I don’t know whether AC or DC would be a better choice if we were starting from scratch now, but both systems were proposed and tried very early in the history of electrical power generation and I’m pretty sure all the obvious arguments on both sides were aired right from the start.
DC wasn’t really a viable option at the start because of the transformer issue you mentioned. The local power lines carry ~100x higher voltage than what you get in your house, and the long distance power lines up to another 100x on top of that. Without that voltage step up, you’d need 100-10,000x as much wire.
Modern semi conductors change the game considerably though. In a lot of areas, the big iron transformers are getting phased out and replaced with switching power supplies, which suggests that it could be economically efficient now, if not for the requirement for a 50 or 60hz sinewave and existing stuff.
A DC based system would have advantages of not requiring rectification on many end uses, give some minor improvement in corona losses in transmission, and would allow for variable speed generators. It would come at the cost of controller-less induction motors and clocks that use the AC signal to keep time. I’m not sure about the cost of doing the voltage step-up/step-down because both methods are still in use. I’m not sure which would be the better choice now, but it is an interesting question.
DC wasn’t really a viable option at the start because of the transformer issue you mentioned. The local power lines carry ~100x higher voltage than what you get in your house, and the long distance power lines up to another 100x on top of that. Without that voltage step up, you’d need 100-10,000x as much wire.
Modern semi conductors change the game considerably though. In a lot of areas, the big iron transformers are getting phased out and replaced with switching power supplies, which suggests that it could be economically efficient now, if not for the requirement for a 50 or 60hz sinewave and existing stuff.
A DC based system would have advantages of not requiring rectification on many end uses, give some minor improvement in corona losses in transmission, and would allow for variable speed generators. It would come at the cost of controller-less induction motors and clocks that use the AC signal to keep time. I’m not sure about the cost of doing the voltage step-up/step-down because both methods are still in use. I’m not sure which would be the better choice now, but it is an interesting question.