Hi there. I've recently been working with a charity in the UK called EWB UK (Engineers Without Borders) who run Outreach workshops in schools to encourage children to think about a future in Engineering.
One of these workshops (Power to the World) gets the students to think about how electricity affects the world around us and what we would do without it. We look at how building a generator in an African village could change the lives of the townfolk; how it allows access to the internet and what that means for the education and well-being of the local children.
An important lesson in the workshop is that there are many difficulties in building generators in locations where resources are scarce. This is shown to the children in a hands-on task where they get to build their very own turbine blades under the scenario that the local generator's blades have broken. Each group is allocated resources based on a country (Western countries get lots of card and tape, where the African nations may only have a couple of sheets of paper to build with).
The challenges that they face in building the turbine with these limited resources will help the attendees to realise that we are very privileged in the West to have an abundance of materials at our disposal to build with, but that with the right thinking that you can still make fantastic innovation from little resources.
These turbines are built on cotton reels (the big plastic kind) and are tested against a mechanic lift challenge. We tape a length of string attached to a penny to a cotton reel and, by coupling the groups' turbines to this reel with some tape, we measure the efficiency by how fast the penny reaches the top. Through this testing phase, we communicate with the teams as to why certain designs work well and other not so much.
I'm currently working on an extension to the workshop that would hook the axle up to a bicycle dynamo, to convert the wind energy into DC rather than simply kinetic energy. This wouldn't be a production ready wind turbine, but a demonstration of the principals looked at in the workshop. I'll save that for a later 'ible though...