[andromeduck]

3. Skin effect becomes more of a factor. HVDC can use the whole cross section of the wire to carry power whereas AC only uses the surface. At longer distances, the material savings of thinner/lighter wires offset the higher equipmet costsat eitherend.

[sbaiddn]

That's not really a problem because the current caring portion of the cable is an aluminum sheeth (good conductor, but expensive and not as strong) over a steel core (poor conductor but strong)