The D4, operated by Infomaniak Network SA in Geneva, is a fully underground data centre. It utilises 100 per cent of the heat it generates and feeds it into the city’s district heating network. This provides heating for up to 6,000 households – without the need for conventional cooling and with no energy loss.
To what extent is your company a pioneer in combining entrepreneurship and sustainability?
To our knowledge, D4 is the first data center to fully combine:
- recovery of 100% of its heat, injected into a public district heating network;
- a closed-loop circuit that requires no external water supply;
- no conventional air conditioning;
- an industrial operation located in a residential area with no impact on the landscape or the neighbourhood;
- and fully open-source documentation so that anyone can replicate it.
It’s a paradigm shift: digital technology is no longer a consumer of end energy, it becomes an energy intermediary serving the community.
Did you know that…?
Every watt that powers our servers then heats 6,000 homes in winter, or supplies 20,000 five-minute showers a day in summer — the same renewable energy, used twice. At full capacity, D4 avoids burning 2,700 tonnes of wood pellets or 1.1 million m³ of natural gas per year: that’s 3,600 to 5,500 tCO₂eq avoided annually, and 58,000 over 20 years. Wood pellets are officially renewable — except that trees are cut down to produce them, and burning them emits fine particulate matter. In the context of global warming, every tree counts.
Photo by INFOMANIAK NETWORK SA
How do you manage to survive in the market?
We control our entire value chain end to end in Switzerland, with no offshoring and no critical subcontracting. With today’s geopolitical tensions, hyperscaler price increases and the risks of extraterritorial dependency, this is exactly what the market is looking for. Our infrastructure runs on 100% local renewable energy, nearly 30% of which comes from our own solar power plants or from local partner plants. kSuite Pro is one of the very few alternatives to Microsoft 365 and Google Workspace that is developed and hosted entirely in Switzerland. Our European markets have grown by 69% in Germany and 59% in Italy, with over 50% overall growth in 3 years.
Who is behind D4?
This innovation was conceived by Boris Siegenthaler, Chief Strategy Officer of Infomaniak and its founder since 1994 — who has just transferred majority voting rights to a public-interest foundation to permanently safeguard the company’s independence — and by Julien Bonnat, Head of Data Center, who coordinated and brought this vision to life on the ground. And behind them, the 340 employees who drive the company’s vision forward and win the customers who fund it all. It would not have existed without the Bistoquette housing cooperative (bistoquette.ch) for the location, SIG for the district heating network, the Canton of Geneva for institutional support, the Raiffeisen bank for financing, and E4S (EPFL, IMD, UNIL) for the independent documentation.
Nominated Business Model: D4 – energy-efficient data centre with heat recovery
Company: INFOMANIAK NETWORK SA
Photo by INFOMANIAK NETWORK SA
