Hacker News Reader

Oh, that is completely not true for commercial AC power transmission -- just look up at a big power pylon and see the multiple power conductors per phase.

See the pretty blue picture: http://en.wikipedia.org/wiki/Skin_effect

Skin effect in copper is about 9mm at 60Hz

View on HN

I assumed that skin depth at 50/60Hz is on the order of 20mm and that 40mm diameter conductor is not entirely practical to install on pylons (or generally in longer lengths than few meters), obviously I was slightly off in that estimate.

That's part of the reason those power lines are steel-cored with copper jackets; the other reason being strength, of course.

They're Aluminium over a steel core, not copper. A copper over steel version would be significantly heavier.

headsmack yes, of course.

Reply on news.ycombinator.com