Coal power plants: Aluminium’s dirty little secret

In total, the aluminium industry used 918TWh of electricity in 2019 for electrolysis, of which 588TWh was from coal power plants. This means aluminium electrolysis is responsible for 6% of all global coal power generation, which was around 10,000TWh last year, according to the IEA. This is more than all the electricity generated by coal plants in the EU-28 last year (470TWh, according to Ember’s EU Power Sector in 2019 report). Of that 588TWh coal-fired generation used in aluminium electrolysis, China consumed 72%, whilst producing 56% of the world’s aluminium.

The dependence on coal has been getting worse: aluminium electrolysis rose from having 49% of its electricity from coal in 2006, to 64% in 2019. This was in a large part due to captive coal power plants built to fuel China’s new aluminium plants. Meanwhile, the total electricity sector actually reduced its reliance on coal, as more wind and solar power took market share (see Ember’s Global Electricity Review).

In China, coal-fired electricity that powers the aluminium electrolysis process resulted in almost half a gigatonne of CO2 emissions (460 million tonnes) last year.