District-heating with casting water

The Net Zero Lab Valais is modelling energy systems to evaluate the replacement of natural gas with renewable energy sources to increase energy efficiency and to decrease waste. With this goal, one of the first completed projects is a transfer of waste heat from the casting process at the Novelis Sierre plant to the Technopôle – a nearby building complex. The energy supply corresponding to a power of around 200 kilowatt-hours covers about one third of the energy demand of the Technopôle, which hosts research-based companies and consulting firms as well as university offices.

Creating synergies by capturing energy in use

Casting aluminium ingots requires cooling water during the process. As the liquid aluminium origins at the melting oven with around 750 degrees Celsius, water is used to cool down the liquid aluminium to its required shape. During this process, the water heats up. The energy of this heated water is then exchanged and sent into warm water pipes to the Technopôle.