Scrapyard Windpower Realities

By Hugh Piggott

This ebook was originally sold in paper form during the 1990s but has been unobtainable for a while. It was superseded by my "Windpower Workshop" published by CAT publications in 1997 (and 2011). In many ways it is obsolete advice to wind turbine builders, but it does have a refreshingly different perspective. The text is interspersed with cartoons by Cathy Dagg, also of Scoraig. This is a historical curiosity, republished for fun. Enjoy.

• Language: English
• Publisher: Hugh Piggott
• Release date: Jun 20, 2014
• ISBN: 9781311856043

Hugh Piggott

Born in 1952, educated in Edinburgh and Cambridge. I have lived off-grid on the remote Scoraig peninsula in the Scottish Highlands since the mid 1970s. I have designed and built a lot of wind turbines, and also teach courses and write books so that others can learn how.I am still very active building, installing and maintaining wind, hydro and solar systems for neighbours and other clients.A number of organisations around the world have adopted my designs and teach courses themselves or build wind turbines. (http://www.windmepowerment.org) I spend a lot of time helping people with their projects and answering questions over the internet. I rely on sales of my books for income but to a large extent my work has become "public domain" or "open source" which is great so long as I continue to make some kind of income.

Book preview

SCRAPYARD WINDPOWER REALITIES

(1992 EDITION REVISITED)

by Hugh Piggott

(author of A Wind Turbine Recipe Book)

Copyright 2014 Hugh Piggott

Smashwords Edition, License Notes

This ebook is licensed for your personal enjoyment only. This ebook may not be re-sold or given away to other people. If you would like to share this book with another person, please purchase an additional copy for each recipient. If you’re reading this book and did not purchase it, or it was not purchased for your use only, then please return to your favorite ebook retailer and purchase your own copy. Thank you for respecting the hard work of this author.

TABLE OF CONTENTS

PREFACE

THE BAD NEWS

RPM AND RATIOS

RIDING OUT THE STORM

GENERATORS

PERMANENT MAGNET ALTERNATOR

PROPELLERS

TOWERS

CABLES

BATTERIES

CONCLUSION

PREFACE (in 2014)

Scoraig is a peninsula on the beautiful west coast of Scotland. Access is by small boat. and there is no mains electricity grid here. When I came in 1975 we used oil lamps. I milked a cow every day. The winter nights were long and dark. Often the wind would shake the roof. After a couple of years I learned to charge 12-volt batteries using wind energy. And I got obsessed with harnessing the wind. Nowadays we have internet and dishwasher and freezer etc. all from wind and solar power, but in those days a simple light bulb seemed like a miracle. It's fun to remember those days.

Scrapyard Windpower Realities started as a series of magazine articles that I wrote in the early 1980s to document my experiences with building wind turbines (or windmills as I called them). What follows here is the updated edition (with Cathy's cartoons) that was sold by CAT in Wales from 1992 until the publication of Windpower Workshop. I am tempted to update it further, but it needs to remain in original form. After all, my later works are really just updates of this document, so this is a snapshot from twenty years back.

What has changed? I did a lot more work with scrap stuff, as money was scarce in those days. But it's hard to provide 'windmill plans' for others to follow, based on scrap materials. The essence of re-using scrap is to use what you find, and that will be different for each person who goes looking. Nowadays I have more money and I try to use widely available materials that you can buy (or search for in the scrapyard if you have the time). My designs nowadays are easier to build and more efficient, but I also feel that I have strayed from the path of low-impact living somewhere. Gone are the days when I would climb among heaps of cars to rescue 12-volt bulbs, bits of wire and switches for my home. And the days of modifying a washing machine to run off a 12-volt battery.

I wrote instructions for tilt-up towers, but the idea was new to me then. For fifteen years I had been clambering up windmills and assembling them piece-by-piece at the top. It was only when I started teaching windpower courses at CAT that I realised I could not encourage others to do this (in case they fell off). So I had to learn to make tilt-up towers.

(The above photo shows the untwisting job I had to do every few days with an early windmill whose wires dangled off the tail instead of passing down the centre of the yaw bearing.)

It's actually much easier to work at ground level, and then hoist the machine up on a tilt-up, but it took a long time to get over the sense of anticlimax that I felt watching the windmill up there but being down below myself. Working at the tower top was exhilarating.

The mainstay of my early work was the 'dynamo' (called a generator in North America) which was the DC machine used in vehicles until the 1960s when alternators with silicon diodes began to take over. Dynamos from buses and jeeps were easy to find in the scrap in the 1980s. Permanent magnets were rare and expensive. I would hate to go back to using dynamos now, but on a windy day they worked well enough. Back then there would have been a couple of dozen machines on Scoraig using dynamos. Each one powered a home with roughly one kilowatt-hour unit of electricity per day, which seems pathetically little now, but it got rid of the oil lamps.

Permanent magnet alternators are a lot more efficient than dynamos. The axial alternator design in this edition is the one where I first conceived the idea of a three-phase stator with non-overlapping coils that is fairly universal in axial flux machines these days. I don't recommend the design here in detail, because I have improved it greatly since, but it's fun to see how it started out.

The tail furling system described here is actually more sophisticated than my more recent designs, but I decided that simpler is better in the end. The seat-belt and cam arrangement is adaptable, but prone to wear and tear. I still use a similar system on much larger machines but the webbing is replaced by chains.