# Prysmian Certifies 525 kV Extruded Subsea HVDC Cable Systems to 90°C, Elevating Bipole Transmission Capacity to 2.5 GW

> Prysmian has completed full CIGRE and IEC type-qualification tests on its next-generation ±525 kV extruded XLPE submarine HVDC cable system at an elevated conductor operating temperature of 90°C, expanding transmission capacity from 2.0 GW to 2.5 GW per bipole.

- **Publish Date:** 2026-09-20
- **Category:** transmission-substations
- **Reading Time:** 5 min
- **Original Source Citation:** [Prysmian Group Technology & Innovation Division](https://www.prysmiangroup.com/en/media/press-releases/525kv-hvdc-cable-90c-qualification-milestone-september-2026)
- **Tags:** Prysmian, HVDC Cable, 525 kV, Subsea Interconnector, Transmission Capacity, Cross-Linked Polyethylene
- **Canonical URL:** https://voltformer.com/news/prysmian-certifies-525kv-subsea-hvdc-cable-90c-2500mw-throughput
- **Markdown Source:** https://voltformer.com/news/prysmian-certifies-525kv-subsea-hvdc-cable-90c-2500mw-throughput.md

## A 25% Increase in Power Throughput Without Seabed Expansion

Traditional extruded HVDC subsea cables operate with maximum conductor thermal limits of 70°C to avoid premature dielectric space-charge accumulation and insulation degradation.

By synthesizing an advanced proprietary cross-linked polyethylene (XLPE) compound and high-conductivity copper conductors, Prysmian successfully validated 90°C continuous operation, unlocking 2,500 MW throughput on a standard 525 kV bipole link.

## Transforming North Sea and Mediterranean Grid Architectures

The qualification delivers immediate benefits to European TSOs developing 2 GW standardized offshore grid hubs, allowing existing seabed cable corridors to transmit an additional 500 MW of renewable power without widening environmental rights-of-way.

Commercial manufacturing will commence across Prysmian’s specialized submarine plants in Arco Felice (Italy) and Pikkala (Finland) for upcoming trans-European subsea interconnectors.

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