Another year, another portfolio review by Alcoa.
The US aluminium producer has just announced a five-year review of around 4.0 million tonnes of alumina capacity and 1.5 million tonnes of smelter capacity.
Assets will be improved, curtailed, closed or sold.
It's not quite an annual event but Alcoa shareholders have been here many times before as the company keeps trying to move down the cost curve in the face of chronically depressed prices.
On the London Metal Exchange (LME) three-month aluminium has ground steadily lower over the course of 2019 and at a current $1,720 per tonne is close to the near three-year low of $1,705 recorded earlier this month.
This time around, however, Alcoa is throwing an extra ingredient into the cost-cutting mix - sustainability.
The company "expects to be the lowest emitter of carbon dioxide among all global aluminum companies".
Going green is the new differentiator in the cut-throat business of making aluminium.
Aluminium is one of the metals expected to benefit from the "green revolution" given its recyclability and light-weighting potential in the automotive sector.
However, its green credentials have recently come in for some serious scrutiny.
The part suspension of the Alunorte alumina refinery in Brazil last year and closures in China this year have served as a reminder that aluminium has its own tailings dam issues, a sensitive topic after the devastating dam failure at Vale's Brumadinho iron ore mine.
Moreover, aluminium is only as "green" as the power source used to make the stuff, particularly since power is such an important input in the aluminium smelting process.
Alcoa is hoping to leverage its existing strengths on both fronts.
Its entire production chain is certified by the Aluminium Stewardship Initiative, it boasts "the lowest carbon footprint of any (alumina) refining system in the world" and is one of the lowest emitters among major aluminium producers.
Around 70% of the electricity powering its smelters comes from renewable sources, a ratio that Alcoa hopes will rise to around 85% after its portfolio review.
Alcoa has the advantage of being based in North America, which thanks to Canada's massive hydroelectric dam system has one the highest renewable energy profiles of any major producing region.
Hydro power accounted for 82% of North American aluminium production last year, according to the International Aluminium Institute (IAI).
Latin America was close behind with 77%, albeit with a much smaller smelter network.
In Europe hydro power fed 75% of aluminium production last year. Rusal's giant Siberian smelters are an important part of that calculation.
If these are the "green" aluminium production hubs, the "black" ones are in China, the world's largest producing nation, and in the rest of Asia. Hydro powered around 10% of aluminium output in each region last year with coal accounting for the rest, according to the IAI.
Coal is a particularly problematic source of power for any metal that wants to claim it is environmentally sustainable.
Chinese producers are increasingly reacting to this emerging power-source differentiation in the aluminum production sector.
Hongqiao Group, the country's largest producer, last week announced it will take the lead in developing a "green aluminium" industrial park in Yunnan, a Chinese province rich in hydropower resources.
It will follow a trail blazed by other Chinese producers such as Chalco and Henan Shenhuo, which have also been building out "green" capacity in Yunnan.
Since most Chinese producers are prohibited from building more aluminium production capacity, new plants in Yunnan are replacing older, coal-powered smelters in heavily industrialised provinces such as Shandong.
But while part of the country's aluminium production is migrating to hydro-rich provinces, another part is locked into stranded coal deposits in the northwestern provinces.
That means the evolving green-black aluminium differentiation is not going to go away any time soon.
How Much To Go Green?
The question is whether sustainable "green" aluminium will end up commanding a financial premium over non-green metal.
Is differentiation a mere branding exercise or can it be a financial driver as well?
"We have a series of products right now that are either focused on being low-carbon or being made on a certain amount of recyclable material (...) that have been able to command a premium in the market-place," according to Roy Harvey, Alcoa President and Chief Executive Officer.
However, Harvey conceded on the company's quarterly earnings call that "this is just a nascent market" which will "take time to develop."
Alcoa hopes that what is a niche market today becomes a global market tomorrow.
Alcoa's sustainability message is, according to Harvey, "something that is a natural addition and is in fact the way that Alcoa's succeeds into the future because we do the right thing and because at some point the market recognises that is value in that responsibility."
The aluminium industry is just at the start of its own green revolution.
It is being driven by producers such as Alcoa, Rusal and Norway's Hydro, all of which already enjoy high renewable energy inputs into their smelters.
The next phase will be the evolution of the smelting process itself.
Alcoa and Rio Tinto have formed a joint venture, ELYSIS, to commercialise a smelting process that generates oxygen and eliminates all direct greenhouse gas emissions.
The aim is to have a technology package for sale in 2024, either for retrofitting existing smelters or building new greenfield plants.
Apple is also part of the joint venture, a clear sign of the interest from consumer groups in ensuring their metal ticks all the sustainability boxes.
It's just part of a bigger technological rethink by aluminium products.
Rusal, for example, is working on ways of converting waste such as "red mud" into saleable products. Its Sayanogorsk smelter site already processes or sells over 90% of the waste produced and the goal is to move the rest of the company's smelters up to a similar ratio.
Expect similar announcements from other producers to follow.
The concept of "green" aluminium is only a couple of years old but sustainability looks set to be a defining feature of this market for years to come.