi is referring to wireless LAN, not to any device that happens to use the radio spectrum. Use "wireless", or "radio", or "remote".
"obviating batteries entirely"?
i don't think this solar/wind setup can work during those still nights.... so there will still be a need for batteries, don't worry demand for batteries isn't going anywhere....
It seems to be that this is targeted more towards microsensor networks (802.15.4 etc). The idea is that you scatter a whole bunch of very-low power sensor devices around a sensor field, which form an ad-hoc network which supplies sensor data from across the field. Because it is too difficult/expensive to replace the batteries on the sensors, scavenging energy from environmental sources (wind, vibration, solar) is a very good idea. It turns out that vibrational energy alone is almost enough to power some of today's ultra-low power sensor nodes.
And I bet they'll be flying on Pringles-can wings before my car does.
"Obviating batteries entirely"? They misspelled "recharging". They still need a battery for low-wind sensor telemetry. But 7.5mW is less than what 5x5mm of solar panels get. Store the surplus in a battery, and half a square centimeter can power them.
--
make install -not war
From AQFL: Broadband Reports and Boing Boing say WiFi doesn't "stand for" wireless fidelity. It's a pun on "Hi-Fi" and "wireless fidelity" doesn't mean anything.
Ant(Dude) @ Quality Foraged Links (AQFL.net) & The Ant Farm (antfarm.ma.cx / antfarm.home.dhs.org).
Windmill? DARPA is working on dust sized devices that work off of ambient vibration.... catch up with the times. Smart Dust is an old idea.
s t/
http://robotics.eecs.berkeley.edu/~pister/SmartDu
MOTAR the imperious
The principles behind things like the device described have been known for some time, but as energy requirements to do stuff decreases they increase in usefulness.
When I viewed this page on a threshold of 3, there were 5 comments. 2 of them were full of utter crap. What is wrong with moderators today? Don't they think before modding something up?
A ten cm. diameter photovoltaic cell will, under most circumstances, provide an average power of way more than 7.5 mw. Obviously, you would have a problem at the earth's poles with six month nights. You would have an even bigger problem with snow packing almost any kind of small windmill I can imagine.
Mother nature has ways of fouling almost anything that moves. If you want to deploy remote sensing, you really have to make it simple, rugged and idiot proof. Moving parts won't after a while.
10cm?!?! You'll decimate the local Japanese beetle population! We can't have that. Somebody alert PETA!
How long the absence of wind will drain the battery and the wifi signal become weak.. Bye bye hosting my website?
What's the big deal? One of CowboyNeal's fart could produce that.
How about a wifi powered wind detector?
obviously the moderators are not supposed to actually argue the validity of a comment, you cannot expect all moderators to have a great knowledge of every topic. they are in place to keep conversations on topic, not to do fact checking, that is what the comments are for.
"Alcohol, cause of, and solution to, all of life's problems" -Homer Simpson
yes, yes, truer words were never spoken!
I demand that you cease and desist from your masturbatory halucinations. Move your bowels and brush your teeth instead.
And don't forget to clean the fecal contaminants from your toothbrush.
I enjoy defecating, especially in good company and accompanied by a fine chianti. How about you? Tell me. Yes, now! Do! I insist! Lesbian industrialists of the world, unite!
What's with all these over-engineered solutions for the developing world? My mom still has an old foot-powered sewing machine. If people could run a sewing machine with their feet, why not a generator?
In Soviet Russia, the Wi-Fi powers the Wind!!!!
Just put a hand crank on the windmill. Energy can be stored in a spring. When the critical capacity is reached, a jack-in-the-box can pop out. We're through the looking glass, people!
Wind powered machine that detects.. well..air.
Thank You... we need to drop this crappy HIFI type of mentality in the Wireless Network world. Unfortunely WiFi has stuck and we will have to wait until something new pushes it out. Same with WiMAX. WLAN is good but it does'nt roll off the tounge like WiFi. ;) ...
We need something that is easy to say, means something, and is well known by the masses.
NetLink, NoWire, WiLap, WiWorld, ComNet, LapCell, InfoLink, LapRad, RadLink (yeah that's cool
ok I'm done... anyway think about it and lets start a new wave of cool acronyms.
www.acronymfinder.com
Might be a good place to start.
