You can build a simple wind speed meter with a tiny electric motor with a propeller or fan blade. On a day when the wind is dead calm hold it out the car window and drive down the road. Use a volt meter to read the voltage at different speeds. As you pick up speed the voltage will go up so you need to make notes, 5 mph = 1 volt, 10 mph = 2 volts, 15 mph = 3 volts and so on. When you get up to a pretty fast speed like 40 or 50 mph it may max out the voltage of the motor so you won't be able to read the wind speed above that speed. It takes a little bit of experementing with motors and fan blades to find a good combination that work good together. It is simple and it works.