Reducing the Carbon Footprint: Aluminium Smelting with Changing Energy Systems and the Risk of Carbon Leakage

This paper presents an analysis of the smelting trends and potential opportunities to reduce the overall greenhouse gas emissions from the primary aluminum industry in total, both direct emissions from the production processes and indirect emissions from the electric power used. Presently, 71% of the aluminum is produced with electricity from fossil fueled power plants, and while the introduction of wind and solar generation of electricity is accelerating, these have technical constraints and limitations. On average, indirect emissions from the power used dominate as emission source, so de-carbonizing the electricity production through low-emission power sources is crucial for the primary aluminum production in order to meet carbon emission targets. Globally the best result will be achieved by maximizing aluminum production in regions that can provide low emission power. However, national or political objectives can sometimes counter this by re-directing the use of existing hydro power used by aluminum smelters to eliminate local emissions from the process, in order to meet national goals. While this may reduce carbon emissions regionally, the result may be an increase in the industry's global emissions through increased production capacity using non-renewable high emission level power sources in other regions. Indeed, the carbon footprint of primary aluminum production has increased significantly this century due to an increasing transition of the energy mix towards fossil based power.