The new 3.0 MW direct drive permanent magnet generator wind turbine from Siemens (image courtesy of Siemens Energy)

There has been much interest in the development of direct drive systems in recent years, since the elimination of the gear box theoretically the turbine system more reliable.  What Siemens appears to have done is to take that a step further – by eliminating half of the components at the top of the tower, there is less maintenance for the service technicians to have to worry about.  This is good for onshore systems, but even more valuable for wind turbines that are to be located offshore, far from land. It also means, in theory, more uptime for each turbine, thus allowing them to produce electricity over wider intervals.

Siemens installed the first prototype of the SWT-3.0-101 at the beginning of December 2009 close to the town of Brande in Denmark. Siemens entered the wind energy business through the acquisition of the Danish company Bonus Energy A/S approximately five years ago, a company that had been in business since 1980, as Danregn Vindkraft. This company was a pioneer in the early days of recent interest in wind power, and was a logical acquisition for Siemens as it looked to enter the market. The Siemens Wind Power business unit is still headquartered in Brande. The permanent magnet generator is being produced by the Large Drives business unit within the Siemens Industry Sector.

The compact nature of the nacelle for the new wind turbine from Siemens means that it is easier to transport than other systems (image courtesy of Siemens Energy)

Siemens first tested direct drive systems in the form of two 3.6 MW concept turbines in July 2008, leading to the 3.0 MW prototype installed late last year. While Siemens acknowledges that they were not the first to market with a direct drive permanent magnet generator system, the company appears to have deliberately taken its time with the development of its own systems. In a news release from late last year, Mr. Stiesdal indicated that rushing to the market with immature technology was not an option for Siemens. While the nacelle contains new technology, the blades, rotor hub, tower and controller were developed from existing products. Full commercial launch of the new turbine through serial production, is expected to commence next year, with a number of systems being installed around the world in the meantime.

One comment from Siemens is worthy of note for the permanent magnet industry and its supply chain. In a promotional video that was released to coincide with the launch of the new turbine, Ernst Frendesen, Director of Global Sales and Proposals for Siemens said that the

“market demand that we expect on this machine will be extremely big and therefore for a period, we think that the magnet demand will outweigh the production capacity.”

This is a very significant comment. Attempts to ascertain the specific amount of permanent magnet materials used in SWT-3.0-101 turbine design were declined by the company for reasons of confidentiality, and so at the moment it is difficult to determine just what this statement means, and on what basis it was made. It is clear, however, that Siemens is putting the permanent magnet industry [and indirectly, the rare earths supply chain] on notice.

Schematic of the new 3.0 MW direct drive permanent magnet generator wind turbine from Siemens (image courtesy of Siemens Energy)

Mr. Stiesdal has kindly agreed to do an interview with me on the SWT-3.0-101 wind turbine and its direct drive, permanent magnet-based drive system, which I will post to Terra Magnetica once completed, along with any other developments in the area of DD PMG turbines as they happen.

In the meantime, however, I wanted to mention that I have now uploaded a PDF file that contains the slides from my talk, titled “Recent Developments in Permanent Magnet Gear Systems & Machines” – click the aforementioned link to download it.

The primary purpose of any gearing system is to convert between speed and torque. Typically using a rotating input power source, we want to either increase or decrease the speed in the output shaft, via a converse decrease or increase in torque – and vice versa. Typical examples of such systems are automobiles [where we want to convert the high speed of the rotary crank shaft in the internal combustion engine to a relatively high torque at the wheels] and wind turbines [where we want to convert the high torque but relatively slow movement of the turbine blades, into the high speed required by typical generators]. This conversion between speed and torque is actually a form of power conversion from one part of the system to another.

A key drawback of using mechanical systems for such conversion is that there is friction, wear and tear. Only a few gear teeth mesh at any one time, the rated torque values are by necessity lower than peak torque because of fatigure issues, and there is a lot of lubrication and maintenance required. In addition, failures of such devices tend to be catastrophic – when a mechanical gearbox fails – it fails!

Enter the magnetic gearing system. With no contact between elements, there is no friction to cause wear and tear. Multiple magnetic poles are engaged and thus the systems are highly efficient at converting power. Input and output shafts can be isolated too, which presents additional options for the mechanical designer.

