GUH: Subsea Cable Failures Threatening Offshore Wind Expansion

UK-based trade body Global Underwater Hub (GUH) is working to tackle failures in underwater cables, which, it says, could derail global offshore wind ambitions.

GUH says that the reliability of subsea cables is “paramount” to the success of offshore wind and the energy transition, but that failure of these cables is all too common, to the point that the cost of insuring them is becoming prohibitive.

GUH chief executive, Neil Gordon, said: "It’s estimated that around 85% of the total value of offshore wind insurance claims relate to subsea cables. Insurers are losing money underwriting cables with the average settlement claim in the region of £ 9 million. Brokers have warned that the high number of cable claims is affecting capacity and coverage and the cost of repairs typically runs into millions, with warranties rarely covering the high cost of business interruption.

“If these critical components become uninsurable, offshore wind projects around the world will be derailed, making global 2050 net zero targets completely unachievable.”

Globally, GUH said, over £620 billion of investment in offshore wind farms is anticipated by 2030 and, for the world to hit net-zero emissions by 2050, the generating capacity from offshore wind must increase by a staggering 1,120 GW. The subsea cable sector for offshore wind has been estimated at £100 billion over the next ten years.

Gordon added: “This scale of expansion and opportunity can only be achieved by installing and maintaining thousands of miles of reliable cables under the seabed. There is an urgent need for a holistic approach to finding solutions which can be implemented as offshore wind increases in scale and technical capability with higher voltages and dynamic elements.”

Subsea Cables Forum

GUH said it has established the Subsea Cables Forum to bring industry together to develop a roadmap for "improving the quality, reliability, and therefore insurability, of cables which is crucial to achieving global offshore wind ambitions, particularly in the nascent floating offshore wind arena."

This will involve the development of a set of industry-led, recognized standards and best practice guidelines, encompassing the life of the cable that would be adopted by developers, suppliers, contractors, warranty surveyors, and others and accepted by insurance bodies.

According to one developer, as cited by GUH, the cost of insuring a 1.2GW offshore wind farm over its lifetime is in the region of £ 350 million and insurance brokers estimate that the costs of floating offshore wind will be 30% higher than fixed bottom ones.

Gordon explained: “With the shift from fixed to floating offshore wind, where the dynamic nature of floating cables is even more challenging, the critical issue of their reliability must be addressed as a matter of urgency.

“It’s clear there are inherent issues affecting the performance and reliability of subsea cables that are within the industry’s control. Failures can stem from any stage in the cable lifecycle – from design to manufacture, handling and installation, through to operation and maintenance.

“Identifying potential weak points throughout the lifecycle of the cable is imperative to ensuring this offshore infrastructure operates robustly and efficiently to bring clean, green renewable energy ashore.

"We need better information sharing and a move away from a siloed approach, that is often ‘secrecy driven’ and ‘NDA heavy’. Introducing shared learning, data logging and increased transparency will create a more open environment for best practice to be developed.”