New Zealand leads the way in high temperature superconductors

Roebel winding of an HTS cable
Roebel winding of an HTS cable

This week, the 18th International Superconductivity Industry Summit (ISIS-18) will take place in Wellington.  The Summit brings together various companies – both local and international – involved in the commercialisation of high temperature superconductors: a technology with implications for power generation, electronics, and mass transportation, and in which New Zealand has significant involvement.

Superconductivity has been with us for a century.  When cooled to only a few degrees about absolute zero, certain metals become superconductive – that is, they have no electrical resistance, and no internal magnetic field.  This property of metals is used to construct superconducting magnets – some of the most powerful types of electromagnet known. Well known examples of such magnets include MRI and NMR machines, and some of the magnets used in particle accelerators.

In the last 20 years, however, scientists have begun developing a new kind of superconductor – whereas the traditional ‘low temperature’ (LTS) type need to be at temperatures of -270 C and cooled with liquid helium, new ‘high temperature’ superconductors (HTS) can conduct at (a relatively high) -200 C with the aid of liquid nitrogen.

The advance has caused a great deal of excitement due to the potential for increased efficiency in electricity/power transmission, improvement of mass transportation motors (with many benefits), and improved communications.

In addition, New Zealand has been at the forefront of the technology’s development, and New Zealand companies involved in its commercialisation could potentially become powerful export earners for New Zealand.

For more background, see this Sciblogs post by Dr Shaun Hendy.

The SMC spoke to some of those involved in the conference, and gathered their comment on the implications of HTS and what it means for New Zealand.  (Registered journalists can access images in the SMC Resource Library)

Alan Lauder1 ,  Executive Director of the Coalition for the Commercial Application of Superconductors (US industry body), and chair of the International Superconductivity Industry Summit, comments:

How close are we to being able to employ high temperature superconductor technology in power generation and transmission, and what kind of efficiency and environmental gains can this be expected to result in?

“There is an increasing worldwide demand for more electricity as it is a clean source of power and instantly available by throwing a switch.  In addition to increasing need for additional generation sites there is also an underlying requirement to transport the power from remote location where the power plants, wind, solar, nuclear, natural gas or coal, would be located to the major load locations, typically cities, where the power is consumed.

“Most power grids around the world are stretched to the limit (hence occasional blackouts) already and will not be able to accommodate the additional demand, which is projected to increase by 50% by 2030.  Hence the need for a new option in long haul transmission that is environmentally and aesthetically attractive and brings major efficiency improvements and resiliency to the grid.

“There have been two dozen demonstrations of HTS cable used in the normal alternating (AC) current power supplies and several of these demonstrations have been actual insertions of short (up to 600 meters) lengths into the grid at transmission level voltages (12.5 to 138kV).  Transmission operates at much higher power.  An HTS direct current (DC) cable for transmission would have an efficiency advantage of 2-10% versus conventional overhead high voltage power lines.

“Additionally, the HTS cables would be underground, eliminating the large towers that currently carry the cable and because it is DC there would be no magnetic field generated and hence no electromagnetic (em) radiation. And under direct current (DC) operation the resistance of a superconductor is absolutely zero.  If you started a current flowing in a loop of superconductor, it would literally continue to flow for ever.

“For major construction of long (1000s of miles) of HTS DC transmission cable to begin, it would take at least 15 years to complete validation testing and put manufacturing in place.  Also, wind turbines are high and heavy.  Replacing much of the motor mechanism with HTS components would reduce the size and weight by about 50%, thereby allowing more power to be generated and increasing efficiency.”

What kind of benefits can we expect with HTS in future in mass transport systems that utilise superconductivity?

“Rail transportation systems are already electrified in most parts of the world.  Japan is looking at running HTS cable alongside the tracks to provide the electric power.  HTS magnets could also be used to levitate trains and this too is being pursued.  Savings in motor size and weight from HTS is typically about 50%.

“Likewise, ships are moving to electric drive and HTS is of considerable interest as major reductions in size and weight translate into more storage space for passengers or cargo.  HTS drive motors also result in much higher efficiency, greater fuel economy, longer cruising range, quieter and less vibration operation.   A large, 49,000HP, ship drive motor for a navy ship is built and awaiting installation and testing in Philadelphia.

