Photo by Enertech
Author: Federico Re Ferrè
Key Points of the Article
- The exponential increase in energy consumption linked toartificial intelligence and digital services This makes it urgent to optimize data center cooling. The heat generated by these facilities, if properly recovered, can be transformed from waste energy into a renewable resource.
- The heat recovery is now one of the most effective strategies for limiting the energy impact of data centers. The thermal energy produced by the server cooling process can, in fact, be reused in district heating networks or in industrial processes.
- The most advanced case studies show that waste heat can be used to heat buildings, swimming pools, or livestock farms, creating a model of circular economy that combines environmental sustainability and economic savings.
- The Northern Europe is leading this transition thanks to existing district heating infrastructure and favorable climatic conditions, which allow for the consistent use of waste heat throughout the year. However, promising projects are also getting underway in Southern Europe that aim to harness heat for agricultural and industrial uses.
- Heat recovery from data centers, as demonstrated by projects carried out in Italy as well, continues to prove to be a practical and sustainable solution to address the energy challenges of the coming years. As digital consumption increases, this technology will become increasingly strategic for the green transition of businesses and cities.
The increasingly widespread massive and capillary of theartificial intelligence, along with an ever-expanding selection of digital services, led the data center to become increasingly energy-intensive: second the IEA in the 2022 i data center They consumed about 460 TWh per year, a figure that is expected to rise, with estimates suggesting consumption will approach 1,000 TWh in 2026.
Data centers are becoming increasingly more energy-intensive not only because of power they consume but also due to cooling required to prevent the machines from overheat from overheating.
Over time, in addition to trying to reduce or avoid energy consumption associated with cooling, research has also focused on the possibility of recover this energy and use it for other purposes. In this article, we’ll look at the most interesting case studies from recent years and future prospects.
Table of Contents
- Heat Recovery for District Heating in Stockholm
- Heat Recovery at the Milwaukee School of Engineering
- Heat Recovery and Heat Exchange for Trout Farming in Norway
- Heat Recovery as an Energy Source for Cities
- Heat Recovery in Data Centers: The Project by the Startup Deep Green
- On-chip heat recovery in IBM supercomputers
- Italian Projects for Heat Recovery from Data Centers
- Why Is Heat Recovery More Widespread in Northern Europe?
- Heat Recovery from Data Centers: A Resource for a Sustainable Future
Heat Recovery for District Heating in Stockholm
An excellent example of heat recovery is undoubtedly the Swedish data center high-security Pionen; owned by the company Banhof, the data center is located in a decommissioned nuclear bunker under the White Mountains.
The former bunker has been completely renovated and expanded and is now one of the largest in the world. The cooling is provided by two Carrier 61XWH0802 AquaForce® units connected in series to provide approximately 690 kW of cooling and 975 kW of heating capacity to be fed into the nearby district heating network. Energy recovery for the district heating offers significant benefits, such as reduction in CO2 emissions from heating homes and a short payback period (estimated at about 3 years).
Heat Recovery at the Milwaukee School of Engineering
Another interesting example is that of the Milwaukee School of Engineering, Wisconsin. The school is equipped with a supercomputer, nicknamed Rosie, which helps students with their studies in various fields ofengineering, such as robotics, artificial intelligence, autonomous driving, and much more. The supercomputer processes the 60% of the energy needed for the entire the campus.
The campus cooling system and that of the supercomputer room They’re the same: in the summer, the hydronic cooling system first the campus, and then the supercomputer that can receive water at a higher temperature. In winter, on the other hand, the supercomputer comes cooled using outdoor air and circuits of free cooling.
As a result the heating of the offices is entirely provided by recovered heat and the water consumption has been cut in half.
Heat Recovery and Heat Exchange for Trout Farming in Norway
In Norway , on the other hand, a fish farmer, Hima Seafood, and Green Mountain Technology have entered into an agreement to reuse waste heat from a large data center. The trout breeding pond has been connected to the data center via pipes: the The heat released by the data center heats the water enough to raise fish, and at the same time the data center is cooled to operate safely, thus creating a circular project.