I don't want a pickle; I just want a Motor-Cycle! A four foot cop arrived with a five foot gun!
But I like WLAN!
There is a lot that can go wrong with remote equipment. Small equipment has different problems than big equipment. I've installed both. Basically, I've learned from the horror stories told to me by others. Critters cause problems. People cause more problems (especially vandalism and theft). I would rather install a quite compact package with batteries and a small photovoltaic than something with a windmill. 7.5 mw average power is produced by a solar cell that is quite a bit smaller than the proposed windmill. You will really have to locate the aforementioned windmill quite a bit higher than you will the photovoltaic.
Anyway, I don't see what they have against batteries. The battery pack required to power the equipment for a year is cheap compared with the labor cost of installing the sensor. That plus a small photovoltaic would yield a system that would operate almost forever anywhere on the surface of the globe (or off it for that matter) even at the north pole.
Actually, that one point has been misses in tfa and the posts I have seen so far. There's no point for saving a hundred bucks on the price of the sensor at the expense of almost any other parameter. The labor involved in installing these sensors is very very expensive. It's way more expensive to go back to replace one defective sensor.
"Where are you, sir?"
"In my office"
/. bug #926803 - Why I can post.
I think that pamphleteering, having now changed into electronic spam, means that there is in emergencies, a less ready supply of bumphodder.
This is from another decade in another century but it is still good reading:
Jul 12 1993, 1:25 am Newsgroups: sci.geo.geology, ca.earthquakes
Date: 12 Jul 93 00:33:06 GMT
Local: Mon, Jul 12 1993 12:33 am
Subject: Navy Releases ULF Earthquake Precursor Study
(Not) REPRINTED WITH PERMISSION FROM: GEO-MONITOR
Vince T. Migliore (408) 749-6770
65 Washington Street, #400
Santa Clara, CA 95050
(Excerpts)
Navy Releases ULF Earthquake Precursor Study.
The Naval Command, Control and Ocean Surveillance Center (NCCOSC) released an important report on baseline noise levels in the ultra-low frequency (ULF, 0-3 Hz) and extremely low (ELF, 3-30 Hz) ranges, that are critical in the search for electromagnetic precursors to earthquakes.
The report, "Long term ELF background noise measurements, the existence of window regions, and applications to earthquake precursor emission studies" is by Jack Y. Dea, Peder M. Hansen, and Wolfgang M.Boerner, and appears in the journal Physics of the Earth and Planetary Interiors, Vol.77, 1993, pages 109 to 125.
The study is important to amateur earthquake researchers for at least three reasons:
1) It establishes the fact that ULF monitoring for earthquake precursors is a worthwhile endeavor.
2) It provides a wealth of technical data that enables amateur scientists to replicate the system design.
3) It identifies a low noise "window" that theoretically makes it practical to design a simplified, and therefore low cost alternative to the monitoring equipment.
The fact that the Navy is willing to fund a long range study of low frequency electromagnetic signals is an indication that there is some merit to the hypothesis that large earthquakes are preceded by low frequency transients or changes in the noise level.
In 1990 a team headed by A. Fraser-Smith of Stanford's STAR Lab reported finding such signals prior to the Loma Prieta earthquake in California in 1989.
In June 1992 a small conference was held in Lake Arrowhead California, entitled "Electrial Precursors to Earthquakes: Fact or Fiction," at which a number of papers were presented on this hypothesis.
This research methodology seems not to have generated a lot of momentum, except among a handful of dedicated researchers. The Navy report, now, tends to lend some degree of credibility to the use of ULF signals as precursors and provides important "normal" statistics on the standand noise levels in the ULF/ELF ranges.
Technical Details:
The report provides a gold mine of technical details that may allow other researchers to duplicate equipment needed for UFL monitoring.
The basic design uses a 90,000 turn pickup coil with a high permeable mu-metal core. This is housed in a shielded container with a built in pre-amp.
The signal is then cabled to a central location where it is amplified and fed through a 40 Hz low-pass filter and a 60 Hz notch filter.
