Wind turbines use the impact of wind to turn two or three propeller like blades around a single rotor, which is connected to a main shaft. It is the spinning of this shaft that creates electricity.
Many conventional wind turbines use a gearbox, which connects the blades to the generator and is one way to increase blade rotation speed in order to generate electricity in low to moderate wind speeds. Direct Drive turbines do not use a gearbox. Hence they are cheaper to make, lighter, more reliable and cheaper to maintain. In addition, they provide better yield, especially in light winds.
This technology is expected to become the technology of choice in the coming years, especially for offshore wind turbines (where low maintenance is vital) and because many of the available high wind locations have already been used.
A 3MW direct drive turbine consumes close to 2 tonnes of rare earths permanent magnets. The wind turbine market is expected to account for approximately 30% of the global growth in the use of rare earths magnets from 2015 to 2025.