>>12141691>transcontinental HVDCthat's an interesting concept.
on most of transmission lines they use aluminum(it has lower weight but higher resistance than copper) instead of copper. the weight difference allows for bigger distance between the towers
one very cool concept is the Ultra HV point-to-point discharge system proposed by tesla with the terminals fixed at high altitue (in rarefied atmophere) this concept does work in principal but it has many problems for example it produces too much wideband EM noise it would contaminate all the radio spectrum, this is similar to a spark gap but on a huge scale, high power spark gap radio are now prohibited for that reason they are only allow it on celebration days related to radio, there's another device that uses "ground conduction" but it also has more or less similar problems of too much EM contamination because it also uses pulses (tunned in the VLF bandand) if you use sine waves this would make it very clean but you loose a lot of the benefits of the wideband pulsed signal (the benefit is that you have much more freedom on the sizes for the receiving antenna, pulsed signals are wideband thats their "nature") the VLF part of the system is need because this range has good ground and water penetration compared to higher frequencies but the fundamental of the VLF needs too large antennas that's were the wideband nature of a pulse comes handy.
