Since 2020, Meta’s hyperscale data center — spanning 50,000 square meters on an industrial estate on the edge of the city — has been pushing warm air generated by its servers into the district heating network under Odense. That heat is then dispersed through 100,000 households hooked up to the system, with Meta providing enough heat to cover roughly 11,000.
Germany has this concept implemented in a lot of places, too.
Ironically this results in some problems now. For example the city Salzgitter (100k inhabitants) is heated by the local steel plant – which currently transitions towards green steel. Their transition also leads to a shut down of their blast furnaces, leaving the inhabitants of Salzgitter out of heating.
No idea what their plan is to replace it, though.