AmpaCity superconductor

innogy lighthouse project on smart grids

Das längste Supraleiterkabel der Welt: AmpaCity bringt eine technologische Weltpremiere nach Essen. (Quelle: RWE)

Freezing cold electricity highway

innogy brings a world premiere to Essen: as part of the AmpaCity project, 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 is made possible by extremely cold temperatures. The core of the “high-temperature superconductor cable” (HTS cable) is cooled down to approximately minus 200° Celsius. At this temperature the resistance of the ceramic conductor is reduced to zero – electricity can flow almost completely without losses. These HTS cables are regarded as a forward-looking technology for space-saving and particularly efficient transmission of electricity.

The phenomenon of superconductivity was discovered more than 100 years ago. However, due to the extremely low temperatures involved, utilising this effect has been extraordinarily difficult.

On this project innogy collaborates with Nexans, a leading European cable manufacturer; Project Management Jülich and the Karlsruhe Institute of Technology (KIT). The AmpaCity research project is supported by the German Federal Ministry of Economic Affairs and Energy.

AmpaCity can replace up to five conventional 10,000-volt cables. In addition, fewer transformer substations are required, because superconductors can transmit even large electricity volumes at a lower voltage. In this way valuable spaces in the city are freed up for other uses.

With the project launch of AmpaCity in 2011 the superconductor has become part of the research project on intelligent electricity distribution in the city. After type verification and testing in Nexans’ high-voltage test lab were completed, manufacturing of the cable commenced. Ground-breaking and underground engineering followed and the cable was laid. Since the superconductor was officially commissioned on 30 April 2014, it has been integrated into day-to-day grid operation and the testing phase continues.

Timeline diagram depicting milestones of the AmpaCity project (Source: RWE)

AmpaCity in pictures

A giant cable reel: laying the superconductor cable
Installation and laying of the cable.

Partner von AmpaCity

innogy is also active here

Find out more about other innogy technologies in the renewable energy sector

innogy provides numerous options for an efficient and comfortable supply of electricity from renewable sources. We are also active in the following sectors.

More information

Proactive Distribution Grid

Smart electricity grids of the future

Smart Operator

Flexible grids for decentralised generators

Smart Country

Smart network concepts for country areas