Cable monitoring ‘a potential operational risk’ for floating windfarms

The report says the cable components most exposed to mechanical failure are outer cable sheaths and integrated optical fibre. Dynamic cables also present a potential operational risk for floating offshore wind assets and, given the increased cyclic load conditions and higher mechanical stresses for dynamic cable sections, mechanically induced failure is a key risk factor. Hence, says the Carbon Trust, “there is clear demand for condition monitoring across many stakeholder groups… but few cable condition monitoring technologies have been demonstrated in the field.”

The authors of the report say addressing technology barriers in the early stages of development will be crucial to derisk dynamic cable condition monitoring technologies and ensure a clear route to adoption. They identified several ‘knowledge gaps’ and technical and commercial barriers to the deployment of dynamic cable condition monitoring generally, that are not specific to any single technology solution, including a general lack of awareness of and confidence in possible condition monitoring technologies. 

There is, they say, a lack of confidence in the business case for condition monitoring and applications and systems, and a lack of knowledge sharing, collaboration, common language and metrics across the industry has led to prolonged delivery of prototype solutions, a general lack of consistency with design and solutions, and a repetition of mistakes.

In addition, say the authors of the report, there is a lack of clear translation of technical data and analysis to meaningful insights and recommendations; a lack of certainty on data storage approaches suitable for vast quantities of data recorded through long-term condition monitoring; and feasibility of developing software to interrogate the monitoring data and provide the analysis; and a lack of availability of operational windfarms with the capacity to deploy both a new technology and an established survey method for demonstration and validation.

“Many of these industrywide barriers… need to be addressed upfront, otherwise there is a risk solutions are developed without clear routes to adoption and/or with limited usefulness in deployment,” the report states. “Collaboration across the supply chain is essential to increase the technology readiness level of condition monitoring technology… and with no single technology yet mature and proven, and each having varying strengths and weaknesses, it is necessary to continue supporting the development of multiple solutions.

“Given the necessity for testing, from laboratory scale through to trial deployment in the field, there is a significant risk the development of all technologies will be delayed if suitable facilities and demonstrator projects are not established quickly enough. To enhance system development, it is worth exploring the potential for combined prototype testing of multiple technologies… and there is further potential for combined solutions and integration in the cable manufacturing process, requiring collaboration between monitoring equipment suppliers and cable manufacturers.

“Addressing technology barriers in the early stages of development will be crucial to derisk dynamic cable condition monitoring technology and ensure a clear route to adoption. Collaboration across the supply chain is essential,” the report authors conclude, noting operational costs associated with continuous monitoring of offshore wind infrastructure “are routinely underestimated.”