My class enjoyed the lessons and materials provided by the kits from Flinn Scientific in order to design, build, test, redesign, rebuild, and retest both wind and water turbines! The key part of these experiments is to have students learn the process of inquiry and engineering by allowing them several attempts at redesign and retest in order to get their best results through modifying and recognizing design flaws.
Here are the links to both kits:
Wind Turbine Designs and Testing Set Up Water Turbine Testiing