Terna, Tyrrhenian link: Nexans begins laying high-voltage subsea cable between Sicily and Sardinia

• The work concerns the western section of the project, which will connect Termini Imerese (Palermo) and Terra Mala (Cagliari)
• For the first time, a  high-voltage direct current (HVDC) subsea cable will be installed to a water depth of 2,150 meters
• The total investment for the Tyrrhenian Link, one of Terna’s three projects included in the REPowerEU program, amounts to approximately €3.7 billion

Rome, September 16, 2025 – Terna, the Italian Transmission System Operator, and Nexans, a global leader in the design and manufacturing of cable systems and services, today started, from Fiumetorto, in the municipality of Termini Imerese (PA), the first installation phase of the Tyrrhenian Link’s western section. Once completed, the connection between Sicily and Sardinia will set a world record for the greatest installation depth of a high-voltage (HVDC) subsea cable, reaching 2,150 meters below sea level and establishing new benchmarks for the electricity transmission.

Terna will invest a total of approximately €3.7 billion in the project, which also includes the eastern section between Sicily and Campania, where installation of the first of the two cables was completed in May.

“The start of laying the western branch between Sicily and Sardinia marks a decisive step for the Tyrrhenian Link, as it represents a milestone of historic significance: for the first time, a high-voltage direct current subsea cable will be installed at a depth of up to 2,150 meters, the deepest ever reached by a high-voltage subsea  cable. This project confirms Terna's ability to adopt design and operational solutions capable of addressing and overcoming unprecedented technical and engineering challenges," stated Giuseppina Di Foggia, CEO and General Manager of Terna. 

"In line with our Industrial Plan, we are moving forward with the construction of the Tyrrhenian Link, a key infrastructure for the national electricity system that benefits from €500 million in funding under REPowerEU. Last May, we completed the first of two cables between Sicily and Campania and we have scheduled the conclusion of the laying of the first cable of the western section at the beginning of next year. It is Terna's responsibility to provide the country with the infrastructure required to achieve the energy transition goals."

From a technical standpoint, the infrastructure consists of two 500 kV high-voltage direct current (HVDC) subsea  cables, totaling approximately 970 km in length, with a transmission capacity of 1,000 MW. Specifically, the laying of the first connection of the western section will be carried out by Nexans in two phases: the first, 200 km long, will be completed in September 2025; the second, around 280 km, will begin in December 2025.

The connection  between Sicily and Sardinia, approved in September 2023 by the Ministry of Environment and Energy Security, will stretch for 480 km between the Fiumetorto landing point (PA) and the Terra Mala landing point (CA). The converter stations will be built in Selargius (CA) – from which an underground cable of approximately 30 km will run to the coastal landing — and in Contrada Caracoli, in the municipality of Termini Imerese (PA), connected to the marine landing point via a roughly 7 km underground route.

In addition to its strategic and technological value, Tyrrhenian Link stands out for its focus on environmental sustainability. In both islands involved in the project, activities have been launched to uproot and replant olive trees located in the areas designated for future converter stations. Moreover, Terna has undertaken measures to protect marine ecosystems at the cable landing points, carrying out transplantation of Posidonia oceanica in Sardinia and Cymodocea nodosa in Sicily, selecting the most suitable areas to promote plant rooting.

Thanks to its transmission capacity, the project will make a significant contribution to achieving the decarbonization targets set out in Italy’s Integrated National Energy and Climate Plan. The high-voltage subsea cable , essential for the security of both the Italian and European electricity grids, will connect the three regions involved, increase exchange capacity, and enhance the capacity and flexibility of the national transmission grid.