CERN heats French village with waste heat
Innovative reuse of waste heat keeps households in a nearby French village warm without emissions.
Published on February 2, 2026
CERN's Large Hadron Collider (LHC), located on the French-Swiss border, now does more than just particle physics. Since January 2026, the residual heat from the accelerators' cooling system has been reused to heat the nearby town of Ferney-Voltaire. This makes the LHC a pioneer in a circular energy model.
Thermodynamic engineering at Point 8
This technical change, which was completed in mid-January 2026, is a major modification to the particle accelerator's cooling infrastructure. Historically, the enormous heat generated by the accelerator's cryogenic and electronic systems was released into the atmosphere via evaporation cooling towers. The new configuration captures this thermal energy at Point 8 of the 27-kilometer ring, just 2.7 kilometers from Ferney-Voltaire. Instead of dissipating the energy, the system directs hot water through two custom-built heat exchangers, each with a capacity of 5 MW. This hardware integration enables the transfer of thermal energy to the district heating network without mixing the LHC's industrial cooling water with the municipal water supply.
Scalability and reliability during downtime
The current capacity of 5 MW is not a hard limit; CERN energy coordinators indicate that with the two heat exchangers installed, the capacity could theoretically be doubled to 10 MW, provided that the primary research mission is not compromised. However, the reliability of this energy source will be put to the test in the coming months. The LHC is scheduled for its Long Shutdown 3 (LS3) starting in the summer of 2026 in preparation for high-luminosity upgrades. Luminosity is an indication of the number of collisions within a given time, referred to as light. The higher the brightness, the more data the experiments collect, allowing rare processes to be observed. Despite the temporary halt to particle collisions to improve luminosity, CERN wants to continue to supply Ferney-Voltaire with heat. With the exception of a five-month period, the company will continue to supply 1 to 5 MW to the village.