TRIMET Aluminium SE and Iqony Fernwärme GmbH have taken a major step toward decarbonising industrial heat by launching the feed-in of waste heat from TRIMET’s aluminium smelter in Essen into Iqony’s district heating network.

The project enables the recovery of approximately 31,000 megawatt-hours of unavoidable industrial waste heat per year, enough to cover the heating demand of more than 5,500 households across Bottrop, Essen and Gelsenkirchen. Instead of dissipating unused, the heat generated during aluminium electrolysis is now reused to supply carbon-neutral energy to the Ruhr region.

The system captures process heat directly from TRIMET’s electrolysis furnaces via specially installed heat exchangers. Four ventilator stations channel the heat through water-filled tube bundles, heating the water to around 130°C. Under high pressure, the heated water is transported through a newly built pipeline system to an energy centre, where the heat is transferred into the district heating network.

The project became possible after TRIMET adapted its aluminium production to fluctuating electricity from wind and solar power. Both companies have invested several million euros and are operating under a 20-year cooperation agreement signed in 2023.

Following successful trial operations, the facility is now set to enter regular operation, strengthening regional energy security while significantly improving the environmental footprint of district heating in western Germany.