One of the best ways to measure wind speed is to usean anemometer. You could go out and buy one, but I find it much more fun to build my own. There areseveral types of anemometer tochoose from, but I am going to build one that uses electromagnetic induction. Normally, we think of electric potential as something you can get from a battery. But you also can get it from induction. It turns out that changing magnetic field also creates an electric potential.