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The proposed route for the town of Salivoli in Piombino (Livorno)
Mappa Toscana


  • New path
  • Existing path
  • Marine path
  • Possible alternative
  • Transition station
The area identified for the construction of the Suvereto conversion station (Livorno)
Mappa Suvereto


  • Delimitation of TERNA areas
  • Delimitation of TERNA areas (Not fenced)
  • Cable power lines for connection to the 380kV section
  • Existing 200kV power lines
  • Aree di intervento
    (Nuova Stazione HVDC SACOI 3 e opere connesse)
  • Access road to the new Conversion Station
Scarica qui la mappa con la versione precedente del tracciato.
Path of the terrestrial power line cables in the locality "La Torraccia" in San Vincenzo (Livorno)
Mappa Toscana 2


  • Existing overhead power lines
  • Terrestrial power line for connection to the existing aerial / cable transition support
  • Marine power line for connection to the submarine cathode system
  • Support for the existing air / cable transition of the power line
  • Presumed location of the earth-sea joints
New route proposed for Santa Teresa Gallura
Mappa Santa Teresa di Gallura


  •   Overhead Cable Transition Area (Marmorata Scenario)
  •   Marmorata landing (Drilling)
  • Existing cable duct (Rena Bianca)
  • Existing overhead lines (SACOI)
  • Marmorata underground cable route
  • Marmorata underground cable route (SS By-pass)
  • Possible route for one of the pole cables
Go here to download the map of the previous route .
The area chosen for the construction of the new HVDC station in Codrongianos
Mappa Codrongianos


  • Delimitation of TERNA Areas
  • Delimitation of Enel Production Areas
  • Overhead power lines for connection to the 380 kV section
  • Existing 200 kV power lines
  • 200 kV Connecting Route
  • Available Area for Extending 380 kV Section
  • New Area for HVDC SACOI 3 Station
  • Access road to the new Conversion Station
  • Survey Area with Georadar (800m x 0.5m)

Click on the locations to find out more about our interventions.

The events

Terna incontra Tuscany and Sardinia: the two regions involved in the important project to improve the efficiency and cost-effectiveness of the Italian electricity system: Sa.Co.I 3. On 25 September 2018 the process of consultation with the Italian territories was started, giving residents from these two regions the chance to inform themselves about the forthcoming changes. A series of informative meetings were held with the communities involved before the authorisation process began; the “Terna Meets” events were scheduled, one for each of the Municipalities involved in the project: in Tuscany on 25/09/2018 in San Vincenzo, on 26/09/2018 in Suvereto and on 27/09/2018 in Piombino; in Sardinia on 02/10/2018 in Codrongianos and on 03/10/2018 in Santa Teresa Gallura. During the meetings, residents were able to attend dedicated sessions to find out more information about the project, request clarifications and submit their own comments. After considering the requests of local stakeholders, Terna has presented two different project options during the local council meetings in Santa Teresa Gallura on 26/10/2018. Terna confirmed its full willingness to continue the dialogue with citizens to develop a shared plan which will make the area's electricity system safe and reliable. With this in mind, in Santa Teresa Gallura on 22/11/2018, the second “Terna Meets” event was held to present to citizens about the shifting of the landing point from “Rena Bianca” beach to “La Marmorata” beach: thus it would be possible to remove 15 pylons from the current overhead line (around 4 kilometres in all).
As with the previous case, further studies were carried out in the Municipality of Suvereto; during public consultation phase, Terna presented the works planned within the municipal area, which provide for the construction of a new conversion station at Suvereto, built in an area bordering the existing electrical substation owned by Terna.
The location presented by Terna for the conversion station received several comments from the local community; in particular, Terna was asked to reduce the land consumption needed for the station area. Having collected the requests of the local communities, Terna presented a new project solution with no additional land consumption, which places the construction of the new conversion station within the existing perimeter of the station area, which in turn will be featured in a reorganisation plan for the internal spaces. Terna presented the new project solution to the residents of Suvereto during a "Terna Meets" event on 22/03/2019.