Going a step further – fully integrating magnetic gears with electrical machines such as motors and generators, results in superior, best-in-class torque densities for any electromechanical / electromagnetic power conversion system. This result makes magnetic gearing a very promising technology for a variety of devices, including the possibility of highly compact, high powered traction motors for in-wheel drives for vehicles. Torque densities of up to 140 kNm / m^3 have been achieved, with the ability to produce up to 35 kW of power in a single in-wheel traction motor.

My presentation in Florida covered the recent developments in this area, including low gear ration and high gear ration systems, the history of research into magnetic gears, as well as some potential applications. These are early days for such systems, but I think it’s only a matter of time before they are widely deployed.

You can download a copy of the paper from here.

It could have gone either way; but what did happen next, is in my mind a fascinating case study on the value of scientific collaboration in the absence of a profit motive, combined with a remarkable leap of faith, to successfully overcome political, geographic, cultural and scientific challenges.

Late in 1984, the Concerted European Action on Magnets [CEAM] was born at a meeting in Brussels, the result of a unique coming together of the leaders of five European academic laboratories. This was a time before the fall of the Berlin Wall, before the Single European Act and before the European Union. It was a time when the bureaucrats of Europe were trying to find ways to help member countries work more closely together, as part of efforts to reduce mistrust and to achieve the objective of a more integrated pan-European economic system. This is a system that today most Europeans simply take for granted, but at the time, it was far from clear as to whether or not it would, or could, be achieved.

By the end of its remarkable eight year run, CEAM eventually produced over 1,000 research papers and well over a dozen patents as a result of the research of over 150 scientists, engineers and product designers, from 93 participating laboratories in 13 countries. Crucially, CEAM produced enduring relationships and collaborative efforts among key research groups within Europe, who to this day continue to work together in areas of magnetics research. Just as important, CEAM enabled the creation of a new generation of research scientists and engineers, whose Ph.D. studentships and activities were made possible in whole or in part by CEAM.

I put it to you that the CEAM approach is potentially an effective model for the creation of a framework for reviving rare earths research and development, and the subsequent “incubation” of new technical talent for this sector, in the USA, Canada, Europe and beyond. It is imperative that the Western rare earths supply chain [such as it exists today] realizes that its constituent members are part of a single international “ecosystem”, and that the most effective way to challenge the People’s Republic of China in this area, is to work together within a framework NOT motivated strictly by profit or limited by national borders.

To learn more about CEAM, why it was so successful, and the six steps that could be taken to apply the CEAM model to the revival of rare earths research and development in the West, you can download a copy of my new paper on the subject: “The Concerted European Action on Magnets: A Model for Facing the Rare Earths Challenge?” in PDF format.

Take a read, and let me know what you think by adding comments below.

The research was conducted at IBM’S Zurich Research Labs in Switzerland, in conjunction with Fujifilm. What’s interesting is that just as hard disk drive media has gone from longitudinal recording, where the data bits are stored lengthwise, to perpendicular, where the bits are stored perpendicular to the surface – the same concept has been applied here to magnetic tape. The result in both cases is a significant increase in areal density of storage. Thinner tape can also be used with this technique, which means more tape can be stored on a spool. the particles used are made from barium ferrite – more commonly seen in everyday ceramic ferrite magnets.

However, the new tape technology created a problem:

Increasing the density of data that can be stored on a tape makes it more difficult to reliably read information. This is already a problem because of electromagnetic interference and because the heads themselves will retain a certain amount of residual magnetism from readings. To overcome this, the IBM group developed new signal processing algorithms that simultaneously process data and predict the effect that electromagnetic noise will have on subsequent readings.

Since tape backups are still a mainstay of any self-respecting IT department these days, this new development will hopefully make their lives easier. And let’s face it – if your IT department is happy – YOU’RE happy, and vice-versa, if you know what I mean….

The folks at IBM say that it might be as long as five years before the tape material is ready for prime time, but even so, this new development may well extend the lifespan of this data storage technology for many years to come.

