High Voltage Direct Current (HVDC) underground cables have been in commercial use since the 1950’s. Today, HVDC underground cables can carry medium and high power (100 MW up to 1,000 MW) over distances above 50 km.
So far, HVDC transmission has mainly been used in submarine applications, either connecting offshore wind farms to land or transmitting high electrical power over long distance through the sea were overhead lines cannot be used.
Increasingly, HVDC cables are beginning to be used also for on-shore transmission projects. As higher power loads need to be transported over long distances across land, more and more thinking goes into creating HVDC a long distance overlay net, so called “electricity highways”.
HVDC underground cables can safely transport high power loads over long distances with minimal losses. In addition to this transport efficiency, only a limited number of cables are required, hence allowing narrow trenches. HVDC underground cables are compatible with HVDC overhead technology and can be combined in sensitive areas.