Heat in the Cloud: District Heating, GlattbruggSerena Peier, Rebecca Grobotek, Matteo Bianchi, and Linus Ham

As the world’s second-largest data centre operator, Digital Realty makes its scale tangible in Zurich—with one of Switzerland’s largest data centre campuses, a powerful multi‑megawatt footprint, and a network of locations that spans the globe.

The heat of our digital infrastructure is invisible yet immense, and it escapes into the atmosphere. At Digital Realty Glattbrugg, as is the case almost everywhere else, this energy is lost, providing warmth only to the birds flying overhead.

What began as a pioneering energy vision ended as a cautionary tale. The Airport City heat network aimed to utilise data centre waste heat in Opfikon, but despite the involvement of key players and ambitious intentions, the project is currently on hold.

While IT and data centre assets have a short lifespan and construction costs account for only a small proportion of the total investment, district heating networks demand high upfront investment, long payback times, and stable partners—yet operators can relocate, go bankrupt, or simply opt out, in a legal landscape not built for this dependency.

When heat sources are uncertain, flexibility is essential. Above-ground pipelines provide a cheaper, quicker and more adaptable means of connecting fluctuating energy producers, such as data centres, to the urban infrastructure, making energy flows visible and responsive.

Moving from soft incentives to binding obligations, stronger laws would require data centres to disclose their waste heat and present concrete reuse plans. They would also require data centres to co-finance the necessary infrastructure. This would make waste heat, formerly ignored, a reliable pillar of urban energy planning rather than a lost opportunity.