Aluminium sector relies on natural gas for recycling scrap into feedstock, contributing ~2% to the global industrial CO2 emissions. Hydric resources are used as cooling media for aluminium direct chill casting, and waste heat is typically rejected to nearby water bodies, instead of using it in district heating networks. Process integration between aluminium plants, urban and regional energy systems promotes energy security, lower environmental impact and energy-efficient use of valuable resources. Renewable energy integration, like electrification and biomass gasification, helps diversify and defossilize heavy industry energy supply, traditionally based on fossil natural gas. Power-to-gas-to-power, carbon capture and use, and storage systems offer further advantages by mitigating the effects of seasonal availability and prices of electricity and fuels. By implementing an industrial battery capable of handling renewable energy intermittency [3], reversible solid oxide cells can partially supply heat to fired furnaces, as well as electricity to electrical furnaces, rolling processes and heat pumping systems of the district heating network.