Appendix D: Statusseminar

Site:           Statusseminar
                Supraleitung und Tieftemperatur-technik
                Cologne, Germany
Date Visited:   10-11 June 1996
WTEC Attendees: R.D. Blaugher (report author), 
                D. Larbalestier
Hosts:          Dr. Bernd Himmerich, VDI Technologiezentrum, 
                   Physikalische-Technologien
                R. Mann, VDI Technologiezentrum, Physikalische-Technologien

BACKGROUND

Following discussions with Prof. Dr. Herbert Freyhardt (University of Gottingen) and the organizers of the Statusseminar, David Larbalestier and R.D. Blaugher were subsequently invited to attend this meeting and asked to present overviews of U.S. activities in HTS power applications and conductor development. The Statusseminar was organized to provide an assessment of recent progress on the German federally funded program on high temperature superconductors and related low temperature technology. The VDI Technologiezentrum Physikalische-Technologien (Drs. B. Himmerich and R. Mann) organized this meeting on behalf of the Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie (BMBF), i.e., German Federal Ministry for Education, Science, Research, and Technology. MinR. Dr. J. Bandel was the representative from the BMBF for the superconductivity program and at the Statusseminar provided the opening welcome and comments on the purpose of the meeting. This meeting, called the "5th Statusseminar" on "Supraleitung und Tieftemperatur-technik" was held in Cologne, Germany, on June 10-11, 1996.

The meeting was attended by over 200 researchers from the German universities, industries, and national laboratories involved in power-related and electronic research using superconducting components. The first day was devoted to HTS power applications and related materials research on conductors and melt-processed YBCO. The second day covered primarily HTS electronics and related materials and some refrigeration activities in support of the electronics effort. The format for each day was fairly similar: each morning and part of the afternoon was devoted to a series of 20-30-minute plenary talks, followed by a two-hour technical poster session combined with industrial exhibits. The meeting was then reconvened for a panel discussion, the panel being comprised of the plenary speakers to allow audience questioning and additional input to the plenary presentations. The entire day's session was then concluded with a summary presentation providing some key observations and general remarks. The first day, "Tageszusammenfassung," was provided by Prof. Dr. Peter Komarek from the Forschungzentrum Karlsruhe (FZK).

The opening comments on the first day from MinR. Dr. Bandel were to some degree very similar to those expressed by his counterparts in the U.S. federal agencies and provided some perspective on the history and prospects for future German government funding on HTS. "Following the discovery of HTS in 1986, which presented a highly optimistic outlook for SC, it was quickly realized that this enthusiasm must be moderated by a consistent effort leading to technological development of these difficult ceramic materials." Bandel indicated that good progress has been made, which raises the prospects for approval of a new five-year program on HTS. He expected Ministry approval of the new program on HTS at ~DM 40 million/yr. (~$27 million @ DM 1.5/$) when the current one expires in 1997. (Note: with the industrial cost share, the total effort would be ~DM 60 million/yr.)

A major effort on HTS that provided funding to industries, universities, and national laboratories, initiated by the Federal Republic of Germany in 1992, was to be completed in June 1997. This five-year program was funded at ~ DM 40 million for the first year and at DM 37-40 million for the subsequent four years. The BMBF funding that goes to industry requires a 50% cost-share for the large multinational companies. Universities are normally funded at a full 100%. The BMBF funding for the national laboratories mainly goes to Karlsruhe and Julich, in the amount of ~ DM 6 million/yr. The university salaries for the professors are usually paid by the universities, which thus compliment the BMBF support. In contrast to the U.S. DOE program, the BMBF provides nearly half (~ DM 20 million) of the total program to the universities. Additional national laboratory funding for SC comes from other federal sources like the Bavarian Superconductive Initiative and the Lower Saxony Partnership, which includes companies like Solvay GmbH and utilities. Both provide support that is mainly non-material-related. The ministry not only encouraged but directed participants to collaborate under the BMBF program, which thus promoted university/ industry/national lab joint programs. An example of this joint collaboration is the Siemens fault-current limiter program with Prof. Kinder (Technical University of Munich) and Prof. Wordenweber (Forschungzentrum Julich) providing materials support to Siemens on YBCO thin-film processing. The competition for BMBF funding, which is highly intensive between the universities, industry, and national laboratories, has, nevertheless, led to extremely strong collaborations that have benefited all parties and significantly advanced the applications development. The implementation of interdisciplinary efforts between the universities and industries for demonstration of HTS prototypes will be one of the main topics for future emphasis and funding by the BMBF.

