Next time you are in wine country, check out the Wind Machines.
The purpose of these windmills is not to generate electricity. In fact, they are powered by electic motors, and their purpose is to disturb the airflow over the vinyard to keep the ground level warmer at night.
They have been using these things out in California for as long as I can remember, so at least thirty years. This is not exactly a newly discovered phenomenon.
That would make sense. If you power a fan, it generates airflow. But if it’s natural airflow that powers a propeller, then the propeller is going to slow down the natural airflow.