[ggm]

No, you don't need superconductors. HVDC works fine, and minimises transmission losses to an acceptable level for long distance transfer of power.

[justinclift]

For reference:

  HVDC transmission losses are quoted at 3.5% per 1,000 km (620 mi), about 50% less than
  AC (6.7%) lines at the same voltage.

https://en.wikipedia.org/wiki/High-voltage_direct_current#Co...