Adopt a turbine!

If you’d like a homebuilt wind turbine but can’t find time to build one then you might consider adopting one built in a workshop course?  V3Power are offering several wind turbines and parts on this basis here.


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Build your own windmill workshop course on Scoraig April 23rd 2016

I am planning to hold a course here on Scoraig in April.  We’ll build and test a wind turbine as usual.  Accommodation is provided from Saturday 23rd to Saturday 30th April 2016.  These will be the arrival and departure days.  The course will run for six days from 24th to 29th.  Your partner may be able to find accommodation here too without attending the workshop. Please ask for details.

See photos of 2012 course (plus video) , 2013 course, 2014 course and last year.   Cost will be £750 including accommodation.  I may be able to offer a limited number of student discounts if there are enough people paying full price.

Contact me for more details and to book a place.  I do not plan to travel around teaching courses any more as I already did that for 12 years or so.  This may be your only opportunity to be taught by me personally, although there are several other groups worldwide offering courses based on my Recipe Book or derivatives of it.



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My electricity supply here

I don’t write enough about what goes on here at home on Scoraig so here is a run down on where my electricity comes from. I have two windmills and a collection of solar PV panels.  800 Ah Rolls 4000-series battery and 48 V and two Outback VFX 3 kW inverters.


The big windmill charges the 48 V battery via a couple of heaters in series.  We get very little heat in low winds but almost all of the power goes to battery charging with very low cut-in around 60 rpm.  As the current increases to (say) 20 A we get about 1000 W to the battery and 300 W of heat.  When it reaches 40 A we get 2400 W at the battery (assuming 60V) and 1200 W of heat.  The heat (combined with waste heat from cooking) is sufficient for our well insulated house most of the time.  I prefer the windmill should not go a lot higher output than that, but it’s turbulent site in NW gales so we do see much higher surge outputs and there is trip that brings in extra heaters as a braking load when the voltage reaches 140 V (7.5 kW).  I had a bad accident with this windmill (tower buckling) in a bad storm last January, and nowadays it is governed to about 1 kW average into the battery.  It looks lazy but it does all we need.

The smaller windmill is an AWP from Zimbabwe but the blades are locally made from wood.  It runs through an MPPT controller (I have tested both Classic and Tristar) that enhances the peak output to about 1500 watts.

The Solar array consists of 4 strings (pairs) of big 240 Wp 30 V modules and 2 strings (fours) of little 80 Wp 17 V modules totalling about 2.5 kWp.  These feed into the battery, and surplus power (wind and solar) is dumped to hot water using a Tristar PWM diversion load controller.  When the water tank is hot, the excess power is diverted to AC heating loads using a phase control SSR.  We also have some evacuated tubes for hot water.

Electricity consumption is running at about 6500 kWh per year.  (The UK domestic average is 4200 but I also run my business and the extended family house next door).  We do most of our cooking with electricity, using a kettle, toaster, microwave, induction hob and halogen oven.  We also recently replaced the gas oven with a big electric oven.

When the wind stops and there is not much sunlight the batteries get a bit of a fright, and I have to fire up a diesel generator.  This has run for an average of 150 hours per year over the last two years, feeding about 2-3 kW of power into the system.

Posted in my own projects, Scoraig, wind systems tutorial | 5 Comments

free KD-reports

Adriaan Kragten writes:

As I am retired for some years now, I no longer need income from selling my KD-reports about small wind turbines. So I have decided that from now on all my public KD-reports can be copied for free by anybody. This concerns ten more reports with former prices in between € 20 and € 40. My most important report is certainly KD 35: Rotor design and matching for horizontal axis wind turbines. Report KD 196 gives questions and answers about each chapter of KD 35 in English and in Dutch. A list of all 46 free public KD-reports is given as the first item of the menu KD-reports on my website: All reports have a rather long title which gives a good impression of the content.

The most recent report is KD 598: Ideas about the 3-bladed VIRYA-0.65 water turbine with 20° inclined shaft coupled to the generator of the VIRYA-2.68 windmill for 12 V battery charging.

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Nice CAD model of 4200 blade

“Hello Hugh.

My name is Josue (Joshua if it is easier for you). I live in Colombia, South America.

I would like to share this file we made for the 4200 blades. This is the Adobe 3D version. (You’ll need the Acrobat Reader DC in order to see it.)

This file was produced using a CAD program called Solid Works.”

Josue has offered to share the solid works file, and if you are interested in this I will put you in touch with him.


Here is the Acrobat version he sent to me : Aspa V1
 You probably won’t be able to view it with your browser but if you download the file and open it with Acrobat Reader DC then you can play around and view the model from all different angles.

