Copper cables only conduct electricity under resistance, meaning the cable heats up and energy is lost. In contrast, superconductors conduct electricity without loss. Their use in cable and generator projects thus increases the efficiency of the electricity supply infrastructure. With this in mind, the German Federal Ministry of Economics and Technology is promoting the cost-effective production of superconductive band conductors at the manufacturer Zenergy Power with funding of 3.5 million euros.

Using this funding, the production process for second-generation (2G) superconductors will be expanded and optimised. Zenergy Power is then able to prepare for industrial mass production of the new conductor material. The government’s goal is to reinforce the leading position of German companies in this branch. This approved funding is one of the highest ever received by a single company in Germany for the further development of 2G superconductor cables. When compared to vacuum coating processes, the new continuous chemical capture process at the manufacturer reduces costs thanks to the use of relatively simple, commercially available materials and an adapted ink printing process. The new superconductive cable not only reduces the production costs for superconductive generators, but also eliminates the need for rare earths with their critical availability that are essential for constructing permanent magnet generators.

With its coating technologies, the manufacturer is able to produce homogenous 2G superconductor cable at lengths of 100 metres. Production is made in continuous roll-to-roll processes. Longer cables and greater cable quantities are currently not manufactured, mainly due to the small size of the systems currently in use. As Dr. Michael Bäcker, the manager of 2G cable development, explains, “The chemical capture process is considered as the coating process with the highest technical demands, but also with the greatest economic potential. We are therefore extremely pleased to receive the support of the German government in our path towards qualified production through the SupraTech project.”

Zenergy Power estimate the total costs for the SupraTech project (“Superconductors for energy-based applications”) at six million euros over a period of three years.

Versatile superconductors

Using superconductor technology, electricity suppliers and the metal industry can generate, distribute and convert electrical energy more efficiently. For example, the aluminium industry can save 50% of the energy required for heating metal blocks before forming by using a magnetic block heater with superconductors. In wind turbines, 10 MW generators with superconductor technology are smaller and lighter than 5 MW generators with permanent magnets, meaning offshore wind farms can be operated with 25% more economic efficiency. In addition, electricity grids can be adapted quickly and inexpensively to cope with increasing power demands and decentralised renewable energy generation by implementing fault current limiters with superconductor technology. BINE project information will be published in September on this subject. More background information can be found in the “High temperature superconductors” project information (06/2010).
In another project from the German Federal Ministry of Economics and Technology, Siemens and the Karlsruhe Institute of Technology show how power plant generators can work more efficiently using superconductors.