The German energy transition makes it necessary to extend the transmission grid. Karlsruhe Institute of Technology (KIT), together with the grid operator TenneT, now studies the use of superconductor technology as an alternative to conventional power cables for short grid sections within the framework of the ENSURE Kopernikus Project. The superconductor cables designed by KIT for this purpose are efficient and powerful. After successful testing, they might allow for a more compact construction of power transmission lines in the three-phase grid.