Re:The humble USB cable is part of an electrical revolution
by VLM on Tuesday October 22, 2013 @10:34AM
(#6592155)
"power transmission with DC is actually quite a lot more efficient than AC."
And the subject to google for is insulation breakdown and compare the equations relating peak voltage and RMS voltage. Intuitively you need to insulate a high power transmission line to handle the highest voltage it'll ever see at any instant, which and unfortunately the peak voltage is a microscope amount of time at the tiny peak of the sine wave, but the DC equivalent power you can get out of a sine wave is only the much lower RMS voltage, whereas a DC line can carry peak power continuously, so for a given line $100M budgeted toward cable insulation can insulate more power if its sent as DC rather than AC.
And the subject to google for is insulation breakdown and compare the equations relating peak voltage and RMS voltage. Intuitively you need to insulate a high power transmission line to handle the highest voltage it'll ever see at any instant, which and unfortunately the peak voltage is a microscope amount of time at the tiny peak of the sine wave, but the DC equivalent power you can get out of a sine wave is only the much lower RMS voltage, whereas a DC line can carry peak power continuously, so for a given line $100M budgeted toward cable insulation can insulate more power if its sent as DC rather than AC.