Windmill on the way to New Mexico USA. A windmill is a mill that converts the energy of wind into rotational energy by means of vanes called sails or blades. Centuries ago, windmills usually were used to mill grain (gristmills), pump water (windpumps), or both.The majority of modern windmills take the form of wind turbines used to generate electricity.
Photo courtesy: Diplov Bhurtel/USA