The sensitivity of the instrument is such that it is capable of detecting the Schumann resonances.
Geo-Monitor has heard from other sources that the total amplification is between 50,000 and 80,000.
The coil has a natural 1/f decrease in sensitivity as frequency drops. Background noise levels have an effect on this sensitivity.
"The terrestrial and near-terrestrial sources change the 1/f characteristics to an approximate 1/f (to 1.25 exponent) in the 0.1 to 2 Hz range.
As magnetospheric and ionospheric activity rarely produce signals above 2 Hz and Schumann signals become significant only above 5 Hz, there exists a valley in the 2 - 5 Hz region."
There is a discussion on antenna orientation and signal strength at various frequencies. For practical purposes, amateurs may want to focus on the low noise window in the 2-5 Hz region.
The field strengths recorded for the E-W, N-S and Vertical antennas, respectively - for 3-4 Hz were:
-61.1 dB, -58.7 dB, and -57.9 dB, with std. dev. of 3.0 2.2 1.5.
The sensor outpu
From a few days ago this article is about the latest hopeful in wind generators:
"Design creates pull on the back side, contributing to 40%+ wind conversion efficiencies; doesn't kill birds; runs more quietly; and doesn't need to be installed as high, blending better with landscape. Generating costs estimated at 3.5 cents per kilowatt-hour, surpassing conventional energy sources.
It is an idea similar in concept to those spinning adverts sometimes seen outside shops: A steel drum cut in half, top to bottom welded back together to form a "S" along a central pivot."
The major design fault for all national grid wind generators is the timing and quantity of the wind, of course. I doubt that the need for cut outs will be the same for "one off" specialist, miniature machines.
Did anyone else read this as: Mind-powered WiFi sensors ?
Well, if the labour of installing the system is expensive, the perhaps the cost of sending people out to remote areas to reaplce batteries also isn't very cheap?
Replacing batteries is really expensive. That's not what I'm proposing. What I am saying is that with enough batteries plus a small photovoltaic, you could power a 7.5 mw load anywhere on the surface of the world almost forever. Been there, done that. In fact, my work on the subject (thirty years ago) has probably saved my former employer millions of dollars by now.
Low power wireless sensors are more likely to be using Zigbee etc. It isn't just the power for the Wireless stuff, but also the host CPU. A Wifi device needs a big fat-assed stack (+ lots of CPU) while a Zigbee device can probably live with a very small CPU and less than 1kB or RAM. There are a lot of very low power devices in this range.
Engineering is the art of compromise.
10 squared centidiameters would be approx. 5 ft. per hour and kelvin. That would be CONSIDERABLY too much!
I use WLAN in my networks; It's simple to type and it makes sense.
I don't want a pickle; I just want a Motor-Cycle! A four foot cop arrived with a five foot gun!
Well you could put windmills on your roof. However there are some problems.
The first, as the other guy said, is they tend to transmit annoying noises into the house if they are on the roof. Not technical problem, but annoying enough that most people wouldn't stand for it.
Only the largest mansions are big enough for several windmills. A windmill causes turbulence around it, which cuts the efficiency of nearby windmills. To get 6 windmills on the roof you are looking at maybe 10 watts from each - not very useful. There is some complex site analysis needed to get windmills dense.
Windmills need to be high. 100 feet (30 meters) above anything else in the area. That is a tall tower.
Most houses are not constructed for windmills on the roof. Think of a sail, you need a lot of bracing designed in to resist the movements. Either a special tower, or guy wires are needed to hold it in place. The special tower is out because the rest of the house isn't designed around that load, so that means you have wires running from the top to the ground (not roof because the tower is too tall!)
Solar on the roof works. If you live in a desert the claimed payback (with government subsidies) can be as little as 4 years (8 typical I'm told), so you should investigate them. However if you live in a colder area they are not worth it. My payback would be about 30 years from what I can tell.
Solar hot water works in places where solar electric does not. So nearly everyone should look into it. Looking close at the hot water panels in my area though, I've noticed that most people forgot to dewinterize them one spring many years ago. So for most people the hassle of maintaining such a system ends up more than the savings. Still something to look into.
Windmills are a great idea. Just not on the roof.