What Is the Optimum Size for a Wind Turbine?

Wind turbines have grown tremendously during the last 20 years and it is of interest to investigate how large they can be expected to be. In the present paper several structural aspects have been studied in order to see how they develop as a function of size. It was found that as long as thrust and centrifugal forces dominate, then most aspects of the turbine are independent of scale, provided geometric similarity scaling is performed. The most important deviation from this rule is that selfweight of the blades results in stresses that grow linearly under geometric scaling. The effects of selfweight appear to become important for the largest machines currently available. (5MW)Copyright © 2007 by ASME