“These rail and ship advances could be commercialized now.  And, of course, if we ever get rechargeable batteries to power cars that brings us back to the electric power grid needs.”

How will HTS be applied to the electronics industry?

“HTS is used in the electronics industry already.  About 6,000 mobile phone base stations are equipped with HTS filters that dramatically improve performance.  Other electronic applications in communications and radar have been demonstrated to be vastly superior technically.  And low temperature superconductors (LTS) have many commercial applications – MRI and NMR and big science projects, accelerators and colliders, would and could not exist without superconductivity (LTS).

“All these advantages do not come for free.  For most applications the current cost of HTS wire is too high and HTS must be cooled with expensive cryogenics.  It is, however, only 21 years since the discovery of HTS and true manufacturing facilities have not been built because there is little commercial demand.”

How close are we to understanding the fundamental physics of superconductivity, and why has this proven so elusive? What will a more full understanding of the underlying processes allow us to do eventually?

“Finally, the understanding of the fundamental physics underpinning high temperature superconductivity is an enormously challenging task.  The grail in this specific field would be the ability to predict superconducting systems, including operation at room temperature, which would eliminate the need for cryogenics in applications.”

Simon Arnold, acting CEO and management board member of the NZ HTS Industry Association, comments:

“The International Superconductivity Industry Summit (ISIS) 2 is the international industry body for commercial users of superconductivity.  The main ISIS meeting covers a review by participant organizations of the status of commercialization activity in their region.  The agenda covers the four main market areas for superconductivity: the wire itself; electronics; magnets; and power system equipment.”

What is the difference between high- and low temperature superconductors?

“LTS is a mature technology underpinning a multi-billion industry in MRI body scanners and higher resolution NMR.

“Products based on HTS are just entering market now, and because of HTS’s much higher operating temperatures products based on them are much less demanding in terms of their working environment.  This not only offers the potential for greater flexibility for products currently based on LTS, it opens up the use of superconductors to improve large scale power systems equipment.  This is potentially a very large market and simply isn’t a possibility using LTS.

“However, despite their advantages HTS are complex ceramics and practical conductors need to be highly engineered.  This makes them currently significantly more expensive than copper or LTS, although the price gap is expected to close as production volumes increase.”

How do New Zealand and HTS fit together?

“The NZ industry is recognized as world leading in HTS technologies, and this is reflected in it sitting as an equal with Japan, Europe and the US in ISIS.  New Zealand’s position initially stemmed from the discovery by a team at DSIR (later Industrial Research Ltd) in the late 1980s of the material that was to become the first to be exploited as HTS wire.  Since then NZ researchers (and over the last decade, NZ companies) have maintained work on wire development and built on this foundation so New Zealand is now selling and developing a range of products based on HTS.

“In 2004, HTS-110 Ltd was formed to manufacture and sell HTS based magnet systems.   After little more than five years HTS-110 is now bringing to market HTS nuclear magnetic resonance (NMR).  NMR is one of the more complex magnet based analytic technologies and HTS-110 is the first to market internationally with such a product.”

Donald Pooke, CEO of HTS-110(2) says:

“”When compared with LTS NMR our HTS NMR magnets are smaller, much more robust, they can be turned off (most LTS NMR is always on), can be easily cooled by mechanical coolers, don’t need liquid helium and are much less sensitive to environmental factors such as vibration etc.  This means NMR can be taken out of specialist suites and moved into the laboratory and into industry.  We think this will represent a step change in the use of NMR by introducing a whole new large group of users to this analytic technique.”

“Building on HTS-110’s NMR capability IRL is working with HTS-110 on developing small volume HTS MRI.  This holds the promise of using MRI much more extensively in industry (e.g. for product inspection) and medical centres and clinics (e.g. for imaging joints).

“These HTS NMR and MRI products won’t compete directly with their LTS equivalents, for example we don’t envisage an HTS whole-body MRI machine in the near future because of the high cost of HTS wire, but as noted the technology  will open up the use of NMR and MRI in a much wider range of environments.”

