Wind is one form of available energy. This is a simple vertical-axis wind turbine (VAWT) which you can make for no cost in half an hour (or even 10 minutes!) from stuff you already have, then enjoy seeing it spin!
The pictures and videos may be enough for you, but written instructions are here too if you want.
It turns in a light breeze or even by your breath, and in a steady moderate wind it whirls impressively fast!
Wind Whirlers can be decorated so as to illustrate principles of optics and perception.
They can play a useful part in education: in Geography, studying weather; and in other science projects - such as the physics of friction, airflow and angular momentum.
I've demonstrated this quick craft project, in the past several years, with repeated success: as a Youth Group activity; as an Ecology-Centre activity with schoolchildren and in a shopping mall demonstrated quickly to passers-by; and at The Big Tent 2008 environmental festival.
It's fun to decorate your own Wind Whirler, to enhance its visible proclamation that Energy is Free for Everyone! And when poised, whirling, its ever-varying motion helps us to relate to the atmosphere around us, our weather and our environment, in a satisfyingly personal way.
When I've carried one with me as I travel, it seems to be an eye-catching attention-getter that people often have asked me about, leading to interesting conversations.
It also makes use of what's often thrown away - plastic bottles!
Fun - free - decorative - and educational!