January 19, 2008

Maglev Magnetic Levitation in Wind Turbines

During the last decade, countries like Germany, China and Japan, installed a high speed train system based on magnetic levitation. These trains are known for there energy efficiency, on time performance and low maintenance.
The advantage of using magnetic levitation in wind turbines is that of reduced maintenance costs, and increases life span of the generator. The magnetic levitation that they use is between the rotating shaft and the fixed base of the machine, basically taking the place of ball bearings. Such magnetic bearings have been used for decades in smaller turbines and pumps by Ebara, Leybold, Seiko-Seiki, and others. However these magnetic bearings can't handle being bumped around much (the magnetic force isn't that strong), and they need actively controlled electromagnets (to keep the levitating magnets from crashing--play with some magnets for a minute or two and you'll see why). Making magnetic bearings strong enough to handle the loads a wind turbine would put on them is hard, and would use exorbitant amounts of power just keeping the electromagnets running strongly enough. However, the World watch article says the new Chinese device (invented by Guangzhou Energy Research Institute and Guangzhou Zhongke Hengyuan Energy Science & Technology Co.) uses "full-permanent" magnets, meaning there are no electromagnets, only cleverly placed permanent ones, so it should use no power. It sounds like they will be used on small turbines (perfect for home use), which would be similar in scale to the pumps and industrial turbines currently using magnetic bearings. But who knows, in a few years it might be possible to scale them up.
Hopes are that maglev wind turbines, will be 20 time proficient then usual wind turbines, and the maintenance would drop to as low as 50 %. Maglev wind turbines should also have the advantage of 1000 amplified production hours compared to the traditional ones, and they might prove to be the solution for carbon free clean world.