Windmills of Scoraig

An informal tour, by Hugh Piggott year 2000
This tour is always out of date :-)
things change too fast

CountZ.com
since 7th October 2000

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This is an very brief guide to the windmills which provide electricity to households on a small peninsula with no road access or power lines (called Scoraig). I hope I don't step on too many toes by telling it like it is and describing our experiences of various commercial makes, old and new.
Links to machines below:- Ampair, AIR, LMW, Proven, Survivor, winco, chinese
My own designs, including also the African AWP3.6 and the ITDG alternator

Here is some text to read, while you wait for the pictures to load

Intro Hugh Piggott
Windpower fanatic. Born Scotland 1952, educated Edinburgh and Cambridge. After graduation, went back to the land in NW Scotland where I remain. For 4-5 years I did without electricity except what I could rob off 12V vehicle systems on rare shopping expeditions, by connecting an elderly car battery to bits of loose wire. This ran my cassette tape machine.
In 1978 I got seriously bitten by windpower and have been partly or totally obsessed with it ever since. This is a windy place and very dark in winter, so there is a strong sense of victory when you can harvest energy from a crashing gale and swamp the house in dazzling light. Lots of bits would drop off my windmill(s) but I persevered and ended up making windmills for most of my neighbours. They still ring me up when they need the windmill fixed. There are about 30 windpower systems within a few minutes' walk of my house.
In the late 1980s I decided to broaden my perspective and I started working on windmills built by others. I was amazed to find that bits drop off them too (I thought it was just me). In fact it turned out that I was pretty good at fixing windmills by then and so I did some work with manufacturers, testing and developing machines, in the demanding conditions we have here. I also wrote up some of my ideas and helped teaching courses at the Centre for Alternative Technology in Wales. Stopped milking a cow and bought a fax machine.
More recently I have designed a windmill for manufacture in Africa and also installed some direct AC hydro systems. I find hydro very exciting because it provides much more energy at lower cost (on a good site) and you do not need batteries. I hate batteries.
In 1999 and 2000 I have worked as consultant to a TV company, designing and installing a wind/hydro system for castaways on an island.. I have also been doing another developing world project for ITDG, culminating in a permanent magnet alternator design you can download for free.

Ancient History

When I moved here in 1974, most people used oil lamps for lighting, because this was simpler than running a diesel generator. There is not a lot of money around on Scoraig, but the atmosphere is generally quite relaxed. Planning and discussion are favorite occupations. The working day is often curtailed by bad weather, so there is no point in being in a hurry.

One neighbour had an old battery charging 'Freelite' made by Lucas.
I would take my tape machine 12 volt battery along to him for charging, but I also messed around trying to build a windmill myself. The first attempt was a bicycle-hub dynamo which I sat on the rooftop. It worked, but it was really noisy in the house. In those days I was a 'back to the land' hippie type, and my resources were pretty thin.
..
I struggled for a long time to build something workable, but that's another story. We had a lot of fun finding out what worked and what didn't. This single bladed machine for example (built by my cousin, Topher Dawson) worked after a fashion but the pitch control system never quite got perfected.

I had a lot of help from friends like Alan Bush, Alan Beavitt, and countless others, and I read some books. Around 1980, I made quite a number of 2-bladed windmills based on 24volt dynamos from Austin Champ Jeeps. Many of them are still in use today, although they have been repaired and modified a few times over the 20 years.. Output is around 300 watts from a 6 foot diameter rotor.

and as the trees have grown, I have had to increase the heights of them.

Here is an old Winco being moved to a new site by a tractor, complete with its tower. Sadly this machine is no longer working today. The linkages wore out and the commutator gave constant problems.

Year 2k

During the 1990s a number of windmills were imported to Scoraig, and I learned a lot more about the art of wind turbine mechanics. Much of what I have done has been repair work, because I was using secondhand parts, or fixing up something which fell apart unexpectedly. I developed some designs of my own at the same time, and published some stuff about how to build small wind turbines.

What follows is a guide to the ones which are around in year 2000 (I am struggling to update it in places too), and what stuff has happened getting to here. Awful things do happen to small wind turbines, as you will see, but remember - these machines are working, and bringing joy and light to their owners. Being a mechanic I mainly see the breakdowns.

Links to machines below:- Ampair, AIR, LMW, Proven, Survivor, winco, chinese
My own designs, including also the African AWP3.6 and the ITDG alternator

Here is the LMW3600 which was installed here, to heat the Primary school, in 1990.

the view is southeast, up the loch.
This machine taught me that I was not the only person who had problems producing a good design of windmill. We had a lot of problems with the LMW during the first few years.
It makes a very loud humming noise which swells and reverberates.
The tail furling system didn't work properly, and it ran too fast, which wore out the blade edges.
This in turn caused vibration, fatigue and failure of vital parts such as the tail, and the alternator mounts.
In other words it fell apart, repeatedly.
I have modified the tail so that it furls at about 2kW and it has now gone for several years without problems. We have gradually grown used to the noise and we don't notice it these days.

some blade erosion in this picture.
Ultimately, this has been a successful installation, and it keeps the school supplied with ample electricity, although it never could have provided sufficient heat. The average output is under 1kW - not enough to heat a building of that size. But the rotor diameter is large (5m. 16') and so it catches plenty of power in low winds, to keep the school supplied with light, and power for computers, vacuum cleaner, photocopier, etc.. And in windy weather it does produce enough surplus to heat one room to a very nice temperature.

