Engineering360: "UK and Morocco to connect with world’s longest subsea cable"

Wouldn't it be better to make the generators DC and convert to AC at the receiving station? Then, there would be only one conversion loss. Now, there's loses from AC to DC and then, DC to AC.

The insulation requirements on the windings inside the generators would be impossible to achieve if their output was to be at the very high voltage used in the undersea transmission line. The undersea link is long enough that transmission of AC would result in extremely high losses due to capacitive coupling and probable RF (60 or 50Hz) radiation from the cables. Therefore you generate in AC, transform it to very high voltage, rectify it, transport it to the distant users, then invert it back to AC, etc. This approach has been used for decades already, and has efficiencies over 90% (if I remember correctly).

--JMM