Since then, I’ve had the chance to play with a number of their prototypes.  I had initially been a little confused as to what the technology was all about, but having a chance to play with the different configurations gave me a better feel.  In addition, earlier this week, Design World magazine published an article with an update on the correlated magnetics technology, with a couple of videos. I had some difficulties getting the first video to play, but the second gives a good overview of the products and how they work.

As the Design World article says:

You can program, or code, the behavior of complementary magnetic structures by varying the polarity (and optionally the field strengths) of each source of the arrays of magnetic sources making up each structure. This capability, along with a cost-effective manufacturing capability, provides a multi-dimensional framework for design and development of magnets having unique spatial force functions that meet specific alignment, coupling, and release criteria.

Check out the new article today. I am told that a team from Correlated will be attending the Magnetics 2010 Conference in Florida, and will be bringing a bunch of prototypes with them.  If you’re attending the meeting, take the chance to have a play with these magnets.

Disclosures: none.

The first takes places on the day before the Magnetics Conference in Orlando, Florida, and is being run by Dr. Peter Campbell in conjunction with that event. Peter is a highly experienced technical expert on magnetics and does an excellent job when it comes to teaching and training on magnetics:

The Selection and Design of Permanent Magnet Materials in Today’s Economic Climate

January 27, 2010 8AM – 5PM : Disney Hilton, Orlando, Florida, USA

Instructor: Dr. Peter Campbell

From the organizers: “This workshop will explain the available tradeoffs for all the major types of permanent magnet material, sintered and bonded, anisotropic and isotropic, and provide an overview of the prospects for any important new material developments.  It will provide a thorough explanation of magnetic circuit design incorporating permanent magnets, including how to assess the magnet’s stability, and demonstrate how finite element analysis is used to validate and optimize a design.  Relevant case studies will be used as illustrations throughout the workshop.”

Cost: $695

Web site: http://www.magneticsmagazine.com/conf-2010/mag_conf10_workshops.php

The second event, which only popped up on my radar screen last week, is being run by three companies involved in magnets [Alliance LLC], magnetic sensors [austriamicrosystems USA Inc] and magnetizing and testing [Magsys Magnet Systems]. It looks like it will be a good practical introduction to these subjects:

Magnetics Workshop for the Automotive & Alternative Energy Industry

February 1, 2010 9AM – 5PM : Michigan State University, Troy, Michigan, USA

Instructors: Dan Vukovich, James Murphy & John Michalik

From the organizers: “This is a one day workshop tailored to bring an understanding of design, pricing and selection criteria for magnetic materials, equipment used for magnetizing and testing, and the design and application of magnetics sensors. the workshop is formatted specifically for professionals in the automotive and Alternative Energy industries. Presentations will include theory, practical design, application examples and market information.“

Cost: $120

Brochure Web site: https://docs.google.com/fileview?id=0B62nxVIP5PHKYjMwYTNiNTEtMjIzMS00YjI3LTllMDUtMjMxNjNhZjQ3OTE5&hl=en

Registration Web site: https://docs.google.com/fileview?id=0B62nxVIP5PHKZDc3YjJkN2QtM2IwOC00ZDBhLTk3ZDEtYTUyMjI5YTMwZmZj&hl=en

The device is actually an upgrade to an existing electromagnet, and uses a special coil design called a Bitter solenoid, in order to generate the intense magnetic field. This design, first invented by Prof. Francis Bitter while working at MIT prior to World War Two, consists of stacks of copper plates, instead of wire coils, in order to carry the massive currents that are required for the electromagnet. The working inner bore of the new magnet is approximately 32 mm [1.25 inches] in diameter.

The increment from 35 T to 36 T came from creating a new arrangement of the copper plates in the Bitter solenoid. The researchers at the NHMFL plan to apply this new arrangement and upgrade the rest of the electromagnets at the lab, in order to increase the overall magnetic output of each. As an added bonus, according to laboratory:

[t]his cost-neutral modification means a higher magnetic field can be created using the same amount of power, 20 megawatts. By comparison, the magnet at the Grenoble High Magnetic Field Laboratory achieves its 35 tesla using 22.5 megawatts of power.

