Have you ever wondered why "windmills" are in all of the vineyards and orchards? They're not windmills, but instead frost protection fans. Not your ordinary fan given they are most often powered by large automobile engines or big electric motors. Here in the Walla Walla wine area it can get cold in the Spring, Fall and Winter and you need a way to raise the temperature in the vineyard to avoid damage. The theory is that the temperature 30-40 feet in the air is warmer than at the ground. The fan mixes the warmer air aloft with the cold below raising temperatures anywhere from 4 to 6 degrees. So if you have a 30 degree frost night in the spring and are able to run the fan, those precious buds will survive the evening.