It looks great, but the fan model is slightly off.
The fan blades are tapered towards the hub:
The are also rotated from the axel by 45 degrees:
and are flat, not bent backwards at the tips:
Also, if you are looking at them from the front, they spin in the direction of the edge of the blade thats front most. The wind hits them, and slides off the blade towards the part of the blade in the back. (if the spin is in the opposite direction, something will look "off" to people, but it will probably be hard for them to figure out whats wrong without really looking at them.)
(If you tilt them when modelling before spin multiplying them and the rotation is wrong on the final model, tilt the blade in the opposite direction and then spin the blades to correct that appearance easily.
That fin in the back is also usually not thick and is flat, or is thicker towards the front of the windmill than the back. It doesn't pivot side to side like a fish's tail.. the "tail" aligns the entire top windmill structure with the wind so its always has the blades facing the direction of the wind.
(If you watch this video at 3:35 at half speed, you kind of get how they look in action.)
(You'll note the spin looks wrong.. thats a camera speed issue creating the false illusion of the blades spinning the opposite way.)
Also of note, they use them to pump water from an underground well... so the windmill could also be the required power source for well to pump water.
Please forgive if it looks like I'm nit picking as that is not intended. You asked for creative input so I'm hopefully providing it.