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How to Build a 17-ft Wind Turbine
agentfive writes "The people over at Treehugger have found an amazing little article on how to build a 17ft - 3kW+ output Wind Turbine. Apparently this is the latest project of OtherPower.com and the site has a variety of other engergy saving/producing projects including a Homebrew Maytag Gas Battery charger."
Tie Rush Limbaugh to a post.
until the first moron posts the usual "it will NEVER produce as much energy as it consumed during production !!!!111" propaganda...
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
I'll take 2 please, mounted side by side, in opposite directions, my current window fan just isn't cuttin the mustard...
Don't anthropomorphize computers: they hate that.
I think if you replace the term windtunnel with windmill the answer will become clear.
That or if you bothered to read the article.
I read the internet for the articles.
DIY stories so far today:
Homebuilt 19" Mini-ITX Server Rack
The Floating Powerbook
A Practical Guide to DIY LCD Projectors
How to Build a 17-ft Wind Turbine
And it's only 2:45pm EST.
Did Bob Vila donate a large sum of money to Slashdot or something?
____
~ |rip/\/\aster /\/\onkey
If you saw it on Monday, why did you submit it?
and what use might a windtunnel in my apartment be? It's not like I'm designing fighter-jets or the new Ford here.
:-)
Wind Turbine, not Wind Tunnel. You can stick it on your roof and run a cable to your computer. Poor man's power, as it were.
Don't feel too bad, though. I misread the headline the first time as well.
Javascript + Nintendo DSi = DSiCade
After lots of real bad articles (like that beamer), this is finally some REAL DIU.
Starting from the copper wire and magnets, there is actually some real construction involved.
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
Much as I would love to generate my own electricity, a wind turbine isn't likely to be allowed by my town.
Pretty much the only clean energy that I could generate legally is solar, and that's just not cost effective, especially in Massachusetts.
It's obviously for your dog! Now you can simulate the head-out-the-window-of-your-car experience right in your very own studio apartment.
Turbine != Tunnel
not sure if you were being funny or stupid...but there you go...
Hey, all I want to know is how many birds it'll kill...we have a real starling problem where I live.
[RIAA] says its concern is artists. That's true, in just the sense that a cattle rancher is concerned about its cattle.
I like some of the sites they link to. Some useful stuff. Like how to make a rocket out of a match.
http://www.matchrockets.com/
Before internet, I once payed $2 out of the back of a comic book to learn that.
I've been looking for something like this. Now I just need a death ray to use on my homeowner's association and I'll be good to go.
perl -e 'foreach(values %SIG){$_="IGNORE";}while(){}'
Yeah slashdot has fallen in stories, it might be the editors are going out and meeting peope ro something :)
he runs off the grid in Vermont, with a battery-power system, some solar cells, and a river paddlewheel turbine, and has a ridge on his 42 acre property that he could site this on.
Which is why he uses a laptop instead of a PC - easier to wire it to trickle feed from the battery system.
-- Tigger warning: This post may contain tiggers! --
... to power their websites.
slashdot effect in... er... effect.
John Maynard Keynes: "When the facts change, I change my mind. What do you do?"
Wired had an article this month about rooftop solar power that was kinda cool. I thought that the project they highlighted (no pun intended) could be DIY with a little money and time.
Great ideas often receive violent opposition from mediocre minds. - Albert Einstein
this kinda reminds me of a guy made a small powerplant for his stream... He actually got money back from the powercompany as he was now supplying instead of drawing power :) hellacool... I wonder if this will be the same case?
Bad link in the article text. It's here.
This is my post. There are many others like it. If you don't like what you read here, go try one of the others.
Talk about Passing Wind!
Oh wait, it's been done, sort of.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
I've been following the work of the Otherpower.com folks for a while now. They're damn good DIY engineers. Not only are their wind turbines quite nice, but my interest was also piqued by their use of single-cylinder Lister engines. Coupled with a biodiesel recipe, it looks like they can run their entire shop for 8 hours on a single gallon of carbon-neutral gas.
One of my lifelong goals is to live simply, on a large plot of undeveloped land somewhere. I'm glad there are people like the Otherpower folks who are paving the way as far as alternative energy creation, and being considerate enough to document their work as they go.
May the threads progress competently.
They need to beef up the power to their servers which are already crashing and burning...
"It's a tarp!" -- Dyslexic Admiral Ackbar
Windmills Do Not Work That Way!
...of the turbine plans over at birdkiller.com.
with a more accurate headline.
The website doesnt really show YOU how to build one.
Rather, it shows you photos of the various steps taken by someone else to build one.
Sure, you could probably look at the photos and read the descriptions and use your brain to fill in the missing details and build one yourself, but there would be additional work/calculations needed.
It's still a pretty frickin cool project though.
Of course, that could be a bonus if we're talking about pigeons.
"OH SHIT, THERE'S A HORSE IN THE HOSPITAL!"
I've never really gotten an answer to this question:
What are the implications or potential problems from removing energy from Earth's weather systems? Is the energy we're removing negligible enough to be ignored? Could it potentially change weather patterns by blocking/slowing wind?
Do we have any information about changes in weather from other man-made things such as cities? I've heard beltways can cause enough heat to slow/redirect some weather. (I know that birds of prey use updrafts caused by hot highways to help them gain altitude using less energy)
Any reliable sources for this kind of information, or are all sides biased?
