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Comment by ngvrnd | Hacker News Reader

not just a cost question but a resource availability/energetic cost of resource extraction question.

If it takes more and more fossil fuel use to extract the increasingly rare components of the renewables, then renewables may not be able to save us.

I don't know if it is true, but it is a legitimate question which is worth knowing the answer to...

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A gram or so of silver per kW is the rarest component of PVs, and the total ammount of (recyclable) silver per year the PV industry uses is going down even as production increases. The copper is less than a commensurable amount of steam generation. Silicon refining energy is a hundredth or so of output and declining rapidly steel in a nuclear reactor outmasses the silicon and has a lower but rapidly closing energy requirement. Frames can be aluminium or even wood. The glass outmasses steel in a nuclear reactor, but not concrete, and has a lower carbon footprint than concrete and is reusable.

Wind uses copper and niobium, neither of which are essential to the concept. The copper is currently more than steam generation, but some can and is being swapped for abundant aluminium. Magnet free stators are being worked on extensively and are close to cost competitive. Steel use of the largest turbines is competitive with nuclear so iron alloying materials are a wash.

Nuclear uses zirconium, uranium, cadmium, silver, and a variety of other exotic elements as well as the copper for the steam turbines. It is difficult to find out how much, but back of the envelope (0.1% of the fuel assembly being control rod so 0.2g/GJ) would indicate it's more constrained by silver and cadmium than PV is by silver. Plus it is high level waste at end of life and you need it all up front.

The only question is whether the concrete in wind is worth the CO2 as this is the only resource where nuclear wins.

There are no "increasingly rare components".

So, no, it is not any sort of legitimate question. It is, rather, concern trolling.

My guess is he's talking about Lithium and if so that's not concern trolling, Lithium mining is very expensive and if we want to go full renewable we'll need some major storage capacity. There's obviously ways around that, hydro storage being the most obvious, but it is something to think about.

The question was too vague to guess what it was about, if anything. It presupposes there is some resource used for renewables that is scarce and for which there is no viable substitute. Without identifying any, it is just trolling: there must be trouble somewhere, what can you come up with for me to carp about?

Lithium is about electric cars, not about renewable energy production.

To the popular imagination, it is easy to make a popular misconception linking renewable energy to rare earth minerals, because for good or for ill electric cars are a dominant facet of green technology. There is a not uncommon narrative that "electric cars are actually bad for the environment because they require scarce metals." News stories abound.

https://www.reuters.com/article/us-metals-autos-neodymium-an...

https://www.forbes.com/sites/kensilverstein/2022/02/06/the-f...

Rude pedantic ill-tempered dismissals of conversation as "carping" discredit a good cause more than a thousand fusion startups do. Perhaps if you want to win hearts and minds, engaging in both education and a little empathy would do wonders for your position. And to the betterment of the discourse hereabouts.

"Rare-earth" metals, are not, in fact, scarce. Insisting otherwise is misinformed at best, or disingenuous in your case, because you have already been told otherwise.

I am misinformed. But you are impolite.

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