I think if I were to build an alternative-energy system to provide electricity for my home, I would want to combine several methods together with the aim of creating a varied and constant source of power - for example, solar panels, wind power, and a water wheel (if I were lucky enough to have a small river nearby) all feeding into a bank of batteries for storage, and then powering the house. That said, how feasible is wind power for someone like me? Is it reasonable - and cost effective - to build or purchase some sort of windmill that would generate an amount of electricity that would be worth storing? Does a windmill have to be 100' tall and blot out the sun? Would it take 100 years of use to recoup the cost in power savings? All this assumes that I live in an area where I have a good amount of wind, and not a lot of neighbors to complain. :D
Wind power
Thu, 2005-01-20 15:28 — jgunn5066
Comments
bump...
...I'm looking at you, Rod!
OK OK! :-)
Here we go.
So now if all went well, you should have wound 9 identical coils, and now they need to be wired together. To do that please refer to the nightmare of a sketch below.
I color coded each phase in hopes it makes it easier to understand how it's wired. There are a few important points to note. Most important is that all the coils (at least on a three phase turbine) need to be wound in the same direction. Whether that's clockwise or counter-clockwise doesn't matter, just as long as they are all the same. If you had one coil wound opposite the other two, it would cancel out one of the correct coils, severly limiting output. In addition, all three groups of three coils must also be in the same wind direction, or you'll end up with interaction problems, also severly limiting output. So, just make sure all your coils are laid in the same direction, and you'll have no problems.
So tying coils together, you need to wire the "end" lead of the first coil, to the "start" lead of next coil in the proper phase. (that being every third as shown in the sketch above) and do the same from second coil to the third. When you get to the end lead on the third coil of a phase, you will be connecting it to the end leads of the third coils of the other two phases. (you don't need to take them to the center to terminate them. I just drew it that way to clarify) The start leads of the first coil in each phase are your output leads. (hopefully the sketch makes more sense than the explanation)
So to physically tie the leads together, I prefer an uninsulated crimp sleeve (or a piece of copper icemaker tubing if the wires are too big for common crimp sleeves) To do this requires a few steps for a long lasting, trouble-free connection. First, with the coils positioned as they will be in the stator, (and I prefer to do it right in the stator mold, but it's not necessary) trim the wires to length between coils. (if using icemaker line, have the wires overlap instead of butting together) You need to remove the epoxy insulation from the magnet wire, and the best way to do this is to take a torch and litterally burn it off where you'll be making the connections. Then take some sandpaper to remove residual epoxy and shine up the wire. Before placing the leads in the crimp sleeve, slide a piece of heat shrink tubing over one of the leads and slide out of the way. Put the leads in the crimp sleeve and crimp. I highly recommend soldering the connection as well, and it's best to use a silver solder. Afterwards, slip the heatshrink over the connection and heat it to shrink. Repeat for the rest of the connections, including the end leads of the three phases. There should be a total of seven connections to make.
How to handle the output leads is up to the individual. Most people would just have the wires exit the mold, and connect to a screw drilled through the stator's edge. I prefer to embed brass toilet bolts in the stator, and solder the leads to the bolts. Once you have the coils wired, now is a great time to find a way to temporarily secure them so you can move them as a group. An easy way to do this is to take pieces of fiberglass laying across the legs of two coils, and use CA glue to bond the two together. Do this to all nine places, then carefully flip the coils over, and do the same to the other side. At this point, the coils will be a pretty rigid, single mass.
Next, stator mold construction.
Winder pictures
Here are a few pictures of my winder. The long screw would get clamped in a vice or B&D Workmate bench. The removable end-plate allows you to remove the coil after winding and taping.
bump..... any help?
Fri, 2010-06-04 20:06
bump..... any help?
*
:-)
http://www.neo-aerodynamic.com/default.html
O'Connor Hush Turbine
O'Connor Hush Turbine
http://www.hushenergy.com.au/hume_turbine_images.php
And this one also.
Wind Wing
http://www.venturacountystar.com/news/2007/aug/05/developers-trying-harness-earths-energy-new-way/
Windbelt
Wow! it's been awhile. :-)
Windbelt, Cheap Generator Alternative
This is a small generator for lighting up LEDs or a radio.
It uses a belt that vibrates in the wind instead of a wind turbine.
http://www.popularmechanics.com/technology/industry/4224763.html?series=37
Clever find Ponyboy, Yea, it
Clever find Ponyboy,
Yea, it could be upscaled quite easy. It can be homebuilt easily too.
BUT . . . . . . . (ya just knew it was coming, didn't you?) Scaled up, this thing would be horrendously loud. You think people gripe about windmill "swoosh", how about the buzzing drone of thousand of vibrating belts?
Dang! Almost!
