Wind is an important source of renewable, green energy. The purpose of this science fair project is to build and operate a windmill generator.

Air invisible; it doesn't make sounds; you can't pick it up and throw it. So how do we know it exists? Help your second grade scientist figure it out.

In this windmill model science project, you will build a windmill to learn about wheel-and-axle machines and how these simple machines are used to do work.