NKT has qualified a 525 kV HVDC extruded XLPE subsea power cable system for continuous operation with a conductor temperature of up to 90 °C, marking a significant advancement in the company’s development of its next-generation high-voltage cable technology. The fully qualified cable system gives transmission operators greater flexibility in how HVDC cable systems are designed and operated. Depending on project requirements, the higher temperature capability can be used to support higher transmission capacity, reduce material consumption, and optimise overall system efficiency.

– This qualification marks the next step in our continuous development of HVDC cable technology. The higher temperature capability increases the power transmission capacity while giving customers greater flexibility in how they design and optimise their cable systems. With this advancement, we can help our customers increase transmission capacity with cost-efficient solutions that can be deployed within existing HVDC infrastructure, says Anders Jensen, Chief Technology Officer in NKT.

The new power cable system strengthens NKT’s position as a technology leader and supports the growing demand for efficient, reliable, and high-performing HVDC systems for offshore wind, hybrid interconnectors, and future cross-continent transmission lines.

The increased operating temperature is based on NKT’s market-leading technology platform and enabled by an upgrade of the insulation system. The inner and outer semiconductive layers have been redesigned using a new material developed and qualified in a joint project between NKT and material partner Borouge International. This enhancement forms the core of the improved thermal performance of the cable system and supports the long-term reliability and robustness required for critical transmission infrastructure.

– As a global technology leader in advanced polymer solutions for extruded cable systems, Borouge International brings a strong track record in power transmission infrastructure, as well as extensive innovation capabilities and deep technical expertise. The qualification of Borlink^™ LE0650DC, our new semiconductive material developed as part of our long-term collaboration with NKT, marks another important milestone in advancing HVDC cable technology, says Bart Verheule, Vice President Marketing, Energy, Borealis, now Borouge International.

NKT’s new 90 °C technology portfolio includes power cables with voltage levels of up to 525 kV HVDC for both on- and offshore installation as well as power cable accessories.