Superconductivity: Powering tomorrow’s rail and data infrastructure

Managing extreme loads and power demands

Railways face peak service times; data centers wrestle with intensive computing loads. Both require robust load balancing, real-time energy management, and power quality control.

High-Temperature Superconducting (HTS) cables meet these demands through exceptional transmission capabilities. They’re up to 10 times more compact than conventional cables, reducing land use and installation costs while eliminating energy losses entirely.

A single superconducting cable delivers over 2GW in AC and more than 3GW in DC, using a trench just 0.5 meters wide. This space-saving design proves invaluable in urban environments where land acquisition poses challenges. A 15kV AC HTS cable can transmit over 100 MVA at distribution levels—a significant market advantage.

Inside data halls, superconducting high-current low-voltage cables reduce required space by 24 times compared to conventional solutions. This ultra-compact design delivers ultra-high current density, virtually zero transmission loss, and dramatically cuts the overall footprint.

Ensuring reliability and redundancy

Continuous operation is non-negotiable for both sectors—downtime means delays, data loss, system failures, and safety risks. AI data centers demand “five nines” availability (99.999% uptime), while railways require similar redundancy to ensure 100% on-time departures and arrivals.

Superconducting cable systems include complete redundancy in both the High-Temperature Superconducting (HTS) cable and cryo-cooling system. Maintaining balanced loads ensures system redundancy, supporting the highest operational reliability standards. Superconducting fault current limiters (SFCLs) add critical protection by automatically limiting overload currents without disrupting service. This safeguards transformers and circuit breakers while enhancing grid stability, power quality, and overall reliability.

Solving power conversion challenges

Superconducting DC cables eliminate unnecessary conversions between renewable sources and end applications, avoiding the complexity and losses of traditional power electronics.

Yet, both sectors depend heavily on power electronics, typically involving AC-to-DC conversion through inverters or converters. Harmonics and filtering prove critical for maintaining power quality. Furthermore, superconducting cables produce no electromagnetic fields—a safe, trouble-free solution that avoids potential interference.

Optimizing cooling and thermal management

Cooling operations for traction electronics, substations, servers, batteries, and UPS systems present ongoing challenges in reducing power consumption and achieving higher performance standards.

Superconducting cables don’t emit heat. Compared to conventional resistive cables, they’re more compact and generate no heat, eliminating the need for additional HVAC cooling while reducing associated electrical load and CO₂ emissions, and thereby preventing overheating and minimising energy waste.

Unlocking renewable energy integration

Renewable energy integration has driven investment for years, increasing solar and wind use at stations, depots, and data centers—often with on-site solar and Battery Energy Storage Systems (BESS). Smart grid interaction, including demand response, load shifting, and peak shaving, is becoming standard.

Superconductivity acts as a game-changer for renewable integration. The HTS-DC pairing solves the renewable energy paradox: we can generate clean power, but struggle to deliver it efficiently where needed. Solar farms and wind turbines often sit far from cities, and every kilowatt lost during transmission means burning more fossil fuels to compensate.

Superconducting DC cables transport very large currents at low voltages over several kilometers with no voltage drop—ideal for connecting remote renewable sources to high-demand urban applications.

This capability enables fully carbon-free, modular energy solutions through Uninterrupted Power Plants (UPPs): modular microgrids integrating HTS low-voltage DC loops for maximum reliability and seamless off-grid operation. Both rail networks and data centers can operate on dedicated renewable microgrids, eliminating fossil fuel backup and achieving true carbon neutrality.

Superconducting cables transmit DC power with zero loss, making them ideal for solar panels operating at 1500V DC. They guarantee full power delivery, maximizing efficiency for rail tracks or data halls, and suit BESS systems where DC is transmitted efficiently using HTS cables.

Optimizing energy consumption

Increasing public and regulatory pressure to lower down energy consumption and carbon emission forces industries to transform and define upgraded electrical systems including

• Smart energy optimization including Alternative current and Direct Current electrical distribution
• Digital twins for simulation and energy modeling including the adoption of Innovative Grid Technologies (IGTs) – Superconductivity is part of those new technologies that are supporting the modernization of the grid.
• Modular design for energy scaling and fault isolation – the sFCL (superconducting Fault Current Limiters) are more and more considered as a way to reach the unmanned operation for sub-stations. No dependence on human factor in case of fault and the best protection for electrical equipment forming part of the substation.

Railway revolution in action

SNCF Réseau’s pioneering installation at Paris’ Montparnasse station demonstrates concrete benefits: higher capacity, reduced losses, and more efficient energy use.

The HTS cable was designed to fit existing ducts while delivering zero-loss, zero-environmental impact operation with no complex permitting. Built to handle fluctuating loads without service interruptions, the system represents a world first—withstanding fault currents up to 40 kA in just 200 milliseconds.

Data center revolution

AI workloads are transforming data centers from “server warehouses” into power-hungry, ultra-complex infrastructure hubs—now comparable to power plants in energy demand. AI racks consume 30-100+ kW each, with some hitting 120+ kW. Whole facilities are planned at 500 MW to 1 GW+—a city’s worth of electricity.

The superconducting approach delivers ultra-high current density, virtually zero transmission loss, and a dramatically smaller footprint than conventional cabling solutions. This presents significant advantages for data center applications in terms of energy consumption and operating costs. Compactness allows for reduced civil works and more efficient project execution, entailing enhanced profitability—earlier facility operation generates faster return on investment.

Several stakeholders are incorporating superconducting systems into feasibility studies. Microgrids using superconductivity are increasingly implemented to achieve greater independence from grid operators and potentially shorten project timelines.

Direct solar integration proves ideal: PV panels produce hundreds of renewable MW at 1500V DC. Superconducting microgrids designed with HTS cables rated for 10 kA at 1500V ensure continuous, off-grid renewable energy power transfer of 30 MW to power data centers. When paired with renewable generation and energy storage in hybrid microgrids, HTS technology enables data centers to operate continuously, sustainably, and independently of the main grid.

The infrastructure revolution ahead

Superconductivity is redefining two of society’s most critical industries by delivering resilience, efficiency, and large-scale sustainability. By replacing copper with direct current superconducting cables, rail networks and data centers gain higher capacity, lower energy losses, resource conservation, emission-free transmission, and improved safety—all in a compact footprint.

This transformation extends beyond individual sectors, creating the backbone for an entirely electrified, sustainable energy system where renewable generation, efficient transmission, and high-demand applications work in seamless integration. Leading companies like Nexans are developing end-to-end solutions supporting the rollout of this scalable, future-proof architecture powering our transition to a fully electrified, sustainable future.