Aluminum smelters in the energy transition: Optimal configuration and operation for renewable energy integration in high insolation regions

Abstract

The aluminum industry consumes about 4% of global electricity but requires stable power supply as long power outages are catastrophic. We investigate how the aluminum industry can maximally integrate variable renewable energy resources while remaining competitive. This can be achieved by (i) modulating production and (ii) utilizing storage. We develop an hourly linear optimization system for integrating variable energy sources and apply it for identifying the optimal configuration and operational profile for UAE-located smelter. Operating with the optimal renewable energy and fossil mix and a novel power modulation scheme, consistently reduces costs between 2.2% and 5.3% for fuel prices ranging between $2.4-$8 per MMBtu and integrating more than 40% of power by solar PV without storage. This reduces process emissions intensity from 5.13 to 2.87 tCO2/tAl. In all cases of RE integration, modulation confers a significant cost advantage with savings ranging from 7.5% to 10% for the fuel price range. Operating the smelter with 100% renewable energy portfolio could be achieved by installing 5.4 GWp single-axis tracking PV, 0.2 GWp wind, 18 GWh of battery storage and 47 GWh of hydrogen storage but with a 26% premium for 2020 high gas-price system costs.