~D
This sig has been enciphered with a one-time pad. It could say almost anything.
Looks like their webserver is running from a wind turbine!
I am trolling
I'm pretty sure most towns won't let you construct a 17 foot windmill in your yard. There are a lot of ordinances where I live, and I see this as being against at least several of them.
Also, don't windmills produce tons of noise, to the point where they actually are a cause of noise pollution? That ought to make your neighbors thrilled.
/. ++
Here
I keep telling myself I need to learn how to weld. I really do
"I'd rather be a lightning rod than a seismometer." -Ken Kesey
I read the site the other day when it appeared on Hack-A-Day. At that time it was a 400w turbine at 48 volts. I hate when submittors overglamorize the title of the article to get it posted.
Considering that the article said that at ~100 rpms, there was 6 amps @ 6 volts (36 W), and that at ~1000 rpms (heavy wind?) he predicted about 400W, it seems an iffy proposition to power a desktop computer.
Poor men use laptops, I guess.
(Only read the first page before /. killed the site. Later pages might have
had more info.)
Google, text only:w ww.otherpower.com/17page1.html+&hl=en&lr=&strip=1
& safe=off&c2coff=1&q=flying17foot.JPG&btnG=Search
& safe=off&c2coff=1&q=site%3Awww.otherpower.com+turb ine&btnG=Search
http://72.14.207.104/search?q=cache:hHhkzdBOglAJ:
Google, image of turbine:
http://images.google.ca/images?svnum=10&hl=en&lr=
Google, images of turbines on their site:
http://images.google.ca/images?svnum=10&hl=en&lr=
carmaHore.
otherpower.com's servers are apparently powered by a 17' wind turbine
Scarry that the world has such stupid people in it...not only do you misread it, but you launch an elitist attack into your misread of it. You are truely an idiot.
awesome
Well, in their defense, Hackaday stole two of slashdot's links yesterday, so they cant be doing too bad.
Nice, but I need plans for an 18-ft turbine.
In order to make your own 17' wind turbine, you will need the following items:
1) Seventeen tubes from paper towel rolls.
2) A roll of Duct tape
3) Ten cans of Bush Beans
Next week, we put it all together.
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
Environmental Disasters I tell you!! Fire up the coal burner.
Sweet, I just need 403333 of these for my delorian and I'm outta here!
Main article Google cachew w.otherpower.com/17page1.html+&hl=en/ w w.otherpower.com/17page2.html+&hl=en/ w w.otherpower.com/17page3.html+&hl=en/ w w.otherpower.com/17page4.html+&hl=en/
w w.otherpower.com/maytag.html+&hl=en/
Page 1
http://66.102.7.104/search?q=cache:hHhkzdBOglAJ:w
Page 2
http://66.102.7.104/search?q=cache:hHhkzdBOglAJ:w
Page 3
http://66.102.7.104/search?q=cache:hHhkzdBOglAJ:w
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http://66.102.7.104/search?q=cache:hHhkzdBOglAJ:w
Homebrew Maytag Gas Battery charger
http://66.102.7.104/search?q=cache:nS2Uc8eVrxIJ:w
Religion and science are both 90% crap..but that doesn't negate the other 10%.
It takes a village...worth's pile of shit to completely hit this thing.
wicked strong magnets...well technically, wondermagnet is selling but rumage through the website and see if you can figure out their business relation ship to otherpower, I can't.
If you are into this DIY power generation, do visit their site...they also homebrew hydroelectric systems. And the participants in their discussion groups include a few very well versed engineers with good ideas for off the grid living.
SLASHDOT: news for people who can't concentrate on work or have no life at all and got tired of yelling back at the TV.
Windmill? You looking to make flour or something?
-FL
The only wattage mentioned is "36 watts" from turning it by hand, and using not a WATTMETER, but a voltmeter. Voltmeters are notoriously inaccurate at measuring "wattage", especally of weird waveforms you're likely to get from a homebrew generator. Also if thye were turning it by hand as hard as they could, the output should have been around 250 watts, assuming an average efficiency generator. So if we use these figures, it looks like their homebrew generator is only about 12% efficient.
This is not a great example of good DIY-ing.
What are the implications or potential problems from removing energy from Earth's weather systems? Is the energy we're removing negligible enough to be ignored? Could it potentially change weather patterns by blocking/slowing wind?
I doubt it, since all wind turbines operate at such low altitudes that higher tropospheric activity is not affected. Weather resides in the first 10 miles or so of the atmosphere, whereas turbines are installed within ~.3 miles of sea level (Denmark has some that are actually seaborne). It'd be like wondering whether fish swimming a couple thousand feet underwater affect the waves at the top. There's plenty of empty volume for the fluid (whether it be air or water) to bypass any obstructions (turbines, trees etc.). And there's a lot of terrain nearby with no wind turbines at all.
I've studied wind turbine and helicopter rotor design (they have some remarkable similarities, and differences). For wind turbines, the airspeed gradient through the blade disk isn't as great as you may think.
As for "bias," well, I've noticed that many deem any opposing opinion as "biased." So what ever.
The 10 foot wind tunnel I have now was really starting to show it's age . . .
Pretty Pictures!
I'd think the Jet stream and other major sources of wind are largely unaffected. What impact do all the turbine jets on airplanes have on weather patterns?
the real problem is that windturbines spoil the nice views! Just ask the people on Martha's Vineyard.
