I paid a premium for that cooper wire. Here in the Northeast they went with aluminum for most house service panel hookups. It’s almost criminal.
-SB
From the pole to the weatherhead that is standard, probably everywhere. With copper at $4 a pound aluminum may again become standard from the weatherhead through the meter base to the main breaker - unless the customer specifies copper.
There was a period of time in the 70s where there was a shortage of copper, so they used aluminum for interior wiring of homes. Now, aluminum is a conductor, and it can be used, but there are careful steps that need to be taken to ensure proper connections because there is a major issue with dis-similar metals, heating/cooling expansion/contraction, and such that requires special connections. Most electricians at the time weren't really well trained in such changes, and thus, we had a TON of corroded and eroded connection points both in the main breaker boxes and in junction boxes within the walls and ceilings of house where the connection would become poor, overheat, and either fail or cause a fire.
Our company, at the time, always used copper for the service entrance conductors and underground leads to customers' homes. We did use aluminum extensively for overhead wire because of its weight advantage, usually with strands of steel in the core for tensile strength. Most of your overhead wiring is aluminum with a steel core because in terms of economics, it is far superior to copper. Yes, you need larger conductors to carry the same current, but it is still cheaper for the wire and much cheaper for the structures/poles to carry the physical load of large aluminum conductors compared to copper.