It occurred to me as I made a farming oriented SSP game in 64 to try things out that there was something fairly vital missing to my grain fields, and that was something to power the quern so that I could get others thing done during the winter season. After some thought I realized there are some problems in the way of power generation in the game currently: - Complexity: The more complex something is, the harder it is to translate into the game and get implemented. Most systems of steam, wind, waterwheel, etc, all end up being fairly hard to implement without creating an entire system for them to work in, like BTW did. - Fits the Game and Time Constraint: Some types of power really sit just on or after the estimated time given that is latest viable, 1500 AD I believe is the mark. - Isn't a carbon copy of another mod: Adding something that another mod already has makes this mod look less impressive, especially when it's something as signature as windmills. So with all of that said, enter the Vertical-axis Windmill: The concept is simple, something you construct right above a quern to power it at a reduced speed from hand powered but at the advantage of it being constantly powered rather than sitting there doing it yourself. The upside is getting other stuff done, the downside is reduced output due to speed and of course wearing away your headstone if you don't remove it when you're done or aren't paying attention. To go back to the earlier problems mentioned: - Complexity: It's simple, just something you construct over your quern with unobstructed air in at least two directions for airflow, no gears or complicated systems required. - Fits the Game and Time Constraint: This type of windmill has been in use since the Persians for things such as grinding grain and pumping water. Attached to mudhuts. Just about as safe as it gets on that one. - Isn't a carbon copy of another mod: The two major mentions of windmills I found in other mods I could find was obviously BTW, which has a large mechanical system attached to a horizontal-axis windmill, which is what everyone seems to envision when they think of windmills, the other was a picture posted by Eloraam about redpower 2, in which you can potentially attach a vertical-axis windmill to a power generator of some kind. The difference between the one I suggest and BTW is the simplicity, you literally attach a rod and then the blades to the rod for the quern, nothing extra fancy about it. The difference between what I suggest and what I found on the redpower 2 post is that this doesn't generate power, would be smaller in scale, use different materials, and probably look quite a bit different. We have sticks, reeds, and paper, there you have the basics needed to construct the windmill: To make the windmill require metal in order to make so you can't build one straight out of the caveman era is the central power could be constructed from support posts (so saw required) placed upwards and topped with a hollowed out log, and then and the central axis is then supported by the horizontal support beams placed outwards from the hollow log. From there, the blades would be constructed of either thatched sticks, reeds, or even paper overlayed onto a framework of sticks or reeds; that part is largely open. Once 4 to 6 blades are attached the construction would be complete and it would start to rotate as long as there is enough clear space on two sides for air to flow. - TLDR: Use vertical windmill design to provide a simple to implement and build structure for use in quern rotation.