Yea, it could be upscaled quite easy. It can be homebuilt easily too.
BUT . . . . . . . (ya just knew it was coming, didn't you?) Scaled up, this thing would be horrendously loud.
:-)
Dang! Almost!... And I would have gotten away with it too if it wasn't for
those pesky kids!Rod! :-)Yeah, I figured it would be noisy. Have you ever put a blade of grass between your thumbs and blew
into it to make a LOUD screeching noise?
:-)
Looks like somebody took some big corrugated culvert pipe... :-)
http://www.helixwind.com/en/
FloDesign Wind Turbine
http://www.flodesignwindturbine.org/index.php
When things go wrong
Yikes!!!! So, you ever wonder what would happen if the control systems in one of those huge commercial wind turbines were to ever fail? Well, wonder no more! Check out what happened yesterday. http://www.liveleak.com/view?i=cdd_1203701257
Rod, don't let us down...
Rod,
you were so good at posting pictures for the first year or so... what is up with the PMA? Do you have props? Steel for a tower? Test Data? You could run your PMA with a motor and give a calibration (volt's per RPM)! Don't leave us hangin!
Thanks for info on your continuing saga.
I just found this, so I decided to edit my post (hopefully it will still work in a day or two..) http://seattle.craigslist.org/see/zip/584598143.html
In short, have you considered a used HAM radio tower? Can it handle the load?
Windmill hiatus
you were so good at posting pictures for the first year or so... what is up with the PMA? Do you have props? Steel for a tower? Test Data? You could run your PMA with a motor and give a calibration (volt's per RPM)! Don't leave us hangin!
Thanks for info on your continuing saga.
Ha, yea, sorry about that. That project got back-burnered when I came across that good deal on solar panels. Then the good deal came along on solar hot water collectors. So that's been a bit over $10,000 in CASH sales that I put out, and being opportunistic whenever log related tools come along, money gets spent on them first. (which BTW, I'm going to be picking up another cant hook and logging chain tomorrow)
Then I decided to go from 24v system to 48v, so I'll have to wind all new coils and build a new stator. (I've thought about using the PMA as is on a Lister engine running on WVO, but I'm not sure the stator could survive at 600 RPM) And finally, I'm loosing my "workshop" at work since we're moving. Blade making is going to take up some room I just don't have right now. Looking at things from a realistic standpoint, I doubt I'll get to finishing up a working wind turbine before the home gets built.
winding coils
Sun, 2010-04-25 20:34
hey rreidnauer, do you have any more info on winding coils? im interested in learning more about building a wind mill...
also, it appears that the stator is placed between the 2 rotors... is this correct?
Ohhhh, where to begin . . .
Ohhhh, where to begin . . . . Such a short question requires a very long answer, and very complicated that this instruction may do little good. What I learned came from no single source. I recommend you stick with a previous design unless you are exceptionally intuitive to this stuff. Hugh Piggott's books are a great resource to copy from. But should you dare to blaze a trail, read on.
Alright, first thing before you can even think about winding the coils is, you need to have your rotors picked out. Once you do that, you can start to figure out the size and shape of the coils. The "legs" of the coil which radiate out from the center of rotation need to be the size of the magnets on the rotors. Making the legs shorter will induce less electrical current, as a magnet passing parallel to the coils generates no current. Making the legs longer increases overall coil length, thereby increasing electrical resistance which in turn converts to heat and lost energy. Best way to describe it is, you should just be able to fit the magnet through the hole in the coil. You also need to decide on a coil thickness. 3/4" is a good compromise, but anything from 1/2" to 1" will work. Any smaller, and you run out of room for the windings, any bigger, and you start to separate the magnets too much, and magnetic flux drops off exponentially. The best way to figure out the coil shapes are to draw it out as you've seen in my pics in earlier postings. With your rotor size determined, draw an arc of the magnet's reach closest and furthest from center. That's the distance your coils' legs need to be. You then have the challenge of drawing nine equally spaced, radiating lines from center. This represents the space allowed for the nine coils. Then referring back to the magnets, you should mark on either side of those radiating lines, half the diameter (or width if not using round magnets) of the magnet. This will be the leg width. With this information, you should now be able to draw you coils. The "perfect" stator will have a magnet's diameter/width cover one leg each of two adjacent coils AND the hole in a coil should be the same width as the diameter/width of a magnet. Note the picture below, and you'll see I came very close to perfect, as you can see I have both legs of #2 and #3 coils fully covered, while the magnet nearly fits in the hole of #1 coils.
OK, so that's determining coil size. Next up is calculating windings, but I'm gonna take a typing break.
OK, I have simmered down :-)
OK, I have simmered down :-) so I'll continue with the tutorial.
