10 August 2022

Learning how to build a small wind turbine, part I

Years ago, I had read an article in the Guardian about short courses you could do around the UK. I hadn't been looking for anything, but I tend to read the newspaper cover to cover (except the sports section) so I read that too. And there was one course that really grabbed my attention. It was "building a tiny house" at the Centre for Alternative Technology in Machynlleth. I hadn't heard of that place back then, but it did plant something in my brain. And doing that course didn't quite fit with my life at the time, but I never forgot about it.

When I had a summer ahead of me and no plans of going seriously abroad, I pondered what I would do with it. And one of the things I thought of was doing an interesting course. So I headed for the CAT website. And there I found the course "build a small wind turbine". And that sounded fab! I quickly texted Kate to see if she would be interested as well. She was, but she didn't anticipate being in the country at the time. So I registered on my own.

I really like renewable energy! I was already on the path to getting solar power, but that only works during the day, and the wind might also blow at night. I didn't think I would generate very much with a wind turbine, but at least more than nothing. And it would be an interesting skill to learn. So I looked forward to it! And then the day came.

I drove down in the electric car of Partneriaeth Ogwen, and checked in. It was a weekend course so a room was included. The room looked nice! So I got rid of my big bag, took my small bag with things such as a notebook and a water bladder, and went back down to reception. There were some 10 people sitting there silently. I joined them and started conversation with some random people. I figured we had something to talk about: our desire for wind energy! And I was right. But then the instructors appeared and took us to a lecture room. The instructors were Tom, who led the course, and who had done that 71 times before, and Esther, who was less into construction and more into placement.

My room

We also need a little round of introductions. Some people had much more concrete plans of what to do with this course than others! One man was already living off grid, but he mainly relied on solar, and that can be an issue in winter. One man had inherited the  ancestral farm on the Irish west coast. One man had come all the way from Belize. One lady wanted to start an off grid sort of communal living project. Et cetera!

I liked the little theoretical lecture. Tom explained why are blades needs to have the shape it has, and why you would put six coils opposite eight magnets. And he explained what sort of electronic ware you need to have between your turbine and whatever you want to power with it. That sort of thing! I learned a lot. And then we started working. Tom and Esther took us to a beautiful barn on the amazing terrain of CAT. I really liked the place! I already decided I want to come back.

What we started on were the blades. We subdivided ourselves into groups of two, and started on a blade per group. Blocks of wood in the correct size were provided. Tom had said that in the end, they would just pick the three blades that were the most similar to each other, and make them into our final product. I thought it would be an enormous amount of work, but we had to go tools and it was a lot quicker than I had thought! I especially liked the draw knives.

Starting on the blade. Pic by Sheridan

I had teamed up with a lady called Sheridan. And while working together we also just got to know each other. 

From time to time, Tom dragged people out of their work on the blades to have them make coils. The course had a custom-made coil making device, and it took three people to work it. We made our two coils! And then it was time for lunch.

At CAT, do you get fed well! And I suspect they had grown most of the food we ate. All of it was vegetarian. Vegan options were also provided. I think they know who they are and what audience they attract!

After lunch we had to solder in the coils together in the right configuration, and cast them in resin. Tom was very apologetic about the resin. It is hydrocarbon based, and can't be recycled. But it is difficult to avoid! We also incorporated some glass fibre for tensile strength.


Finished coils in the mould for the resin

ChristmasWhen we had cast it all it was time to stop. There was about an hour until dinner time. Esther mentioned a pub not far away, but Google Maps indicated it was about a 30 minute walk, so going before dinner made no sense. I just retreated to my room to have some time on my own. And after dinner I went for a run. I had decided I could do that first, and then join the others in the pub.

I had no map and very little internet signal, so I was running largely blind. I first went around random paths in the quarry where the centre is located. But after a while I saw a cut in the hillside not too far away. That looked like a bigger track, going somewhere. I made a beeline to it and indeed, it was a fine agricultural road to run on! And it went to a big wind turbine. On the top of the hill I had much better internet signal, so then I could see on satellite imagery that the track looped back to the Centre. Surely it was used by vehicles used for wind turbine maintenance. So I continued! Unfortunately, the quality of the track went downhill rapidly, and soon I found myself confronted with an impenetrable tangle of ferns and brambles. I gave up! And just retraced my steps. That way I had to run a lot longer than I had intended, but I really didn't want to have to wrestle through such hostile vegetation over a considerable distance.

Run views

Time to turn around 

I got home, had a shower, and hot-tailed it to the pub. There was a nice group of some six people there! And they were still having a good time so I just joined in. When it got quite dark we walked back. One interesting day done! And would we manage to have the turbine ready the next day by the close of day? Stay tuned!

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