However... what people fail to realize over and over is that the route for most of the worlds aluminum is from China to Iceland to China again. In tankers burning fuel like there is no tomorrow.
The biggest gain would be in how to refine the aluminum without shipping across the world twice.
Of course, China wouldn't have to use coal if they chose not to, and cargo ship bunker fuel produces some very nasty pollution besides CO2, but in the world we live in it is far better for carbon emissions and probably for the environment in general, to use Iceland as the aluminum smelting hub.
I keep seeing this about "shipping" being a major contributor to greenhouse emissions but some brief googling shows it's only 2.2%. This seems very little considering how much is shipping across the oceans and compared to electricity generation and ground-based transport.
Yes, that'd be nice. People are working on solutions, but the only economically viable way to refine the material is to use a highly intensive electrolysis process. My quick google search is showing 17,000 kWh/ton of aluminum [1].
It's currently economically viable to refine in Iceland, but China is the #1 producer of raw aluminum [1] [2]. Iceland only has 3 smelters, and the combined capacity is less than the 9 largest smelters in the world, 2 of which are in China.
Citation [1] also has mentions of how much better the process of smelting has become.
>So, within 60 years, by improving the technology, fluoride emissions have been reduced more than 15 times (Table 2) and annual amounts of fluorinated residues have decreased from 1500 ton after WWII to 60 ton today.
From a purely energy standpoint, raw aluminum production has become vastly more efficient [4], with kWh/kg dropping from ~27 in 1940 to ~17 in 2000. The theoretical minimum is 5.99 kWh/kg [5]
[1] https://www.sciencedirect.com/topics/engineering/aluminum-pr...
[2] https://en.wikipedia.org/wiki/List_of_countries_by_primary_a...
[3] https://en.wikipedia.org/wiki/List_of_aluminium_smelters
[4] https://www1.eere.energy.gov/manufacturing/resources/aluminu... (page 40 of the PDF, numbered 25 on the page)
[5] https://www.aceee.org/files/proceedings/2003/data/papers/SS0...
Great post, saved it for future reference!
Do you know how China powers their much larger smelters?
And do you know if these possible difference in aluminum smelting is considered when the carbon footprint for something like a mostly-aluminum Tesla is made?
Looks like largely coal. [1] This surprises me, as China has some truly massive hydroelectric generation stations which would be ideal for smelting.
>And do you know if these possible difference in aluminum smelting is considered when the carbon footprint for something like a mostly-aluminum Tesla is made?
I'm sure it's considered, but really don't know more than that. There is a big push in the manufacturing field to get ISO 14001 (environmental) certification. Many large manufacturers are requiring that of their suppliers. I'm unfamiliar how well the certification would allow tracing back emissions. Even if there were a higher carbon footprint on production, some of that can be cancelled out by better energy efficiency of the vehicles. The cost per pound and cost of repairs can be higher on aluminum.
Tesla, in its push to be economical, appears to be going with steel on the Model 3 (compared to aluminum on Model S).
>Chowdhry highlighted the key advantages of steel over aluminum as being the lower production equipment costs, the lower worker training/skill needed to work/operate steel, the lower compensation and cost savings of steel workers versus aluminum workers, and the lower repair costs. [2]
We've seen significant increases in aluminum per vehicle [3], though much slower than estimates from 40 years ago would have said. The CAFE standards implemented in the Obama era seemed to kick things into gear, notably with the Ford F-150 switching much if not all of its body to aluminum.
[1] http://www.world-aluminium.org/statistics/primary-aluminium-...
[2] https://evannex.com/blogs/news/112953413-tesla-model-s-vs-te...
[3] https://www.statista.com/statistics/496185/pounds-of-aluminu...
[4] https://en.wikipedia.org/wiki/Corporate_average_fuel_economy