>This seems to be trying to say that we can't make aluminum without copper, but that seems nonsensical.
The far better argument is that, if it were simple to replace copper with aluminum, this would create a ceiling on the price of copper. However, this hasn't happened. Many applications of copper can theoretically be replaced by copper, but in practice the reactivity and thermal performance issues of aluminum can be challenging. Aluminum wiring in homes, for example, has a very bad reputation.
This isn't fatal, but it is a problem. And if society doesn't plan for it, it could become a more painful problem.
> Aluminum wiring in homes, for example, has a very bad reputation.
It has an undeserved bad reputation now, but it deserved the bad rep back in the 60s and 70s. The problem wasn’t solely the aluminum conductors themselves, it was also the terminals on wiring devices. The material the terminals and screws were made out of worked fine with copper, but the thermal expansion profile did not work well with aluminum conductors. That caused arcing and fires, so the wiring device manufacturers figured out a material that works well with both copper and aluminum for wiring device terminations. Wire manufacturers also made changes to ensure better terminations. If you look at the terminals of a light switch or receptacle, it will say Cu/Al on it, signifying it is suitable for use with either type of conductor.
This was solved 50 years ago, it’s similar to being scared of flying on a modern jetliner
because the De Havilland Comet ripped itself apart in the 1950s due to the engineers not understanding the stresses from repeat pressurization cycles.
For existing installations of pre-1972 wire, you can buy splicing devices (similar to a WAGO lever nut) that connect to the aluminum conductors inside the box and allow you to connect a copper pigtail to the wiring device, you also have to use an anti-oxidant grease to prevent oxidation.
That being said, I’d still wire a house with copper because you can use #14 Cu for a 15A circuit but you need #12 Al for the same circuit, the NEC does not allow use of #14 Al romex.
> In North American residential construction, aluminum wire was used for wiring entire houses for a short time from the 1960s to the mid-1970s during a period of high copper prices. Electrical devices (outlets, switches, lighting, fans, etc.) at the time were not designed with the particular properties of the aluminum wire being used in mind, and there were some issues related to the properties of the wire itself, making the installations with aluminum wire much more susceptible to problems. Revised manufacturing standards for both the wire and the devices were developed to reduce the problems. Existing homes with this older aluminum wiring used in branch circuits present a potential fire hazard.
I live in a home built after 2000 that had aluminum wires run to its heat pump. A few years back coolant leak from the heat pump lead to huge electric usage before the aluminum wiring lit on fire and shorted itself out. Since repaired, but was told at the time original installer didn't correctly do the aluminum grease on the exposed wire parts.
That said I think the wiring there is still thick aluminum.
Not sure I really have a point - all things equal I'd prefer copper, but it seems like aluminum can be fine when done right too - just riskier when done to the quick and dirty homebuilder standard.
The far better argument is that, if it were simple to replace copper with aluminum, this would create a ceiling on the price of copper. However, this hasn't happened. Many applications of copper can theoretically be replaced by copper, but in practice the reactivity and thermal performance issues of aluminum can be challenging. Aluminum wiring in homes, for example, has a very bad reputation.
This isn't fatal, but it is a problem. And if society doesn't plan for it, it could become a more painful problem.