Freiraumschule Kritzendorf wind turbine workshop

At this alternative school I led a four day hands-on workshop about wind energy for the kids. We constructed a small wind turbine and installed it on a simple tower in the school yard.

Project facts
Wind turbine construction course

Wind turbine typ: Self-designed, 70cm Rotor diam. demonstration model
Venue: Alternative pedagogic School
Participants: Around 7
Date: February 2016

To make it more fun, we started without a real plan for the project and discussed the options we have right on site. I brought only the essential parts and the kids came up with their own ideas on how to design the turbine. The turbine serves as an object for experiments and study of electrics and electronics.

Tech facts

We used an AC motor from a fan as a generator, directly driven by a two-bladed rotor (68cm Diam.), hand carved from a single piece of wood. We built a simple construction from wood and some pipes which carries generator, rotor and a tail vane from plywood. There was no overspeed control system, since it is such a small machine only for demonstration.

The generator on a simple mounting structure

The direct drive was chosen to keep the project simple (no gearbox) and it required the generator to be rewound before it could be used, to get a higher voltage/rpm ratio. I prepared this in advance and used 2x the number of turns on the generator’s 4 coils.

The generator then had an output of around 8V at 400 rpm. The rewound generator was of course less efficient, but the whole turbine was not built for efficiency, its purpose was to be a demonstration model.

The Turbine

There was a self-soldered bridge rectifier from Schottky diodes to get DC output for battery charging or to run other electronics off the wind turbine.

Social Impact

For the kids it seemed to be a very interesting week, I got a lot of positive feedback. They had the chance to discover a new topic in an interesting and creative way and learn about electrics, physics manufacturing and the use of tools. The wind turbine can be seen by everyone entering the school and it catches glances all the time!

A nice view..


The turbine has been taken down for the winter and for maintenance. Of course, there were some issues of wear and tear as well as corrosion. It was supposed to be a simple model and not designed for a super long lifetime. The kids will fix the machine on their own.

Turbine down for maintenance.

Jonathan Schreiber
I started PureSelfMade in 2013 to develop and spread practical knowledge on homebuilt small wind turbines, independent energy systems, off-grid lifestyle and more. In my hands-on workshop courses I teach simple and effective solutions for those subjects and share my enthusiasm with like minded people. Read about my background.

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