UK offshore wind growth hinges on solving subsea cable reliability and insurance hurdles

Globally, more than US$800 billion of investment in offshore wind is anticipated by 2030 and the industry must add roughly 1,120 GW of generating capacity by 2050 for the world to meet net-zero targets. In the UK, government ambitions for offshore wind are similarly expansive: ministers have set targets in the range of 40–50 GW by 2030, and independent projections foresee installed capacity of around 42.7 GW by 2030. According to Energy Global, that national ambition and an extensive project pipeline create a strategic opening for the UK’s subsea power cable supply chain to scale up and capture significant export value.

Subsea cables are the linchpin of both fixed and floating offshore wind farms. As floating wind grows , with its more complex dynamic cable systems , cable manufacturing, installation and maintenance must expand accordingly. Energy Global reports the subsea cable sector for offshore wind could be worth in excess of £100 billion across manufacture and installation over the next decade if the UK succeeds in tripling manufacturing capacity and doubling research and development as proposed in the Offshore Wind Industrial Growth Plan.

Yet the opportunity is shadowed by a persistent and costly problem: cable performance and reliability. Industry trade body Global Underwater Hub (GUH) has identified cable failures as a major barrier, particularly as floating foundations increase exposure to dynamic stress. Energy Global’s reporting cites industry data indicating that some 80% of offshore wind failures relate to the cable system, with repair bills commonly in the £10 million–£40 million range and downtime often extending 40–60 days. Those figures are already influencing risk models and commercial decisions across projects and insurers.

Insurance market strains are acute. At a recent GUH event, insurance experts described subsea cable underwriting as loss-making for many carriers; one attendee noted that 85% of the total value of offshore wind claims relate to subsea cables, while average settlement claims are in the region of £9 million. Brokers told Energy Global that rising claim frequency and magnitude are eroding capacity and increasing premiums, with one developer estimating lifetime insurance costs for a 1.2 GW project at about £350 million. Floating wind, brokers say, can add about 30% to those insurance costs compared with fixed-bottom projects. If certain cable exposures become materially uninsurable, developers and financiers could be forced to defer or cancel schemes, jeopardising wider 2030 and 2050 decarbonisation goals.

The Industrial Growth Plan identifies future electrical systems and cables as priority areas for UK excellence alongside offshore installation and O&M. That strategy is grounded in the country’s track record , large fixed offshore farms, decades of subsea engineering from the oil and gas sector and established port and vessel capabilities , but the plan also recognises material constraints: supply-chain bottlenecks, rising costs and technical challenges around cable design, testing and lifecycle management.

Addressing these constraints requires co-ordinated action across industry and government. Energy Global and related industry commentary point to several levers: accelerating domestic manufacturing capacity to reduce reliance on long supply chains; investing in R&D and testing facilities targeting dynamic cable reliability; developing a skilled workforce for complex offshore operations; and creating procurement and contracting approaches that allocate lifecycle risk more transparently between developers, contractors and insurers. The UK government’s recent moves to procure additional offshore capacity and reform Contracts for Difference arrangements suggest policymakers intend to sustain demand, which could underpin long-term investment in supply-chain scale-up.

Financial engineering and commercial models will also be central. Given the scale of potential repair costs and business-interruption exposure, industry sources argue for new risk-sharing frameworks, extended warranties tied to demonstrable reliability testing, and blended finance to support early-stage manufacturing and repair capability. Energy Global’s reporting underscores that such measures could reduce the tail risks driving insurers away and bring down overall project insurance costs.

Operational improvements are equally important. Better seabed surveying and route planning, more robust cable armouring where appropriate, enhanced monitoring and quicker mobilisation for repairs can all reduce failure frequency and shorten outage durations. Lessons from subsea engineering in oil and gas, coupled with targeted innovation for dynamic cable stressors unique to floating wind, are likely to yield the most immediate gains.

For industrial decarbonisation stakeholders , ports, manufacturers, vessel operators, insurers and grid planners , the message is clear. The UK has a credible demand signal and industrial heritage to lead in subsea cable systems for offshore wind, but realising a potential £100 billion-plus opportunity depends on solving persistent reliability and insurance challenges now constraining investment. According to Energy Global and industry bodies, only by aligning policy, procurement, technology development and risk management can the submarine arteries of the UK’s future power system be made resilient and affordable enough to underpin the country’s 2030 ambitions and the global drive to net zero.