Power cables with zero resistance

How far are high-temperature superconducting cables from routine grid use?

High-temperature superconducting cables have run in live grids in Essen, Korea and Shanghai, at distribution voltages of 10 kV to 35 kV, and a 110 kV prototype is in test operation in Munich. These are a few specialised links, and most operating figures come from project partners or suppliers. Routine use would need proof that the whole system, including cooling, is cheaper to run and more reliable than conventional options, and none of the sources reviewed is an independent long-term dataset that shows this.

AI illustration · Illustrative scene, not a photograph of the specific device or experiment.
WHERE WE AREPilots

Close. Early pilots are running in the real world.

Several cables have been in service in real grids, including the Essen link for seven years according to its project page. A 50 kV DC fault-current limiter has been tested in a laboratory. These are a small number of specialised installations, mostly reported by their owners or suppliers. The 110 kV Munich prototype is still in extended test operation, and no full commercial link at transmission scale was found in the sources reviewed, so the stage is pilot rather than scaling.

The tech tree

Everything recorded on Vrulum that this future needs, oldest foundations at the top and the goal at the bottom. Lines show what each step requires.

What it takes: Power cables with zero resistance Unlocked Being researched Locked
  1. 2014Superconducting power cablesPilot and early commercial Unlocked.
  1. 2014Urban cable link in a live grid, EssenDone Unlocked.
  2. 2019Cable in commercial service at 23 kVDone Unlocked.
  3. 2021Kilometre-scale 35 kV cable in ShanghaiDone Unlocked.
  4. 2024110 kV prototype in extended test operation in MunichIn progress Being researched.
  5. 2024Fault-current limiter tested at 50 kV DC in a laboratoryDone Unlocked.
  6. Date not recordedFull 12 km SuperLink cable in commercial useNot started Locked.
  7. Date not recordedIndependent multi-year data on whole-system energy, availability and costNot started Locked.
  1. GoalPower cables with zero resistanceGoalRequires: Superconducting power cables, Urban cable link in a live grid, Essen, Cable in commercial service at 23 kV, Kilometre-scale 35 kV cable in Shanghai, 110 kV prototype in extended test operation in Munich, Fault-current limiter tested at 50 kV DC in a laboratory, Full 12 km SuperLink cable in commercial use, Independent multi-year data on whole-system energy, availability and cost. Locked.

The road so far

4 of 7 steps done, 1 in progress.

  1. Done · 2014Urban cable link in a live grid, Essen

    The AmpaCity project in Essen, Germany, linked two substations about 1 km apart with a single three-phase HTS cable at 10 kV. Nexans reports a rating of 2,300 A and 40 MVA, and says the link was in operation for seven years. The cable length is not stated. [1]

  2. Done · Jul 2019Cable in commercial service at 23 kV

    KEPCO's Shingal and Heungdeok substations, about 1.1 km apart, were linked by a 23 kV, 50 MVA three-phase HTS cable. The trade report, dated September 2021, says the project was completed in July 2019 and was still in service at the time of the report. The installed cable length is not stated in the source. [2]

  3. Done · 22 Dec 2021Kilometre-scale 35 kV cable in Shanghai

    The Xuhui project in Shanghai connected two substations with a 1.2 km cable at 35 kV and 2,200 A design current. The supplier says it entered operation on 22 December 2021. The operating claim is supplier-reported. [3]

  4. In progress · 9 Oct 2024110 kV prototype in extended test operation in Munich

    THEVA reports that a 110 kV HTS prototype was commissioned at the Menzing main substation, Munich, with Stadtwerke München, on 9 October 2024, with a power rating above 500 MW. The supplier says the prototype is being tested in operation to prove its performance and reliability. No installed length is given. [4]

  5. Done · Dec 2024Fault-current limiter tested at 50 kV DC in a laboratory

    SuperGrid Institute tested a resistive superconducting fault-current limiter with a mechanical DC breaker in December 2024, on its DC short-circuit generator platform. The prospective 43 kA peak current was limited to 5.5 kA. The release describes a test platform rather than a live network, and calls the limiter a prototype demonstrator. [5]

  6. Not startedFull 12 km SuperLink cable in commercial use

    The SuperLink project in Munich describes a 12 km superconducting power cable to link a southern load centre with a northern main substation. The 2025 project abstract describes this as envisioned, and says the effects on the wider network must be studied before integration. No commercial installation date is given in the sources reviewed. [6][4]

  7. Not startedIndependent multi-year data on whole-system energy, availability and cost

    The 2026 review in Superconductor Science and Technology says active cooling adds to the cost of a superconducting cable and decides its reliability. The sources reviewed do not include a published, independent, multi-year dataset covering cooling energy, outages, maintenance and lifecycle cost for an operating link. [7]

Why it matters

Superconducting cables can carry large currents in a compact cable. That could matter for adding capacity in crowded cities and data-centre campuses. Whether they become a normal grid option depends on whole-system energy use, reliability and cost at a given site, which are still poorly documented.

What stands in the way

  • Cooling is continuous. Refrigeration, pumping and heat leaking into the cold section use electricity, so the zero resistance of the conductor does not make the whole installation lossless. Sources reviewed give no whole-system energy figure for an operating link.
  • The 2026 review says the maximum cable length is limited without intermediate cooling stations. This matters for the 12 km SuperLink plan and for any long-distance route.
  • Cost is high. KEPCO's Shingal project was expected to cost US$12 million against US$3 million for a conventional option, about four times as much. The trade report says KEPCO identified opportunities to reduce the cost, but gives no figure.
  • The 2026 review says superconducting cables have limited black-start capability.
  • Most operating figures come from project partners or suppliers. Long-term availability and maintenance records are not publicly available in independent form.
  • The 50 kV DC fault-current limiter result comes from a laboratory test on a generator platform, not a live network. Recovery after faults and field reliability have not been shown.

Signals to watch

  • A commercial decision or contract for the 12 km SuperLink cable in Munich, following the 110 kV prototype tests.
  • Published multi-year data on availability, cooling energy and maintenance from the Essen, Korean or Shanghai links.
  • A utility tender for a full commercial HTS link at 110 kV or above in a dense urban network. No such tender was found in the sources reviewed for this record.
  • Cable runs in grid service that use intermediate cooling stations, which would show how the length limit is managed in practice.
  • Field results for fault-current limiters after real faults, including recovery time and maintenance needs.

Sources

  1. company announcement
    AmpaCity: optimizing the German city grid
    Nexans, 2014.
  2. news
    Korea's KEPCO Commercializes Superconducting Transmission Solution
    T&D World, 14 Sept 2021.
  3. company announcement
    Superconducting Electric Power
    Shanghai Superconductor, 2021.
  4. company announcement
    SuperGrid Institute achieves first 50kV DC breaking by combining a superconducting fault current limiter with a circuit breaker
    SuperGrid Institute, 20 Jan 2025.
  5. review article
    Superconducting high-power cables and lines: development status and technology roadmap
    M. Noe, T. Puig, X. Obradors et al.. Superconductor Science and Technology, 2 Feb 2026.

Last reviewed 21 Oct 2026.