Windmills: Putting Wind Energy to Work

For hundreds of years, people have harnessed moving air (wind) to do work. The earliest forms of wind-powered machines were sailboats. Wind pushing against the sails of a boat provided the energy to move the boat across the water, saving people the trouble of rowing. Later, people discovered that if they attached sail-like panels to a wheel at the top of a stationary tower, wind blowing against the panels would cause the wheel and the central shaft to which it was attached to turn. The shaft drove mechanisms inside the tower that were used to mill, or grind, grain into flour. These wind-driven mills were called, simply, windmills. And even though wind-driven machines are now also used to pump water from wells and to generate electricity, the name windmill has stuck.

In this activity, students review the engineering design process and discuss how wind can be used to help get work done. They look at a variety of windmills, focusing on the different materials used in the construction of windmills and the type of work each windmill is designed to do. Finally, they use simple materials to build their own windmills to do work.