In early 1996, the U.S. Department of Energy and National Science Foundation asked the World Technology Evaluation Center (WTEC ) to assemble a panel to assess, relative to the United States, how Japan and Germany are responding to the challenge of applying superconductivity to power and energy applications. Although the study was focused mostly on the impact of high temperature superconductors (HTS) on the power applications field, the WTEC panel also looked at many applications for low temperature superconductors (LTS). The market for low temperature superconductor applications is well established, as is that for superconducting electronics, for which there is a separate WTEC panel.1 The panel on power applications of superconductivity was commissioned to identify the roles of public organizations, industry, and academia for advancing power applications of superconductivity, taking both a present and a long-term view.
The study was carried out by a panel of leading U.S. experts in the field. (See Chapter 1 and Appendices A and B for biographies of panelists and other team members). The panel reviewed the relevant literature, then made a one-week trip to Japan to visit sites where work in this field is underway. A subset of panelists then continued on for a week of site visits in Germany and Switzerland. Chapter 1 describes the visits briefly. A complete set of site reports is included in Appendices C (Japan) and D (Europe). The panel presented preliminary findings at a workshop in Washington, DC, in July 1996. Based on its findings and on feedback from workshop participants, the panel then drafted this written report. The draft report was reviewed by Japanese and German hosts as well as by sponsors prior to publication.
Tables ES.1 and ES.2 present the WTEC panel's best assessment of the U.S. program strengths and weaknesses in high Tc conductors and systems technologies as compared to those of Japan and Germany. The United States leads Germany in conductors made from BSCCO-2212 and -2223 and from Tl-1223. It is holding level with Germany and Japan with respect to biaxially textured YBCO tapes and is holding level with Japan in the area of BSCCO-2223 and Tl-1223 conductors. It lags Japan in the area of BSCCO-2212 tapes2.
A particular strength of the Japanese program is that it is enduring. It has strong commitments from government, large multinational companies, utilities, and to a lesser extent, from universities. A cornerstone of Japan's present program is Super-GM, a large-scale national generator and materials development program. Amplifying Japan's national effort is the work of the International Superconductivity Technology Center (ISTEC), whose principal goal has been to develop the materials aspects of HTS. The Japanese program is now the largest worldwide, by about a factor of two as judged by the data in Fig. ES.1. Part of the reason for the larger size of Japan's program is that it is much more involved with LTS conductors than either the U.S. or the German program. This reflects the belief prevalent in Japan's scientific community that the real payoff for superconductivity will come in the twenty-first century, so that it does not greatly matter whether devices built today use LTS or HTS materials, provided no barrier is created to using whichever materials system will make the device more attractive when the market does arrive.
U.S. Competitiveness in Power Applications of Superconducting Materials High Tc Wire Technology
U.S. Competitiveness in Power Applications of Superconducting Materials Systems Technology
The Germans appear to share the Japanese view that LTS programs are very important at this stage of power applications development. Germany has strong programs going back 25 years that are committed to large-scale applications of superconductivity, particularly for fusion applications. Fusion magnets are several meters in diameter and are complex devices requiring large and sophisticated refrigeration systems. The national laboratories supporting this effort (these labs are mainly supported by Germany's Ministry of Education, Science, Research, and Technology, BMBF) provide excellent continuity and a base for large multinational Germany-based companies, especially Siemens. The BMBF program in power applications has now run for four years, and there is a strong expectation that a new four-year program is imminent. The BMBF appears quite firm in its position that HTS work for power applications is both promising and precompetitive. The BMBF program also appears to be strongly interactive: for example the BSCCO conductor program involves extensive collaboration between Siemens, Vacuumschmelze, Forschungszentrum Karlsruhe, and the IFW-Dresden. The biaxially textured YBCO program, which is industry-led, also features important contributions from universities and national laboratories.
*Does not include Maglev ($3.5 billion over 5 years), a large percentage of which is for land acquisition and construction. Note also that U.S. dollar equivalent amounts for the Japanese program were calculated using 1996 exchange rates (¥100/$), which have fluctuated considerably since then.
Fig. ES.1. R&D related to power applications of superconductivity: 1996 funding profiles of the United States, Japan, and Germany.
U.S. activities are highly leveraged from the program of the Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE). Small start-up companies play a major role, and collaborations have been vital to the rapid progress that has occurred in the United States. Demonstration devices using HTS are more widespread in the United States than in either Japan or Germany. The schedule for further scale-up is ambitious, but the actual implementation appears to depend strongly on a healthy federal- and utility-funded program.
Trends in the relative standings of the United States, Japan, and Europe in the field of conductor technologies do not appear to differ greatly from the present situation: assuming a continued commitment to coated conductors, panelists anticipate that the U.S. program in YBCO tapes will lead both Japan and Germany.
In the area of superconducting systems technology , the panel estimates that the United States is lagging Japan in generators, magnetic levitation, and fault-current limiters, and is lagging Europe (specifically, ABB Group) in transformers. The WTEC panelists believe that U.S. systems technology is level with Japan with respect to current leads, power cables, transformers, and flywheels, and is leading Japan and Germany with respect to motors and superconducting magnetic energy storage (SMES). The United States is also leading Germany in the areas of power cables, current leads, and fault-current limiters.
