Prysmian Qualifies 525 kV HVDC Submarine Cables for 90°C Operation

Prysmian has completed testing and announced it is ready to establish a new global standard for HVDC submarine cable systems, qualifying its 525 kV submarine energy cables for operation at an increased temperature of up to 90°C.

The breakthrough is founded on the higher withstand temperature of the cable's plastic insulation while operating, which raises the maximum power transmissible through a single 525 kV link from the current industry standard of around 2 GW to 2.5 GW.

The development allows higher power transfers to be achieved without increasing voltage or the size of converter stations and offshore platforms. This enables more efficient power transmission in multi-terminal grids and hybrid interconnectors that combine long-distance energy transmission with offshore wind generation in a single, better-utilised asset.

The new 525 kV 90°C technology has the capability to transfer energy to power up to 2.5 million homes — an increase of over 500,000 homes compared to the previous generation of 525 kV system technology.

Raul Gil, EVP Transmission at Prysmian, said: "Thanks to this innovation, quite simply, we can make the essential energy projects that modern electricity connections need, more affordable. That should then over time pass into people's wallets as we cut energy bills. And this is not a trick to keep bills down through subsidy, but a real long-term sustainable solution."

Srinivas Siripurapu, Chief R&D, Sustainability and Innovation Officer at Prysmian, added: "This technology is not only a European first but also sets the global standard of what is possible for submarine energy cables."

The qualification was announced from Prysmian's Milan headquarters on 2 March 2026.

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