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.
Pöörleva pea ja isereguleeruvate tiibadega tuulikud saavutasid suurima tõhususe 19. sajandi lõpupoole, mil Euroopa tuulikute võimsus oli arvestuste kohaselt umbes 1500 megavatti.