By Kjell Schroder, The University of Texas at Austin, Stevenson Research Group and MRS Student Chapter
Big Picture – Magnets for wave power turbines
At the heart of the technologies for generating energy from wind and wave sources are turbines that convert motion (from air or water pushing on a solid) into electricity. The redirected motion moves a magnet, which in turns causes a changing magnetic field that induces an electric current. Wave power does have a major advantage over wind (and solar) because it is less sensitive to weather, leveling output and making grid capacity more predictable and reliable. The DOE has estimated the US could generate upwards of 400 TWh/year from tidal streams and ocean currents.
As with all renewable technologies, building “farms” of generators for wave energy requires high upfront capital investments. These costs discourage investors and utilities because they lead to long periods before a return on investment. Magnets represent one of the largest costs for wave-power generators, due to the specialized size and shape requirements.
Overview – Powder injection molding magnetic materials
Recently, researchers at the MDEA Materials Institute at the Universidad Carlos III in Madrid, Spain have looked at composite materials with magnetic properties formed by powder injection molding (PIM). The composites are made from metallic and polymer powder precursors that are injected into plastic mold and then cured. PIM has applications for magnetic materials in motors and wind generation as well. The resulting magnets are cheap, the process is adaptable to a large variety of designs, and is highly scalable.