HVDC (high voltage direct current) technology is the preferred way to transmit large amounts of energy long distances through submarine and subterranean cables because the cables experience low power losses and the technology permits greater controllability of power flows.
Controllability is one of the key advantages of HVDC as compared to alternating current. This feature allows power on the Atlantic Wind Connection network to be actively controlled and directed to the north, central or south where and when it is most needed.
At the land-based point of interconnection with the terrestrial grid, an onshore converter station converts the power from HVDC back to the appropriate AC voltage and frequency for delivery into the terrestrial grid.
The system is so flexible that when the winds are calm and there is little offshore wind power production, power from conventional generating plants can also be directed to the north, central or south on the offshore network to other land-based points of interconnection where the power is needed. This flexibility helps contribute to a reliable and cost-efficient power transmission network.