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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.
"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
Why not use windmills to power our computers coolingfans?
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".
You missed my flywheels reference! See the Wired article in May 2000 (it's free online) that talks about the future of flywheels as battery replacements. It's not that far out there that you could have a tiny windwheel and a tiny flywheel that would provide enough storage for a day's worth of power, say.
Freelance tech journalist for the Economist, MIT Technology Review, Macworld, and others
IDEA! Put windmils behind the air-outputs from our computer cooling fans and use the energy to power more cpu cooling fans to spin more windmills....
(it's a joke, laugh.)
Blessed are the pessimists, for they have made backups. -- 0 1 My two bits
"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
RE Flywheel
Those will be cool when we have lightweight cheap materials we can use to shroud a flywheel. Why shroud them? Two reasons.
First is drag. Can't have resistance from air slowing down your wheel. Keep it in an evacuated container.
Second is saftey. If you want to store a meaningful bit of power you'll either need alot of mass or rotational velocity, or both even. Now, think of what happen is there's a defect in your high-speed high-mass flywheel and its parts decide to take seperate vacations. Did you think FRAGMENTATION GRENADE? Good, go to the head of the class. You need to keep potentialy dangerous fast-moving high-density bits from coming into contact with people and things that people value.
Another problem with flywheels of any significant mass or speed is the gyroscope effect. But, that's not as big a deal as finding a wonder-material to protect the flywheel from the atmosphere, and us from the flywheel.
Blessed are the pessimists, for they have made backups. -- 0 1 My two bits
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
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?
10cm?!?! You'll decimate the local Japanese beetle population! We can't have that. Somebody alert PETA!
How about a wifi powered wind detector?
Solar doesn't work at night--wind does. And in applications like this, the more you can get, the better. As for snow packing; it doesn't snow everywhere. And with exceptions of certain places, I can't really think why it should be impossible to keep something like this working for a long time.
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
I cant seem to find the page but I was looking at flywheels a while back and a simple solution to the 2 problems you list where solved. Basically the flywheel was floating on magnets in a vacum in a steel drum. the company listed the life of the flywheel at 50 years with zero maintinance. basically you could bury them and that takes care of the vacation problem. I think i may have missed your point though, because i dont really understand why you think this would require a lightweight material or that we dont have it yet. it would be easy enough to create a really dense and strong flywheel and not push it to its limits, reducing the need to worry about the thing exploding.
"Alcohol, cause of, and solution to, all of life's problems" -Homer Simpson
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!
"basically you could bury them"
Okay, that works for a FIXED aplication. I made an asumption on portability, or at least some ease in relocation and a minimal impact on the enviroment. Having to dig a small bomb shelter for the flywheel and shroud could piss off the enviromental types.
Blessed are the pessimists, for they have made backups. -- 0 1 My two bits
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!
"Where are you, sir?"
"In my office"
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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?
What an idea! You could create more an more power... perpetually.
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.