Submarine ac cables have been installed for voltages up to 500 kV.
A 400 kV double circuit submarine cables link, 42 km long, 2 x 1000 MW, has been in service between Sicily and Italy for about 10 years. A total of 1032 Mvar of shunt reactors are installed for reactive power compensation.
A shorter link, about 5 km long, also at 400 kV, has been in service since 1985.
Three core 400 kV cables have also bene manufactured and installed in Scandinavia.
At 345 kV, it should be possible to attain about 90-100 km using single core cables.
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