Superconductivity: Revolutionizing energy networks

Superconductivity was again a primary focus during the latest CRU Wire & Cable Connections Summit 2025, taking place in Prague from 24-26 June to which Nexans took part. As the global energy landscape undergoes a profound transformation, wire and cable manufacturers play a pivotal role in enabling the future of power generation, renewable energy and electrification. Nexans is determined to be one of them, and leading the charge towards greater electrification and accelerating energy transition. Yann Duclot, Nexans Acceleration Units Director, presented how superconducting cable systems can play a crucial role in this matter and how this groundbreaking technology will contribute to shape future energy networks.

Key highlights were on:

• Introduction to HTS cable systems
• Advantages in high-efficiency energy transmission
• Technology maturity and business opportunities

HTS solutions will help address challenges and opportunities with regards the amount of grid and transmission lines needed to support the electrification of economy and Renewable Energy Transmission. This conference echoed the latest CIRED edition that was held the week before in Genève, emphasizing the importance of superconducting cable systems for a sustainable energy transition

Boosting the resilience of electricity supplies

An aging and inadequate power grid is widely seen as one of the greatest obstacles to the restructuring of power markets in the United States, Europe and elsewhere. Utilities face several converging pressures: steady load growth, unplanned additions of new generation capacity, rising reliability requirements, sharp price volatility resulting from new competitive forces and stringent barriers to siting new facilities, particularly extra high voltage equipment.

Proposals for conventional grid expansion are facing persistent challenges, just as it is becoming apparent that industry reform cannot succeed without renewed grid investment, new transmission, and distribution capacity. Consequently, new technologies that can increase the electrical capacity and flexibility of this vital network attract increased attention. Adapting power networks is essential to cater for new sources of consumption – including electric vehicles, heat pumps, electric heating and industrial processes – as well as accommodating power flows from distributed generation.

Furthermore, there is a pressing need to boost the resilience of electricity supplies. In an all-electric future, fossil fuels will no longer provide a fallback. Transmission and distribution grids will need to be more resilient than ever. Downtime is not an option.

Superconductivity to accelerate the Energy transition & help address energy grids challenges

Superconducting cable systems have a critical role to play in addressing these challenges. As well as being highly energy efficient and reliable, superconducting systems are less disruptive to install and require much less space than conventional cables and overhead lines. Moreover, their capacity to transmit power is enormous: a single cable can handle more than 3 GW – enough to power a large city.

Moreover superconducting systems are more cost-effective and therefore easier to deploy than conventional copper and aluminium cabling – particularly in urban power grids. Savings are achieved through minimal land take and a reduced need for electrical infrastructure such as substations and transformers.

Superconducting cable systems are not just theoretical – they are now a reality. Leading grid operators already rely on superconducting cable systems for resilient, cost-effective electricity distribution.

HTS cables have a number of additional qualities that make them attractive for use in electricity networks

• HTS cables are capable of carrying extraordinarily high currents – far greater than conventional copper or aluminium cables. This makes it possible to transmit and distribute electricity at much lower voltages.
• they can transmit a phenomenal amount of power relative to their size. To put this in context, a single HTS cable with a diameter of 17 cm (about 6½ inches) can transmit 3.2 GW. This is equivalent to the power of three nuclear reactors.
• Superconducting cables produce neither heat nor electromagnetic fields, so there is no interference with surrounding power, telecom and pipe networks.

Together, these properties mean that HTS cables are uniquely suited to solving some of the major challenges now facing distribution and transmission system operators, as well as other major electricity users, including transport operators.

La supraconductivité aide à relever les défis de l'industrie ferroviaire

High-temperature superconducting cables have a number of technical and physical characteristics that make them strong candidates for applications in power grids.

Superconducting cable systems power up the electrical grid, revolutionize the energy transmission reliability, elevate energy network resilience and minimize infrastructure impacts

Many sectors now face great challenges that could be overcome by extending the use of groundbreaking technologies like superconductivity: refurbishing energy infrastructure, enhancing network reliability,combining efficiency with environmental responsibility whilst ensuring economic sustainability and performance,

Transport, heating and industry will all need to be electrified in the coming years if net zero goals are to be achieved. Finding ways to boost power supplies is a priority.

