Anyone have info on the Breezy 5.5 homebuilt plans?

[PHinker]

Googling around this afternoon, I ran across the

Prairie Turbines website which is selling plans for a 5.5 Kw homebuilt.  Looks like they're only selling plans and a micro-controller and you're on the hook to build/purchase the rest.  I searched fieldlines but didn't see any reference to this.  If this has already been discussed, I apologize for the wasted bandwidth.

Looks like they're advocating the overdriving of a 3-phase induction motor which you connect to the grid without an inverter.  I know this sort of thing has been touched on briefly before but just wanted to know if anyone has more information than is on their site.

Thanks,

Paul

[stevesteve]

Phinker,

I don't see any furling capability in their pics.

The blades look anything like as good as most of those on this forum.

I am not convinced about the grid-tie capability. The controller looks very simplistic in the only photo and there is no information (that I could see in a quick look) about voltage/phase matching to the grid supply.

I would want to know much more before parting with my hard earned $$.

[stevesteve]

Duh!

Should have read:

"The blades DON'T look anything like as good as most of those on this forum."

[Hank]

Overdriving an induction motor (asynchronous) will feed power back into the grid (if you are connected to the grid) and is self regulating for voltage and frequency. The micro controller probably disconnects the grid power when rpm's are to low otherwise it will be driven as a motor using grid power. It must rotate at about 1800 rpm to generate power.

[tdmack]

Your right Hank.  This generator technology is not new or mysterious by any means.

What is new is a step back in our approach to blade design.  It is as important with this generator that the blades develop drag at high wind speeds as it is that it start up at low wind speeds.  Pitch controls not only add complexity to a design they add a potential for failure.  A goal has been met with this blade design in that they do their job very well, they are extremely easy to build, and be economical (they cost around $25).  Are they pretty?  Well beauty is in the eye of the beholder.

I would be more then happy to answer any questions that you have.

Tim

   

[stevesteve]

Tim and Hank,

Thanks for clarifying the generating part of this. I'm showing my ignorance and will try to read up about that... it sounds interesting.

On the blades front... if it works and it is simple then I would be happy with that. I guess the 'Prairie' part of the name is a clue. This looks like it is designed for folks with wide open spaces. The blades may not be so efficient but built large enough they work fine with this type of system. Unfortunately I only have a litle space so I am looking to maximise my efficiency.

If I had a prairie farmstead I would be tempted to give one of these a go. As to looks, Tim they look fine. I think most turbines are attractive and I would be happy to have one spinning away, winding in electricity.

[PHinker]

Tim,

   I didn't realize anyone from Prairie Turbines was reading this forum or I would have directed my question directly to you.  If you've been reading these boards for any length of time, you know that most folks have decided that four blade rotors can cause some serious stress in turbulent winds.  Have you guys had any trouble with the blade roots or yaw bearing at turbulent wind sites?  Also, have you had any of your units up and running for a significant length of time?  I'm sure folks here would love to see any data you've collected and are willing to share.

   Personally, I like your approach in that it appears to be simple and affordable.  It would be very instructional to many (I think) if you could relate any experiences you have had concerning dealings with the local electric coop with respect to getting the okay to connect your unit to the grid.

   Thanks,

   Paul

[tdmack]

Thanks Paul, this is a very affordable turbine with good power output.  

We tested a variety of blade and rotor combinations.  When we're talking about 5500 watts there is just no way getting around a large rotor (even if you aren't on the "Prairie":) .  The 4 blade rotor let us use shorter blades and still get a great low speed start up (at low wind speeds it's all about surface area).  We built and tried 3-blade rotors with longer blades which worked well but tended to over power our generator at higher wind speeds. They also had substantially more flex which could (and did) result in a tower strike in high winds (45 to 60 mph).

We haven't really had any problems with the yaw assembly probably because it is super strong.  We built ours (and recommend) out of a salvaged combine wheel hub.  I'm not sure what a combine with a full bin of grain weights but I'm guessing it's at least 35 times what the generator weighs.  It's all mounted on 6" steel pipe with (4)5/8 inch wire rope for guys each anchored into 1.33 yards of concrete (around 4000lbs).

We might have some stress from our 4 blade design but I we've pretty much handled it with material sizes.

[Geek]

How long have you been working on this project? how long has the 5.5 unit in the picture been flying. I am very interested in getting a grid tiein and I would also love to hear of your dealing with the local electric company. Sorry to ask so many questions  but I have been burned before buying plans online, though I must admit I am almost ready. I just need some info on exactly how I can gridtie (from my own local E company) and the track record of mill in question. Dose anyone know how many of theses 5.5 units have been built and where they might be found churning out the sweet clean juice.

Thanks,

Geek

[tdmack]

Geek, you'll have to check with your power company to get their connection "standards".  The book has a copy of general standards for a company using detent metering.

We've gotten a pretty mixed bag of reports back from people who have contacted their local power companies.  It seems like the larger the power company the more positive the response.  Some of the smaller companies do not have a clue as to what asynchronous generation is or how it works.  One company required that the generator complied with a UL code that was for an inverter, saying that if it didn't have that particular code stamped on the controller it wouldn't be accepted for connection to their circuits.  They must have took the matter up to higher management and at some point later stated that have to test the generator to make sure that it was an asynchronous generator and that it wouldn't degrade the quality of the power in their circuits.  