Not many small windmills are built to give good service in very windy conditions.
They work OK on other sites, where there is less wind, but in an exposed coastal location like ours the problems show up early.

Some of my neighbours have owned AIR machines from Southwest Windpower (Arizona), but their life expectancy has been about 2 weeks. Commonest failures are burned out electronics and broken blades.
After-sales service has been absolutely brilliant. Spare parts and replacement machines have been supplied promptly and without quibbles. On one site the machine was upgraded to an 'industrial' (very expensive) version free of charge, and this has lasted almost for a whole year on one occasion.
Here is a picture of the site.

The owners live in the little house on the right. We had to fix a piece of sheet metal to the tail after the yaw bearing started to seize up. It's quite a powerful machine for its size, given a good wind. But we all know about it when it is running - it's almost as noisy as the LMW in normal conditions, and when it hits full power it's louder than a chainsaw.

The other family who had an AIR machine were lucky enough to be given an old Marlec FM1800 as a replacement. This is a sturdy machine,even though the electrics are horribly complicated.

We have now moved this machine up the hill to get away from the trees.

We tried Marlec Rutland72 watt machines for a few years, but the stators would normally fail after about one year, and you can only replace the stator a few times before the bearings work loose, and then you need a new alternator. Marlec gave up making spare stators for their older models, and I began to lose interest in Marlec. Especially since they 'upgraded' the fm1800 by giving it only 2 blades.

One machine which gets full marks is the Ampair Hawk

It only produces 100 watts but at least it goes on doing it through outrageous storms, and years of service with little or no attention. The only thing which has been a real problem is the regulator. These tend to burn out. Brushes can also give problems but this is rare/unknown on Scoraig.

For 2 years I ran a Survivor S3000 wind turbine, which I had bought ex-demonstration. It was rather out of date, and is now badged 'Synergy' instead. I believe they have also put sliprings on it. I never had problems with cable twist, but I did have problems with rain running into the yaw bearings, so that they fell apart and the machine flew off the tower top. I also had a blade root failure (see picture) where the mounting plate cracked across. It ran for a few hours with 2 blades. This type of cracking has happened to me before, with a Whisper 1000 'spring plate'. Seems like a highly stressed piece of plate.

The furling system is fascinating, based on a hinge at the topmost point, from which the windmill hangs. High winds blow it upwards until the tail and blades are horizontal.

Another 'downwind' machine, which has fared much better here is the Proven.

Here is the 2.5kW machine at Scoraig. I did some development work with it around 1995, leading to the use of double springs in the governing system. This windmill does not furl by turning away from the wind as most others do. It governs its blade speed accurately using centrifugal force to alter the pitch of the blades.

The system puts quite a high stress onto the blades and springs, which have sometimes cracked, and failed. For example the blades on the Castaway machine at Taransay have just failed after very nearly two years of high wind duty. One blade disappeared entirely.

Cracks in the polypropylene blades occur at the hinge points.
Proven have recently introduced Polyurethane hinges for their blade roots and these are proving to be much more robust.

Scoraig is also the home of the prototype Proven 6kW machine which is owned by my cousin Topher Dawson (boatbuilder and wind turbine blade fabricator).

No more machines were built in this 'monocoque' style. The beam on the right is for a balance weight, which is also unique to this prototype. This windmill has worked well for about 3 years, with some nursing from its owner. Unfortunately, the production versions still have some problems to be worked through, but as usual, Proven Engineering are working on solutions!

In this picture you can see the magnet rotor inside the alternator.
The cover was removed to improve cooling, and it looks nice too, wheeling along.

Here's a picture of a chinese wind turbine which I have been testing. As supplied there were problems with its balance and its furling system. After some early problems in 1998, it has settled down to be quite a nice reliable machine .

PS we did have a blade fly off during the winter 2000-2001 and I have now put the blades from the survivor on it. this is typical of the sort of 'swift and grotty' repairs which keep scoraig windmills going on a shoe-string long after they would have been abandoned on other sites.

We also have some machines of my own design here, for example the brakedrum windmill
(as written up in the Plans available from Picoturbine.com)

and the African 36
(see this link too)
This wind turbine powers our home.

and now another one power Scoraig Secondary School

And one for william at Rhireavach..

another is located at Badrallach on the tarmac road, 10 miles from Dundonnell:-

Here is another one on Scoraig, installed sumer of 2000 for Bill Burstall

In this one you can see 3 AWP machines out of the 7 which are now up and running in this area.

We have had some early problems related to manufacturing quality of the alternator shaft, and cracks in the fibreglass blades, but there are no real technical challenges remaining for this machine. It works. It just remains to get on and install them.

Another one to shout about is the 4kW heating machine I built with help from Alan Bush and African Windpower in Zimbabwe (who made the stator for me). African Windpower are working on a production version.

The blades were made on Scoraig by Topher Dawson.

In the next picture you can see it being lowered for repair in June 2000.
It does have occasional problems, with rotor balance, stator insulation, and suchlike, but it has run pretty consistently for nearly three years.

Here are a couple of pictures of locally produced prototypes using the alternator I have designed for ITDG for local manufacture in sri lanka and peru. see also this link for details of the alternator and how to build one.

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