Alright, so now, you should know what size coils you can have, you can make a coil winder. The way I did it was to make cardboard template from my drawn coil layout. The winder is made of a 3 piece wood sandwich. The center piece is the shape of your coil hole. The outer pieces are larger than your wound coil, but should be marked where the coil shouldn't get any bigger, so you don't wind too much and make the coil too large. (I'll take a picture of mine when I'm back at work on Monday) There are also two cutout's in the winder that allow you to tape the coil legs once wound while still in the winder, so they don't spring apart when you go to remove them. Some people just have their wire start in the tape notch, but I prefer a separate hole. This allows for the transition between coil layers to happen at the outside of the coil, and keeps the legs perfectly parallel and dense. Here's a rough sketch of what it should look like:
Now, you need to get into the really difficult mathematical portion of the build. This math will help determine your number of windings and wire size. So many things come together at this point. I'll try to work through them one at a time. First, you need to decide on several factors. What voltage will you be using? What maximum wattage from the windmill do you want? What size windmill do you wish to build? (which also effects windmill speed)
(Ugh, my head is spinning just trying to remember all the steps required. Bear with me)
OK, first. Go to this site: http://warlock.com.au/tools/bladecalc.htm Select imperial units if working here in the States, leave number of blades as 3, TSR as 7. Change blade efficiency to 0.35. Select a reasonable windspeed for where you'd like to reach maximum output. (I prefer 20 MPH, but you may like 15) Play with the blade radius numbers and hit calculate, and note the wattage. The wattage calculation shown is what is obtainable from the rotor, NOT necessarily what the generator will put out. Try different blade radius-es until you get your chosen wattage you'd like to produce. Now change the windspeed to 8. This is a good "cut in" speed, the speed at which a windmill's voltage rises to meet the voltage of your battery bank and begin charging. Much slower, and you risk stalling the rotor blades under a charging load. The RPM is what we are interested in. With this RPM, we can begin to calculate the number of winding turns per coil. OK, headache time. Knowing you battery bank voltage, you will use this calculation:
Target DC voltage + 1.4v rectifier loss + line loss x 0.7 AC to DC gain / 1.73 star gain / number coils in one phase = AC volts per coil. (LOL, I know what you're thinking)
Let's break it down. Let's say our Target battery bank voltage will be 24v. Add to that 1.4 volts. (that is the voltage that will be lost to the rectifier which converts AC to DC) Also add whatever your expected voltage drop will be between your windmill and batteries. Here's a calculator: http://www.csgnetwork.com/voltagedropcalc.html So for example let's say 24v system, 1000 watt generator, that's 41 amps (watts divided by volts) and lets say it's a 50 foot run of #8 cable. That's 3.1 volts line loss added to the above calculation. So we are up to 28.5 VDC. Now we get some benefits, converting AC to DC actually increases voltage, so we multiply our 28.5 by 0.7 for 19.95 VAC, and we divide by 1.73 for phase interaction within the generator, for a value of 11.53 and divide again by the number of coils in a phase, which in a three-phase, nine-coil generator is three, so that gives us 3.84 AC volts per coil. This is the required voltage of a single coil at the RPM generated at our windspeed cut in point of 8 MPH. (I told you it was going to be a headache!!)
At this point, you should really have your magnet rotors built, because you'll need to get data with a test coil, since magnet's flux strength will differ between shapes and sizes. You'll need a few things for the test. A test coil. (I simply used some inexpensive 20 ga "doorbell" wire) A tachometer (I used a cheap laser version I got off ebay) An analog (not digital) voltmeter, and something to rotate your rotor up to "cut in" RPM. (I used a battery drill and made a simple adapter to fit over the threaded rods) My first coil, I just wound like 50 turns and ran a test.
From that test, I turned the rotor at cut in speed, and read the voltage coming off the coil. I took the voltage value, divided by the number of turns to get volts per turn. Now, knowing that our hypothetical target voltage per coil above was 3.84, you divide that by the volts per turn and wala, you have the required number of turns per coil.
Next, determining coil wire size and deciding between single or parallel conductors, but time for another typing break.
a couple of questions
1 your "battery bank voltage" is nominal. my lead acid battery in my car charges @ 14.4 V, so 2 of them would be 28.8 V.
Aside from that, the charge/discharge voltage difference for Ni-Fe batteries are very large, I believe 1.71 V/cell for charge, and have a nominal voltage of 1.2 V. How do you deal with this very high disparity.
I like Ni-Fe, cuz I can get used cells super cheap, they are pretty easy to refurbish, and the high charging voltage allows you to simply hook up the cells to your solar array, without a charge controller (10 x 1.71 = 17.1V, so I won't overcharge them).
topping them off with a generator will be difficult, though, as most chargers operate at ~14.4V, which won't even touch the requirements of the bank. Also, I am a bit scared of burning out my 12V electronics @ 17-18V. I may use only 9 cells (I have a line on pallets of 80 AH cells), which would lower the charge voltage to 15.39V and would give a smaller nominal voltage of 10.8V. Anyway, I am thinking to make one of these specifically to run off a diesel genset to charge my batteries. Any thoughts?
