Generators in many of the newest turbines have started using neodymium magnets. Nedodymium is a rare earth, produced in China. China’s rare earths processing has had serious environmental concerns, as has Lynas Corporation’s rare earths processing facility in Malaysia (which will be supplied by ore from the Mount Weld mine in Western Australia).
As well as the environmental concerns of processing the ore (which is commonly found with radioactive elements such as thorium), the high cost of neodymium is also presenting trouble for manufacturers relying on them, such as China’s Goldwind. Neodymium magnets have enabled Goldwind to produce direct-drive turbines, which do not use a gearbox and are more efficient due to having less moving parts.
So it was interesting to read that German turbine company Enercon use no neodymium in their giant E-126 (the world’s largest to date), which is also direct-drive. A short note from Enercon’s magazine Windblatt (edition 2, 2011) explains:
Discussion about neodymium – ENERCON does not use material
In recent weeks, media reports about the use of neodymium in wind energy converters gave rise to public discussions. The element belongs to the rare earth metals and is mined primarily in China − sometimes at the expense of health hazards and considerable damage to the environment. Neodymium is needed to make the permanent magnets that are used in the generators of other wind turbine manufacturers. The reports made blanket statements about an alleged dirty side to the clean wind energy that presents itself as an environmentally friendly alternative to nuclear energy. Contrary to what the media reports suggested, ENERCON wind energy converters generate environmentally-friendly power totally without neodymium. The gearless design on which all wind turbine types – from the E-33/330 kW to the E-126/7.5 MW – are based employs an annular generator with separate excitation. The magnetic fields required by the generator to produce electricity are created electrically. Due to this design, ENERCON turbines are built completely without permanent magnets.ENERCON thus feels that also from the point of view of environmental and health aspects, its choice of WEC design has been confirmed. “We are a high-tech company that sets great store by environmental protection,” says ENERCON Managing Director Hans-Dieter Kettwig. “Our choice to rely on separately excited generators was the right one, not only from a technological but also from an environmental point of view.” According to Kettwig, renewable energies need to be viewed in their entirety in order to offer a convincing alternative: Producing clean energy is one thing; however, sustainability in production is just as important. In this respect, ENERCON once again takes on a pioneering role in the wind energy industry.