“Piemonte-Savoia” HVDC Electrical Interconnection

Engineering and execution of works for the design of the “Piedmont-Savoy” electrical interconnection between Italy and France.

The HVDC underground connecting cable project, also known as the “Piedmont-Savoy” interconnection, will have a strategic role in increasing electrical supplies and will allow for energy exchanges between Italy and France up to 1200 MW. It also represents an important new step towards creating a single European electricity market. When fully operational, this new electricity interconnection will increase the transmission capacity between the two countries, from the current 2650 MW to 4400 MW, an increase of over 60%.

This turnkey project consists of a direct current high voltage underground cable system (± 320 kV HVDC) with extruded material insulation technology. The project consists of the engineering, production and installation of two 600 MW bipole circuits covering a distance of 190 km between the substations at Piossasco, near Turin (Italy) and Grand’Ile in Savoy (France) for a total of approximately 95 km on each side of the border. The Italian line shall commence at the Piossasco power station in the province of Turin, until the State border at the Frejus safety tunnel.

Most of the line extends for approximately 73 km along the A32 motorway which is part of the Frejus Safety Tunnel, 13 km long in total, approximately 6.5 km of which is in Italian territory. The remaining 22 km runs alongside provincial roads (SP 589), municipal roads and agricultural land.

There are numerous artefacts along the route, mostly related to the motorway as well as various galleries, the latter dedicated to the link.

System testing is scheduled for 2019. The total length of the link represents a world record for HVDC underground cable interconnections using extruded material insulation technology.