Posted in construction, People | 9 Comments

Lifting handle for the magnet rotor

I never like lifting magnet rotors into the mould.  The rotor for the 4F is very heavy, having 20 big ferrite magnets on a 50 cm disk. So I made a handle to lift it.  I had to make two of the holes in the mould base a bit big to accommodate the nuts on the ends of the handle studs.  Worked really nicely and not hard to do!

Posted in construction, ferrite magnets, my own projects | 1 Comment

Homebrew stuff for sale

John Gambill has some useful stuff for homebrew wind for sale.  He lives at
Hotwire EnterprisesDiversion Load 003
102 W. Fulton St.
Tarpon Springs, FL 34689, USA
(727) 943-0424

He has diversion loads and blocking diodes and some low power Chinese alternators ($99 each) for 12 volt homebrew projects.  Contact him for more details.  I can’t comment on whether you will get a good deal or not.

Here in the UK I know of a guy Russell Evans (Mobile – 07456 976374) who is selling a mix of kit that he cannot use for some reason.   The Alternator is a Ginlong GL-PMG-1000 1kW alternator for grid tied application.  It can do 1kW at 450 rpm.  Drive plate included.  It needs blades though.  Big ones I would suggest.  The third thing is also from Ginlong, a rectifier/protection box or “controller” sometimes known as a “wind interface”.  This is a pretty important thing to protect your inverter and so far as I know the Ginlong product is fit for purpose.  Since SMA stopped making them the only other one I know of is by ABB aurora and much more expensive.  I guess you have to buy your own heater to go with it as a dump load. On offer is the GinLong shunt that goes with kit. There are also the Isolator switches. “One of these has been adjust so that it has battery isolators, these short circuit the 2 generator to act as break.”

From Clipboard

I cannot vouch for either of these people but I pass on their offers for you to negotiate directly as you see fit.  Just thought I would oblige them by letting folks know about the stuff they have on offer.


Posted in construction, People, products/technical | 1 Comment

webcam view from tail

This turbine is based on my design although it owes a lot to the Otherpower book too.  You could say via the otherpower book.   Nice video.

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Windempowerment in Ethiopia

Wind Empowerment Jijiga 2015 from Wind Empowerment on Vimeo.

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Offset angle of the furling tail

I got asked a question that a lot of people ask me, so I thought it worth answering here.

Hi Hugh my name is Bill looking through your book A Wind Turbine Recipe Book I am a little confused with the tail vane lower stop. If the tail is allowed to travel 110 degrees it would seem you would be 20 degrees to far in the opposite direction and the blades would never face the wind squarely. Does the tail come off the lower stop during normal operation? What am I missing? Thanks in advance.”



Here is a plan view of the Recipe layout.  The alternator frame is mounted onto the yaw bearing off-centre, in order to create a ‘yawing moment’ that tends to swivel the turbine around sideways to the wind. The tail is deliberately angled a little to the opposite side in order to balance this tendency and to keep the turbine facing squarely into the wind under most conditions.


2 offsets


The above picture tells a story.  The left hand turbine is the design I used up to 2008.  After that I switched the offset to the other side so the machine furls to the left instead of to the right.  I will skip the reason for this change here, as it is not very important.  But it has been very interesting to watch when there are two machines of the different designs in the same field of view.  They often look like the above picture.

We tend to assume that the tail always points downwind.  That’s what it’s designed to do, right?  But looking at the above picture, this is what you actually see when there are two wind turbines with the same wind direction. The tail vane swings off the downwind direction.  It’s very noticeable when they swing in different directions.

It’s not at all unusual to see 20 degrees error between the tail and the wind direction, and often the difference is larger.  Why does this happen?  To understand it you need to think about the forces on the tail.  Before the blades start turning, the tail acts just like a wind vane, but when the blades are spinning they catch a large thrust force that is centred a bit off the centre of the tower-top yaw bearing on which the machine swivels.  The purpose of this offset is to make the machine move edge-on to the wind and protect itself from overload in strong winds.

The thrust force is counteracted/balanced by the tail, but it moves a bit sideways first.  It’s like a boat settling in the water as you climb in.  The boat settles to get more buoyancy.   The tail needs a bit of an angle to the wind to create the lift force needed to balance the blades’ thrust.  Hence the 20 degree angle in the Recipe design.

I hope this helps explain the logic.  There’s a lot to say about furling systems.  They are very simple in some ways, and extremely complex in reality, but they do the job.


Posted in construction, my own projects, Uncategorized | 2 Comments