Hot Water from CERN’s Large Hadron Collider Cooling System is Now Being Used to Heat Local Homes and Businesses in France

      The European Organization for Nuclear Research, known as CERN, is now utilizing waste heat from the cooling system of its particle accelerator, known as the Large Hadron Collider (LHC), to heat local homes and businesses in France. Heat recovered from the LHC has been supplying a heating network for a residential and commercial area in the nearby French town of Ferney-Voltaire since mid-January. It is expected to supply heat for the equivalent of several thousand homes.

     The LHC is 27 km in overall length with eight surface points, one of which is near Ferney-Voltaire. The cooling water that cools the equipment heats up, and instead of using cooling towers to cool the water and then release it to the atmosphere, now the hot water initially passes through two 5-MW heat exchangers, which transfer thermal energy to the new heating network in Ferney-Voltaire. 

     Right now, only one heat exchanger is in use, and in the summer of 2026, the LHC will be shut down for a multi-year maintenance and upgrade period. However, cooling water will still be needed, and between 1 and 5MW will be supplied to the heating network during the log shutdown. After the upgrades are compete both 5MW heat exchangers will be operational, potentially doubling the heat output. According to CERN:

“Other projects include CERN’s Prévessin Data Centre, inaugurated in 2024, which is equipped with a heat-recovery system set to warm most site buildings from winter 2026/2027, and the future recovery of heat from LHC Point 1 cooling towers to supply buildings on CERN’s Meyrin site. Together, these initiatives will save 25–30 GWh per year as of 2027, marking significant progress in CERN’s responsible energy management.”

       In Ferney-Voltaire, the recovered waste heat is fed directly into the town’s district heating network.

References:

Heating homes with the world’s largest particle accelerator. Now operational, a new heat exchange system is reusing hot water from part of the Large Hadron Collider’s cooling system to heat homes and businesses in the local area. Kate Kahle & Anna Cook. CERN. January 28, 2026. Heating homes with the world’s largest particle accelerator | CERN

CERN. Wikipedia. CERN - Wikipedia

World’s most powerful particle collider supplies heat to thousands of French households. Georgina Jedikovska. Interesting Engineering. January 29, 2026. World’s most powerful particle collider supplies heat to thousands of French households