Strong northern winds (Shamal) blow throughout the year in the eastern parts of Iran (Sistan and Baluchistan, Southern Khorasan and southern parts of Razavi Provinces).
Though this natural phenomenon is more prevalent all over the country during autumn, and in winter, winds may keep blowing, but the eastern parts of Iran are an exception in that even when there is no wind in other parts of Iran during spring and summer, these parts are affected by winds known as “120 days winds / black winds” the speed of which sometimes gets to 100 km/hour.
The endless wind almost all over the year along with the scarcity of water resources were two factors which encouraged our ancestors to make an efficient use of this natural energy, as a result of which windmills locally called “Asbad” were invented.
The Neshtifan windmills are built in a multi-storied form to exploit the wind.
Smart technique to grind grains
Asbad is one of the most significant architectural structures of Iran in its desert regions which converts kinetic energy of air (wind) into other forms of energy.
Asbad is a smart technique to grind grains, a technique which goes back to ancient times when the people living in the eastern parts of Iran in an attempt to adapt themselves with the nature and transform environmental obstacles into opportunities managed to invent it.
Iranian architects' smart utilization of a natural threat i.e. strong and annoying winds and rendering it to an exceptional opportunity for the production of a strategic product like bread is not short of a miracle.
As a result of abundant and free of charge energy of wind in parts of the eastern region of Iran, one can see 40 windmills built side by side without any worry that energy may one day run out.
During the 120 days winds period, winds pass through the wind catcher openings and rotate the wheels and vanes, the heavy weight of the milling machinery and wheel is exerted on the axis and rotates the millstones.
The windmills are designed in such a way that winds encounter no obstacle to reach them, as a result of this concern, windmills are built on high elevations.
To make the optimal use of the wind, all the uniform windmills of a village or town used to be concentrated at a single location on the highest spot of that area.
Another reason for this strategy related to the fact that since all the windmills were built as a complex plant in a single area which sometimes stretched over an area of 1 km wide, it acted as a barrier against the annoying storms for the nearby villages / towns.
Therefore, it served two useful functions: grinding grain and protecting the village / town against storms.
The two story windmills designed horizontally had vertical axis and the wood, mud and brick were the main construction materials.
The 1,000 year old windmills of Nashtifan
These amazing windmills are among the oldest in the world. Located in the Iranian town of Nashtifan, initially named Nish Toofan, or “storm's sting,” the windmills have withstood winds of up to 74 miles an hour. With the design thought to have been created in eastern Persia between 500-900 A.D., they have been in use for several centuries.
Made from clay, straw, and wood, the windmills stand up to 65 feet in height with grinding stones in a room below for pressing grain into flour. And while there are about thirty similar mills around the area, in 2002 the windmills of Nashtifan were registered as a national heritage site by Iran’s Cultural Heritage Department, unique in that they are one of the few still operational.