alt Hacker NewsI think the author is speaking authoritatively about things they may be less familiar with, or where they really want to push a particular doomsday / degrowth agenda (the only prescription at the end the article is that we need to stop technological progress). This paragraph in particular caught my eye:
> Bah! Who needs copper anyway, when we have so much aluminum?! > Have you thought about how aluminum is made? Well, by driving immense electric currents through carbon anodes made from petroleum coke (or coal-tar pitch) to turn molten alumina into pure metal via electrolysis. Two things to notice here. First, the necessary electricity (and the anodes) are usually made with fossil fuels, as “renewables” cannot provide the stable current and carbon atoms needed to make the process possible. Second, all that electricity, even if you generate it with nuclear reactors, have to be delivered via copper wires.
This seems to be trying to say that we can't make aluminum without copper, but that seems nonsensical. First, 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. Second, the comparatively tiny amount of material needed for electrodes is a completely wacky argument. And renewables not being able to provide "the stable current" needed for smelting?
I'm not cherrypicking here, there's a lot of assertions of this type in the article. Essentially, everything is doomed and there's nothing we can do, because we're going to run out of copper. And fossil fuels. And there's absolutely nothing that can replace them, ever. And therefore, we shouldn't build AI datacenters? That's what it says...
Replies
> 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.
> 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 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.
> as “renewables” cannot provide the stable current
Stopped reading right after that nonsense.
>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.
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.