Today, I wrote a post for TreeHugger about a company that is proposing to build a colossal magnetic levitation wind turbine. Magnetic levitation (or maglev) is an interesting technology that has been around for a while.
A series of German patents for magnetic levitation trains propelled by linear motors were awarded to Hermann Kemper between 1937 and 1941. Today maglev is being used in a number of ways, according to the MagLev Wind Turbine Technologies web site:
Today MAGLEV trains operate in Germany, China and Japan. MAGLEV trains currently hold many land speed records and are most noted for energy efficiency, on time performance and low maintenance. MAGLEV systems are also used in sophisticated ship elevators, amusement park rides, aircraft carrier catapults and a variety of other conveyance applications.
The big advantage in using maglev in wind turbines is that it reduces maintenance costs, and increases the lifespan of the generator. But there is very little information out there on how maglev is actually implemented in wind turbines. A post on Worldchanging says:
[They're] probably using Halbach arrays in a system like the Inductrack invented at Lawrence Livermore Labs several years ago. Any permanent magnet system would doubtless need lots of Neodymium (“rare earth”) magnets, which may have questionable sustainability when mined in large amounts, but as it happens China is rich in that element–in fact, energy.buzz points out that China owns 90% of the world’s market of rare earth magnets.
Hmm….it would be great to see some more definitive information published on this subject.