The UK’s transition to net zero emissions is facing a significant challenge in the transmission of renewable energy from remote generation sites to areas with high demand. A new report, co-authored by researchers from the University of Cambridge and commissioned by the Institute of Physics (IOP), points to high-temperature superconducting (HTS) cables as a potential solution.
HTS cables have ultra-high power density and nearly zero energy losses, allowing for efficient underground transmission of large amounts of electricity without the need for overhead lines. This could help move electricity generated offshore or in remote locations to cities and industries with minimal loss.
“The real attraction of superconducting transmission is that it allows us to carry more electricity, over longer distances, without wasting energy or disrupting the environment,” said Professor Tim Coombs from Cambridge’s Department of Engineering, a co-author of the report.
Traditional aluminium cables can lose between 5% and 10% of transmitted electricity as heat. In the UK, this equates to around 25 terawatt hours lost annually—energy valued at approximately £3.75 billion. HTS cables cooled by liquid nitrogen eliminate electrical resistance and waste, turning these losses into savings.
A single buried HTS cable can replace several conventional lines in terms of capacity, reducing land use and visual impact—particularly important in urban settings where space is limited. This technology could help preserve landscapes while supporting growing renewable power connections.
“Grid bottlenecks sometimes force operators to curtail generation, wasting clean power,” said Coombs. “HTS cables could act as low-loss ‘superhighways’ to move renewable energy exactly where it’s needed. They could also be used to feed the output of large solar farms straight into the grid, without the need for long new transmission lines. HTS makes every unit of clean electricity count — reducing reliance on fossil fuels and easing the need for costly new power stations.”
While initial costs for HTS are higher than those for aluminium alternatives, reduced losses and improved reliability may offset expenses over time.
Coombs’s team has contributed advances in defect-free HTS tape fabrication, cryogenic cooling systems, and methods for integrating HTS into existing grids using both alternating current (HVAC) and direct current (HVDC).
“Cambridge research has always combined fundamental discovery with practical application,” said Coombs. “In superconductivity, that means moving from the lab bench to systems that can really carry the nation’s power.”
International projects have already demonstrated operational superconducting cables in countries such as Germany (AmpaCity), the United States, Japan, and China.
With increasing demand expected due to electrification trends in transport and heating sectors across Britain, researchers warn that swift action is needed if the UK wants to avoid falling behind other nations.
The IOP report calls for major demonstration projects within Britain—a buried HTS link capable of meeting actual grid needs—to establish standards and supply chains necessary for widespread adoption.
“This should be treated as a national priority,” says Coombs. “A field trial on British soil would place us at the forefront of a technology set to grow globally over the next half-century. The benefits are not just environmental — they are industrial and strategic too, helping the UK bridge the gap between promising prototypes and full-scale deployment.”
If successful domestically, British expertise could support international initiatives like a European Supergrid or Asian renewable networks through export opportunities in components such as superconducting cables or cryogenic systems.
For government policymakers aiming at climate targets while managing costs—and for industry seeking efficiency—the adoption of HTS offers advantages ranging from landscape preservation to lower bills.
“Superconducting transmission is not a futuristic dream — it is a practical solution to today’s challenges,” said Coombs. “By investing now, we can secure energy security, lower costs, and ensure the UK leads in a technology the world will soon need.”
Tim Coombs is a Fellow of Magdalene College at Cambridge.