With rotating roofs and self - adjusting sails, windmills reached their zenith by the late 19th century, when it was estimated that European mills were churning out some 1,500 megawatts of power.
فقد قُدِّر ان الطواحين الاوروبية كانت تنتج في تلك الفترة طاقة تعادل حوالي ٥٠٠‏,١ ميڠاواط .‏