The 500k-ton typo: Why data center copper math doesn't add up

The funniest part is beyond the typo, the complete lack of physical intuition from the analysts who circulated this. 500,000 tons is roughly the weight of 1.5 Empire State buildings. If your rack busbars weigh more than the structural steel of the facility housing them, you have a geotechnical engineering crisis on your hands. It is wild that we reached a point where financial modeling is so decoupled from physical reality that nobody paused to ask if the floor would collapse.

With regards to the copper market: it keeps surprising me that some people seem to assume copper is a hard requirement for conducting electricity.

In reality copper is just convenient. We use it because it's easy to work with, a great conductor, and (until recently) quite affordable. But for most applications there's no reason we couldn't use something else!

For example, a 1.5mm2 copper conductor is 0.0134kg/m, which at current prices is $0.17 / meter. A 2.4mm2 aluminum conductor has the same resistance, weighs 0.0065kg/m, which at current prices is $0.0195 / meter!

Sure, aluminum is a pain to work with, but with a price premium like that there's a massive incentive to find a way to make it work.

Copper can't get too expensive simply due to power demands because people will just switch to aluminum. The power grid itself had been using it for decades, after all - some internal datacenter busbars should be doable as well.

This sort of mistake is easy to make when you're mixing up your units; if they kept to one system of measure, it would've been trivial to catch, before or after release.

Amazingly ironic that in an article about a typo, there is a typo.

> "Tat sounds like the ultimate catalyst for the commodities market and copper has been hitting records."

"Tat" should be "That", imo.

It’s interestingly related that Amazon is also buying a copper mine: https://www.wsj.com/finance/commodities-futures/amazon-is-bu...

The error in the original article has been corrected.

https://developer.nvidia.com/blog/nvidia-800-v-hvdc-architec...

> If the "half a million tons" figure were accurate, a single 1 GW data center would consume 1.7% of the world's annual copper supply. If we built 30 GW of capacity—a reasonable projection for the AI build-out—that sector alone would theoretically absorb almost half of all the copper mined on Earth.

Quickly doing such "back of an envelope" calculations, and calling out things that seem outlandish, could be a useful function of an AI assistant.

These kinds of errors are not rare in the media.

Even among engineering fields routine handling of diverse and messy unit systems (e.g. chemical engineering) are relatively uncommon. If you work in one of these domains, there is a practiced discipline to detect unit conversion mistakes. You can do it in your head well enough to notice when something seems off but it requires encyclopedic knowledge that the average person is unlikely to have.

A common form of this is a press release that suggests a prototype process can scale up to solve some planetary problem. In many cases you can quickly estimate that planetary scale would require some part of the upstream inputs to be orders of magnitude larger than exists or is feasible. The media doesn't notice this part and runs with the "save the planet" story.

This is the industrial chemistry version of the "in mice" press releases in medicine. It is an analogue to the Gell-Mann amnesia effect.

With a higher voltage you can reduce your copper needs by a substantial amount. Seems if copper cost was a concern this would be what these data centers would do.

I wonder how many 'innocent' inaccurate data is taken by journalists to use for their agenda. I think this happens a lot in the age of AI.

Efficient markets!

Checking the arithmetic in every paper published seems like an good use case for LLMs. Has someone built a better version than uploading a PDF to ChatGPT and asking it to check the arithmetic?