Engineers install longest urban superconductor cable in history

The Karlsruhe Institute of Technology (KIT), along with commercial partners RWE Deutschland and Nexans, has launched the ‘AmpaCity’ project to highlight the advantages of superconductors.

The first stage of the project was to replace a 1km-long high-voltage cable connecting two transformer stations in the Ruhr city of Essen with a three-phase, concentric superconducting 10kV cable designed for a transmission capacity of 40MW.

High-temperature superconductors (cooled with liquid nitrogen) have been ready for deployment in energy-related applications for some years now, although they have yet to be used on a large scale.

At temperatures of around -200°C, the material is transformed into an almost perfect electrical conductor, being able to transport at least 100 times more electricity than copper. Despite the cooling jacket, the compact design of the superconductor means that it can transport five times the electricity of a similar-sized copper cable — and with much fewer electrical losses. Thanks to improved production processes, superconducting wires are only now available in sufficient lengths and quantities.