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diy solar

Do 200w wind generators exist?

Maybe i should say the videos online are not what i predicted to see. The video above with the red vertical axis turbine. It appeared to be spinning fast yet produced nothing. Was it his user error? Im starting to watch more professional type vids. Just watched one showing which motors work best for making your own generator. I have some used RC plane and RC car motors. A ton of different propellers. The video showed it is possible to get voltage but its not very much. Also i think there is an issue with KV. You would have to spin the motor too quickly unless you did a gearbox.

This version looks neat. Its a vertical axis but almost has an airfoil shape. Too bad they dont make a smaller and cheaper 250w version. Also not stocked in the US and $200 shipping from Italy. https://www.makemu.it/prodotto/wind-generator-domus/?lang=en

Or this guy. Ebay has a 100w version. Their website is showing a 300w, 400w, and 500w version. I like these a lot!!! Says they self brake by nature of the design. I wonder how loud that would get? If i could find one of these in the states i would totally hop on it. (and go for a spin!!) https://www.makemu.it/prodotto/wind-generator-smartwind/?lang=en
 
wopachop said:
ve been thinking about this. Is there a density to wind? Does a 10mph windspeed at 20 feet high have more direct and forceful air molecules than a 10mph windspeed at ground level? I wonder if close to ground level you get wind bouncing around sideways and it slows down the blades.
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1/2 atmosphere, density, is at 18,000 feet. I doubt 10 feet will make a difference.
 
Vertical mills by nature,(VAWT) work steadily but with low output, Horizontals (HAWT) can provide more windswept area and respond to changes in wind direction (and intensity) quickly , giving a highly variable (but temporarily higher) output (IMO , unless they are well sited and on a very tall tower).
Mine will be working today because of the hurricane offshore.
Horizontal mills are more complex with more moving parts needed to keep them aligned with the wind and to brake them in high winds. I find more blades also assist in preventing runaway but providing more resistance to activate the furling mechanism. I have never seen a small scale Vertical mill produce any usable power except to maybe charge a cell phone (2 watts minimum needed, as I found out by making my own portable charger from solar walk lights).
Hugh Pigott's book mentioned earlier is one of the best, he is a master of this technology, the Fieldlines forum has alot of info on building a large scale VAWT but so far I not not seen it succeed.
 
It seems the horizonal is more efficient because of all the technology we put into airfoil design. It looks like the vertical stuff is on the rise though. They are putting large vertical turbines on top of buildings. Claim to spin slower and make less noise.

There is a guy on youtube saying some of the data for vertical axis from years ago was actually falsified. Starts around 30:00.
 
Alot of them are just mobile art now. They work, but not effectively. Due to the normally slow rotation, they are often geared, which adds to the resistance. Also consider weight, which a horizontal does not really have, a HAWT only deals with thrust, but a (large) VAWT has a substantial element of vertical weight involved which becomes resistance itself. Once rotating , the "flywheel effect" can keep them going even when the wind dies down, something that does not happen with HAWTs, they slow very quickly. The VAWT is a great concept, but to date I have not seen anyone using them to produce meaningful power. Maybe this guy can, who knows? We will see, but I would rather explore proven technology rather than try to invent new approaches, like his furling idea (notice the furling takes place opposite rotation, so an old school centrifugal weight slider?)
I would like to see a video of one in operation along with the meter readings, but this appears like a massive PR funding campaign, a full page or two on Google of advertising and funding opportunities, no pics or videos of any actually doing anything. Many questions, given the weight involved, how long will bearings last? How to stabilize in a high wind event? Dump Loads? Mechanical relays? Sure, HAWTs have similar problems, they are complex and require much maintenance, on a small scale they are great learning experiences and sometimes fun, othertimes they can be quite dangerous.
 
Might want to review this long thread - all about what you are looking at -
diysolarforum.com

Building the sickest ® VAWT ever. Brilliant minds unite please!!

--- TL;DR update we are getting somewhere now. managed to reduce diameter while increasing flux to play with. I am not yet so far as to give output data. Only predictions can be found in this long thread. ALSO!! (unfunded) snag remarks are NOT welcome here. constructive criticisms is both...
diysolarforum.com diysolarforum.com
 
Thanks will check out that thread.
This is a good example of when i said wind turbines seem unpredictable. You take a generator, place the shaft vertical, attach blades to make it spin, yet they produce no usable power? If its RPM related, the engineers cant adjust the shape of the blade to spin the correct RPM for their target wind speed? One of the main reasons im looking to buy a unit instead of DIY is because i hoped they already got the RPM dialed in for say 15mph.

Wish that 500w Italian unit wasnt $600. Maybe i will write the company and ask them for pasta sauce recipes. Also will try to remember to ask if they know of any videos showing the unit producing power.
 
Thanks again for the links. Im starting to see what makes a vertical setup tough. You need it to have enough surface area to catch low speed wind, but not blow itself apart during gusts.

You know how there is regenerative braking? I dont know how it works. Can it adapt electronically?
Why cant you build a vertical setup where the generator could adjust it wattage on the fly relative to RPM.
In low winds the generator would have little resistance and spin easy making little power.
Then as the RPM increases the generator adjusts to become a more powerful generator with larger resistance, so the RPM can stay constant and not rotate too fast and explode. It would be a way to brake and slow down by making it harder to turn the motor.