Roof Shingle power sources. There are now a number of suppliers.
r 17.html
http://www.kingsolar.com/catalog/mfg/uni-solar/sh
Uni-Solar shingles are unique and have been honored with thePopular Science Grand Award, " Best of what's new (Environmental Technology)," and Discover magazine's "Technological Innovation Award" for best innovation (Environment).
The PV shingle permits roofs of commercial and residential buildings to evolve from mere protection from the weather to a source of electric power. The flexible, thin-film solar cell shingle blends into roofing pattern of traditional asphalt shingles or roof tile.
This is a really fascinating article. Power generation is an interesting concept but I've never really seen a detailed explanation of how a generator is built, what engineering trade-offs go into such a construction, etc. I consider myself pretty well educated by I'd be at a complete loss to do this on my own. It's really neat to see the engineering that goes into making power. Suddenly this seems so much more accessible- like something I really could do myself.
to power the wind turbine? And then use the wind turbine to power my PC? :P
In the alternative energy crowd it's actually very popular to build one's own wind turbine instead of purchasing one pre-built. There are kits available, but some design them from scratch.
Often it's rather sobering looking at a wind speed map that your region isn't quite windy enough to make a turbine pay for itself. One needs Class 4 speeds at a minimum, and then you've got to deal with city ordinances about various crap with building a large structure.
homebrew hydroelectric? Like daming up the creek in your back yard? That sounds like about the coolest thing ever. Do people actually do that? That would be so fun.
I've been doing 3 phase permanent magnet motor controllers for many years now, and I find the amount of magnetic material in the OtherPower alternators to absolutely insane. OTOH, I think they do it that way for simplicity of construction and to get zero cogging torque. i.e. They could use only 1 ring of magnets and use metal coil forms on a steel plate. The problem then is that the magnetic poles tend to "stick" to the metal ones and you get what's known as cogging torque - you can feel these sticky spots as you turn the motor. They also use an absolutely huge air gap (the full thickness of the coils) which leads to flux going between poles instead of throught the coils - another source of inefficiency. OTOH, they sell magnets to people wanting to replicate what they've done ;-)
Sounds like they found the blueprint of a Roman windmill at an archeological excavation. Try http://www.metric4us.com/ 95% of the people on earth find the Ancient Imperial units just funny.
Whoa! *IDEA*
Then you could have a never-ending supply of wind for your turbine! This is gonna be great, I'm getting goose bumps. Now where's my hammer?
How can you "steal" links from Slashdot when all Slashdot does is link to other sites? Not that I really care who links what first or where it comes from.
I would have liked to have seen the pictures. But (sigh) that link has blanks where the pictures should go - is anyone else having problems viewing the pictures?
Hamster power is where the real future is!
Laptops are too expensive for poor men.
My landlord had a stroke when i installed a dish, i imagine he'll implode with that 17 feet fan.
Here's where you can rent a video to learn how.
Ok, it's good for areas that has no power yet and it's good on the environment but, how much does it cost? What is the ROI?
7 35_3857-3320-5_406_664-0,00.html/
I spend $30 on electricity every month and if it costs $2000 and saves me $10 a month that's 200 months...
If you say no ROI at all it's just environment friendly I would rather buy Wind Energy from the local Power company.
Here in MN, Excel energy sells wind energy for $4 a month...
http://www.xcelenergy.com/XLWEB/CDA/0,2914,1-1-2_
and what use might a windtunnel in my apartment be? It's not like I'm designing fighter-jets or the new Ford here.
You'd use a wind tunnel to carry away heat from the latest AMD and Intel chipsets as well as GPUs from nVidia and ATI.
You'd use a wind turbine to gather up the air at the other end and turn some of that wind back into electricity at the other end.
Or just chop local birds into salsa while you generate green energy. You can't save the environment in one way without farking it up some other way, it seems.
Nice project btw, but a little behind the times. I thought Mother Earth News beat this dead horse into glue and snorted the entire production run when it came to alternative energy.
If my grammar and spelling are off, I am [distracted/tired/careless] (take your pick)
Just like that. Yes they do, even rigging up their own generators from wire and magnets...there are photos on the site. You ever wanted to tell the power company to eat your shorts? There's how its done.
SLASHDOT: news for people who can't concentrate on work or have no life at all and got tired of yelling back at the TV.
What impact do all the turbine jets on airplanes have on weather patterns?
A noticable effect, actually. And not due to their effect on winds but rather the contrails left behind. See here for more information.
atleast they are doing something. 12% efficiency may suck compared to what professional power producers can come up with, but it's still better that sitting on you ass not doing anything.
I'd take 12% if it meant I was saving some money and the enviroment.
Sean D.
"Hmm. I am to metaphor cheese as metaphor cheese is to transitive verb crackers!"
Wow you read the first page of the article so your better than most slashdoters. but the 36W 6v 6a version was on one test coil. with all 12 coils running at normal speed it should pull the 400W.
Paying taxes to buy civilization is like paying a hooker to buy love.
My buddy's dad did this. He even got a permit for re-directing the stream from fish and game that also allowed him to put pet trout in the pond. (the local birds loved that idea) Anyhow, he is an electrician for the local school district, and did this in his spare time. To keep it easier, he didn't bother with regulating the power. Instead, he just connects the unknown voltage and frequency to a heating coil embedded in his tile floor via a thermostat. It would be supercool to power his whole house off the dam, but that would be more expensive to implement. He may well do that eventualy, but for now he is happy with just having free heat. They live in the interior of British Columbia (Canada) so it gets quite cold in the winter. The stream runs almost all winter, but he occasionally has to revert to wood heat when it gets really cold.