-peter
Alright, first off, 14.4
Alright, first off, 14.4 volts is not a nominal voltage for a lead-acid "12 volt" battery. An at-rest fully charged 12v battery's voltage is 12.70v, and when discharged to 70% capacity, it's voltage is 12.36v (again, at-rest) OK, so what's with the 14.4 stuff then, right? Well, that is a case of overvoltage being delivered to the battery to drive the amperage into it. A battery is very similar to a water tower. With a water tower, you are going to need more PSI to pump water into the tower, than the tower is already pushing back with. And, the higher your pump pressure, the faster the water will go in. A battery is the same way, except its "electrical pressure" (voltage) instead of water pressure. Realistically, a car's regulator just working to maintain a constant 14.4 volts is actually quite hard on a battery (hence one reason car batteries usually don't last long) but it is the simplest solution in the automotive world. (hurry and get it charged up so it's ready for next use)
You're jumping ahead of me a little here, but a permanent magnet, axial flux generator's voltage increases linearly with RPMs. So if you reach a "cut-in" voltage of say 12.5 at 100 RPM, you then know that the generator will reach 25 volts at 200 RPM. (open circuit) Now, when the generator is directly connected to the battery, a phenomenon occurs, that the battery bank itself will regulate the voltage. (at least up until the battery reaches capacity, then voltage will rise quickly, heat up, and boil off electrolyte if left unchecked) So what happens, is the overvoltage being produced by the generator gets converted into amperage, and you see that case of higher voltage pressure, faster charging pattern. (I'll get into the math of how to calculate it in upcoming posts) This kind of answer's you second question. You really don't have to account to much for a voltage difference. If the bank voltage is a little higher (say near full charge) vs a low battery, the windmill will just start charging at a slightly higher RPM.
I'm not real well versed on the Nickle-Iron "Edison" batteries, but I do know they handle over-discharged states without damage. I can see your worries of sending too much voltage to your appliances while the windmill would be charging, driving your 12v Ni-Fe bank up to 17v (if that's what they really charge at) Sure, you can use 9 cells and simply account for the voltage difference when designing your cut-in speed voltage. Heck, if you have it wrong, it just means your cut-in will occur at a slightly higher or lower windspeed. (not a real big deal unless you get too slow a windspeed cut-in) So if you planned your windmill for 9 cells, but didn't like the voltage (say your 120v inverter drops out under load) and you added a 10th cell, your cut-in would occur at approx 1/10th more than the 9 cell cut-in speed, so say the original planned 15.4v at 8 MPH, it would now be 17.1v at 8.9 MPH. (15.4 / 8 * 8.9 = 17.1)
The thing with wind and hydro is, you don't have a way to throttle back the incoming power like you do in a car with induction magnetic field control regulators. And you can't just disconnect the battery from the generator either, as it will unload the generator, and without that electrical resistance the generator will run away and self destruct. You have only one option, and that is a dump-load controller which, when the battery is full and voltage begins to rise, the dump-load controller will have a voltage setpoint, where it will close a switch that is connected to a 12 volt load (heating elements?) of at least as much amperage that your windmill is capable of putting out. The controller is a little more complicated than that, but it's roughly how it functions.
I'm not sure about your diesel powered charging system for the Ni-Fe batteries. I have no idea how they'd respond to an automotive alternator. You'd have to play around with it and make sure it doesn't overcharge and boil your electrolyte. (shouldn't if 9 cells is 15.4v, but I don't know)
thanks rod
I have almost no wind at my land. Someday, I may build a 50m tower at the top of the mountain and get a bit of what wind there is, but the mountain is out of range of my current location. Anyway, I don't want to have an "automotive alternator" but a linear flux alternator (which I can tune myself), I will have to determine how to regulate the rpms.
Thanks again.
-Peter
next part
to the series rod? You should seriously just write a book. I'd review it for you for the low low commission of a signed first edition.
-Peter
Oops, I forgot about this.
