Yesterday marked the kick-off of GreenDC, a new knowledge-building project that brings research scientists and industry together to tackle the challenge of making data centres more sustainable.
Project lead Hanne Kauko traced GreenDC back to earlier research efforts on cooling and surplus heat utilisation dating back to 2016. While several projects have explored these topics over the years, few have resulted in implementation. GreenDC goes a step further by including issues that have become increasingly central in recent years. In addition to cooling efficiency and heat recovery, the project addresses grid impacts, peak power demand, land use and environmental considerations.
Kauko acknowledged that public debate around data centres often centres on high energy use and unclear societal value. She noted that even surplus heat recovery can sometimes appear more like a justification for grid access than a real priority. At the same time, she emphasised that data centres are indispensable for health services, transport, energy systems and digital infrastructure. The question, she argued, is not whether Norway needs data centres, but how they can be developed responsibly. Sustainability, she stressed, cannot be reduced to CO₂ emissions or power usage effectiveness (PuE) – the main sustainability metric for data centres; it must also include flexibility, grid strain, heat utilisation and impact on the environment.
Chido Nnoli, adviser at the Research Council of Norway and case officer for the project, described GreenDC as both timely and strategically important. As a Knowledge-Building Project for Industry (KSP), he emphasised that active involvement from industry partners will be crucial, both in shaping research priorities and ensuring that results are translated into practice.
Attention then turned to presentations by the industry partners, representing some of the most experienced and forward-leaning actors in the Nordic data centre landscape: from large-scale operators to specialised technology suppliers.
From megawatts to responsibility
Modern data centres are no longer quiet server rooms hidden in office basements. They are, as Verne CTO Tate Cantrell put it, “information factories”: high-density, liquid-cooled facilities designed for AI and advanced computing, operating at power levels that would once have been unthinkable. In Norway, expansion plans point towards capacities of 100 megawatts and more, and in some regions multiple operators are clustering within a few kilometres of each other. The scale alone raises a question: as computing power increases, how should responsibility scale with it?
One area where scale and responsibility meet is surplus heat. Operators are increasingly designing facilities to enable large-scale heat recovery at higher temperature levels. Some of Verne’s facilities, for example, are designed so that up to 80 per cent of the generated heat can be recovered. Yet across Europe, only 1.8 % of data centre heat is currently reused. The technical potential exists; the bottleneck lies in creating viable heat markets and identifying partners able to absorb the energy, particularly outside dense urban areas.
In Ringerike, this tension becomes tangible. Within a radius of just a few kilometres, operators have secured grid reservations amounting to close to a gigawatt of potential data centre capacity — an energy concentration Norway has not seen before. Hscale has already installed large-dimension piping to enable future heat export and has signalled willingness to supply surplus heat, even free of charge. But as Pelle Gangeskar noted, data centre operators are not district heating companies. Realising the value of surplus heat requires parallel development of local infrastructure and companies for operating the infrastructure.
Some participants also pointed to alternative energy service models, where cooling itself could be provided by a dedicated external operator, in much the same way that district heating companies distribute heat today. Such approaches would require new forms of coordination, but illustrate that the relationship between data centres and local energy systems need not be one-directional.
Inside the data centre walls
If surplus heat is to become a resource rather than a by-product, the internal systems of data centres must also evolve. Thorn Fredrik Hemsen, Managing Director of Armaturjonsson, pointed to an often overlooked part of the discussion: the cooling infrastructure itself. While attention tends to focus on servers, switchgear and power systems, long-term performance and environmental footprint are also shaped by material choices, water quality and piping design.
Hemsen argued that changes in cooling technology, including increased use of liquid-based systems, require new approaches to materials and installation practices. Composite and plastic piping systems can reduce corrosion risks and lower production-related emissions drastically compared to traditional steel solutions, and smoother internal surfaces can reduce pumping energy. Yet established standards and fast-track construction timelines make it difficult to implement such a change. Sustainability, he suggested, must include the entire installation, not only operational energy use. Both aspects will be addressed in GreenDC by professor Dimitrios Kraniotis at OsloMet, who will have several master's students associated to the project.
Flexibility was another recurring theme. Alexis Sevault, CTO at Cartesian, presented modular thermal energy storage systems designed to smooth cooling demand and reduce peak loads. Rather than replacing cooling infrastructure, such systems can act as “trim” capacity — storing cooling when conditions are favourable and releasing it during peak periods. In Nordic climates, this could mean capturing free cooling at night and using it during the day, reducing peak power demand without compromising operational reliability.
Beyond efficiency gains inside the fence, Sevault also pointed to emerging flexibility markets. By enabling data centres to participate in ancillary services, thermal storage could create additional value streams while supporting grid stability. Whether and how such models apply to different types of data centres is one of the questions GreenDC will explore, in collaboration with the regional grid operator, Tensio.
Lab-testing of high-tech equipment for the data centres
Efficient cooling is key to reducing operational energy use and increasing surplus heat utilisation. Immersion cooling is widely seen as the most promising approach, although it remains at a relatively early stage of technological maturity. In Luleå, RISE has built laboratory facilities for testing and developing novel solutions for data centre cooling and surplus heat recovery. Through GreenDC, Mattias Vesterlund, project manager at the ICE data centre facility in Luleå, will assist SINTEF in building a test site for two-phase immersion cooling using ultra-pure water, at SINTEF’s thermal laboratory facilities in Trondheim.
