Waste data centre heat supplies Geneva DH system
5th August 2025
SWITZERLAND: Two Trane heat pumps, with a total capacity of 3.2MW, are upgrading waste heat from a data centre to supply hot water a district heating network in Geneva.
Officially inaugurated in January, the Infomaniak data centre in Geneva, Switzerland sets a new benchmark in sustainable digital infrastructure. Uniquely located in a residential neighbourhood, this underground facility — built beneath a 150-apartment eco-district — has no visual impact on the landscape. Powered entirely by locally sourced renewable energy, it recovers waste heat and recycles 100% of the energy it consumes into usable thermal energy.
Designed to accommodate around 10,000 servers at full capacity in the 1800m2 basement area of a residential neighbourhood, the data centre operates with a waste heat recovery system enabled by two Trane XStream RTWF heat pumps.
The heat pumps convert the low-temperature heat energy emitted by servers, inverters, ventilation and other elements of the data centre, from 45°C to 67°C in summer and up to 85°C in winter.
At full capacity the data centre generates an estimated annual output of 1.7MW or 14.9GWh. By using energy that would otherwise be lost, the system helps avoid the combustion of 3600tCO2eq of natural gas or 5500tCO2eq of pellets per year.
Prior to installation at the site, the Trane heat pumps were tested and performance-validated under laboratory conditions at Trane’s state-of-the art laboratory in Charmes, France.
In addition to the Trane heat pumps, all other essential components for the data centre, including ABB inverters and EBM Papst fans, were manufactured in Europe.
Infomaniak’s data centre cooling system operates without traditional chillers, relying instead on two innovative modes that eliminate the need for conventional mechanical cooling and reduce environmental impact.
In normal mode, the heat generated by the servers is captured and upgraded by heat pumps, then fed into the district heating network. The cold released during this process is used to cool the servers, creating a highly efficient, circular energy system.
In backup mode, if the heat pumps are temporarily inactive (for example, when the heating network cannot absorb the recovered energy), the system switches to direct free cooling using filtered outside air — with no active cold production involved.
At full capacity, the new data centre will house some 10,000 servers (200 x 47U racks).
The project has received multiple accolades, including the Swiss Ethics Prize and the Cantonal Sustainable Development Prize, acknowledging its contribution to climate mitigation and responsible innovation.
Currently operating at 25% capacity, the data centre is expected to reach full operational capacity by 2028 and continue its heat supply for at least two decades.
