Transportation of electricity using power cables often results in losses, especially over larger distances, which effectively reduces the potential efficiency of the delivered power for all sources that rely on this technology. This may be particularly relevant for renewable generation sources, where resources such as wind or hydro power can be far away from the point of consumption.
Superconductors are state-of-the-art in different applications, such as magnets for medical tomography (MRT). The AmpaCity project introduces an innovative technical solution for efficient electricity distribution using superconductors. These systems can carry 100-times higher energy density compared to standard copper cables. With the AmpaCity project, the company innogy brings a world premiere to Germany: two transformer substations in Essen city centre were linked with a superconducting cable for the first time. The underground cable transmits electricity over a distance of one kilometre almost completely without losses. This replaces up to five conventional 10,000-volt cables.
The AmpaCity project is a showcase for the application of high temperature superconducting cables for medium voltage power distribution without any losses in an urban environment. First sets of field data have been obtained and will be used to set up similar solutions using high temperature superconducting devices in daily life.
A typical 380kV 1.1 GW transmission power line shows losses of roughly 1%, or 11 MW, per 100 km. This results in yearly losses of 96 MWh per 100 km. In addition, specific losses of distribution grids are higher. The usage of superconducting cables mitigates significant parts of losses in the electric grid.
Analyses of the economic aspects of the application of high temperature superconductivity in medium voltage power distribution are being conducted. In order to proceed with the application of high temperature superconductivity in medium voltage power distribution systems, further field studies with increased transmission distances and capacities are necessary, especially in large cities and/or large industrial areas.