Over the past months, the consortium has worked collaboratively to define the specifications for the technological innovations to be developed within the project and the plan for the validation tests of these technologies. This collaborative spirit was exemplified during the workshop hosted at Nexans facilities in Halden (Norway), where experts from the consortium shared knowledge and aligned perspectives in this sense.

The specification process has been structured into several phases:

• Prototype design specifications:
  Definition of key materials, norms, restrictions, cross-sectional areas, and operational temperatures for the new HVDC cable systems, including eco-design and environmental considerations.
• Predictive models and algorithms:
  Specification of predictive models and algorithms to improve the understanding of HVDC cable systems’ performance, ageing, and reliability. This phase aimed to define robust frameworks and input/output parameters to ensure accurate performance predictions under varying operational scenarios.
• Advanced monitoring and fault location systems:
  Definition of requirements and design specifications to monitor at least 125 km of fibre length in 525kV HVDC cables and ensure accurate fault detection using fibre optic-based sensors.
• Validation frameworks:
  Development of the plan for laboratory tests, field trials, and operational procedures, setting Key Performance Indicators (KPIs) to evaluate the monitoring systems’ effectiveness.