Gyro mills are very fascinating, but I wouldn't have high hopes for them as sources of low cost energy. That is unless you could also fly the gyro mill in a cro

Gyro mills are very fascinating, but I wouldn't have high hopes for them as sources of low cost energy. That is unless you could also fly the gyro mill in a crosswind manner. This article by Moritz Diehl describes very well the expected power output for a crosswind device. https://pdfs.semanticscholar.org/f5da/681fe152e5a81264f8a919d3222cba7f45d4.pdf https://pdfs.semanticscholar.org/f5da/681fe152e5a81264f8a919.... Also it's important to note that the potential power output for any of these systems are proportional to the cosine of the tether angle, meaning that most of the advantage airborne systems to traditional turbines won't be so much that they can reach higher winds, but just the smaller amount of material required.