The Windmills of Nashtifan

I rabbitholed this morning into the windmills of Nashtifan. They are vertical axis wind power generators that directly drove grain mills, set into clay walls as structure. The grinding areas are below the turbines. They were built thousands of years ago, and still function.

Windmill complex built thousands of years ago

I blew up and cropped that picture to show detail

same picture, showing detail

The video from This article on them being registered as a national heritage site by Iran’s Cultural Heritage Department shows how they worked.



The site has been suggested as a UNESCO World Heritage site.

Really NEAT old tech!!

The reason this fascinates me is my property has a lovely long edge that faces the wind both dirctions it generally comes from. I love the idea of putting a wall with savonius rotors in it (vertical axis wind turbines that can made out of scavenged materials.) I honestly can't say if I heard of these windmills sometime in the past and had just forgotten, or came up with it because it makes sense to me, but either way, the designs are pretty much the same. The only difference is my design has curving walls to block the wind so it can only go in through the direction of turn. I noticed the article linked says

The one downside to such windmills is that because the wind panels rotate horizontally, only one side will be absorbing the wind energy while the other half of the device will essentially be going against the wind current and thus wasting energy in order to do so.

With the way they built the huge wooden turbines, and the maintenance requirements, I can see why they didn't block it with curving walls, but I can make the blocking out of removable panels, which they didn't have the option of using.

I'm fascinated....  :D

It looks to me like they did block the wind with walls, if the wind is coming from the top of the picture, eh?  In front of each turbine is a wall that blocks ~6/7ths of the face and channels the 1/7 gap to the tips of the vanes on one side, no?

Simon Foreman wrote:It looks to me like they did block the wind with walls, if the wind is coming from the top of the picture, eh?  In front of each turbine is a wall that blocks ~6/7ths of the face and channels the 1/7 gap to the tips of the vanes on one side, no?

My error, you are correct. I was looking at pictures, and must have seen more shots from that side than the windward side. I wasn't awake yet this morning when I posted. Thank you for catching that!

That's cool!

From Wikipedia:

Simon Foreman wrote:It looks to me like they did block the wind with walls, if the wind is coming from the top of the picture, eh?  In front of each turbine is a wall that blocks ~6/7ths of the face and channels the 1/7 gap to the tips of the vanes on one side, no?

I noticed the same thing, scrolled down to say this as well... ha ha. The video also shows the rotation (CCW from above) which appears to get pushed by wind passing through the slot as you describe.
A simple vertical axis wind turbine such as this with flat vanes would need the wall shroud to make it work, and probably gives it a boost by channeling the wind or building up pressure. Not to mention the structural necessity for the upper bearing of the thing!
A more modern VAWT with aerodynamic vanes (such as Savonius) wouldn't need any shroud.

Pearl Sutton wrote:

Simon Foreman wrote:It looks to me like they did block the wind with walls, if the wind is coming from the top of the picture, eh?  In front of each turbine is a wall that blocks ~6/7ths of the face and channels the 1/7 gap to the tips of the vanes on one side, no?

My error, you are correct. I was looking at pictures, and must have seen more shots from that side than the windward side. I wasn't awake yet this morning when I posted. Thank you for catching that!

Cheers!  I feel particularly eagle-eyed now.  

I think what's particularly cool is the low embodied energy materials providing a 1000 years of service. I'm sure they needed upkeep - but were clearly doing their job well enough to do that upkeep. Compare that with the lifespan of the average cell-phone!

Found another video that shows a bit inside and from the rear, but I didn't have time to watch it with subtitles on and most of it is not in English. The first ~9 minutes is about the windmills: