A wind turbine or windmill moves by the force of the wind. You powered the paper windmill by blowing on it. Windmills and turbines can be used as a source of energy. A spinning turbine can be used to turn a system of gears. Gears are wheels with teeth around the edges that come together and turn each other. Gears can perform a variety of jobs. Wind turbines are often used today to create electricity by moving a magnet and copper wire around each other.