Most states have a renewable energy policy and have mandated that a certain percent of all power come from green energy.  I think when local (power co) management is pressured by a customer to place a wind generator in service and have to go to upper management for approval or guidance.  Higher management who are more aware of government rules, regulations, and new policy are then instructing locals to be more receptive of requests.  I must say that all contacts that I have personally had with my power company have gone smoothly.  One other thing on power companies, I have not heard any reports back from anyone saying that a power company has outright refused to allow one of these generators on their grid.

Local building codes?  Now that's another mater all together.  The set I hear the most are: maximum height 100', must be 200' from residence, and must be set back from property line 2 times the height of the tallest point on the turbine.  There are places that have no building codes at all concerning generator and structures.  Check locally.

Until Breezy 5.5 there just was not much out there on homebuilt induction generators.  We spent 3 years getting it right or very close.  The prototype which is pictured on our website is our original generator.  I will tell it has been through hell.  In the final configuration it has run about a year and a half.  It has been through several storms, which produced straight-line winds in excess of 70mph in which it remained on-line and generating.

The structure, yaw assembly, and frame of this generator are heavier than the 25Kw Carter, which sits to the west at the same site as the prototype.  We used the big Carter for a platform in which to design Breezy and made is stronger and more reliable.  

Tim

[tdmack]

Geek, you ask how many of these are up and running?  There are just two, the prototype and the unit on the demo-trailer.  However, it won't be long until these start popping up all over.  We've sold the book/plans to people in seven countries now (consider it was published only three months ago).

Tim

[Geek]

Thanks for the info It has been a week now since I sent for the info from my power company. After I get that cleared I guess I will get the plans and start gathering materials.

Geek

[tdmack]

Thanks Geek.  If you need additional information let me know.

Tim

[hpysheep]

I ordered the Breezy 5.5 plans which you were selling on Ebay and on your site.  After sleeping on it, I noted a few items which appear to conflict.

The Prairie Turbine site claims you are using a Nord 7.5hp 3 phase motor to cogenerate 5.5kw of single phase power.  Also on the Praire Turbine site, the reason for using a 3 phase rather than single phase motor was that it was readily available surplus and that one phase is used for voltage regulation.

This makes me believe that the Breezy 5.5 should be renamed as the Breezy 1.7 as unless I am confused, 1.7kw is all you are going to get out of only one winding of a 7.5hp 3 phase motor.

Hoping you can enlighten us.

Gary

[tdmack]

Gary, first of all, thanks for your order.  You should be getting your plans today.

Not knowing how you arrived at your 1.7kw figure I'll explain how we arrived at ours.  The method we use is to actually clamp an amp meter to the supply lines to the motor and measure the current flowing in the circuit.  Then we use the formula: P= IV to arrive at the power being produced.

When Breezy 5.5 is max'd out (actually when our turbine begins to limit the torque applied to the motor shaft), we measure 23 amps flowing in the circuit.  Using the formula above we simply multiply 23amps X 240volts = 5520 watts (maybe we should call it "Breezy 5.52").

The power produced by the motor has much more to do with the turbine driving it then the size of the motor (easy guys, I'm still talking about asynchronous generation here).  If you connect a smaller motor to Breezy's turbine, a 5 hp for example, you would be over driving the motor and probably burn it up shortly (regardless of what the motor data plate says).  This is so much a fact with wind power that you can almost determine the power capabilities of a wind turbine by simply looking turbine it's self.  When comparing Breezy 5.5 to other types of turbines consider that Breezy's turbine is turning (and pretty much held) at speed around 120 RPM and is a four blade turbine over 18` in diameter.

Gary, I see that you have referred to our web site as "should be looked at as another snake oil site" (on a seperate thread).  I must say that I find that remark quite offensive.  And as for myself I would be quite sure of my facts before making such a comment especially if I were as ignorant of the principles of this type of generator as you would lead us to believe you are by your statements.

In contrast we have done our research and also relied on the research of others to present this turbine and the plans for it.  But you don't have to believe me. In 1974 at the Technical Institute of Vaasa in Finland a study of how "squirrel cage" 3-phase motors excited and driven as generators behave unexpectedly under different wiring and load configurations.  I believe some of the results of that study may still be available at: http://www.saunalahti.fi/elepal/moottori/gener_e.html.  Also on a Danish website I have found an excellent description of the principles of asynchronous generation, you may want to take a look at this: http://www.windpower.org/en/tour/wtrb/async.htm .

Since I believe in the phrase "put up or shut up" I would like to extend an invitation to anyone wishing to see and measure the output of our turbine for themselves. We're located in central Kansas 20 miles south of Abilene.  My only request is that you call first so that we can schedule a time.  If you can't make it yourself and have a friend or relative nearby, we'd be happy to show them too.  You may find our contact information and a phone number at: http://www.prairieturbines.com