Oops, I forgot about this. Yea, I'll get back to it here shortly.
bump
Mon, 2010-08-30 05:55
bump
Ugh, yea, I know. I'm
Ugh, yea, I know. I'm slacking. I've just been burried with al kinds of things. I just got in from 12 hours on the road, so I'm in no state of mind for another chapter. I'll try to fit one in here sooner or later.
how about these magnets
Sat, 2010-06-12 17:01
http://www.magnet4less.com/product_info.php?products_id=792
it sounds logical that the more magnets i can put on my rotor, the more efeicent it will be (this is obvously up to a certain point, a magnet 1/2" wide wouldnt create a strong enough magnetic field across the stator gap to work effectively)
so using these wedge magnets i can get more magnets in the same space.... now, with this i would be going from your example using 12 magnets and 9 coils to my 16 magnets and 12 coils... still maintaning the 4;3 ratio. do you see any issues with this.
only thing i can think of is that coils are going to have to be on the small side.
and for number sake, i have thinking of doind a 15ft dia prop.... but i am also thinking of more than 3 blades, but i havent looked into it allot.
here is some monthly average wind speeds for where i currenly am in southern california.
it is broken down monthly, jan-dec, and the last is anually, a note, this data was collected from a automatic weather station from 1996-2006.
TWENTYNINE PALMS EAF |KNXP|1996-2006| 7.0 7.8 8.5 10.4 9.5 9.7 8.3 7.8 6.9 6.7 6.6 6.9 | 8.0
and for anyone interested here is the page.
http://www.wrcc.dri.edu/htmlfiles/westwind.final.html
Alright, back to it. So
Alright, back to it.
So now you know how many turns you require, and you know the dimensions of your coils. Now you need to figure out how to pack the maximum amount of wire into your coils that the number of turns and dimensions allow. The reason is, you want to get the lowest resistance possible, because with higher resistance, not only are you loosing potential charging energy, but that resistance gets converted to heat, and yes, it's possible to burn up your generator. You'd think just going with the biggest gauge wire you can fit in the number of turns required would be best, but it's not, because the round cross-section of wire allows for a lot of wasted space between wires. The smaller the wire, the less wasted space. So if you can find a wire gauge with half the cross-section area and use two of them in parallel, you can get more copper in and less wasted space. (even 3 or 4 parallel strands are a possibility) So, with multiple conductors making up more copper and less wasted space for the same amount of turns, that can only mean you have less resistance in your coil. The down side is, they are more difficult to wind and keep in a neat, tight, parallel configuration. Referring back to my earlier sketch, I say your start lead(s) begin at the hole, you'd wind counter-clockwise. This is because as you complete one turn, the wire(s) move over to start the second turn. This action will force parallel strands to not lay together during this transition, and you end up with a wider coil in this spot. You can probably see in this pic that the outer portion of the coil is wider than the rest.
Ideally, you'd want your coil winder just wide enough to fit "X" number of conductors per layer, plus one half conductor. This is because as you start the next layer, the wires will lay in between wires of the previous layer, filling the maximum amount of space. With the secondary layer of wires in between wires of the previous layer, you save about 7% in height, compared if they were stacked directly on top of one another. Another sketch to clarify.
If your winder isn't quite right, you can sandwich in a bit of cardboard to get a width that makes it work out. Also, if winding multiple conductors, I found that while winding and reaching the end of one layer, the best way to get maximum fill is to put a half twist in the pair, so whichever conductor was the lead conductor in the first layer, will also be the lead conductor of the next layer. See if this animation helps visualize the concept.
So, what size conductors should you use? Well, that takes some figuring. The best place to start is finding out what the diameter of different gauge wires are, and figuring out how many conductors you can get in width and depth of your coil legs, and see if the total adds up to the number of turns you require. http://en.wikipedia.org/wiki/American_wire_gauge has a chart of wire diameters for various wire gauges. Keep in mind that epoxy coated magnet wire is going to be a little bigger than the bare wire figures given, so add approximately 0.002"
Next post, putting it all together.
KaBoom Ricco!
Yikes,
I've been up close and personal with a farm of those things on the North West tip of PEI. Granted the wind was realtively calm.
After seeing that footage, I don't want to get within 5 km of one if it's really blowin' out.
Wow! They are popping up
Wow! They are popping up all over the place here in SW PA. Always a big fight when they plan a development of them.
WOW
Holy Crap!!!!!!!!!!!!!!!!! That was some great footage
Marcus Ward
Brilliant Idea!
http://www.popularmechanics.com/technology/industry/4224763.html?series=37
This design is brilliant!
I read some of the comments on that page, and some people bring up some interesting points:
1) What about varying wind speeds?
2) Could multiple bands be set up in an array?
3) Wind direction?
4) Scalability? Could it be made to produce more energy per unit?
Direction could be handled easily enough just by putting a weather vane type fin on top with it mounted on a rotating base.
For multiples, I imagine a rack or grid of these thing set up on a frame of some kind. The frame would then be an a swivelling base to change with the wind direction.
