I would have like to see the sky not so dark. That way the windmill had been in more sihouette.
The composition might have been a bit more interesting.
Good job though !
The clouds, especially mid left are superb but the subject itself does not do an awful lot for me but you have managed to convey a feeling of wind here. good luck
Technically, it's not a bad photograph, but it's not really a silhouette. Also, the windmill is tilting a little to the left which is somewhat distracting.