If you had read the article more carefully, you would have noticed:
:P
So far the machine works quite well. It has such a huge swept area compared to our previous machines that it seems to start up in practically no wind, and it's making a little power by the time the anemometer says 5 mph. At 10 mph it's doing around 400 watts and at 16 mph it's up around 1.5KW. Above that I believe the blades are overpowered a bit by the alternator. I do see 2KW from it frequently and I've seen about 3800 watts from it a couple times in very high winds, but overall I believe the blades are held back a bit in higher winds by the alternator. I can improve it by adding a bit of resistance to the line - this would allow it to speed up in higher winds and the blades would run more efficiently - but as it is it seems very slow and peaceful, and it rarely goes over 200 rpm It's producing quite a bit more power than I can really use. So I'll leave it as it is, it's quite a good low wind machine I think.
Around where I live, that'd make about 600 watts or so on average. Not bad, really. Too bad they didn't provide detailed schematics or cost estimates
"/etc/rc.d/rc.sysinit is a gimp plugin and must be run by the gimp in order to be used."
They get sued and arrested by the state for damaging wetlands in Washington if they try it. You can't even build a house within several hundred feet of a creek out here anymore.
slashdot effect in... er... effect.
Sure is.
I was trying to get on over lunch to do a bit of posting and it just wouldn't serve. Guess I'll have to put it off 'til tomorrow.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Why not get a generator with an electric motor plugged into a battery, and then use the generator to charge the battery and exceess for other use?
One cu ft of air weighs .0807 lb according to http://www.physlink.com/Education/AskExperts/ae650 .cfm
So the aperture of the 17 ft windmill is 227 ft^2 and a 10 mph wind is moving at 14.7 ft/sec so 3337 ft^3 of air is moving over the windmill every sec. That's 270 lb of air evey sec.
Since E=1/2 m v^2, E = 29172 ft-lb/sec. I'm not sure if I got my mass conversion factors right but that's about 40 kW kinetic energy.
So until turbines get way more efficient this is probably something we won't have to worry about.
Basically, air is *heavy*.
Give a man a fish and you have fed him for today. Teach a man to fish, and he'll say "WHERE'S MY FISH, YOU IDIOT?"
Seventeen feet is good, but get that baby down to ten feet and I'll be able to mount one on an electric car and tour the world!
Strange things are afoot at the Circle-K.
The true question is what's the average windspeed (and how many watts he gets at that speed).
I couldn't find it in the article (but again, most of the article was /.ed for me).
As for cost, I believe 1 kW/hr 365 days a year @ $.08/kWh runs $700.80.
Depending on the scale of what he's doing (and his location) he may increase his cost efficiency by skipping the battery array and selling excess power back to the telco.
How do they expect people to eat enough beans to make wind to power a 17' turbine? Now a 1.7" one I could understand. Maybe use an extra CPU fan and some duct tape. It'd be interesting to see how much power a sack of White Castles could produce. Not as efficient as burning the methane directly, but interesting.
It's easy. Just buy a book, a set of oxyacetylene tanks, a torch, goggles and gloves, and a bunch of scrap steel. $500. If you get a cutting torch your rig will be able to cut steel plate.
Or, take a course at the local community college.
Mig is faster but Oxyacetylene is way more fun. Tig is da bomb, of course, but it's real $$$ for a good setup.
I've got a few old books from the 20's-60's at home about motor and generator design (and some modern electronics textbooks which arn't as helpful, go figure). From what I know, air core generators suck. Its quite amazing that these guys were that modivated but didn't think about designing a better generator (or for the $700 the spent on the magnets and windings just buying one). A quick google search picked this up..
/ 91
http://www.fieldlines.com/story/2003/12/27/202634
This is not to say that I think your right about DIY generators. I think a perfectly good generator could have been built. A good lathe and mill would have been more than adequate.
Comment removed based on user account deletion
That's why my turbine has solid, plastic shields on the front and back.
It generates far less energy than expected, so I'm in the process of building several more.
Get some sections of EMT conduit and a brazing torch. (it looks like a propane torch for plumbing) Everything should be less than $50. Brazing is reasonably strong. For example, the bronze rods have a tensile strength of 50 to 60 thousand pounds per square inch. Of course your brazes will have a much smaller cross-sectional area than 1 square inch.
One big question: how noisy is this sucker?
If you are really considering the idea of planting one near your home this matters! (Or more correctly, the noise level defines what you mean by "near your home").
For Windmills to kill people who complain about windmills killing birds? That I would LOVE (and pay) to see. As I see it, the only birds who get killed are the ones to dumb to see the giant spinning blade of death in their path, survival of the fittest, natural selection. Fucking hippies.
The editors of Slashdot.org are still trying to figure out the right amount of time to delay a story from Hackaday.com so as to not look suspicous...
Right now were hovering around 36 hours.
...debunked here [PDF] among other places.
Other recent research supports the idea that birds can see wind turbines perfectly well and mostly tend to keep their distance. There are a few kills, but the turbines aren't the bird-blenders they've been made out to be.
he's too far out in the boonies to get commercial electricity; what he makes is all he gets!
