A method for defining wind turbine setback standards

Abstract

Setback distances established by regulatory authorities to minimize the probability of blade fragment impact with roads, structures and infrastructure can often have a significant impact on wind farm development. However, these minimum distance requirements typically rely on arbitrary rules of thumb and are not based on a physical or probabilistic analysis of blade throw. The work reported here uses a probabilistic approach to evaluate the effectiveness of current standards and to propose a new technique for determining setback distances. This is accomplished through the use of a dynamic model of wind turbine blade failure coupled with Monte Carlo simulation techniques applied to three different wind turbines. It is first shown that common setback standards based on turbine height and blade radius provide inconsistent and inadequate protection against blade throw. Then, using a simplified dynamic analysis of a thrown blade fragment, it is shown that the release velocity of the blade fragment is the critical factor in determining the maximum distance fragments are likely to travel. The importance of release velocity is further verified through simulation results. Finally, a new method for developing setback standards is proposed based on an acceptable level of risk. Given specific wind turbine operational parameters and a set of failure probabilities, the new method leverages realistic blade throw modeling to produce setback standards with a valid physical foundation. Copyright © 2011 John Wiley & Sons, Ltd.

Retracted: Analysis of blade fragment risk at a wind energy facility

“…Since their report, there has been a renewed interest in modeling risk, with several authors reporting on analysis of that risk. [5][6][7][8] The state-of-the-art modeling approach is 6 degrees-of-freedom motion of the blade fragments with aerodynamic loading. Simplified models do not match the results of the 6 degrees-of-freedom models; Sørensen 9 showed that drag ballistics do not capture the downwind distance and the range for vacuum ballistics is too far.…”

Planning for sustainable development of energy infrastructure: fast – fast simulation tool

“…This is a result of applying mathematical methods and representations of empirical models. Among those statements, there is the opinion of Rogers, Slegers and Costello [16], who argue to expand the offsets among rows, simultaneously proving that the distances between turbines in a row are of lesser importance. There is a team of Meyers and Meneveau, who are the advocates of a similar model.…”

Analysis of blade fragment risk at a wind energy facility

“…Larwood and van Dam reported on the history of this risk and the modeling of rotor fragments in the context of safety setbacks for wind turbines. Since their report, there has been a renewed interest in modeling, with several authors reporting on fragment analysis . The state‐of‐the‐art modeling approach is six degrees‐of‐freedom (6DOF) motion of the blade fragments with aerodynamic loading.…”