atNorth Signs Heat Reuse Deal with Calentix for 300MW Sweden Data Center

atNorth has signed a project development agreement with Swedish heat recovery specialist Calentix to deploy heat reuse technology at its up to 300MW SWE04 data center in Sollefteå, Sweden, marking another step in the Nordic data center sector's push to integrate waste heat into municipal energy systems.

The agreement will see Calentix lead the development of a potential heat recovery solution designed to feed surplus heat from the SWE04 facility into the nearby Långsele district heating network, which is operated by Swedish utility Adven. Under the first phase of the project, heat recovery is expected to reach 1.6MW, with the potential to scale to approximately 20MW as the campus develops. The initiative will require between 2km and 10km of new pipelines to connect the data center to the district heating network, with the partners targeting first heat delivery in the second quarter of 2029.

As part of the arrangement, atNorth will provide access to surplus heat generated at SWE04, along with site integration and the necessary infrastructure interfaces. The two companies have already completed an early feasibility study confirming that heat recovery from the site is technically feasible and that there is local interest in advancing the opportunity. Attention now shifts to determining whether the project can become technically and commercially viable, encompassing technical design, site planning, commercial principles, and the agreements required among the various parties involved.

The partners acknowledged that the central challenge will be structuring a solution that creates value for both sides. Calentix will lead project development and financing, while atNorth makes the surplus heat available for dispatch to the local heating network — an arrangement the companies said allows each partner to focus on its core strengths while creating a practical pathway for the heat to be absorbed into the local energy system. The partners aim to sign a heat purchase agreement in 2027, after which they will proceed to a final investment decision.

The deal adds to atNorth's growing portfolio of heat reuse initiatives across the Nordics. In August, the company partnered with sustainable infrastructure firm Selected Group on a heat reuse project at its DEN02 data center campus in Ølgod, Denmark. atNorth first announced plans for SWE04 in February; the site, located at Hamre Industrial Park in Långsele, will be developed on a 50-hectare plot and will support direct liquid cooling with densities of up to 1MW per rack. The company currently operates SWE01 in Kista, a Stockholm suburb, offering 12MW of capacity across 6,400 square meters, and is developing SWE02, a 30MW facility near SWE01 that is due to go live in the fourth quarter of 2027. The agreement underscores the growing emphasis on waste heat recovery as data center operators seek to reduce environmental impact and demonstrate community value amid rising energy demands from AI and cloud workloads.