SAPEI HVDC link

The largest HVDC link in the Mediterranean Sea.

The SAPEI link is the second link from Sardinia to the Italian mainland. Terna - Rete Elettrica Nazionale SpA , awarded the HVDC converter stations, one in Fiume Santo, Sardinia and the other in Latina, on the Italian mainland to ABB in 2006. The HVDC system is a bipole of a total of 1 000 MW, and is an important strategic link to ensure a strong connection of Sardinia, the second largest region in Italy.

Already in the 1960s ABB supplied mercury-arc valves and HVDC control systems to the first HVDC link from Sardinia. This was a 200 MW transmission from Codrongianos on Sardinia to San Dalmazio in Tuscany, south of Florence and was commissioned in 1967. This link runs over the French island Corsica.

The SAPEI HVDC undersea link delivers surplus power from the island of Sardinia to the Italian mainland, and strengthens Italy's power grid near Rome. Italy is today the world’s biggest importer of electrical power, and interconnections like this one can deliver enough electricity for one million homes.

Each pole is rated 500 MW at ±500 kV with 1 000 A as nominal current. The DC cables are laid beneath the Tyrrhenian Sea at depths of up to 1,600 meters.

Main data
Commissioning year:	2011
Power rating:	1 000 MW
No. of poles:	2
AC voltage:	400 kV (both ends)
DC voltage:	±500 kV
Length of DC submarine cables:	2 x 420 km
Length of DC underground cables:	2 x 1 km (Fiume Santo) + 2 x 14 km (Latina)
Main reason for choosing HVDC:	Length of sea cable