alt Hacker News> First, no, power can be delivered by wires made out of aluminum and indeed, it often is, I don't think that much of the transmission grid is copper
Seconded, aluminum works just fine as a conductor. I’m pretty sure that all overhead utility distribution conductors are a steel core wrapped with aluminum conductors and air for insulation, and I’d bet that underground distribution conductors are also aluminum.
SER cable from the utility transformer secondary to your meter socket also uses aluminum conductors.
You usually need to go up a couple of sizes for aluminum vs copper (#1/0 Cu ~= #3/0 Al) but it depends on the specific ampacity.
> I’m pretty sure that all overhead utility distribution conductors are a steel core wrapped with aluminum conductors
That's the classical setup, but there's been some innovation. These days there's also stuff like aluminium alloys which don't need steel reinforcement, or aluminium reinforced with carbon fiber.
But indeed, copper is vanishingly rare.