Apocalypse Cancelled, Sorry, No Ticket Refunds
When looking at property out in the country, water rights are a common issue - who has rights to use the water from the river/stream? Because if you move in and start using water upstream of someone else that has been using the water for 100 years on a farm, then they'll get mad. Anyone have any idea if water wheels and power generation are subject to water rights?
free electric to run a few pcs :) although you better keep a ups between there for when the wind dies down.
The problem is that i dont have the reasorces to build a thing like this, if i did i would love to, do any slashdotters know a good place to buy wind turbine kit.
I don't understand your response. The original poster was asking what might happen if wind turbines extract a significant amount of energy from the atmosphere, versus trees for example. It's probably reasonable to assume that when energy is extracted from wind, the wind slows down or stops, and the numbers show turbines don't have much effect.
The "butterfly effect" is largely a literary metaphor. Technically, its the tendency of a model to be sensitive to inital parameters. I'm don't see how that has anything to do with how much the wind slows down or changes direction as the result of one or 100 windmills placed in its path.
Maybe, you could find a configuration of windmills that if large enough and strategically placed could result in stopping the Gulf Stream, or something like that, but that wasn't really the question.
Give a man a fish and you have fed him for today. Teach a man to fish, and he'll say "WHERE'S MY FISH, YOU IDIOT?"
Large scale deployment of wind power induces climate change.
Higher Logics: where programming meets science.
he may increase his cost efficiency by skipping the battery array and selling excess power back to the telco.
Somehow I don't think Ma Bell would appreciate that. Seriously, though, powerco-approved inverters cost more than batteries. And in most places, they only pay wholesale rates ($0.03/kwh) anyways. You're much better-off cutting them entirely out of the equation.
"I assumed blithely that there were no elves out there in the darkness"
Imagine you get your wind turbine.
i mney
... Convection is the transfer of heat by the motion of or within a fluid. ...
Now imagine you live in a quite sunny place (Texas ? lol)
And that you have the know-how or the money to buld a plexiglass veranda + a chimney.
Et Voila !! you have a solar chimney for generating power...
http://www.nationmaster.com/encyclopedia/Solar-ch
"A solar chimney is an apparatus for harnessing solar energy by convection of heated air. Solar power describes a number of methods of harnessing energy from the light of the sun.
In its simplest form, it simply consists of a black-painted chimney. During the daytime, solar energy heats the chimney and thereby heats the air within it, resulting in an updraft of air within the chimney. The suction this creates at the chimney base can be used to ventilate, and thereby cool, the building below. In most parts of the world, it is easier to harness wind power for such ventilation, but on hot windless days such a chimney can provide ventilation where there would otherwise be none. Wind power is the kinetic energy of wind, or the extraction of this energy by wind turbines.
General concept of proposed solar chimney power station
Enlarge
General concept of proposed solar chimney power station
This principle has been proposed for electric power generation, using a large greenhouse at the base rather than relying on heating of the chimney itself. The main problem with this approach is the relatively small difference in temperature between the highest and lowest temperatures in the system. Carnot's theorem greatly restricts the efficiency of conversion in these circumstances."
So cheap convection veranda + cheap home made wind turbine + Batteries = Electrical power in the middle of any hot/sunny desertic place.
Of course this particular turbine is not the best suited for this particular use, but generating wind is not that hard when you have a readily available power source...
Then, this is slashdot, whe should know about generating wind 8)
It takes 40+ muscles to frown, but only four to extend your arm and bitchslap the motherfucker
They're probably unemployed loser programmers who just have too much time on their hands and rather than spending their time doing what they should be doing -- asking their government for retrianing -- are trying to distance themselves further and further from the all-inclusive global mind.
Stewart Brand lead a SWAT team of Homeland Security forces to shoot them before they make him squeal like a pig during his next weekend jaunt out of the city to bring light unto the inbreds.
Seastead this.
wtf is up with ppl have to bitch and whine about something that's not coal powered. /have/ the money for nuclear, so don't read about alternative energy if you can't deal with it.
I guess next we'll be slowing the planet's rotation down with wind generators.
It's your own damn fault ppl for where you live - thos city ordinances are to shelter you from having to live too close to rednecks, like the otherpower hillbillies. If otherpower lived next door your precious little house wouldn't be as valuable.
You all
What kind of cat or dog would be good for deflecting bird chunks dropping from the sky, and isn't it going to be heavier to carry above your head anyways? I really think the umbrella is better suited to the task.
OK, I'm dumb about this sort of thing but could they use a car alternator / generator instead of making their own? I suppose they might have to use more than 1 given the scale of this thing...
This is still a handling problem, so you may be better off just concentrating the salt instead of drying it completely. This is what's done with lithium bromide chiller systems; the concentrated LiBr is used as a dessicant.
I've read about people using CaCl2 as an absorbent for ammonia and refrigerating things that way - the absorbent is heated to drive the ammonia into a tank (which is cooled with water during this process) and when the absorbent is cooled the ammonia tank gets very cold.
Time is Nature's way of keeping everything from happening at once... the bitch.
Tim: I know that, Al, now help me here, I can't quite... reach... AAAAIIIII! My balls! My balls have frozen solid!
Made me laugh!
You know what else would be funny? A trick lapel-flower that squirts liquid nitrogen. Amuse your friends! Freeze the stupid look on their faces!
