Large wind turbines are enormous machines. Many 2 megawatt class turbines are now being built with blades of around 40 meters in length, and a rotor hub height of 60 to 100 meters. The total weight is over 200 tons. Therefore, the bearings used in wind turbines are very large, with bore diameters of between 100 mm and 700 mm, and even as much as 2 meters in some instances.
Very few manufacturers worldwide, including MAC, can offer the market a stable supply of such large bearings. Suppliers must have both production capability and the ability to provide sales and technical service in key locations around the world; because the wind-turbine industry is now developing on a global scale.