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I think aluminum is mostly more expensive than steel because energy is expensive, but solar energy makes energy cheap. If a ship's mass were mostly ship rather
by kragen 2y ago
I think aluminum is mostly more expensive than steel because energy is expensive, but solar energy makes energy cheap.
If a ship's mass were mostly ship rather than mostly cargo, making it out of a heavier material would increase its water displacement, which would increase its drag. I don't know if that's a proportional effect; I think it's actually sublinear. But, since most of the mass is cargo, it won't make much of a difference.
If most of the mass weren't cargo, you could ship things more cheaply by sealing the cargo in giant plastic bags and towing it across the ocean behind a tugboat.
- throwup238 2y agoBoth steel and aluminum production depend mostly on the cost of energy, so any improvements that would make aluminum cheaper would also make steel cheaper. Steel also has the benefit of being ferromagnetic so it’s a lot cheaper to pull scrap steel out of the garbage stream and recycle it, but that depends on having lots of scrap steel to begin with. There’s really not a lot of room to make aluminum as cheap as steel, as all economies of scale have by now been mostly realized. The cost of energy is so dominant that it makes sense to run smelting plants idle most of the time with the crucible heated constantly just to take advantage of negative power prices (although there are other factors at play like subsidies and national security concerns). Barring some sort of seismic scientific breakthrough in metallurgy, the current ratio of 2-3x the cost of steel is here to stay. There’s maybe a little room if we reach “peak aluminum” as the fraction of recycled scrap approaches 100%, but I don’t think that would make that much of a difference because we’re likely to hit “peak steel” before then (and again, its just easier to recycle from a logistics standpoint).
- kragen 2y agoHmm, really? I didn't realize that. Thank you!