Heat Recovery as an Energy Source for Cities
Also on the Scandinavian Peninsula another major agreement has emerged, this time between DigiPlex and Stockholm Energy (a Swedish provider of district heating and cooling systems): there aren’t many technical details about the project, but it has been reported that the recovered energy from the data center is sufficient to heat approximately 10,000 modern medium-sized of average size.
The city of Odense, Denmark’s third-largest city, benefits from the Meta’s data center. The Company District Heating Fyn has installed the largest heat pump system of the Denmark in order to catch up 215,000 MWh from data center located in Tietgenbyen and enter it into the district heating network, meeting the needs of approximately 12,000 families.
Heat Recovery in Data Centers: The Project by the Startup Deep Green
On a much smaller scale than the ones we just saw, there is an interesting project by the startup Deep Green. In Exmouth, in England, a small data center is cooled using natural oil which heats thepool water at theExmouth Leisure Center.
The system is capable of maintaining 30°C in the pool for 60% of the time and nearly 96% of the heat generated by the data center is reused. This solution has reduced by 62% the natural gas consumption, resulting in savings of 30,000 pounds a year and reducing carbon emissions by nearly 26 metric tons.
On-chip heat recovery in IBM supercomputers
In Switzerland, on the other hand, IBM has been working on a highly innovative project in collaboration with theETH Zurich and theETH Lausanne. A prototype of supercomputer comes “on-chip” cooling to hot water: of the micроchannels with a diameter of approximately 1 mm are water-powered to 60°C and they come related directly to the processing unit so that cool promptly identify the parties responsible for the majority heat output.
The recovered heat is used to heating the building. IBM reports that it has achieved a heat recovery efficiency of 80%
Italian Projects for Heat Recovery from Data Centers
In Italy, there aren’t many projects similar to the ones just described; for example, we can mention two projects by A2A:
- In 2024, a partnership was launched with DBA Group and Retelit to recover energy from the Avalon 3 Data Center (approximately 2.5 MWt of recovered thermal power and 15 GWh of thermal energy per year) by feeding it into the district heating network in the northwestern part of Milan. The project aims to meet the needs of 2026 the needs of approximately 1,250 households while saving 1,300 TOE per year and reducing 3,300 metric tons of CO2 emissions;
- In 2025 A [… ] is being inaugurated data center designed by Qarnot at the power plant in Lamarmora, recovering approximately 16 GWh by thermal energy annual to 65°C, enough for about 1,350 families, saving 3,500 metric tons emissions of CO2.
Why Is Heat Recovery More Advanced in Northern Europe?
The projects described in this article are just a few of the most important initiatives for for recovering waste heat from data centers, however, some conclusions can be drawn. Most of the most innovative and large-scale projects are carried out in the Northern Europe and there are several ways to explain this:
- Northern Europe has colder harsher and longer cold seasons and, although you can also useoutdoor air for free cooling, these features work well with constant throughout the year, such as that offered by data centers;
- Northern Europe has district heating networks that are extensive and well-developed, which are one of the main sectors for waste heat recovery as we have seen in the case studies. In the Southern Europe Temperatures are milder and the short cold seasons mean that district heating networks are less cost-effective, and consequently there are fewer opportunities to reuse waste heat. On the other hand, meeting the demand for cooling, which is more common in the Mediterranean Europe, is less straightforward and more technologically complex when using waste heat as a starting point.
Heat Recovery from Data Centers: A Resource for a Sustainable Future
Year-round heat generation by data centers makes the data center almost equivalent to a geothermal heat source due to its stability and consistency. Although in the Warmest Countries The reuse of heat for residential purposes is more difficult and limited; however, it is still possible to use heat for industrial and agricultural purposes (such as heating greenhouses).
The reuse of waste heat from data centers has proven to be a valid, reliable, economical, and sustainable in a future characterized by ever-increasing energy consumption by data centers but, at the same time, increasingly stringent environmental sustainability policies.
It is therefore easy to imagine that heat recovery from data centers will become an increasingly common and incentivized option. For more information on this key issue for future sustainability Contact our Enertech Solution team.
