Assuming a wind velocity of 12 meters per second and an energy conversion coefficient of 0.4, then a 100-megawatt turbine would require rotors nearly 550 meters in diameter. To predict when we’ll get such a machine, just answer this question: When will we be able to produce 275-meter blades of plastic composites and balsa, figure out their transport and their coupling to nacelles hanging 300 meters above the ground, ensure their survival in cyclonic winds, and guarantee their reliable operation for at least 15 or 20 years? Not soon.
