The most active effort on SMES in Germany is carried out at the Forschungszentrum Karlsruhe (FZK) laboratory. FZK is constructing a 250 kJ SMES with a toroidal field design to address a power quality problem due to the frequent startup of large motors at a saw mill. Analysis indicates that a SMES system would be ideal for reducing this flicker problem, due to its fast response capability. FZK is also investigating at the Deutsches Electronen Synchrotron (DESY) laboratory the use of SMES as a pulse power source for providing ~10 GW pulses with a 1.0 ms duration at a 10 Hz rate in order to power rf klystrons (Jungst 1995).
At Siemens, the interest in SMES over the last few years has been mostly restricted to design and evaluation studies, with no current plans for development or construction. Siemens, RWE (the largest German utility), and Preussen Electra have completed an evaluation and conceptual design of a 2 MWh/50 MW SMES for use in providing frequency stabilization to the electric system. SMES continues to be of interest, but recent economic studies by Siemens indicate it may be too expensive compared to other storage technologies (Prescher et al. 1995).
It is thought that using HTS current leads, which are now a commercial reality and can be purchased from a number of manufacturers including Hoechst and ASC, would reduce the heat leak in a SMES system. Use of HTS conductors to fabricate a high field, high density SMES is also projected as an interesting future application. An HTS SMES operating at 10-20 T would require a "composite conductor" capable of carrying thousands of amperes with low ac losses to minimize heating for multiple charge and discharge cycles.
The Technical University of Munich has also been conducting research on SMES and is constructing a 1.4 MJ toroidal field system using LTS conductors (Lorenzen et al. 1995). At ABB in Switzerland, energy storage is considered an important area; it has been strongly followed in the past, and an LTS SMES has been constructed for experimental evaluation. At the time of the WTEC visit, a major SMES system using LTS conductor under development for the Swiss railroad had been terminated due to realization of an alternative, less costly, solution. ABB had no plans for SC storage but did plan to continue to evaluate the technology.