[anovikov]

No. We are using AC because it is much easier to convert voltages with AC (by using a transformer) than with DC. Generator can't give very high voltage, it is in the range of a few kilovolts, but that voltage can't be efficiently transported over long distances due to heat losses (yes avoidable with superconductivity), and super high (100s of kilovolts) voltage can't be used by consumers, so when delivered, it has to be driven down to 100s of volts (in a few stages).

Superconductivity will change all of that (maybe in a 100 years or so since existing power infrastructure is worth hundreds of billions if not trillions and is a pain to replace).

[andrewflnr]

Ok, so we only use AC because it lets us use more efficient voltages. I think we understand each other.

[AnIrishDuck]

Also, tying back into what you said about efficiency: AC power can be much more efficient due to this easy transformation. The power dissipated across a resistor (which is a reasonably good model for power lines) is directly proportional to the square of the current passing through it. Thus, by stepping power up to high voltages, you can drastically cut the current and hence resistive losses in the line.

[bencpeters]

...but this whole thread was prefaced on room temperature superconductors. Hypothetically at least, this high voltage advantage wouldn't matter if you could have 0 transmission losses with DC at low voltages.

[bathat]

The point anovikov was making is that AC is not intrinsically more efficient. In fact, it is less efficient over very long distances dues to radiative losses. We don't use AC because it lets us use more efficient voltages today. We use AC because 100 years ago we didn't have the technology to boost direct current to high voltages.

[andrewflnr]

OK, so if we had been able to just blast DC down the lines at 100kV or whatever, that would have been better?