Cometa

Project description:

• Manufacture, transport and install a direct current power cable (250 kV, in a 500 MW system) between the Spanish mainland and the Balearic islands of Mallorca, as part of the COMETA project (Conexión Mediterranea de Transporte de Alta tensión) for Red Electrica de Espana.

Customer challenges:

• The new line had to be connected to Spain's 400 kV grid, from Sagunto, north of Valencia on the Spanish mainland, to the west of Mallorca. The line design was supposed to supply other Balearic islands via secondary 132 kV and 33 kV lines, including the planned lines Mallorca-Minorca and Mallorca-Ibiza-Formentera.
• The route chosen for the cable connection had a maximum depth of 1,410 meters, and more than 145 km of the connection were deeper than 800 meters.

Nexans' solutions: Nexans supplied a 240 km high voltage power cable (250 kV - 750 mm² copper core), protected by double galvanized steel armoring in the deepest section of the route. No splices offshore were necessary, because the cable was armored and supplied in a single length. Nexans also supplied 240 km of optical fiber cable (with 24 fibers. The cables were buried in the seabed at a depth of up to 1000 meters in order to protect the cables from external damage. Installation began in fall 2010, and the entire project was completed in November 2011.