-kgj
-kgj
Next wekk: Build your own Tokamak from off-the-shelf parts!
Did anyone read the article? They show a shop that would make any professional woodworker/handyman jealous. So, did they factor in the cost of the tools, too? No. I'll just turn my A/C waaay down at night and pay for it, thank you very much.
"I assumed blithely that there were no elves out there in the darkness"
Parent comments are inflammatory flamebait
Divide by zero hurts my brain.
The ammonia-absorption cycle has been used for nearly 100 years in refrigerators powered by heat.
I think the downside is that leaking ammonia is capable of catching fire. That, and ammonia is used to make everything from fertilizer to explosives to crystal meth. Widespread knowledge of its versatility is discouraged.
Here's one you can make yourself.
"I assumed blithely that there were no elves out there in the darkness"
No mention of a wattmeter. [...] Plus it's really easy to be fooled when charging batteries-- [details omitted]
A true RMS-reading wattmeter is likely to show much less power.
You don't need a wattmeter when measuring charging power into batteries. You care about watthours of charging, not watthours generated.
Batteries charge according to the integral of the current through them. So an average-reading ammeter (combined with a voltmeter ditto) does the job just fine.
Or just measure the state of charge of batteries of a known capacity over a known interval.
A large magnetic gap.
The gap is not THAT large, because the stator is thin. The use of extremely strong neodymium magnets compensates for the relatively large gap compared to a design with laminated pole pieces through the centers of the coils.
To keep the stator thin, the three phases are laid out in a single layer around the alternator, rather than being stacked three deep, and extra magnets are used instead. This requires twice as many magnets as a stacked design with pole pieces (or four times as many as with a return path through a laminated core). But see below for compensating advantages.
No closed magnetic path.
Wrong. The magnetic path is closed through the rotors.
Each rotor has alternate N and S poles, with the return path between the backside of them through the steel supporting disk. The N poles on one rotor face the S poles on the other. So the magnetic path is continuous - passing through TWO gaps and two disks.
The disks rotate together. Thus the magnetic field is never dragged throutg the disks. This lets you make the disks out of solid metal that is magnetically "hard" rather than laminations of material that is magnetically "soft", and eliminates eddy current losses in the return path.
While the lack of laminations in the center of the coils does increase the gap, it also elminates eddy current losses there as well. More importantly, it completely eliminates "cogging" without requiring any critical measurements or extremely accurate parts placement. Cogging could only be reduced, not eliminated, if cores were used in the coils.
Cogging is the tendency for the mill to "stick" at particular positions (where the gap is minimal) requiring extra force to break it free and start it turning. Eliminating or reducing it is important for windgenerators, because it sets a lower limit on the wind speed that is necessary to get the mill to start after a calm. If the mill doesn't start until wind speeds above the "cutin" for generation (where the peak voltage is higher than the battery voltage), you lose generation in light wind conditions - when you need it most.
This design can be built by hand without any fancy tools and is inherently cogging-free. So the only limit to its startup is bearing friction. It starts turning in the lightest breeze.
No design equations.
You only need equations if you're doing a first design and it must be right. Then you have to do lots of planning and modeling. And you'll usually find out, when you've built it, that you missed something - that the equations you used were too simple for the actual situation, and you need a correction "fudge" factor or a more complicated model.
But when you've done a bunch of similar devices, and established rules of thumb and rules of scaling, designing one more is trivial. Or if you intend to do a bunch and play with them until you get it right you can just start hacking, using qualitative rules of thumb, then tune until you've got it down.
Ever seen a carpenter do equations before cutting wood to build one more shed? You'll see architects do them - or use computer models - when designing a bridge or a skyscraper. But houses, pyramids, and cathedrals were built long before the invention of calculus, and even further before numerical solutions to the hard problems of material strength were even approx
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Firstly, someone should make a mirror of this site and post the URL in response to this post. It's just some guy's site, and these pics are big.
Here goes:
http://aubrey.vima.austin.tx.us/pipestone.html
Tag lost or not installed.
Break even point is important. It's a relativly simple calculation to tell you if a modification or method is worth it. Because, let's face it, it takes energy to make those cells. It takes money and energy to get the materials for the cells. The workers to manufacture the cells use power. Sure, some things are worth paying for, and that's exactly what the break even point is good for. Even if you don't pick the most optimal, at least you know why you didn't pick it, and just how much it cost you.
And no, it's not like crapping out in the lawn. It'd be more accurate to compare the difference between choosing whether you hook up to rural sewage, choose a septic tank system, tile field, or even an outhouse. Of course, electricity is pretty much electricity, so it's an apples -> apples comparison. Your septic waste disposal method, though, has different various issues that are harder to quantify than cost per kilowatt hour.
Though, if you don't like the fact that they're burning coal for your power, feel free to add a suitable 'penalty' when you figure out the break even point.
These shingles, for example, I'd probably invest in them if my other option was a gas or diesel generator in a remote enviroment. Of course, I'd also have to look at the fact that for consistant power, I'd still have to have that generator. So I'd have to be in a very sunny climate, and be needing power mostly during the day. And for what, AC? Washer? I mostly use my computer at night. Trying to use batteries is very wasteful, in that the investment in sufficient batteries, and the extra daylight(or windy, in the case of the turbine) capacity raises costs through the roof. If your power usage is the same during the night as the day, assuming 50% sun, you'd need triple the generation, and plenty of batteries(you loose about 50% of the power when charging a battery).
