|This article is about an older version of DF.|
Generates 40, 20, or 0 power, depending on wind level
For a basic overview of how the different machine parts work and work together, see machinery.
 When it works
A windmill generates power under the following conditions:
- Its center tile possesses the "Outside" tag when loo ed at.
- The map has wind. (Turning weather on/off in the inits has no effect)
- Some maps have strong wind (40 power per windmill), some have weak wind (20 power), and some have no wind at all.
- It is not connected to frozen machinery, such as a screw pump or water wheel in ice.
When all of these conditions are met, the windmill will produce power at its center square and transmit it downwards.
A windmill is placed with, , . It must either be supported by machinery from below or on a stable foundation (floor) under all its tiles. In either case, the build site must be reachable, either from one of the tiles the windmill is being built on or from adjacent surrounding tiles.
 Standard windmill
- Build the windmill.
- Excavate a path under it to the center of its base, 1 z-level down.
- Add a vertical axle, gear assembly or machine there, which will have power. A floor between the windmill and this is fine, but the machine part below will only receive power if it is built after the windmill itself is finished. If you built the machine part first, you may have to deconstruct and reconstruct it to make it work.
 Windmill tower
The "windmill tower" option is useful if you can't dig below your windmill (if, for example, there is a room or underground river there).
- Build a 3×3 platform (or 8-tile ring) out of floors one level above the ground floor.
- Leave the center tile as open space (this is optional, as power will somehow go through the floor).
- Directly beneath the center of the future windmill, on the ground floor, build a gear assembly.
- Build the windmill on top of the platform.
- Connect this assembly to horizontal axles, and power your machines.
- If desired, remove excess floors/stairs.
NOTE: The game will not let you build over an open space unless there's a machine or gear assembly underneath it on the floor below.
NOTE: The windmill is only supported by the center tile, although there is the 8-tile ring below it. If you remove the gear assembly beneath it and there is no floor, the windmill will be destroyed at once. If you disengage the gear assembly, the windmill will not be destroyed at once, but after a short period of time.
 Sunken windmill
You can build windmills underground if the central square in the windmill is "outside" (channel the roof away above it).
 Windmill farm
Several windmills can be linked together via gear assemblies and axles. The first windmill needs a gear assembly beneath it. After that, each windmill will require one gear assembly beneath it and two axles to connect to the next windmill. All windmills produce normal power for the map, but remember that gears and axles will use power produced by the windmills, meaning you'll lose moderate amounts of power connecting your farm together.
 Hanging windmill
- Build building you want powered and up stairs with one tile between them.
- Build down stairs above the up stairs.
- Build windmill directly over building that needs or transfers power.
- (optional) remove the stairs.
This option has one main weakness: It can't be used to power gear assemblies that are linked to levers/pressure plates, because as soon as the assembly turns off it stops supporting the windmill which falls down.
 Using the power
Windmills with stable foundations are harder. A vertical axle or gear assembly beneath the center tile should always be powered, but the actual behavior seems buggy or non-intuitive; if it doesn't work, try re-building the machinery below the windmill.
 Construction Examples