The windspeed thing is trickier. An electronic control that would adjust the tension based on windspeed would probably be the most precise, but then how much energy would it take to operate it? Would it reduce overall efficiency so much to not be worth it? But if a MECHANICAL means of adjusting the tension could be devised... I imagine a regular windmill-type of wheel that would apply tension to a spring of some kind. The spring in turn would apply the proper amount of tensions to the bands? The problems here would be matching the "curve" of the spring's tension to properly match the wind speed. And then the tension would also have to be matched to the number of bands (net sum of tension needed). It would be quite an engineering puzzle to be sure. At best it would probably have to be optimized for a specific range of wind speeds.
I really have no idea how to increase the amount of energy output per unit. Perhaps something with the magnets? (I'm into territory I really have no clue about at this point.) If the energy output per unit was sufficient, then electronically controlling the tension (which seems easier and more precise to me than a mechanical control) would be reasonable.
Then the question is -- how much energy output "per square foot" could you produce with a "rack" of these things? It may just be that it would be so low that you would need an acre of them to power a home, etc. Oh well. In that case, I just wrote a bunch of stuff to amuse myself while I was supposed to be working... muwahahaha
Wind power
Rod,
Didn't know if you'd seen this yet and thought you might find it a good read.
http://www.motherearthnews.com/Alternative-Energy/2007-06-01/Improved-Wind-Power.aspx
Larry
Wind power
Video of a $700 wind turbine being considered for Australian roof tops.
http://www.youtube.com/watch?v=WZ5kX5Yw4eY
Wind power
Here's a little wind power for your cell phone.
http://www.gotwind.org/Orange_Wind_Generator.htm
E-85
"I just wish our gov't would stop encouraging farmers to turn food into energy and focus instead on developing the endless supply of natural energy sources."
This is off topic but I just wanted to say that e-85 is definately not the answer, however it is a bridge to better energy resources. Does any body realize how much our government pays farmers to not grow crops like corn? It is called the crop reserve program. Millions of acres are not in production because we can produce more than we can use or even sell. I vote for using some of this land to reduce our dependency on foreign oil.
double helix design
Thanks for the find on the double helix video, Ponyboy. I have no idea if this is good science, but I hope it is, just like I hope all alternative energy technology is. I just wish our gov't would stop encouraging farmers to turn food into energy and focus instead on developing the endless supply of natural energy sources.
freddy
Wind power
And another.
article
http://www.metaefficient.com/archives/renewable-power/new-rooftop-wind-turbine-tested-the-helyx.html#more
web site
http://oregonwind.com/
Wind power
Pssssst... Don't tell Rod.. :wink:
http://www.mariah-power.com/
Here's the video! :shock:
http://www.youtube.com/watch?v=AnhpeJAS9gY&eurl=http%3A%2F%2Fwww%2Eecogeek%2Eorg%2Fcontent%2Fview%2F569%2F
Wind power
Funny you say that, as the thought had crossed my mind. But at the same time, I really don't want to put any more hinderance on Pennsylvania pushing forward with renewable energy production than they have already done to themselves. Sadly, such a poor choice as this could cause setbacks, both from the people and internally, basically due to ignorance as to why it's not working as well as it should. Somehow, they (the gov't) need to get a better handle on how money should be spent for such things. (power per dollar) I'd love to know who made the decision to go with Southwest Windpower, how much they researched it, and what knowledge background they posses for renewable energy resources, because so far, it looks like $3 a year is probably an opimistic forcast of energy production. Multiplied by 15 units, $45/year isn't a very good return on spending my tax dollars.
I also noted that I haven't found a webpage on http://www.state.pa.us which lists the turbines' current energy production or even where they are all located. Based on my findings at this one location, I can understand why you'd want to brush it under the carpet.
Wind power
But if you buy one of those turbines they throw in a free bridge and some "wet lands property" in Florida... :shock:
Wow! 9.4k in four months, that's pretty bad. Sounds like a good story for the local news.
Wind power
http://www.skystreamenergy.com/skystream/product-info/
I wonder why their video of this thing in action has no sound..... :wink:
I recall seeing this vender at the Pennsylvania Farm Show in January. (no representatives present the entire day) Now, I've had the opportunity to witness one in action (or the lack thereof, you decide)
First, how I got to see one. Pennsylvania paid a grant of $193,000 to Southwest Windpower for the purchase and installation of 15 twelve foot diameter wind turbines throughout the state, in highly visible locations to promote RE production. Southwest Windpower sells the Skystream turbines, which brag of 1.8 Kw output @ 20 MPH, (very optimistic, but achievable) and 400 kWh per month with 12 MPH average winds. A town near me received one of these turbines, and was commissioned on Nov. 30th. So I went to see it on a fairly breezy day.
When I arrived there, I found it mounted on the standard 34 foot tall tower mentioned on the website, as well as the grid-tie inverter and a KWH meter to record it's production, mounted on site. The first thing that caught me as odd, was the fact that it was turning very little, if at all. A strange thing, considering it was blowing around 5 to 10, with gusts easily exceeding 15. Mostly, it was just yawing in the wind. So, I headed over to look at the meter and was quite shocked to see it's recorded output.
