Innovative self-healing fluid-filled power cables that can minimise environmental impact and increase efficiencies could save our network up to £20m over the next five years.

Fluid-filled cables were deployed across 8,000km of the UK’s electricity network in the 1960s and 70s. The fluid forms a key part of the cables’ insulation, prevents the formation of voids and aids the transfer of heat away from the conductor, enabling the cable to run more efficiently. However, overtime these fluid-filled cables can leak and impact the surrounding environment.

The Fluid Cable Care project has found that adding a mixture including tung oil and metal soaps to the liquid enabled it to form a strong, cohesive mass or self-healing fluid (SHF) when exposed to air. The SHF functions much like blood when it forms a scab around a wound, and therefore prevents leaks and protects the surrounding environment.

The project was managed by the Energy Innovation Centre and saw Northern Powergrid carry out research in partnership with system developer Gnosys.

Iain Miller,  our Head of Innovation, said: “Self-healing cables have the potential to improve reliability and benefit the local environments. We spotted an urgent need for operators to prevent fluid-filled cable leaks and we are very proud to be the leading backers of this innovative and progressive solution.

“Our findings mean that leaks will be able to fix themselves, reducing environmental impact and allowing operators to spend resources on activities other than cable repair and replacement. This ultimately means a better deal for customers, the environment and the public alike. We are confident that this solution will soon be business as usual across our fluid-filled cables.”

We have approximately 930km of fluid-filled cables at highly important parts of our network, including 33, 66 and 132kV. We plan to start rolling out this new self-healing cable fluid out across these sections of the network later this year.

The Fluid Cable Care project has completed stage 4 of the research process, demonstrating the suitability of the new fluid-filled cables for commercial, large-scale deployment. The trials demonstrated the capabilities of the SHF in batches of 50 litres. This summer we will undertake real-world deployments of up to 20,000 litres.