Construction has begun on the world's largest production base for magnetic levitation (maglev) wind power generators. According to Xinhua, the base will produce a series of small-scale maglev wind power generators with capacities ranging from 400 to 5,000 watts in the first half of 2008.
So, what the heck is a maglev generator? It improves efficiency by using magnets to reduce friction, meaning that turbines could turn with winds as low as 1.5 meters per second (m/s), and cut-in, or energy-producing, speeds of 3 m/s. The chief developer says this could cut the operational costs of wind farms by up to half, with an overall cost under 0.4 yuan ($US 5 cents) per killowatt hour. Earlier this year, an Arizona based company touted a large-scale maglev turbine, but such technology on that scale has yet to be proved.
For developing countries like China, the technology could be crucial to bringing wind power to places where it is currently un-utilized and perhaps too costly to build. For the developed world too, it could make wind power much cheaper, and wind turbines at home a more realistic option.The company has also said it could even provide roadside lighting along highways by utilizing the airflow generated from passing vehicles (see this idea here).
If licensed to other companies (rather than illegally copied), the technology could help boost China's desperate-to-grow wind power manufacturing industry, which so far has relied on significant cooperation with foreign partners like GE, and has been somewhat stymied by the government's pricing schemes.
But wind is booming in China. It has the world's fifth greatest installed capacity, and is set to reach the government's first major wind goal -- 5 gigawatts by 2010 -- this year.
Though magnets have been used before in pumps and turbines to cut down on the friction of ball bearings, they have typically been electromagnets, which require additional power. The technology behind the generators has not been specified -- obvious concerns about intellectual property in China abound -- but the company has indicated the system relies on a permanent magnet system, which needs no external power, and without which compact DVD and disk drives would not exist.
Many have speculated they use something called Halbach arrays, which help to control the magnetic field. As Jeremy at Worldchanging noted last year, "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." Indeed, China controls 90% of the world market for rare earth elements.
The company notes that the generator's efficiency is 20% better than "traditional" wind turbines. Worldchanging goes on to explain that
The inefficiency of a normal windmill's drive train (which includes the gears, shafts, and bearings, everything that moves except the motor and the turbine blades) is not so terribly big at moderate and high wind speeds. According to a paper by California Wind Energy Collaborative at UC Davis, the average wind turbine's drive train is 87-89% efficient from peak wind speeds down to less than half peak wind speed. However, below roughly a third of peak wind speed, things go rapidly downhill, and by about a quarter of peak wind speed, efficiencies are wallowing sadly in the 30-40% range. The Dutch windmill manufacturer Harakosan advertises a wind turbine that has 93 - 94% drive train efficiency all the way from peak wind speed down to a quarter of peak speed.
Either way, for China's growing wind power industry, the maglev is a huge step, and one made even bigger by the current rush to take advantage of China's potential wind power, estimated around 700-1,200 gigawatts. According to the recently released China Wind Power Report 2007, installed capacity in China could reach 50 GW by 2020, accounting for about 4 percent of total power generation.
Zhongke Hengyuan Energy Technology Co Ltd invested 400 million yuan in the construction and expects annual revenue of 1.6 billion yuan.
Clearly, this is only a start. But the technology sounds promising, and might make wind for the home even more attractive. And, with further investment -- and, ahem, better intellectual property protection -- we might see it develop, get scaled up, and transform the economics of wind power.
Guangzhou Zhongke Hengyuan Perpetual Energy Technology Co Ltd
Global Wind Energy Council
China Renewable Energy Industries Association
SKF FAQ on magnetic levitation in turbines.