Efficient power generation from offshore wind power plants requires powerful, reliable generators that do not cause a disproportionately high logistic effort nor require complex foundations. Theoretically, generators with superconductors can be increased to 10 MW while at the same time reducing a unit’s weight and size. Superconducting generators can also be built with less than 1% of the rare earths required for manufacturing the currently most frequently used permanent-magnet generator. Superconduction, hence, allows building efficient, reliable, and compact wind power plants at lower building, operating, and maintenance costs as compared to conventional generators.
It is the objective of the EU-supported project SUPRAPOWER (SUPerconducting, Reliable, lightweight, And more POWERful offshore wind turbine) to use the high potential of supraconduction to expand use of wind power. The four-year project recently started has nine partners from industry and science cooperating under the coordination of Fundación Tecnalia Research & Innovation, Spain. The partners will develop a wind-power plant with a direct-drive superconducting generator.
The innovative direct drive should reduce transport and maintenance costs and extend the turbine’s service life. The Cryogenic Engineering Division at Karlsruhe Institute of Technology (KIT) Institute for Technical Physics (ITEP) will contribute a cooling system:
Below a certain temperature, superconductors have no electrical resistance and conduct electricity without loss. To ensure proper operation of the superconducting generator, the coils must be cooled below this transition temperature. The researchers at ITEP are developing a rotating low-loss cryostat that cools the superconducting coils to 20°Kelvin (-253.15°C) through pure heat conduction by means of small Gifford-McMahon coolers provided by project partner Oerlikon Leybold Vacuum. “Because the cooling performance of such coolers is limited, we must ensure that heat between them and the superconducting coils conducts well,” says Head of the Cryogenic Engineering Division Dr. Holger Neumann. “Besides, we must consider the influence of rotation on the heat pipes we may use. On the other hand, the cryostat needs a highly effective thermal insulation.” Work on the cooling system will translate the findings from fundamental research to practice. This is attractive to young scientists.
KIT is one of Europe’s leading energy research establishments. Research, education, and innovation at KIT foster the energy turnaround and reorganization of the energy system in Germany. The Institute links excellent competences in engineering and science with know-how in economics, the humanities, and social science as well as law. The activities of the KIT Energy Center are organized in seven topics: Energy conversion, renewable energies, energy storage and distribution, efficient energy use, fusion technology, nuclear power and safety, and energy systems analysis. Clear priorities lie in the areas of energy efficiency and renewable energies, energy storage technologies and grids, electromobility, and enhanced international cooperation in research. KIT is a public corporation according to the legislation of the state of Baden-Württemberg. It fulfills the mission of a university and the mission of a national research center of the Helmholtz Association. KIT focuses on a knowledge triangle that links the tasks of research, teaching, and innovation.
Karlsruhe Institute of Technology
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