I don't read AC A human right
I'm building a smaller scale copy of this.
Anyone interested in windmills should scour the used book sites for books by Hugh Piggott. His books are usable how-tos.
Andy Out!
Unclear what he's measuring with, but it it's a typical DVM, the voltages and currents are peak values, not average. If he's getting good sine waves out, multiply by 0.707. For worse waveforms, the value is lower. He's probably getting under 300 watts out, which seems about right for the machine he's built.
What's making this work is rare-earth magnets. The field strengths you get today from rare-earth magnets are so high that even this simple design will sort of work. But good designs with rare-earth magnets do far better.
What's scary is that his turbine has a wooden hub and no overspeed protection. Most wind turbines are built to feather or turn sideways ot the wind in overspeed conditions. This thing will probably throw a blade in a big storm.
Real Goods will sell you a 3KW watt wind turbine for $5000, or a 400 watt unit for $900. So spending $700 on magnets alone to build your own is not a win. Real Goods units deliver more power from a 4' rotor than this guy gets from a 17' rotor, and they tilt to a safe position in high winds.
It looks real enough to me, but not cost-effective.
Based on previous comments, grandparent appears to be a poor attempt at sarcasm.
"I assumed blithely that there were no elves out there in the darkness"
But I wouldnt call a design "very well done" if it requires $700 of copper, where a car alternator is around 1/10th the size and uses maybe 1/10th the copper.
I'm all for wind power but IMHO this isnt an example of excellent engineeringl far from it. The good news is, it's not hard to do better than this.
The solar thermal industry (and not only this industry) is doing a lot of research in this field. As others have pointed out: This concept is not only known but also applied already. Larger sorption chillers are available from two Japanes companies (e.g. http://www.yazakienergy.com/waterfired.htm).
Especially in Europe interest in this technology has increased immensely in the last couple of years with ~10 companies now working on smaller machines, which could be used in single family dwellings.
For some of the latest research results have a look e.g. at Germany's Fraunhofer Institute for Solar Energy Systems (http://www.ise.fraunhofer.de/) or Google for "Solar Cooling", "Solar Assisted Cooling", "Solar Air Conditioning".
You will be amazed how far this technology has been developed already.
The homemade wind turbine has been made for several years now. This particular turbine is based from the 42v brake-drum trubines. (don't as me why 42v, I don't know either. it's a bastard child of voltage, probably just an error in the way they were winding, or maybe that's all that would fit, hence the reason for the homemade wind generator to evolve into the homebrew alternator method.)
/.'ed.
To be honest, I'm surprised their site has withstood being
There are also several people who build these in 3rd world countries to provide small-scale power to villiages to give them light and power for radios, small tv's, and I think there's even one with a computer somewhere
This is an interesting site and great information for someone who wanted to build their own, but it's hardly news.
Who cares about the ozone layer?...thanks to CFC's I can write my name......IN CHEESE!!!
Thanks for your comments, I didnt realize there was a magnetic path through the backing plate.
You're welcome.
A lot of thought and a number of design iterations went into this family of axial-flux designs. They're a very good match for the job.
But I wouldnt call a design "very well done" if it requires $700 of copper, where a car alternator is around 1/10th the size and uses maybe 1/10th the copper.
$700 worth of copper? What are you doing, mining your own? I doubt even the magnets cost that much.
A car alternator is optimized for a different job:
- keeping a battery charged and electrical systems alive when perhaps a hundred horsepower is available to bleed from - at 749 watts per horsepower so all you can eat is a drop in the bucket.
- Keeping a tight enough regulation on voltage to keep the battery from deteriorating unacceptable for several years, despite the wildly varying shaft speed.
- Alternators can be powered by a belt drive. So the shaft speed / crank speed ratio can be selected arbitrarily. Higher speeds -> faster flux movement -> smaller device for a given power.
- Running for 50,000 - 150,000 miles or so between replacements or refurbishments, which comes out to no more than 1000-3000 hours at highway speeds or no more than about 10,000 hours at a typical cycle.
This makes automotive alternators and similar designs a bad match for windpower service.
- They consume an enormous amount of excitation power - and the most at low speeds. You can't set the wind's "idle speed". You must take what you get. In a car this is no big deal - a tenth of a horse is a drop in the bucket. In the wind this is a very big deal - a tenth of a horse is 75 watts. Stealing power to excite the alternator raises your "cutin" speed, greatly reducing the time you can charge and the amount of charge you get.
- 1,000 - 10,000 hours between rebuilds (depending on weather conditions) corresponds to an alternator rebuild every 6 weeks to 16 months. Totally unacceptable for a mill.
- Mill shaft speeds are limited by the aerodynamics of the blades (in particular the "tip speed ratio" in combination with the blade radius). The bigger they are the slower they turn. The slower the alternator shaft turns, the less it generates - by a square law. But gearboxes and belt drives to raise the alternator shaft speed introduce design complexity, expense, losses, maintainence requirements, and points of failure. So you're better off running at shaft speed - and getting your power by stronger magnets, more wire, and bigger radii.
You could be slightly more efficient on copper with a radial-flux design, like a typical electric motor. But that gives you more weight on the tower and is much harder to construct.