Superconductivity is currently advancing industrial applications, offering significant potential to transform critical infrastructure. Transmission system operators (TSOs), distribution system operators (DSOs) and railway operators need a way to satisfy the ever-growing demand for energy in cities and transport networks. HTS cables are designed to meet that demand

With more than 30 years of experience, Nexans is the leading innovators in superconducting systems. Our proven track record attests to our advanced engineering expertise and capabilities in HTS cables and fault current limiters. We're not just shaping the future, we're helping to power up the electrical grid, revolutionize energy transmission reliability, elevate energy network resilience and minimize infrastructure as well as environmental impacts.

Unleash the power of superconducting cables and systems for high-power energy transmission, paving the way for a more sustainable future.

Superconductivity is currently advancing industrial applications, offering significant potential to transform diverse sectors from power networks and rail industry to datacentres. By incorporating superconducting cables and fault current limiters, the industry can attain exceptional levels of efficiency, capacity, and sustainability. This progress aligns with global objectives for decarbonization and fosters an energy transition.

Great opportunities lie ahead with regards potential applications of superconducting technology, the HTS wire industry is heavily investing to meet growing demand for HTS cables. New production capacities aim to reduce wire costs by a factor of four using advanced industrial processes.

Applications

Recent projects clearly highlight the potential and opportunities of superconducting systems - So far, superconducting cables have been successfully operated in the electricity grid for several years, for example:

• Enhancing Chicago’s electric grid resilience against extreme weather and catastrophic events as well as cyber-attack risks thanks to Nexans HTS cables
• Railways: Upgrading and securing power supply of railway networks at Montparnasse station
• World first Ampacity: first and longest supra-cable in sub-urban power grid in Europe in 2014

#1. Enhancing Chicago’s electric grid resilience against extreme weather and catastrophic events as well as cyber-attack risks thanks to Nexans HTS cables

The Chicago REG project, which went live in 2022, involved the deployment of a new superconducting cable system to link nearby substations. Nexans designed, manufactured and installed a superconducting cable, which uses high temperature superconducting (HTS) wire made by American Superconductor (AMSC). The cable can operate at 12 kV, has an AC current of 3000 A, and can carry up to 62 MVA of power. far exceeding what is possible with conventional resistive conductors such as copper and aluminium. The cable’s high current capacity was ideally suited for densely populated and congested urban areas thanks to its compact footprint. The REG system also has a low environmental impact as there is no local heating or magnetic fields.

#2.Railways: Upgrading and securing power supply of railway networks at Montparnasse station

Nexans plays a pivotal role in the project, drawing on its experience in superconductor technology and electrical infrastructure. The Group designed, manufactured the superconducting cables as well as coordinated their installation within the existing conduits at Montparnasse station.

• COMPACT DESIGN - 2 superconducting cables replace 12 conventional 400 mm² copper cables
• The system was engineered in order to use the existing infrastructure with an overall HTS cable diameter to match existing spare ducting limitations, ensuring ZERO LOSS, ZERO ENVIRONMENTAL IMPACT and a fast project execution.
• A high-performance cable was created to meet specific railway constraints, enabling CONTINUOUS POWER TRANSFER and delivered a groundbreaking milestone with an HTS cable capable of supporting a maximum fault current of 40kA within 200ms - setting a NEW WORLD FIRST in power transmission technology

More pilot and demonstration projects are necessary to persuade cautious grid operators of innovative technologies' benefits and provide them with practical experience - further opportunities abound. 

• Offshore wind: superconductors are also justified in rural areas. The narrow line width limits the impact on the natural environment. Particularly in sensitive natural areas, superconductors offer an ecologically better alternative to the large number of conventional cable routes that are required to connect offshore wind farms. HTS technology is transforming offshore wind energy. The SupraMarine consortium (RTE, ITP, Nexans and a world leader in the Cryogencics cooling systems) is developing a 100km HVAC superconducting export cable that aims at reducing costs by approximately 1 billion euros for a 2 GW offshore wind project.
   
• Supernode ltd in Ireland is developing a superconducting HVDC solution which will also support the industry in becoming more efficient and transmitting electrical power that conventional cables cannot achieve. 
   
• Aerospace: Airbus shared their roadmap towards zero emission flight with superconducting cables playing a critical role. Building on the ASCEND project, the CRYOPROP initiative aims to further develop superconducting technologies to support cleaner aviation.