SUPERCONDUCTING CABLES FOR VERY HIGH POWER TRANSMISSION

Enabling the transmission of several gigawatts of power by developing a new superconducting direct current cable:

• Designing, manufacturing, and testing a superconducting cable system operating at 320 kV and 10 kA
• Validating the magnesium diboride superconductor for high-power electricity transfer
• Providing guidance for TSOs and policymakers on the technical aspects, economic viability, and environmental impact of this innovative technology

In just ten years, superconducting power cables could offer unrivalled solutions for high-power transmission. To meet CO₂ reduction targets, the future transmission grids will need to transfer 2 to 20 GW of electrical power over distances of several hundreds of kilometres from remote wind or solar farms to the final consumption centres. In these new grids, long superconducting cables could carry very high currents – from 5 to 10 kA or more – in combination with high voltages of up to 400 kV without resistive losses.

While several superconducting projects have been launched and operated in AC networks, this demonstration is investigating HVDC solutions. For the first time, a full-scale HVDC superconducting loop, including two terminations and the associated cooling systems, was designed and tested under high voltage. It uses a monopole cable system operating at 10 kA and 320 kV for a transmitted power of 3.2 GW. The industrial maturity of the magnesium diboride (MgB₂) wire technology was demonstrated by the manufacturing of hundreds of kilometres of MgB₂ wire. In addition, the industry partners have manufactured the cable conductor and high-voltage insulation, underlining the system’s high level of readiness.

Apart from the technical achievements of this demonstration project, emphasis was also placed on exploring long superconducting systems (> 100 km) as well as analysing their economic viability and environmental impact, including comparisons with existing transmission technologies.

The results of this project include concrete policy recommendations to facilitate the deployment of the superconducting technology and set the HVDC standard of the future.

• Manufacturing magnesium diboride (MgB₂) wires and the cable conductor
• Investigating the nominal and transient behaviour of an MgB₂ component embedded in the grid
• Investigating and manufacturing a safe and reliable HVDC electrical cable insulation
• Designing and constructing high-voltage electrical terminations
• Investigating the behaviour of the grid with an operating superconducting cable
• Exploring long-length superconducting links

The limited footprint and underground location of superconducting cables facilitate the purchase of easements and result in reduced construction costs compared to resistive cables, especially in dense urban districts. Thus, superconducting links could offer solutions for network operators that face challenges when it comes to installing new cables or upgrading their grids, ranging from the lack of available rights of way to high-load underground connections bridging difficult areas. The economic assessment has shown that for such cases, superconducting cable solutions are already cost-competitive vis-à-vis resistive cable technologies.

Nexans (Leader), CERN, Columbus Superconductors, ESPCI Paris, IASS Potsdam, Karlsruhe Institute of Technology (KIT), Ricerca sul Sistema Energetico (RSE), Réseau de Transport d’Électricité (RTE), Technische Universität Dresden, Universidad Politécnica de Madrid (UPM)

Superconducting cable design

Flyer about Demo 5

Interview with project leader Christian-Eric Bruzek

Dissemination Workshop in La Spezia – Pictures and Presentations