Wind Turbines have steadily grown in size to the point where the largest models have blades of more than 100 meters in diameter. The Gearbox (which connects the rotor shaft to the generator) continues to be the component whose failure results in the most significant cost and downtime. Therefore, the reliability of the gearbox is one of the biggest concerns in the wind industry. At present, wind turbines are generally designed for a 20-year design life; however today's gearboxes generally have an operational life of 7-11 years, per Sandy Butterfield, former NREL Chief Wind Turbine Engineer. Some estimate that the current risk of failure of the gearboxes may have an economic impact as high as $300 Million USD. Gearbox failures are so expensive because of the high cost of repairing or …