Windmill

A windmill is a structure that converts wind power into rotational energy using vanes called sails or blades, by tradition specifically to mill grain, but in some parts of the English-speaking world, the term has also been extended to encompass windpumps, wind turbines, and other applications. The term wind engine is also sometimes used to describe such devices.

Windmills were used throughout the high medieval and early modern periods; the horizontal or panemone windmill first appeared in Persia during the 9th century, and the vertical windmill first appeared in northwestern Europe in the 12th century. Regarded as an icon of Dutch culture, there are approximately 1,000 windmills in the Netherlands today.