Pylon conductor upgrades solve many problems

[dan_b]

HVDC over land on Pylons is already a thing - especially in China. The most impressive of them so far is the Zhundong–Wannan line.
It's 3200km long, runs at 1.1million volts and transmits a max capacity of 12GW. China has another 20 or so running at 800kV of between 1000 and 2000km in length between 5-10GW of capacity.

Am I correct in remembering from school that current flows on the outside of conductors? (Although if that was true, how come the choice of metal involved is so important?)

Only at high frequencies, you won't get much skin effect at 50Hz.

Thanks, I have read that... so maybe

the current density is largest near the surface of the conductor and decreases exponentially with greater depths in the conductor. It is caused by opposing eddy currents induced by the changing magnetic field resulting from the alternating current. The electric current flows mainly at the skin of the conductor, between the outer surface and a level called the skin depth.

explains the growing use of HVDC connectors? I guess advances in insulation materials might have changed the game? Shall we see HVDC on pylons?