"Our results show a significant warming trend of up to 0.72 °C per decade."
Now, I'm still going to laugh at this... we're talking about 2 degrees on average in a decade. And there's just no possible way: the same bogus research that gives us AGW has to be at work here, too.
The only thing that wind farms do is perhaps stir up the air that's already present. Maybe the metal in the towers absorbs heat energy from the sun and reflects it into the air slightly, but that's gotta be it. But it's the same sun that shines on the entire area -- some of it simply hits the tower and doesn't hit the ground. And given the sparcity (is that a word?) of wind farms anyway, the total possible impact is negligible at best.
It's kind like the crazy ideas we hear sometimes about jetliner contrails causing greenhouse effects: it's stupid. But yeah - somebody got a grant to write that nonsense.
They slow the wind. Energy is transferred from the wind to the blades. The turbulence is caused by the method they use to slow the wind. But slowing the wind caused the heat rise. They just did not quantify the observation correctly.