Changes in the relative standings of the United States, Japan, and Europe with respect to systems technologies are more likely than with respect to wire technologies. Present U.S. interest in both fault-current limiters and transformers gives a boost to the U.S. position in both areas and suggests that U.S. transformers might eventually take the lead with respect to Japan and reach parity with comparable German developments. This would give the United States a leading position in transformers, motors, and SMES compared to Japan, and a leading position in power cables, motors, and SMES compared to Germany. The uncertainty of these estimates is addressed in detail in the individual chapters on each component of the power system. The panelists were unanimous in the view that the future position of the U.S. program depends vitally on a strong federal program, since this underpins all of the advances on which the judgments in Tables ES.1 and ES.2 depend. A point that Japanese hosts made to the panelists several times concerns the importance of a strong U.S. program even to the Japanese, although their program was about twice the size of the U.S. program in 1996.
The funding data shown in Figure ES.1 should be viewed with some caution. Because of the diverse nature of the funding mixes that support work in the different countries, the particular uncertainties about industrial contributions, and extent to which contributions to one aspect of superconductivity work carry over to another, it is not easy to accurately count all components of each national program on power applications of superconductivity. Note also that Figure ES.1 does not reflect the budget increase in the DOE program recently approved for FY 1998 ($32.5 million, vs. $20 million in FY 1996).
The goal of the U.S. program is to be first to market power applications of HTS materials. All three countries have this goal, but the Japanese and German view is that significant markets for HTS power applications will take a decade or more to develop. There is a dichotomy of view in this debate that not only encompasses national perceptions but is also associated with the contrast between small-company views (dominant in the United States) versus large-company views (dominant in Japan and Germany). Large companies appear to be more comfortable with working on demonstrations of HTS technology, which might be far from being economic in the near term, provided they are part of a technology-enabling path. Small companies must come to market sooner and thus are looking for more immediate applications, many of which might be economic on a smaller scale. HTS can enter the global marketplace, perhaps bringing superconducting devices to less developed economies that lack the resources to implement the expensive and complex liquid helium (LTS) technologies. Due to the multinational nature of large companies, they are certain to play a large role in bringing superconductivity to market, but it is the small, venture-capital-supported companies that are playing the most vital role in the present U.S. effort.
Because of the dominant role played by smaller companies in the US program, the partnership aspects of the U.S. program, which bring together government, small companies, the stock market, large companies, universities, and national laboratories at the same table, are vital (see Chapter 1). Most technology is still at the precompetitive stage, making continued innovation vital. In Japan and Germany this is clearly recognized as being the case. In spite of the small markets that do now exist, large global markets for power applications of superconductivity have not yet developed, and governments are playing a continuing and important role in funding all programs, whether in the United States, Germany or Japan.
A characteristic of U.S. work has been the development of really outstanding interinstitutional collaboration. There has been a concern that this could be lost in the dynamic budget process that characterizes U.S. government funding of the field; however, for the time being the DOE budget for this program has fared well in Congress, with a substantial increase recently approved for FY 1998. This increase seems well justified since the current U.S. program has been extremely successful with only limited funds. It has generated strong demonstration devices and supported an R&D community that is responsible for many recent successes in conductors based both on BSCCO and on biaxially textured YBCO.
The future for power applications of superconductors has many aspects. Synthesizing the views of all the WTEC panelists, superconductor power applications are immediate as well as long term. Applications that are going to market today are HTS current leads, which couple external power supplies to LTS magnets much more effectively than the copper/LTS leads used up to now. Such leads enable so called "cryogen-free" ("dry") magnets. Toshiba, Mitsubishi Electric, and Kobe Steel/Japan Magnet Technology have been effective at this, as has the British company Oxford Instruments. Also, two U.S. companies are shipping SMES units for power quality purposes.
Dry magnets could be very important to the world market of even LTS magnets, since they remove the need for the complex infrastructure required to supply liquid helium. Dry magnet technologies can make powerful magnets available in the United States, Japan, and Germany not just for physics research but for new applications where no expertise in handling liquid helium exists. Professor Kitazawa of Tokyo University told the WTEC panel that one of the new initiatives of Japan's Science and Technology Agency program was to buy dry magnets and put them into Japanese research institutes that have no prior experience with strong magnetic fields. Such markets are being exploited now.
Next to be exploited will be larger SMES units, which give some spinning reserve and protection against large disturbances to the electricity supply. Next to be exploited after that will be superconducting transmission lines, of which excellent prototypes exist in Japan and the United States. Fault-current limiters, motors, energy storage flywheels, and transformers are all being worked on now. A strong complication in the United States that does not occur in either Japan or Germany is that the U.S. electric utility industry is contending with several years of deregulation and much competition. This is quite different from the relative stability of the Japanese and German electric utility industries.
Chapter 1, by David Larbalestier, explains the study background, objectives, and methodology, then reviews the accomplishments of the U.S. program and makes some general observations on and comparisons between the Japanese and German programs. Chapter 2, by Richard Blaugher, includes extensive background discussion on the history of superconductivity and its power applications, and reviews generation and storage applications. Chapter 3, by Robert Sokolowski, reviews transmission and distribution applications. Chapter 4, by Robert Schwall, covers other applications (i.e., flywheels, fault-current limiters, HTS leads and high field magnets, and cryocooling). Chapter 5, by Jeffrey Willis, gives an overview of HTS conductor technology. Chapter 6, by Masaki Suenaga, reviews the extensive Japanese R&D program in low TC conductors and applications. Biographies of the WTEC team members and site reports on each of the team's visits in Japan and Germany are included as appendices, along with a partial list of World Wide Web sites for the organizations visited abroad and a glossary of technical terms used throughout the report.