Bandel was followed by Dr. M. Kleimaier from RWE Energie AG, the largest electric utility in Germany, who provided some very important perspectives on the consideration of the use of superconductivity within the electric power system. RWE has been fairly active in collaborating on superconductivity-related research on power applications. RWE has recently evaluated, with Siemens, the economics and technical prospects for SMES on the electric power system. RWE has also evaluated the use of SC fault-current limiters with Siemens, American Superconductor, and others. RWE is currently part of the flywheel effort with Siemens and FZK providing utility guidance on the application. Kleimaier's talk, which was essentially the keynote address, was entitled "The Application of Superconductivity to the Energy Technologies -- Its Possibilities for Usage and Market Opportunity." He presented some opening viewgraphs that indicated the importance of the classical work on improving motors/generators, transformers, and transmission cables, and the recent new applications on flywheels, SMES and fault-current limiters.

Kleimaier argued that success in introducing a new technology to the electric utilities is dependent on realization of a cheaper, more efficient solution than the conventional competing technology. In particular for superconductivity applications, there must be a compelling argument with respect to need, i.e., increase in load, demand for replacement of existing components, etc., and the ability to easily integrate this "new" component into the electric power system. The "new" superconducting component, moreover, must meet a fairly stringent list of utility requirements and show some unique operational advantage over conventional technology in order to be even considered. These requirements cover all of the typical electric utility specifications outlining voltage, current, ac losses, reliability, operational performance and servicing, and basic logistical factors such as size and weight.

A comparison of the advantages and disadvantages for the classical applications, i.e., motors/generators, transformers, and cables, showed the usual expected improvements in efficiency, reduced size and weight, and increased steady state and transient stability. Other unique advantages were also cited:

for generators, lower synchronous reactance, which would improve static and transient stability
for transformers, oil free construction and potential current limiting capability
for cables, the capability for higher power levels at lower voltages, no heat input into the ground or ambient containment, and no external field for a coaxial design.

The stated disadvantages for the respective applications were

SC generators would only be economical at "high" MVA levels, which is contrary to current market demand for lower-power units
cables also would only be economical at high power levels, which would create difficulty in accommodating any outage, i.e., would reduce ability to shift load during down time, which is expected to be longer than conventional maintenance and repair
SC transformers would require higher maintenance, require special cooling of the iron core, and may show higher losses under reduced load conditions.

Kleimaier did not comment on the merits of flywheel storage but indicated that the high cost for SMES, especially for the smaller sizes, would limit serious consideration of magnetic storage technology. The ability of SMES to deliver fast response, high power for short times, and "repetitive cycling" capability was cited as its major advantage. RWE, as noted earlier is, nevertheless, deferring further work on SMES in favor of flywheel technology.

SC fault-current limiters have a fairly long list of advantages, with possible scenarios for use within the electric power system, such as improved voltage quality, ability to utilize present distribution systems, and design of new installations with lower short circuit currents. The cited disadvantages are nominal: the need for improvements in the HTS conductor, ac losses, and higher resistance matrix.

Kleimaier summarized the major limitations for superconducting technology:

complexity -- requires refrigeration and thermal isolation
new problems for installation and maintenance -- reliability and life-cycle are unknown
economics -- SC applications almost universally are only economical for large ratings and the initial investment cost may be significantly higher than conventional technology

All of these factors, collectively, cannot lead to a situation that might compromise the electric power system, i.e., use of an SC component in the electric power system cannot, in any way, produce a potential negative influence or weakness in the system.

Kleimaier showed an interesting way to consider the possible usage of an SC component in the electric power system. As reproduced in Fig. Stat.1, Kleimaier's assertion is that use of a superconducting device is more easily considered and tested if the device can be placed in parallel in the electric power system. This arrangement would allow the device to be easily switched out of the network if a problem develops. The installation of transformers, cables, and generators are thus decreasingly attractive due to their requirement for "serial" installation, with the generator requiring a power station for its test and evaluation.

Kleimaier then concluded with these key observations: integration of SC components within the electric power system must be easily accomplished. Except for current limiters, profitable use of SC devices requires high power levels. Even with successful prototype demonstrations, the market in Europe will develop slowly, except for current limiters. Superconducting current limiters appear to have the most potential, since there is no viable alternative technology. Finally, confidence in the new SC technology will only occur with successful testing under "utility" conditions that are eventually carried out within the electric power system.

The other important plenary presentations were by Dr. J. Bock, Hoeschst AG, who outlined progress on HTS high current leads, and by Dr. H.W. Neumuller, who reviewed the Siemens effort. The latter presentation, for the most part, is discussed in the site report for the visit to the Siemens Laboratory at Erlangen. The presentations by Larbalestier and Blaugher were both fairly well received, as indicated by the high number of questions and lengthy discussion that followed each presentation.

Fig. Stat.1. Evaluation of a superconducting device (Kleimaier).

Published: September 1997; WTEC Hyper-Librarian