Yesterday, the Swiss cloud provider Infomaniak officially inaugurated its new data center, which has been recovering 100% of the electricity it uses since 11 November. Located in a residential area of Geneva, on an underground site of the participatory and eco-responsible cooperative of la Bistoquette, the data center has no impact on the landscape and recycles 100% of the local renewable energy it consumes. At full capacity, it will feed 1.7 MW (or 14.9 GWh/year) into the region’s heating network, enabling 6,000 Minergie-A households to be heated a year or 20,000 people to take a 5-minute shower every day. This new generation of data centers, which has already received a number of awards, has been documented by students from EPFL, IMD and the University of Lausanne with a view to making it open source and enabling it to be reproduced on a large scale.
Inauguration of the D4, a data center that is revolutionising the cloud industry
Infomaniak’s new data center, a symbol of technological innovation and sustainability, was officially inaugurated yesterday, with the public authorities and key project stakeholders in attendance. Their collective commitment was essential in making this world first a reality. The project exceeds the standards of similar infrastructures in terms of environmental integration and energy recovery.
Since 2 p.m. on 11 November 2024, all the electricity consumed by this structure, in the form of heat, has already been fed back into the district heating network of the Canton of Geneva. This achievement marks a key stage in the region’s energy transition, transforming an energy-intensive facility into an active player in energy recovery.
Currently operating at 25% of its potential capacity, Infomaniak’s data center will gradually increase its output to reach full capacity by 2028, guaranteeing a sustainable contribution to society for at least 20 years.
The future of the cloud: circular energy with no impact on the landscape
Having already won several awards for the energy efficiency of its infrastructures, which have been operating without air conditioning since 2013, Infomaniak is addressing four major challenges facing the cloud industry with this new data center model:
100% of the electricity used by the data center is reused to heat households via a district heating network.
The facility does not require additional water or air conditioning to be cooled.
It is built on an underground site in a residential area.
It has no impact on the landscape.
“In the real world, data centers convert electricity into heat. With the exponential growth of the cloud, this energy is currently being released into the atmosphere and wasted. There is an urgent need to upgrade this way of doing things, to connect these infrastructures to heating networks and adapt building standards,” explains Boris Siegenthaler, Infomaniak’s Founder and Chief Strategy Officer.
Nothing is wasted, everything is transformed
Unlike existing projects that recycle a fraction of the energy they consume, the system implemented by Infomaniak goes further.
All the electricity consumed (by servers, inverters, ventilation, etc.) is converted into heat at a temperature of 40 to 45°C. This heat is then transferred to an air/water exchanger, which integrates it into a hot water circuit. Heat pumps then raise its temperature to transfer the waste heat from the data center to the heating network.
The originality of the system lies in the use of both sides of the pump:
The gas in the heat pumps expands by capturing the energy in the water, which drops from 45°C to 28°C. This cooled water is fed into the air/water exchanger to cool the servers, eliminating the need for traditional air conditioning.
The gas in the pumps is then compressed to transmit energy to the district heating network, raising the water temperature to 67 °C in summer and 85 °C in winter to meet the needs of the district heating operator.
The recovery mechanism is therefore the same as the one that keeps the servers at an optimal operating temperature. The additional energy required to run the heat pumps is also recycled, and it is the cold released by this process that keeps the servers cool.
“Today, PUE, which measures the energy efficiency of data centers, is no longer sufficient in the face of the climate emergency. We also need to take ERE into account, which evaluates the energy actually consumed compared to the energy reused, as well as the ERF, which measures the proportion of the data center’s total energy that is reused for other purposes, such as district heating. Taken together, these three indicators provide a more complete picture of the energy impact of digital infrastructures,” explains Boris Siegenthaler, Infomaniak’s Founder and Chief Strategy Officer.
6,000 homes heated and 3,600 t CO₂e saved each year
At full capacity, the new data center will house some 10,000 servers in an underground area measuring 1,800 m2. It will provide the heating network with 1.7 MW, equivalent to the energy needed to heat 6,000 Minergie-A households per year or allow 20,000 people to take a 5-minute shower every day.
Geneva will avoid having to burn 3,600 t CO2e of natural gas per year or the equivalent of 5,500 t CO2e of pellets per year, not to mention eliminate 211 lorries per year transporting 13 tonnes of material and the microparticles associated with pellet transport and combustion.
An economically neutral operation
In financial terms, recycling waste heat is a neutral operation for Infomaniak. Without the servers, this data center cost CHF 12 million, including a CHF 6 million advance from the cloud provider to adapt heat levels those required by heating network. Part of this CHF 6 million was provided by the Cantonal Energy Office of the Canton of Geneva (OCEN) and the heating network operator (SIG). The remainder will be gradually amortised by the heat produced by Infomaniak, at cost price.
From finding the site (June 2019) to commissioning the first servers (December 2023), the project took a total of four and a half years to complete, whereas Infomaniak would usually build a data center in two years. The main challenges involved were finding a location that was both secure and close to a district heating network capable of permanently absorbing the associated volume of heat, and negotiating a contract with the district heating network operator.
Good for Europe’s technological sovereignty
This data center strengthens Europe’s technological sovereignty and creates value for many local companies by relying on equipment manufactured exclusively in Europe, with the exception of the security cameras used:
Trane heat pumps (France)
Ebmpapst fans (Germany)
Siemens power rails (Germany)
Siemens switchboard (Germany)
Minkels server racks (Netherlands)
ABB inverters (Switzerland)
Margen generator (Italy)
Meyer-Burger solar panels (Switzerland/Germany)
The local economy will also benefit directly from the impact of this project.
A new generation of data centers that is open source
This innovation can be reproduced and the expertise gained during the course of the project has been made available free of charge. This model works, demonstrating to the cloud industry and policymakers that it is possible to double the value of energy from data centers. It also shows that the digital sector should no longer be seen as an end consumer of electricity, but as an actor in the energy transition.
Infomaniak’s new data center, which was awarded the Swiss Ethics Prize and the Sustainable Development Prize of the Canton of Geneva in 2023, has been documented by UNIL, IMD and EPFL as part of the e4s.center programme to illustrate its energy efficiency in real time and make it easier to reproduce. This work is available for free at https://d4project.org/ and includes:
A technical guide explaining how to replicate this data center model.
Real-time monitoring of data center operational performance
A summary for policymakers with information to improve regulations on the design and sustainability of data centers
Two new similar data centers already planned
To support its growth, Infomaniak is actively looking for heating networks for its future data centers. “We already have 1.1 MW ready to be fed into a heating network, and by 2028, a new data center of at least 3.3 MW will be needed to meet demand. The principle is simple: we buy electricity locally and provide our carbon-free waste heat free of charge,” explains Boris Siegenthaler.
Key figures
Average PUE: 1.09 (European average: 1.6)
ERE and ERF: see online
2 1.7 MW heat pumps
Total area: 1,800 m2
Total budget (without servers): CHF 12 million
Total energy recycled at full capacity: 1.7 MW
Number of servers at full capacity: approximately 10,000 (200 47U racks)
Capacity of the solar power plant linked to this data center: 130 kWp (364 modules)
GPUs currently installed in this data center: Nvidia L4, A100 and H100
Resources
D4 documentation prepared by the E4S group (IMD, EPFL, UNIL)
Short video explaining how the D4 works
Pictures of the D4
Infomaniak’s ecological approach
Press pack