IEA (2020), Annual change in the global energy intensity of primary aluminium smelting and alumina refining, 2015-2019, IEA, Paris https://www.iea.org/data-and-statistics/charts/annual-change-in-the-global-energy-intensity-of-primary-aluminium-smelting-and-alumina-refining-2015-2019, Licence: CC BY 4.0