Let's Talk Magnets for Wind Turbines

For those of you who track the magnet market, we would recommend reading the blog, Terra Magnetica written by a PhD in Metallurgy & Materials who has an uncanny ability to explain technical concepts for the layman (or in this case, laywoman). In a recent post, editor, Gareth Hatch examined an article written by Tony Morcos in the summer issue of Magnetics Business & Technology entitled, Harvesting Wind Power With (or Without) Permanent Magnets. Tony’s article discusses different options available, from a design and sourcing perspective, in terms of magnet technology particularly around one theory challenging conventional wisdom – that Nd-Fe-B (Neodymium Iron Boron) magnets might not necessarily be the most cost effective solution for wind turbines. According to Gareth, Tony’s article highlights, the growing school of thought that permanent magnets are not the Ëœbe-all and end-all’ for wind turbine generators.

We decided to speak to Ed Richardson, Sales and Marketing Manager for magnet manufacturer Thomas & Skinner Inc to gather some additional insight and address some questions we had after reading the article.

MM: Do you think demand for NdFeB from wind turbine generators will create a supply shortage in the next 10-15 years? Why/Why not?

ER: My wife is from Tucson, Arizona, and I once heard someone ask a water expert if Tucson would ever run out of water.   His answer was no.   The money will run out first.   I think this is true for rare earths.   I don’t think there will ever be a shortage. What I think we’ll see is an increase in the price of rare earths.   As they go up, more people will look for them.   New sources (other than the Chinese) will come on line which will stabilize the price at a somewhat higher level than we see today. Remember, rare earths are not rare.   Rare earths are more common than lead in the earth’s crust.   The issue is always if you can get them out of the ground for a profit. As the price goes up, more people will look, and more will be found.   Eventually, a price equilibrium will be reached.   The rub will be that China will play a powerful role in where that equilibrium falls.   It’s that control that is concerning.

MM: Tony discusses the notion of parallel design to hedge against raw material pricing. What is your experience working with manufacturers ” do you think most pursue this type of design strategy?

ER: Parallel designs do occur, but usually fall off the table when you get to the testing phase.   Testing and perfecting a parallel design is typically not a path most companies can afford.   I think you’ll only see different designs emerge if there is a dramatic, sustained price spike in rare earths. I think this is unlikely.   What is probably more likely is a gradual increase over several years.   One thing to remember is that the prices of commodities typically move somewhat together.   For instance, the price of copper and electrical steel spiked right along with the price of neodymium during the past 3 years.     All three have fallen since.

MM: Do you see companies working hard to avoid using permanent magnets or using ferrite magnets with lower and more stable pricing than NdFeB magnets? Where is the trend going?

ER: I do not see companies working hard to avoid using permanent magnets, or moving designs from hard ferrites to neo.   By the pound, hard ferrites are the most widely used magnet material.   This will continue.   They are low cost and readily available in many forms.   By value, NdFeB magnets are the largest seller, due to their significantly higher price.   Engineers will always work through their options to find the best material for their specific application.   Each design has a variety of specifications, including cost, size, and efficiency.   Both hard ferrites and NdFeB magnets provide exceptional options, but they are not the right materials for every application.   That’s why there are so many options, as Tony stated in his article.

MM: Tony states that he believes that sintered ferrite can provide the best ROI for a permanent magnet wind turbine generator. Do you agree or disagree with that and why/why not?

ER: The correct answer is that it depends.   If size and weight are important, than hard ferrites may not be an option.   I think this is true for large wind turbines.   My understanding of wind turbine design is that once you get in the size range of 2.5 MW and above, size and efficiency are drivers of the designs.   Permanent magnet generators with NdFeB magnets are the only choice that fit.   But in smaller wind turbine designs — such as those meant to power a single household or a boat — hard ferrites or a “hybrid” design may be more appropriate.

Editor’s Note: Ed will be moderating a panel discussion at the upcoming Managing Supply Chain Risks for Critical & Strategic Metals conference, co-chaired by MetalMiner, covering rare earth metals, minor metals, platinum group metals and lithium.

–Lisa Reisman

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  • This is a timely article and covers a lot of ground.
    The perception that China dominates the REEs is a common belief. However Australia with the help of increased overseas investment could become a second force in the supply of rare earth elements. This transition is at a critical stage and Australian REE companies are in danger of joining the China cartel… due to their micro-market caps they are very vulnerable.

    Please visit http://www.AustralianRareEarths.com to have a look at the issues and who has what. The site includes a rundown of our ASX listed companies with REEs.


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