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Indeed.

Aluminum is actually a (far) superior conductor to copper per unit mass. It would be used on transmission lines even if it was the same price as copper, because the towers can be cheaper and farther apart. It's in increasing use in EVs due to the lower mass.

Copper is still used when the conductive density matters, like the windings of an electric motor. But if copper prices increase further, manufacturers will make sacrifices to efficiency and power density in order to save cost. And they'll figure out how to better balance the use of Al vs. Cu, perhaps using Cu only for the conductors closest to the core.

We also use copper for transformers, which are fairy "dumb" in their usual design. Solid-state transformers exist, which use much less copper, but are currently more expensive. They will no longer be more expensive if the price of copper goes up too much. And they'll probably get cheaper in the long run anyway, regardless of copper price, in the same way that switch mode power supplies have totally replaced linear supplies in the consumer space.

I've seen increasing use of copper in fairly mundane uses, like computer heat sinks, that used to be aluminum. The performance is a little better, but it won't be worthwhile if copper gets way more expensive. They'll just go back to aluminum, or use some other innovation (carbon heat spreaders, etc.) if price becomes an issue.

> I've seen increasing use of copper in fairly mundane uses, like computer heat sinks, that used to be aluminum.

Copper heatsinks go in and out of style... Copper heat pipes have stayed en vogue, but typically embedded in aluminum blocks.

I'd suppose the fashion goes somewhat with the price of copper, though I haven't tracked it. The heatsinks themselves have gotten far larger as CPUs and GPUs have gotten more power hungry, not to mention RAM and SSDs. A material that's a good tradeoff at one scale isn't necessarily one at a different scale.

At any rate, one should expect many of these trades to go the way of Al if Cu gets more expensive (which it might not). Not all of them, but we'll probably see a bias towards physically larger systems in cases where space isn't at a premium. And also a bias towards active systems over passive, liquid cooling over air, and so on.

We even use aluminium on "dumb" transformers for power transmission. Dry-type transformers tend to be physically larger because they use air and resin (rather than a tank of oil) to insulate, and so the major downside to aluminium conductors (needing a larger cross-section to carry the same current for the same loss) is no longer a limiting factor performance-wise. In most substations, and extra 20-30% physical size of the transformer is a fine trade-off for cheaper construction.

There has been substantial development in a replacement for all copper wires in the form of CCA - copper clad aluminum conductors.

This product combines the advantages of both materials - low price and mass, stable connection, can be soldered etc. while using a small fraction of copper. It's making inroads into aviation and motor vehicle harnesses, and will probably be the default low cost option for new homes in a few decades.

> Second, all that electricity, even if you generate it with nuclear reactors, have to be delivered via copper wires.

This is indeed a massive red flag. You need conductors, but the material they are made of is pretty much irrelevant.

These days you'd have to search quite a bit to find not-ancient copper conductors in the larger electric grid. Aluminium might have a slightly higher resistance, but when you can just use a thicker wire it's almost always the more attractive choice.

If you don't even know that the grid mostly uses aluminium, you probably shouldn't be making big claims about what is and isn't possible with copper wiring.

You can sometimes see green copper transmission lines, but they're all rather old and becoming far less common

Another red flag vis-a-vie energy source is ignoring hydro electric. High energy consumers and areas with a constant surplus of hydro are a good match. One of the new mega dams on Central Asia was restarted and funded primarily by an aluminium conglomerate - cheap and stable pricing at industrial scales.

This is why one of the two major Aluminum smelters is located in Washington. The economics of using hydropower to run the smelter are really good.

> 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.

Thanks for the additional info, I’m interested in learning more technical details about the electrical grid, like conductor size/ampacity but it’s hard to dig up information about it. I work in commercial construction and the highest voltages I ever deal with are 4160V and sometimes 5kV and 15kV, so I know a bit about medium voltage equipment and conductors but I’d like to know more about the utility side.

Are you on a mobile device? Ampacity charts for aluminum conductor steel-reinforced cable are pretty easy to find but most of them appear to be PDFs, like this one:

https://www.prioritywire.com/specs/acsr.pdf

Cables in that table are rated for between 105 to 1,751 amps under these conditions:

"Current ratings based on 75˚C conductor temperature, 25˚C ambient temperature, emissivity 0.5, 2ft/sec wind in sun"

I don't know about other countries but in Canada, I can think of a few aluminum smelting operations and they're all geolocated in close proximity to hydroelectric dams.

Other countries are very much the same. Almost always located near giant hydroelectric generation facilities. Brazil + Russia are two big ones that come to mind. Probably China too.

Iceland has a massive amount of geothermal and hydroelectricity. A large portion of that electricity is exported in the form of aluminum.

What a fascinating sentence to read!

It's an interesting way to frame it, like how California exports water to Saudi Arabia via alfalfa

Aluminum can be thought of as "solid electricity". Base mineral is abundant but transfomation is energy-expensive.

In New Zealand, a hydroelectric dam was effectively build for an aluminium smelter [0]

0. https://en.wikipedia.org/wiki/Tiwai_Point_Aluminium_Smelter

I heard a story from a usually reliable friend, that there are old decommissioned aluminium smelters on the river or in the mountains east of Portland, that closed up back in the early 2000s or so when Google and Amazon and other datacenters started showing up and buying all the capacity from the hydroelectric dams nearby.

It’s an ideology that’s been consistently and often staggeringly wrong since it first became very popular in the 1970s. Historically it’s been popular on the left, while demographic doomer stuff is more popular on the right.

These ideologies are normally used as “problemist” lead ins to the ideology the author is really pushing. For the left it’s usually Marxism or anarcho-primitivism of some kind. For the right it’s cultural authoritarianism, racism, and anti-feminism.

Because it’s problemism, there can be no solution other than what the author advocates. We can’t engineer our way out of scarcity. Only giving up on tech, or maybe a planned economy, can save us. We can’t prevent demographic decline by importing immigrants, heavens no, or by subsidizing reproduction the way we subsidize other long term needs. No, we have to take away women’s rights and push a return to ultra-orthodox religion. It’s the only way.

This hits the nail on the head exactly.

Indeed, an early use for hydroelectric power (1886) was the Cowles process for reducing aluminum. Using solar or wind power is more difficult, but does not have, IMO, insurmountable complications.

>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.

https://en.wikipedia.org/wiki/Aluminum_building_wiring

> 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.

> Since repaired, but was told at the time original installer didn't correctly do the aluminum grease on the exposed wire parts.

I know nothing about grease, but it's pretty obvious that a fuse was missing. You might want to check that such of correct rating is in place now.

It’s more likely to be a breaker in a sub-panel than a fuse.

> Aluminum wiring in homes, for example, has a very bad reputation.

Not just in homes. The U50C tried aluminum wiring in railroad locomotives. That also got a bad reputation.

> as “renewables” cannot provide the stable current

Stopped reading right after that nonsense.

It's a double whammo, because aluminium smelting doesn't require stable current. Modern smelters can modulate their power significantly, with even multi-hour full shutdowns not being a huge problem.

Considering how energy-intensive it is, this means there is quite a big future for using aluminium smelting to soak up dirt-cheap excess renewable energy. Renewables not being stable has suddenly become a feature.