DC transmission applications
High-voltage direct current power transmission

• Long underground or submarine links

Very-high-voltage transmission via submarine or underground cables is always a very costly solution, only resorted to when overhead lines prove impossible. This is the case for submarine links (island power supply, connection of an offshore wind farm, interconnection of two networks separated by the sea) and underground links in highly urbanized or protected areas, or where public opinion is opposed to the construction of new overhead transmission structures.

DC transmission significantly reduces cable costs (there are one or two conductors instead of three, voltage withstand is fully exploited, transit capacity is 100% exploited thanks to power flow control...).

Direct current eliminates the problem of reactive power generated by alternating-current...