Why is alternating current used for transmission?
Man, I can’t believe the level of misinformation out there. AC is used for transmission because transformers can step it up to high voltage for long distance, and down to low voltage for local distribution and use. Power is (naively) the product of current and voltage, but resistance losses are proportional to current SQUARED. Stepping up to high voltage cuts the current and thus the losses; even trying to distribute 110 volts for several miles would require wires so heavy you would go broke paying for all the copper. That’s pretty much what Edison’s DC systems did; he had local power stations all over the place, and they used lots and lots of heavy wires; worse, the voltage delivered to the far end of the network was substantially less than near the stations, so customers were paying for more power than they were getting. When Westinghouse got Tesla’s AC system into the market, all it took was changing a tap on a transformer to put the voltage where it ought to be, and the lower losse
