In this chapter, third and fifth graders co-investigate and co-design wind turbine blades and voltage output. The wind turbine lessons featured emerged from the desire to help students build on their learning about energy transformation. The goals of the challenge were to (a) design a wind turbine blade system that would produce the most amount of voltage possible and (b) apply what was learned in the investigations to the blade designs. A materials list, teacher background information, and outcomes are provided. This book selection includes the Table of Contents, Introduction, References, Internet Resources, and Index.