Hanrahan your sarcasm is unwarranted. Yeah, I know what a thyristor is.
The photo is of part of the HVDC link betwen the N and S islands of NZ, and the monster thyristor stacks are used to convert AC to DC and vice versa.
Ok so as far as voltage goes, yes I should have written that for the same peak voltage, DC can carry more power than AC.
And for long lines, the L/C characteristics of the line can be significant due to resistive line losses. The capcitor has to be charged and discharged though the lines, resulting in loss. This is separate from the losses due to the load current passing though the line.