How close are we to being able to employ high temperature superconductor technology in power generation and transmission, and what kind of efficiency and environmental gains can this be expected to result in?

“New Zealand is also addressing the use of HTS in power systems equipment.

“Internationally there are commercial projects involving HTS transmission cable but wider uptake will take time, perhaps 5+ years.  Part of this delay is simply reducing the higher cost of the HTS wire and demonstrating HTS based equipment (copper is a very mature technology).

“An added factor is that superconducting wires don’t conduct AC completely without resistance.  Power systems are basically AC and, despite the heat generated being low, it is made more significant because pumping heat from cryogenic temperature to room temperature faces a >30X penalty.

“So both robust efficient industrial cooling (deployable in a substation for example) and reducing AC losses are key technologies to aid the uptake of HTS in power systems, and neither has a satisfactory solution.”

Bob Buckley, HTS Group Manager at Industrial Research Ltd (and one of the original team at DSIR involved in the initial discoveries of HTS) says:

“”We recognized these problems and began working on both 3 to 4 years ago. Right now we think in NZ we’re well on the way to at least part of the solution to both problems.

“”First we are developing a pretty clever mechanical cooler that is designed to be cheap, industrially robust and suitable for use with power systems equipment.  There’s a competitive market out there trying to solve this problem, but HTS-110 has picked up the commercialization and they’ve cut a deal with Air Liquide around development and distribution for our technology, so we think we’re on the right track.  We are also finding other applications for the cooler outside HTS.

“”Second we’ve developed an HTS cable that reduces AC losses and allows the high current carrying capacity required in power system equipment.  This is not a transmission cable (they can be wound from HTS wire in a way that reduces AC losses) but a cable for use in winding the large coils used in motors, generators, transformers and the like.  This cable (referred to as Roebel Cable3) is being manufactured in long-lengths by a joint venture between IRL and General Cable Ltd (General Cable Superconductors Ltd). This involves a complex manufacturing process because the ceramic HTS wire needs to be cut in a complex pattern and wound into a cable without twisting. General Cable Superconductors LtdGCS is the only company in the world manufacturing the cable.

“”GCS and IRL are working with a range of partners on projects to demonstrate the utility of the cable in power systems equipment, including a group of New Zealand companies that are developing a HTS transformer using it and Siemens in Germany who is using it in a large HTS utility generator they are developing.””

How will HTS be applied to the electronics industry?

“HTS electronics are being pursued internationally, but not in NZ.”

Additional notes:

1 Alan Lauder is also President of Alan Lauder Inc., Chairman and CEO of Advanced Microwave Applications Corp. Amongst other things, he was formerly chairman of the U.S. trade association for superconductivity (CSAC), and managed the superconductivity programme at DuPont.

2 ISIS has as its members:

  • The International Superconductivity Technology Center (ISTEC), Japan;
  • The Coalition for the Commercial Applications of Superconductivity  (CCAS), US;
  • The Consortium of European Companies Determined to Use Superconductivity (Conectus) Europe, and
  • The NZ High Temperature Superconductor Industry Association (NZ-HTSIA)

The Koreans and Chinese are observers and are expected to join ISIS in the near future.  Many of the large scientific, medical and industrial equipment multinationals feature as members of the individual associations, along with national applied research laboratories.

3 Roebel cable winding is a method of winding HTS cable in an efficient and cost-effective manner.  The technique was developed  by IRL researchers and will allow the faster uptake of the technology.

Further Information

To talk to any of the experts quoted above contact the Science Media Centre on tel: 04 499 5476 or email: smc@sciencemediacentre.co.nz.

Notes to Editors

The Science Media Centre (SMC) is an independent source of expert comment and information for journalists covering science and technology in New Zealand. Our aim is to promote accurate, bias-free reporting on science and technology by helping the media work more closely with the scientific community. The SMC is an independent centre established by the Royal Society of New Zealand with funding from the Ministry of Research, Science and Technology. The views expressed in this Science Alert are those of the individuals and organisations indicated and do not reflect the views of the SMC or its employees. For further information about the centre, or to offer feedback, please email us at smc@sciencemediacentre.co.nz.