Hacker News Reader

Comment by warbaker | Hacker News Reader

On aluminum, the author says:

> “renewables” cannot provide the stable current and carbon atoms needed to make the process possible

This is untrue. Iceland has a huge aluminum industry, using mainly geothermal power: https://energytransition.org/2023/03/geothermal-iceland-this...

Iceland alone accounts for 1/10th of global aluminum production! https://www.riotinto.com/en/operations/iceland/isal

You do need constant, reliable power, as even a brief interruption makes a huge mess when the aluminum/slag freezes in the processor.

View on HN

> You do need constant, reliable power, as even a brief interruption makes a huge mess when the aluminum/slag freezes in the processor

On the other hand: it has a gigantic thermal mass. Combine this with the energy requires to melt it, and you end up with molten aluminium being trucked over our highways [0]. A brief interruption isn't a big deal when it takes ages to solidify.

[0]: https://old.reddit.com/r/pics/comments/3h6r2e/this_truck_car...

Hydro power as well, and usually they put the smelter rather close to the power source to minimize transmission.

But maybe we're still low on copper, IDK, but making aluminum should be rather possible.

Iceland is a tiny country with unusual amounts of energy. Not all renewable sources are the same -- hydropower is fairly reliable too, for example -- but Iceland is just not a useful example for the whole world. The largest geothermal plant in the world by far is in California, but it's a small portion of our total energy use so no one cares. https://en.wikipedia.org/wiki/The_Geysers

You can locate an aluminum plant pretty much anywhere you want, as the energy required to make aluminum is large compared to the cost of mining/shipping bauxite. This solves the main problem with geothermal, which is that it's in random locations around the world that don't necessarily have many people living there.

Any place with significant volcanic activity (e.g. Hawaii) could probably do geothermal power if they wanted to.

Hawaii did do geothermal, but in fact it's so geothermically active their main geothermal plant went offline for a while because lava got shot up their boreholes https://en.wikipedia.org/wiki/Puna_Geothermal_Venture

Minor nitpick:

The energy (electricity) they use to smelt aluminium mainly comes from hydropower, around 70% of it. The geothermal boreholes are mainly used for district heating, which is quite a big energy drain in Iceland. And that means that geothermal is the source of around 65% of the energy used in Iceland.

Reply on news.ycombinator.com