Seismic Response of a 5-MW Wind Turbine: The ShakeOut Scenario

In November 2008, the National Science Foundation (NSF) and the U.S. Geological Survey (USGS) sponsored "The Great Southern California ShakeOut" to raise awareness about the possible ramifications of a 7.8-magnitude earthquake along the San Andreas Fault. Such an earthquake would directly affect Palm Springs, California, a prime location for wind power. California's Assembly Bill (AB) 32 (2006), legislation requiring reduction in emissions to 1990 levels by 2020, reinforces the importance of investigating the influence that seismic events might have on design loads for new large wind turbines. Anticipating that turbines will grow larger than the current 3-MW models with a hub height of 80 m, we examined the ramifications of a motion derived for The Great Southern California ShakeOut on the National Renewable Energy Laboratory's (NREL) 5-MW baseline wind turbine model with a hub height of 90 m. The resulting structural demand is compared for scenarios where the turbine is idling, continues operation, and initiates an emergency shutdown.