With its 750 million euro it is the flagship of Terna’s investments
It connects Sardinia and Lazio 1,600 meters below sea level, the deepest in the world
435 km long, it will have a 1,000 MW. The journey of the first kWh scheduled for mid-2009

By the summer of 2009, the first cable will be completed and by the end of 2010 the second one: 750 million euros of investments, 1,600 meters below sea level, 435 km long (420 km of which in submarine cable), 1,000 megawatts of power. These are the SAPEI’s numbers, the “super electricity line” that will connect Sardinia to the mainland through a double DC 500kV submarine cable.

SA.PE.I. is one of the most important strategic works planned by Terna to strengthen the national electricity system. With its length and power, it will be included in the Guinness book with record-breaking numbers: 1,600 meters in depth: the greatest depth ever reached in the world for a submarine cable. 435 km long (420 km of which in submarine cable): the second longest connection in the world, after the one between the Netherlands and Norway.

Progress of activities

Authorized in only 12 months (also a record), work began in October 2006 after geophysical and geotechnical surveys on the seafloor.
On the basis of the established work schedule, during 2008, 58% of the total investments was implemented. The first of the two submarine cables was laid (435 km, 420 km of which in submarine cable) and the cables on the land were also
laid down.
At the end of November 2008, tension testing was successfully carried out.
Activity is in progress in the two switching stations in Latina and Fiume Santo. Electromechanical assemblies in the first pole of the switching station in Latina were completed; those in the second pole are underway and are being completed.

SAPEI’s project will lead to the following benefits:

• increased safety in Sardinia’s electricity system (the 1,000 MW of the SAPEI correspond to over 50% of the island’s demand);
• possibility of exporting more efficient thermoelectric production toward the mainland (1/3 of power plants is fuelled by coal) and renewable source production, in particular wind-power which is significantly rising;
• opportunity for Sardinia’s electricity operators to participate in the Electricity Market dealings with fewer exchange obligations, guaranteeing at the same time greater flexibility and safety in the system’s operation;
• possibility of implementing the removal of the present 220kV DC connection between Sardinia, Corsica and Italy (SA.CO.I.) scheduled to take place within the next few years, owing to the cable obsolescence after having been in operation for over 40 years.

Obtaining authorization for SAPEI in only one year – a brief amount of time if compared to the 4 years required for the Italy-Greece cable – was possible thanks to an innovative coordination approach that Terna conducted with all the administrations involved. In this way, each technical and environmental aspect was faced in a preliminary phase prior to the project’s implementation. In order to evaluate the effects of the project on the “Santuario dei Cetacei” marine park, in Western Mediterranean, Terna also used the results obtained from successful international experiences such as the Basslink, the DC connection between the state of Victoria in Australia and the island of Tasmania, based on the studies carried out by the Tethys Research Institute that demonstrated that the cables do not produce negative consequences on the marine mammals.

With regard to the environmental aspect, a monitoring plan was conducted on the condition of the
“Posidonia oceanica”, a sea grass representing the most important ecosystem of the Mediterranean
sea. Lastly, TERNA also planned environmental redevelopment initiatives in the Parco del Foglino.
The two cables that form the connection will be manufactured by Prysmian Cable & Systems. The
switching stations on both sides of the Tyrrhenian sea will be built by the ABB group. Civil works will
be implemented by the Association ATI (Associazione Temporanea di Imprese) Pellegrini Acmar.

All Sapei’s numbers

2                    submarine cables, land cables, switching stations
12                  centimeters of cable diameter
22                  meters in height of the switching stations
50                  tons of bollard pull of the cable-laying vessel
70                  technical and environmental regulations
90                  total resources involved in the project
435                km in length (420 km of which in submarine cable) 
500                kV of voltage
1,000             MW of power
1,600             maximum laying depth
5,000             project
7,000             tonnage of the cable-laying vessel
35,000           sq. m. the area of the Latina station
48,000           sq. m the area of the Fiumesanto station (SS)
50,000           cubic meters of land removed
750,000,000  investments in euro planned