The municipal utility of the German city of Norderstedt has begun repurposing waste heat from its own data center into a local district heating network.

The project was undertaken in partnership with air conditioning firm Carrier, which supplied the utility with two heat pumps. The project began in April, and according to local reports, the heat pumps have already provided up to 6.8 million kWh to the grid.

At full capacity, the pumps provide a maximum cooling capacity of around 1.2MW and a maximum heating capacity of over 1.8MW.

The system works by redirecting waste heat generated during the cooling process into the district heating network, easing the load on a system that was previously fully reliant on natural gas. A recirculating air cooler, installed in the new energy center, maintains a stable ambient temperature of approximately 30°C (86°F).

According to the partners, the setup enhances the recovery of usable waste heat by connecting directly to the refrigerant cycle.

“For us, this is a truly showcase project that saves costs in both cooling and heating, avoids wasteful resources, and significantly reduces emissions,” commented Robert Roß, project manager at Norderstedt’s municipal utilities.

The project is seen as a test case and is expected to be deployed at another data center operated by the utility.

Heat reuse from data centers is becoming increasingly popular across Europe. Germany, in particular, has prioritized the connection of data centers to local district heating networks. In 2023, as part of the Energy Efficiency Act, it set a quota for the reuse of waste heat from facilities.

Several German utilities have signed heat reuse agreements over the past 12 months. For example, last June, NTT signed an agreement with Frankfurt utility Mainova to connect one of its data center campuses to the local district heating network.