I thought i read that low RPM generators exists. But maybe they dont? Seems like people often need a gearbox for the low RPM vertical setup to spin the generator fast enough.
 
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wopachop said:
I thought i read that low RPM generators exists. But maybe they dont? Seems like people often need a gearbox for the low RPM vertical setup to spin the generator fast enough.
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I don't believe it's a technology problem, rather a physics problem.

Trying to harvest energy with a wind turbine in speeds under 12 mph is like trying to get solar panels to make power at night. When there's nothing to collect it doesn't matter how efficient the panel is. Most residential sites spend 80% or more of the hours of a year at 12 MPH or less. (Residential = 100' hub height)

Above 12 MPH there's a little bit of energy to collect. Continuing with the solar panel analogy: 12-18 MPH is like the 2 hours after sunrise and before sunset. Not much there but it still feels like our panels are doing something. Most site sites spend 18% of thier time here.

Once the wind speeds get above 18 MPH it's like a solar panel between the hours of 10AM and 2PM. Most sites see these wind speed less than 2% of year.

Oh and don't forget, there's really no predicting when that 2% of the year is going to show up or if your batteries are empty.
 
Is also part of the physics problem that if you build it to produce power in low wind its going to explode in high wind?
I picture the big windmills out in palm springs. They spin pretty slow. I imagine there is so much force its turning a generator with a lot of resistance.

Do those make very little power in low wind? I think they have brakes. If it didnt make power in low wind spinning slowly, wouldnt they apply a brake to save wear and tear on those bearings that leak oil down the side of it? Those things are getting uglier each year. I think a bunch are broken. They aint spinning and have a zztop beard of grease down the neck.
 
wopachop said:
Is also part of the physics problem that if you build it to produce power in low wind its going to explode in high wind?
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That's exactly the problem. Every part of a wind turbine must be able to survive the the occasional high wind event (HWE) without self destructing. That includes the rotor, the generator and the tower to name a few.

I think I've learned many interesting things about wind since I started dabbling in this green energy stuff almost 40 years ago. (Hey, I was 4...). I've noticed hundreds (maybe thousands) of the 100+ year old Aermotor style water pumping wind turbines still spinning. Their design is truly a thing of beauty. A super efficient rotor that makes high torque at low RPM's. The only thing that's good for is pumping a tiny bit of water every minute it spins but since it spins most of the time it end's up pumping thousands of gallons of water. But it's true brilliance is that part of being really efficient at low wind speeds make it really inefficient at low speeds so it can survive almost any HWE.

wopachop said:
I picture the big windmills out in palm springs. They spin pretty slow. I imagine there is so much force its turning a generator with a lot of resistance.

Do those make very little power in low wind? I think they have brakes. If it didnt make power in low wind spinning slowly, wouldnt they apply a brake to save wear and tear on those bearings that leak oil down the side of it? Those things are getting uglier each year. I think a bunch are broken. They aint spinning and have a zztop beard of grease down the neck.
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I've worked in both Palm Springs and Tehachapi. Those are world class site for utility scale wind. You are correct, they make almost no power in low wind and the operators do often apply the brake or yaw them out of the wind during those times. More interesting is that most have lost thier active yaw systems and are welded into plate pointing in the direction of the prevailing wind.
 
OzSolar said:
I've noticed hundreds (maybe thousands) of the 100+ year old Aermotor style water pumping wind turbines still spinning. Their design is truly a thing of beauty. A super efficient rotor that makes high torque at low RPM's.
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Familiar with Oak Glen? The apple place? I think i know what you mean about these. Ive seen one in person. It was spinning slow and pushing down a rod.
 
Most from what I have read are rated way higher so you end up with that or less if you bought a 500. Look at my recent thread where I write I want to do just the same as you. Maybe we can compare notes. There are many naysayers trying to discourage it but it has been done as you can see on the links in the thread I made about wind turbines.
 
I am certainly not trying to discourage anyone, I like wind power myself, nothing like seeing a turbine spinning away, but for real power I depend on my solar array. At the moment, even though we have decent wind, my turbine can only keep my two 12v batteries charged some days. Two extra solar panels on that system keep it charged at all other times. I can run a radio for a few hours (less if I am transmitting), or some LED lights for a day or so, or charge my power tools, but thats about it. If you already have a solar array and want to add wind, fine, go ahead. At least you should be knowledgeable enough now to not expect any miracles. Mine provides some power when I need it most, usually during a white out blizzard or a tropical storm, where solar just doesnt have enough light to throw much to the batteries. It buys me some time till the next sunny day.
 
If I were mounting something on the roof of a vehicle or trailer, I'd probably look at an enclosed squirrel cage type thing, like a smaller Ridgeblade, that would scoop from the front but not be an eye-catching spinny thing.

But I'm weird. ?
 
Rednecktek said:
If I were mounting something on the roof of a vehicle or trailer, I'd probably look at an enclosed squirrel cage type thing, like a smaller Ridgeblade, that would scoop from the front but not be an eye-catching spinny thing.

But I'm weird. ?
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Stealth factor? That had been a priority for me at first as I bought the thin renogy panels precisely for that reasons but I have found now that the wires are very obvious anyway and hard to bend those solar wires. I am getting more used to "coming out" as a vanlifer now as I guess most don't care however a wind turbine is another matter and would certainly draw more attention. So I would be interested in more stealthy designs but I could envision they would cost a lot more.
 
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