Heating Locally: nLighten Data Centre Powers Heat Network

The nLighten data centre in Stuttgart will soon supply excess heat to the local heating network, supporting the municipal it.schule, a training centre for IT and media professions, as well as DEKRA buildings in the Möhringen district.

To make this possible, nLighten has partnered with Wärmelösungen Synergiepark Stuttgart, a joint venture between Stadtwerke Stuttgart and e-con. 

The companies have signed the cooperation agreement required to begin the project, marking the start of an expanded heating network in Synergiepark Stuttgart, expected to go live later this year. The initiative receives funding from the German Federal Ministry for Economic Affairs and Energy.

Turning data centre heat into usable energy

The project demonstrates how data centre operators can collaborate with municipal and private partners to reduce emissions. 

As nLighten powers its data centre with renewable electricity, the recovered heat is sustainable and sets an example for the wider industry.

The excess heat from the data centre is sold to Synergiepark Stuttgart, which processes and distributes it. The local infrastructure is capable of delivering up to 1.8MW of heat output.

A closed-loop water system acts as the heat transfer medium. It captures heat from the servers and uses heat pumps to raise the temperature to levels required by the customers. 

As a supplier, Synergiepark Stuttgart ensures a sustainable, resilient and cost-efficient heat supply for the surrounding area.

Andreas Herden, Managing Director Germany at nLighten, explains: “The heat reuse project in Stuttgart is another milestone for nLighten and demonstrates how data centres can become active shapers of the energy transition. 

“Following our successful project in Eschborn, we are once again proving that Europe’s digital infrastructure can be designed not only to be powerful and connected, but also sustainable.”

Partnership strengthens local heat network

Ulf Hummel, Managing Director of Wärmelösungen Synergiepark Stuttgart, says: “The excess heat project with nLighten creates an added value for everyone involved: it delivers climate-friendly heat for our customers, strengthens the data centre's sustainable business model and represents an important step towards decarbonising Stuttgart’s heat supply.

“As a young company, Wärmelösungen Synergiepark Stuttgart set out to provide climate-neutral heat to the entire industrial area in Vaihingen and Möhringen. Connecting the data centre is the reward for the many years of planning.”

By supplying heat to public and commercial buildings, the project demonstrates a scalable model for industrial heat recovery in urban areas.

The co-operation also supports broader energy transition goals.  By connecting high-demand computing infrastructure to municipal heating systems, the network gains a reliable, low-emission heat source while the data centre improves its environmental footprint.

A model for sustainable digital infrastructure

The Stuttgart initiative follows nLighten’s previous project in Eschborn and signals the company’s ongoing commitment to sustainability. 

It shows that digital infrastructure does not need to operate in isolation from local energy systems. Instead, data centres can provide both computing power and practical contributions to climate targets.

For Synergiepark Stuttgart, the integration creates a reliable and cost-efficient heat supply. By using closed-loop systems and heat pumps, the network maintains consistent delivery temperatures while keeping operational costs manageable. 

The system demonstrates that modern data centres can be part of circular energy networks, returning previously wasted heat to municipal use.

As Europe increasingly emphasises energy efficiency and climate-neutral operations, initiatives like the Stuttgart heat network show that digital infrastructure can play a direct role in reducing urban carbon emissions.