During the last four months (notably, the most windy months of the year for these parts) it's managed to crank out an incredible 9.5 kWh. . . . . . . . . . . . ehhhhhh, . . . . . . . . ahem. . . . . . . . Gee, that's like $0.90 worth of electric. Now granted, it's placed in a less than ideal location, and the tower is rather short, but certainly, it should be able to do better than that, right?
I silently believed this was just another one of those "make it look cool for the consumer" products with no real potential, and my visit has pretty well confirmed that belief. (see ponyboy. I do try to keep my trap shut sometimes :wink: ) I posted cameraphone video here: http://smg.photobucket.com/albums/v328/titantornado/?action=view¤t=windturbine.flv but Photobucket's encoding makes it pretty poor quality, but at least you can hear the wind blowing.
I don't know about others, but if I just spent 12-13K on a wind turbine, and only got a bucks worth of electric out of it in the past third of a year, I'd be pretty darn _____ off. That 193K could have been spent far better on solar panels. At $5/watt, you could have bought 38,600 watts worth, and divided amongst 15 locations, that would be 2560 watts, which, in 3.7 hours (just one sunny afternoon) could have produced as much power as that turbine has in four months time. But I guess solar panels aren't "cool" looking enough to bolster our dear Governor Rendell's RE campaign. Anyone who's got some knowledge of alternative energy production can see it was a totally erroneous choice, but fortunately most folks don't know any better, and I'm sure he knows that too.
Wind power
It took me a while, but I see the outer rim is the gear. That adds mechanical losses and is an unnecessary step. I'd surmise that if you were to allow them to freewheel individually, they will self regulate, because the one producing the most power (highest RPM) at any given time, would electrically unload the slower ones, and allow them to speed up. The way it is now, the ones with the lowest airflow drag down the others. It's got to make a racket too.
Freewheel them, and arrange them in a tight honeycomb pattern, and this could be an interesting concept.
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I guess I should add that you would have to have small individual alternators on each fan, versus one single alternator at the end of the gear chain. That may or may not be a good thing.
Wind power
Micro-Wind Turbines Suitable for City Dwellers.
I don't think the plastic gears would last very long.:?
http://www.voanews.com/english/2007-03-18-voa10.cfm
Wind power
Skystream 3.7
http://www.skystreamenergy.com/skystream/product-info/
I wonder why their video of this thing in action has no sound..... :wink:
Wind power
Very cool looking wind turbine:
WIND TURBINE
Aerotecture Web Site
Louanne
Wind power
You just know that I say to myself, "Oh no" when I see your name pop up in this topic. :lol:
To be perfectly honest, I have no idea if their claims are accurate, as I wouldn't even be able to begin to figure out where to base calculations from. If it really can exceed typical wind turbines of today by 30%, you should be seeing their faces all over the place real soon, because they pulled off a real hum dinger!!! :D
Wind power
Are you sitting down Rod? :D
Cans 30% More Efficient At Collecting Wind Energy Than Turbines.....:wink:
http://www.youtube.com/watch?v=RC8Qe--wB1c
How it works.
http://en.wikipedia.org/wiki/Magnus_effect
Wind power
For the remainder of this post, I'll assume by generator, you are referring to axial flux PMA's.
Well, you can build the alternator as either a single phase, or multi phase. In single phase, you can have a magnet/coil ratio of 1 magnet to 1 coil, but always in even numbers. Great care must be taken as to which direction the coils are wound. (alternating clockwise and counter-clockwise) Three phase is always a combination of 4 magnets to 3 coils to work correctly, and coil winding orientation is always wound in the same direction. More phases are possible, and require different combinations, but really don't see a need to exceed three phases. Like I mentioned before, three phase has much less cogging than a single phase generator, and that is why it is typically used. They are a bit tricky to set up proper arrangements when you aren't familure with them, but once you figure out what is going on, they become easy to understand.
Yes, magnet rotor arrangements can be varied too. The lowest power producer is a single magnet rotor. The reason being, there is nothing guiding the magnet flux of the magnets through the coils to make electricity, so you settle for what interaction you can get from the coil's close proximity to the magnets. Next, there is single magnet rotor with an opposing ferrous rotor. There is a huge leap in performance when a blank steel rotor is fitted on the other side of the coils. Magnetic flux is attracted to the rotor, and forces much more flux through the coils, making much more energy. Keep in mind that this blank plate must rotate in conjunction with e magnet rotor, or else it will generate magnetic braking, as well as some heat. Finally, there is dual magnet rotors (like mine) which produce the maximum amount of energy possible, because opposite poles are aligned to each other, forcing a very strong magnet field of very straight flux lines from one rotor to the other. The steel rotors behind the magnets increase their strength by "steering" flux on the back side's of the magnets to the neighboring magnets. The steel plates increase performance by about an extra 50%. Of course, all this magnet attraction has it's risks. Currently, I have a one inch gap space set on my rotors for the coil stator to fit into. I estimate I have around 2,000 pounds of attraction between the rotors. I'm sure if I were to ever let them come completely together, I'd never be able to get the apart. They are not something to be taken likely, and when not assembled, can be incredibly dangerous. Even when assembled, there are risks, like getting a wrench too close. It scares the heck out of you when that happens. Also, neodymium magnets can be explosive if allowed to collide with others or steel, sending shrapnel at incredibly high velocities. Again, they are not to be taken lightly.
