I thought this "windmill" looked pretty wimpy for electricity generation, and was wondering what it could realistically contribute, given the height of the peaks around this basin. I also didn't notice the propane tank at its base, which, really, should have been a giveaway. While this area is not too high in elevation (I'm estimating between 600-1000 feet; the closest value I can find with resources at hand is for Roseburg, at 528 feet), cold air tends to accumulate on the valley floor. Inversions are common in Oregon's western valleys, but the air, by definition, is warmer higher up. The "windmill" is simply to stir up the cold air when there's a danger of frost, and mix it with warmer overlying air. I'm also guessing there's a burner associated with the propane tank to warm everything a bit.