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.
District heating in Denmark is a closed system. The heated water leaves the Combined Heat & Power plant (CHP) or an industry’s heat pump and runs towards the consumers. In radiators it flows through and you pay for the difference in heat in/out and for tap water/shower etc. you have a heat exchanger that heats up the normal cold water line. The now colder heated water then runs back to the CHPs where it gets reheated.
Denmark may be big on windmills but CHPs are actually another energy technology that’s widespread here.
Ahh, that’s what I was hoping for! I was afraid it might be an open system, making the additional heat exchange from the servers mainly a vanity/pr project… My expectations for sensible utility companies have been damaged by living in America.
But yeah, depending on how much heat has been dissipated by the end of its loop, utilizing the heat from the servers right before it gets to chp would significantly reduce the amount of energy needed to get the temp up to 170f.
I wish we could do something similar, but I guess it would be stealing someone’s freedom or something?
I think you get a surcharge if your out heat is too high, meaning your radiators are running so high that you aren’t utilising the heat effectively, so the end-of-loop water should be pretty cold. Another thing to keep in mind is that CHPs would still generate the waste heat from producing power, so it’s a pretty efficient loop.
Fun fact, the Facebook district heating project was actually a big talking point due to server farms producing much lower heat than what is needed in district heating. People were split on whether it would actually have enough of an impact. As an example, my heat comes partly from a cement factory, a waste incinerator and a CHP as well as minor oil-based emergency heat generators. The CHP is capable of producing all heat by itself and the cement factory and waste incinerator were enough when the CHP had a major breakdown last year during autumn. During winter oil-based heat generators might be turned on to supplement the network on very cold days but they’re expensive to run, so they are only used a couple of days a year.