Turbulence and Wind-Turbine Performance

Activities managed by Rockwell International for the Department of Energy have begun to determine the quantitative significance of turbulence to wind-turbine utilization. At the Wind Systems Test Center three methods are available for analysis of performance data taken in turbulent winds. Frequency-matching, the method-of-bins and most-probable-power methods are described and it is shown that the method-of-bins is the most accurate method for calculating a system power curve for use in energy yield predictions. Limitations and advantages of the analysis methods are highlighted. Wind energy conversion system development subcontracts have resulted in improved understanding of the importance of turbulence in system design. In nine designs, turbulence (gust) considerations have been second only to maximum survival wind speed, in importance to structural design. The experiences to date of the nine design efforts are summarized.