Neodymium a bone of contention in wind turbines
Direct-drive wind turbines often use neodymium as a permanent magnet, but production of the rare-earth magnet has a considerable environmental impact. Will neodymium become the cadmium of wind power?
At the end of last week, portfolio managers at Murphy&Spitz announced that they had removed manufacturers of direct-drive wind turbines containing neodymium from their environmental fund. China is responsible for roughly 97 percent of global production, and the fund managers say that the rare-earth metal, which only occurs in chemical bonds with other metals and minerals and therefore has to be extracted from them, has a great environmental impact. The firm's environmental analyst Nicole Vormann says that entire areas have been contaminated and groundwater made unusable for human consumption.
Siemens and Xinjiang Goldwind are the two wind turbine manufacturers affected, but Enercon – the German manufacturer that made direct-drive turbines famous – does not use neodymium and is therefore still in the fund. A month ago, Enercon published a press release explaining that the design of its direct-drive turbines is based on magnetic fields brought about electrically, so that permanent magnets are not needed. The press release was a response to two reports on the German television just days before the press release, showing what the environmental impact in China is.
The Chinese dominance in rare-earths production recently made headlines when China announced it would be limiting exports of the materials, some of which are used in the wind sector (Renewables International reported).
Direct-drive turbines, which do not require gearboxes, are considered to require less maintenance and are generally lighter than conventional wind turbines. There has long been a debate about whether gearboxes or direct drives are the better option, but in recent years the general consensus has shifted towards direct drives, which are to be used increasingly in offshore wind farms (Renewables International reported) – ironically, where Enercon has yet to become deeply involved.
A recent discussion of environmental impact concerning cadmium rocked the photovoltaics world, with some arguing that the use of cadmium in a certain type of thin-film technology could be dangerous to the environment if the array (or the building on which the array is installed) catches fire (Renewables International reported). (cm)