Getting "specs" is really difficult on an unproven design. It's much easier to copy someone else's model. A really good place to start is Hugh Piggott's How to build a wind turbine. There are plans for several different sizes and configurations in that book. If you choose to venture to self design, then his companion book, Windpower Workshop has quite a bit of technical information as well. The Otherpower forums, www.fieldlines.com can be of an incredible source of data, but the users there are not nearly a polite as here on LHBA, when redundant questions are asked. It's strongly recommended that one use the Google search on their website before asking a question. I'm always up for a challenge, and decided to build my own. There are so many variables that need to be consided when doing so, some of which I'm still not entirely sure I got right. I think I'll save those variables for another posting, should one want to know.
Wind power
Sat, 2007-02-03 10:09
what variables can be "adjusted" in a generator, such as coil position, adding coils, adding another magnet plate etc. ( i noticed on the otherpower website their generator has two magnet plates),
http://www.otherpower.com/wisc/assembly.JPG
also what books did you get (unsure if you posted this earlier this post is getting huge) i'm thinking of building my own much like yours, and do the books have any formula's such as x length of coil wire = y voltage and amperage?
Wind power
Good observation Drh0liday. You are quite right about the arrangement. What the 9/12 setup gives me is a true sine wave, 3 phase alternator. Overlapping coils are not required in an axial flux design I'm using, nor are steel cores. (features common to radial alternators and motors) The use of three phases and a coreless stator, makes for a very smooth running, cog free alternator that starts up really easy. Also, other than the two bearings, there are no moving parts on the alternator. (OK, the magnet rotors are going around, but there isn't any parts interactions to cause wear, other than the bearings themselves)
You're right, alternators and generators are quite similar, difference being AC or DC. But the Permanent Magnet Alternator (PMA, like I've built) is a lot different. A PMA can turn much slower than a typical alternator or generator to make power. Mine will produce 14 volts at only 50 RPM. Alternators/generators can't even come remotely close to that. Auto alternators usually have a minimum speed of 2400 RPM to make power. Why? Well, because typical alternators/generators don't contain magnets, and therefore rely on "self-excitement" to generate their magnetic fields and generate power. It does have it's advantages, like being able to maintain a constant charging current irregardless to operating speed, but the price is they need to be spun at very high speeds which are not typically conducive to wind or hydro operations, without some sort of ratio gain transmission. (which wastes energy through the transfer) With a PMA, the magnetic field is always there, at the same strength, regardless of speed. The disadvantage is, voltage rises equally with speed. So if I were to hit 400 RPM, I'd have 112 volts coming out. The surprisingly good news is, once you've rectified the 3 phase AC power to DC, it can be applied directly to a properly sized battery bank, the the battery voltage itself will self regulate the incoming voltage. What you end up with is a trading of overvoltage for amperage. The wind turbine essentially becomes a amperage pump. The only time you will loose voltage regulation is when the batteries are full, at which time volts will rise rapidly, and if left unchecked, will boil the batteries to death.
About your ceiling fan blade generator, scrap the idea of the auto alternator. (in fact, give up on auto alternators all together) You'll never get the RPM's required to run it. Instead, since you mention ceiling fan blades, get the rest of the ceilng fan itself. It's got everthing there that you already need. Good bearings, a wound stator, blade mounts, what more could you want? The motor, once it's converted to contain magnets on it's rotor, makes for a nice little PMA capable of a few hundred watts. Changing out the blades to some cut from PVC pipe would further increase performance.
question
Fri, 2007-02-02 14:21
:D rreidnauer, i've noticed that you have 9 coils and 12 magnets, do you think that this will provide something close to a sin wave pulse on the generator, or can this only be done with overlapping the coils?
:arrow: http://www.autoshop101.com/trainmodules/alternator/alt102.html
this website was very helpfull for me as alternators are extremely similar to generators,
:?:
also, i was thinking if we're charging lead acid automotive batteries, what's wrong with basically hooking up a set of cieling fan blades with an automotive alternator and weatherproofing the setup? just wondering