This lesson plan includes the presentation as well as the student lab sheet. The presentation has a video link that explains how turbines work and helps to lead students through the lab as needed.
You can use this lab as a demo for the class, or you can have students completely design their own lab. The lab sheet is designed in a way where students can choose what to test for their independent variable (blade design, pitch, number of blades, etc) and they can choose what to measure as their dependent variable(s) such as voltage, amperage, weight it can lift, etc. I use the KidWind Turbine sets, but this lab sheet can also be used if students made their own turbines. You will need multimeters in order to measure amperage and voltage if desired.
Both files are editable for your preferences.