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Using Gas and Oil Technology for Offshore Wind Farms Adapted from Information by the U.S. Department of Energy Although the U.S. currently only has one commercial offshore wind farm in oper- ation, several more are on the horizon. One of the challenges facing the industry is designing systems for hurricane-prone areas. The U.S. Department of Energy (DOE) is developing tools to help designers lower the risk for offshore wind turbine systems. Since additional technology in floating foundations is necessary to make offshore wind development feasible in the deep waters of the Pacific, most of the offshore wind turbine development is currently planned for the East Coast and the Gulf of Mexico - areas which see regular hurricane activity, as well as other extreme weath- er conditions. Both land- and offshore-based wind turbines are designed with built-in mecha- nisms which lock and feather the blades (reducing the surface area that’s pointing into the wind) when wind speeds exceed 55 miles per hour. Essentially, the turbine goes into survival mode until the storm subsides, so it can safely go back to produc- ing energy. In addition to offshore storms being stronger, the turbine’s foundation also has to deal with large, powerful waves. Engineers who design wind turbine systems use models to understand how different loads, like winds and waves, will impact a tur- bine and its foundation. Previously, the DOE has funded work through the National Renewable Energy Laboratory (NREL) to figure out how to predict turbine loading in extreme conditions. Working with the University of Miami, NREL linked its preexisting wind turbine simulation software (called FAST) with the atmosphere-wave-ocean forecast model used for hurricane research and predic- tion to create a new Coupled Hydro-Aerodynamic Interface for Storm Environments. This tool helps wind system designers lower the risk for offshore wind turbine systems located in extreme weather areas. Research priorities of a new offshore wind R&D (research and development) consortium, funded by the DOE, may include a focus on improving the understanding of extreme conditions like those experienced during hurricanes, to better pre- dict potential failure modes of turbines operating in these areas, leading to the adoption of more robust engineering designs. The DOE has been studying the twisted jacket foundation. Used in the gas and oil industry, this design withstood a direct hit from Hurricane Katrina, a category 5 hurricane in 2005, without any damage to the foundation. NREL designed and ana- lyzed a hypothetical 500-megwatt offshore wind plant to be deployed in roughly 80-foot waters in the Gulf of Mexico. Some of the features included a twisted jacket foundation from Keystone Engineering and a customized lightweight direct drive gen- erator from Siemens. Perhaps the most surprising component of this system is the rotor designed by Wetzel Engineering. To optimize the proj- ect for hurricane resiliency and structural efficiency, the wind turbines use a downwind orientation - opposite from the upwind design used in virtually all utility-scale wind turbines today. Upwind turbines use a wind vane and a yaw drive to constantly turn the top of the turbine to face into the wind. A down- wind turbine lets the wind blow the blades away from the tower, allowing them to be more flexible, and permits them to bend in high winds without the risk of them hit- ting the tower, thereby reducing the risk of structural damage during a hurricane. Although hurricanes and the dam- age they can cause remain difficult to predict, with current R&D, the DOE is taking steps to alleviate potential risks to offshore wind systems. This company provides outstanding service! (503) 682-1001 rockmore-intl.com Rockmore International 56 APRIL 2018 WorldWide Drilling Resource ® The World of Minerallss will return next month with Diamond.