What happens next
After listening to the public and agreeing with their suggestions, Terna has made public the observations and answers received. This material is part of the planning and environmental documentation for launching the authorisation process. Click here to download the document (Italian version only) >
Why is the connection important?

The direct current 200 kV electrical connection currently in use between Sardinia, Corsica and the Italian mainland, known as Sa.Co.I 2, was installed in the 1960s and is now obsolete. It is therefore essential to implement a project to optimise and update the system with the new connection, otherwise it will no longer be possible to guarantee adequate levels of reliability for the electricity grid in Sardinia, transfer capacity between the Centre-North and Sardinia will be reduced and Corsica will cease to receive the necessary coverage to meet its demands. To prevent these risks, the Sa.Co.I 3 project has been proposed. Designed to have a low environmental impact, the project will be implemented using the current infrastructure of the Sa.Co.I 2 connection, modernising the conversion stations and laying new overland and undersea cables. The project will enable a total transfer capacity of up to 400 MW.

The project

New cables will be laid alongside the current cables, avoiding additional land use. The new conversion station at Codrongianos will be located next to the existing one; however as far as Suvereto is concerned, the station will be located in the current substation area. The overhead lines of the current Sa.Co.I 2 connection will remain unchanged as they already offer the transfer capacity required by the connection. Moreover, the Corsican grid operator, EDF, has requested an increase in energy withdrawal at the Lucciana substation in Corsica, which therefore also requires the optimisation of its transfer capacity. The Sa.Co.I 3 connection, which is one of the Projects of Common Interest identified by the European Commission, will be implemented using direct current transmission technology, generating an electrical and static magnetic field which does not pose health risks for residents.

The project envisages the installation of two undersea cables between Corsica and the Italian mainland, landing in Salivoli, Municipality of Piombino, two overland cables corresponding to the landing point for the undersea cables in Salivoli and the relative transition point from cable to aerial line, and one alternating/direct current conversion station in the vicinity of the existing electrical substation in Suvereto and its relative connections.

In detail, the project envisages the construction of an alternating/direct current conversion station located in the vicinity of the existing electrical substation in Codrongianos and the relative cable connections to the existing substation, two overland cables corresponding to the landing point of the undersea cables in Santa Teresa di Gallura and the relative transition point from cable to aerial line, and two undersea connection cables between Sardinia (Santa Teresa di Gallura landing point) and Corsica.

The benefits

The Sa.Co.I 3 connection will generate a wealth of benefits for the Italian electricity system, including a reduction in grid losses, a reduction in the risk of energy not supplied, a greater integration of renewable sources and a reduction in market costs of dispatching services. Furthermore, with this project Italy will contribute to the completion of the European Electricity Market, strengthening its role as the natural energy hub in the Mediterranean.


For more information, email

Did you know?

In December 1966, the electricity line that connects Sardinia to Tuscany passing through Corsica was turned on for the first time. It was 413 km long (121 km undersea cable and 292 km overhead line), and after half a century it continues to represent an electrical bridge from the island to the continent.
The decision to construct such a powerful line was to export the production of hydrothermal electrical energy in excess of the island’s needs from Sardinia to Italy. Until 1987 the Sa.Co.I connection was bi-terminal and was used exclusively to transmit energy from Sardinia to Tuscany, using Corsica as a physical bridge for the transfer.
Following the agreement with EDF, a conversion terminal was constructed in Lucciana near Bastia, which enabled Corsica to use part of the energy transferred by the connection.
The Sa.Co.I thus became the world’s first high-voltage direct-current three-terminal connection, and was renamed Sa.Co.I 1. After the construction of the Lucciana substation in Corsica, the decision was taken to rebuild the conversion stations built in the 1960s. Two new substations were constructed, one in the original site of Codrongianos and the other in Suvereto, in the province of Livorno. The new connection, named Sa.Co.I. 2, entered into service in 1992 and used the same overhead power lines and cables as the 1966 system.