Data center waste heat and outdoor air to supply district heating in Salaspils
In Salaspils, Latvia, construction is underway on a system that will recover waste heat from a new data center and add outdoor air as another heat source for the city's district heating network. EKA Baltic has supported the district heating company Salaspils Siltums with a technical and economic feasibility study and technical specifications for procurement.
Two new heat sources for an existing network
Salaspils already has a district heating system that includes wood chips, solar thermal energy and thermal storage. The system produces approximately 65,000 MWh of heat per year. The next step is to recover heat from Tet's DC7 data center, which is being built near the heating plant.
The data center's cooling system releases heat at a temperature that must be raised before it can be used in the district heating network. Industrial heat pumps will provide that temperature lift. The estimated waste heat potential is around 2.0 MW; according to the project information, the heat pumps could deliver approximately 2.6 MW of heating capacity from this source. An additional 1.2 MW air-source heat pump is also planned. Together, this represents about 3.8 MW of planned heat pump capacity.
Outdoor air provides a further heat source alongside the data center. Combining the two matters because both waste heat availability and district heating demand change over time. The new heat pumps will be integrated into a system that can draw on different heat sources as conditions change. Hydrocarbons have been selected as the refrigerants for the heat pump solution.
From feasibility study to procurement
For a district heating company, knowing the amount of waste heat available at one operating point is only the beginning. The source's availability, network temperatures, heat pump performance at part load and interaction with existing heat production all affect the technical solution and its economics.
EKA Baltic worked with Salaspils Siltums on the technical and economic feasibility study and developed technical specifications for procurement. The work also included a review of bids, covering capacity, guaranteed operating points, controls and connection to the district heating network. These details need to be defined before construction and provide a basis for evaluating performance once the system is operating.
Construction is underway
In September 2026, Salaspils Siltums reported that construction of the heat pump system and the connection between the data center and heating plant was underway. The new heating capacity should therefore be described as planned, rather than as a measured operating result.
The project illustrates how an existing district heating system can add local waste heat and electrically driven heat production. For other district heating companies, the practical questions are similar: which heat sources are available near the network, when can they be used, and how can they work alongside existing production?
Read more about EKA's work with heat pumps for district heating.
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