Principle of Science: Conservation of Energy, Alternative Energy

Anybody who has survived a Chicago winter knows about the energy in wind. The Windmill harnesses the kinetic energy of moving air, or wind, into a swing. A swing-like seat attached to a small windmill moves up and down when the wind blows. Turn the windmill with your own weight by simply sitting in the seat, causing the turbine to move air like a fan.

Moving air, or wind, acts on the blades and transfers some of its energy to them. This causes the blades to rotate. Notice the small tail on the fan that keeps it oriented to the wind. As the wind blows, it turns the blades of the windmill, setting two gears into opposing motion. The first gear turns in the same direction the fan blades spin. The second gear, perpendicular to the first, causes a vertical motion that allows the swing to move up and down.

Windmills were traditionally used to grind grain in mills. Today, they’re often used to pump water and generate electricity. Because they’re no longer used in mills, they’re called wind turbines.