The National Renewable Energy Laboratory’s (NREL’s) dynamometer test stand is one of a kind. It offers wind industry engineers a unique opportunity to conduct lifetime endurance tests on a wide range of wind turbine drivetrains and gearboxes at various speeds, using low or high torque. Located in a 7500-$ft2$ building at the National Wind Technology Center south of Boulder, Colorado, the 2.5 MW dynamometer test stand was developed to help researchers improve the performance and reliability of wind turbines and ultimately reduce the cost of the electricity they generate. By testing full-scale wind turbines, engineers from NREL and industry hope to understand the impact of various wind conditions with the goal of improving hardware designs. A few months of endurance testing on NREL’s dynamometer test stand can simulate the equivalent of 30 years of use and a lifetime of braking cycles, thus helping engineers to determine which components...