- Small wind power designs can't afford excitation power overhead - and using permanent magnets eliminate it (at a significant up-front cost). Unlike an automotive alternator, you don't need to regulate the voltage by adjusting the excitation: You can regulate it by letting the load slow the prop (which isn't as inefficient as it sounds - in fact you MUST do this, to get current out of the genny). You further regulate it by designing the mill to furl (typically by turning away from the wind, sometimes by designing the blades so the airflow detaches) when the alternator is maxing out and would overheat. Final control is to add a "dump load" to deliberately waste power that would otherwise overcharge the batteries. So you don't NEED variable excitation to control the mill.
I'm all for wind power but IMHO this isnt an example of excellent engineeringl far from it. The good news is, it's not hard to do better than this.
Most of my comments have been on the axial-flux designs in general, rather than this particular instance. I see that this one has violated some of the rules of thumb that are well-known by the denizens of the board. (And the author admitted this.)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Lots of expensive, custom made parts. Dangerously powerful magnets cast in polyester resin. The dude looks like he's working in a professional level workshop. Oh yeah, I'll just get right on this. Now if only I had a local metalwork shop... or a garage... or, y'know, some tools.
not everything is a science experiment!
Thats what the fine article said. $700
>I doubt even the magnets cost that much.
The going price for disk drive magnets seems to be around zero or slightly lower. I got big box, about 80 large ones for $5 at a surplus place. I shudda offered less.
> - Running for 50,000 - 150,000 miles or so between replacements or refurbishments, which comes out to no more than 1000-3000 hours at highway speeds or no more than about 10,000 hours at a typical cycle.
So once a year you inspect and/or replace the brushes and squirt some grease into the bearings. If you're living off the grid you probably ave plenty of time on your hands.
I get your point about the wasted excitation power. How about you open up the alternator and replace the rotor winding with some good magnets? That also eliminates the need for the brushes and their replacement.
I didnt even mention the mismatch of rotational speeds, as used 8x 5hp gearboxes go for about $8 on ebay. And while you're pulling the alternator off a car, you can grab the serpentine belt too. A good DIY'er should be able to make a large cogged driving pulley out of plywood and popsicle sticks. Not terribly esthetic and might get iced up in a bad winter.
I get your point about the wasted excitation power. How about you open up the alternator and replace the rotor winding with some good magnets? That also eliminates the need for the brushes and their replacement.
You'll find discussions on doing exactly that on the otherpower board. (www.fieldlines.com. It has a search feature or you can use google advanced search and restrict it to that site.)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
So once a year you inspect and/or replace the brushes and squirt some grease into the bearings. If you're living off the grid you probably ave plenty of time on your hands. [...]
I didnt even mention the mismatch of rotational speeds, as used 8x 5hp gearboxes go for about $8 on ebay. And while you're pulling the alternator off a car, you can grab the serpentine belt too. A good DIY'er should be able to make a large cogged driving pulley out of plywood and popsicle sticks. Not terribly esthetic and might get iced up in a bad winter.
Why don't you build one up, join the board, and show 'em how it's done? B-)
Then come back periodically and give them a report on how long it lasts and how much trouble it isn't to maintain it.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
$700 worth of copper? What are you doing, mining your own?
Thats what the fine article said. $700
I looked for that but missed it. Holy cow!
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Why not use 10 car batteries? How about Motorcycle batteries? For lighting there's no need to convert to AC to use regular bulbs. Other stuff could be a problem - I don't think you can't get a 120V inverter at home depot.
That all sounds great in theory. But what you are describing would simply not stand up to use.
Swapping out the windings on the alternator??? Good luck getting it to balance afterward.
Use a gearbox? Again - that would be another point of failure and servicing item.
Living off-grid you need this stuff to work. Also these guys enjoy DIYing with basic supplies. The strong magnets are a bit of a cheat in that department - but what are you going to do? At least the magnets should last a very long time.
People generally make two mistakes when working with home power.
The first is that they pay too much attention to efficiency. A system does not need to be efficient if you have a way to increase the input power. One way to do this is to stop trying to put it on your roof -- if you have a back yard, use it. Less of it to mow, that way.
The second mistake usually made is to go right for electricity generation. I can't stress this enough: take care of heat first, deal with electricity later.
Yes, heat is cheaper by far, but so are the systems to provide it. All you need is a couple small pumps, a storage tank, and either panels or just a really long hose to collect the solar. Reflectors for a concentrator are a very good bang-for-the buck as well. Take the money saved from heating costs and put in in your piggybank to pay for electrical generation equipment.
What happens when you go right for electricity with a PV panel? Your conversion efficiency is lower (most of the sunlight is wasted as heat) and you have electricity some part of the day, so if you want to store the rest of it, you have to buy into an expensive battery bank with ongoing maintenance costs. What happens when you have a tank full of hot water? You get more power out of the sun, and it stays hot (if correctly insulated) during the night.
After heat/hot water is taken care of, you can then take your sweet time looking into a thermopile, or a stirling, or a thermoacoustic, or whatever floats your boat and you can catch a bargain on. Generate electricity from the hot water, and your "storage battery" is just a big vat of water, which is not that hard to maintain.
Of course, this market dynamic may change in several years when the new cold-assembly solar arrays hit the market, but for now, electricity generation is a bad first move.
Someone had to do it.
Well ordering them is kind of a cheat, but you can find them in many places. Dead hard drives for example have nice little Neos I believe.
Hell, I'm building a wind genny out of microwaves.