system
Given the following post, respond as if you're commenting on Reddit:
human
Given the Skin Effect, why not make wires hollow?

If I understand Skin Effect correctly, alternating current basically flows along the surface of the conducting material. Given this, I assume the reason we need thicker cables for high ampere currents (such as those found on high tension poles) is so that the current has more surface area to travel along and it would appear that the volume of the conducting material would not be a consideration beyond a point.

Why not make high tension cables hollow since you still get the higher surface area while saving a whole bunch of metal?
gpt
For very thick conductors, we do make them hollow.  But most electrical signals go at 60 hz, which is very low, and so the skin depth is very high.  The skin depth for copper at 60 Hz is about 8 millimeters, so it's not worth making them hollow unless the radius is much greater than that.