Frog levitating in a 16 T resistive electromagnet (image courtesy of High Field Magnet Laboratory, Radboud University Nijmegen 2005)

To put this into context, 20 megawatts of electricity is enough electricity to power around 6,000-7,000 average American homes. A 2.5 MW saving in electricity [equivalent to the power produced by a commercial scale wind turbine these days], for the same magnetic output, is therefore pretty significant.  During a visit to the NHMFL a few years ago, I was told that the laboratory is required to give plenty of notice to the local municipality in Tallahassee before switching on their electromagnets, because of the massive current draw on the local grid that they cause.

It was in a very high field electromagnet of this type, that the famous picture of the floating frog shown here, was taken some years ago. The strong diamagnetic effect of the electromagnet, on the water molecules in the frog’s body, is enough to counter the effects of gravity.  When not levitating amphibians and other objects, researchers use these types of very strong electromagnets for physics and materials science research.

A team of researchers at Purdue University, led by Professor Babek Ziaie placed a mixture of mineral oil and iron oxide nano-particle onto some ordinary paper. Once impregnated, the thin “scaffold” could be manipulated by using an external magnetic field.

Depending on the properties of the iron oxide particles used, which are around 10 nm in diameter, this “ferropaper” as they’re calling it, could be a cheap way of making soft magnetic laminations for motors and other applications.

The article talks about other applications such as “small stereo speakers, miniature robots or motors for a variety of potential applications, including tweezers to manipulate cells and flexible fingers for minimally invasive surgery.” Although this ferropaper reacts to magnetic fields, this is not the same as being a permanent magnet, so it remains to be seen just how complex one might be able to get, with relevant applications.

Still, the technique might lead to some cheap and easy fabrication techniques for a variety of applications that could make use of such a material.

From R & D magazine:

The researchers fashioned the material into a small cantilever, a structure resembling a diving board that can be moved or caused to vibrate by applying a magnetic field.

“Cantilever actuators are very common, but usually they are made from silicon, which is expensive and requires special cleanroom facilities to manufacture,” Ziaie said. “So using the ferropaper could be a very inexpensive, simple alternative. This is like 100 times cheaper than the silicon devices now available.”

The researchers also have experimented with other shapes and structures resembling [o]rigami to study more complicated movements.

Magnetic origami – sounds pretty cool to me!

The use of algae as a potential source of fuels is nothing new within the world of renewable energy. As Siemens says:

Algae are a valuable source of raw material. For millions of years throughout the history of the world, they have transformed CO2 into valuable organic molecules. Some species specialized in the production of fatty acids and lipids. Their fossilized remains from the dawn of time are the foundation for the petroleum and natural gas extracted today. Algae continue to harbor enormous potential today as suppliers of biomass, biogas, or biodiesel. They are also easy to cultivate. They don’t need anything more than CO2 and water, and preferably wastewater at that because of the nutrients it contains.

The problem is that while it is relatively easy to grow algae, harvesting it is a real pain. Within a liter of water, only a few grams of algae grows at a time, and so the water has to be filterd and drained, which is time consuming.

The solution, according to Siemen’s Manfred Ruehrig, is to add a fine powder of magnetite – iron oxide – into the water.  The algae latch onto the magnetite and, after stirring, the algae-magnetite combination can be easily removed by using an external permanent magnet. Although this has only been done in the laboratory so far, results have been promising, and could lead to the scaling up of the process, using similar processing equipment to that used for industrial magnetic separation. The magnetite would be re-used after separating it from the algae.

According to Siemens, the process would result in less water loss, and thus it could be used for drying in drier areas.

The use of magnetic particles in this way is not dissimilar to well-establish biomagnetic separation techniques used in the medical sector, to separate blood cells, DNA and other biological entities, using combinations of chemically-active magnetic nanoparticles, and powerful magnetic fields generated by specially-shaped magnetic configurations.

It also asks some questions on the lack of an accelerated pace for funding North American rare earth initiatives, and includes one hypothetical situation which, if realized, has the potential to severely disrupt the present rare earth supply chain, long before we can handle such a disruption.

Check the article out, and feel free to leave comments either here or over there, on what you read.