Many classical HVDC transmissions use overhead lines. In most cases, this is in connection with long distance transmission (approx. 600 km or more) of very high power from a remote generating power station. HVDC is used in this application mainly since the cost is lower than for an AC transmission; a line for DC needs only two main conductors, while an AC line needs three. And the losses are lower! But the HVDC converter stations cost more than the AC terminal stations so a certain distance is required to make this use of HVDC economical.
The figure above compares two 3,000 MW HVDC lines for the Three Gorges - Shanghai transmission, China, to five 500 kV AC lines that would have been needed if AC transmission had been selected. It is obvious that much land that is saved by the use of HVDC.
Long distance HVDC applications using overhead lines are found in e.g. USA, Canada, Brazil, China and India.
AC and DC overhead lines in China.