Large Hadron Collider: Cooling water supplies residential area with heat

The cooling water from the Large Hadron Collider (LHC) at the international research center CERN is supplying a nearby residential area with district heating. According to a CERN announcement, the water has been used since mid-January to heat homes and businesses in the French town of Ferney-Voltaire.

This is part of a CERN project to make the operation of the world's largest particle accelerator more energy-efficient. The water is needed, for example, to keep the cryogenics machines of the Large Hadron Collider cool at surface points 8. It circulates through the system, cools the equipment, and absorbs heat in the process. Previously, it would then dissipate the absorbed heat in a cooling tower. Now, the waste heat is fed into the district heating system of the nearby French town instead.

Up to 10 megawatts possible

“In the new plant, hot water first flows through two heat exchangers, each with a capacity of 5 megawatts, which transfer the thermal energy to the new district heating network in Ferney-Voltaire,” explains CERN's Energy Coordinator Nicolas Bellegarde. This is intended to provide heating for several thousand households.

So far, the town has only used about 5 megawatts, but in the future, the heat supply for Ferney-Voltaire could be doubled with the two installed heat exchangers. However, that will take some time. In practice, Ferney-Voltaire will initially have to live with less waste heat from the LHC: in the summer of 2026, the research center plans to shut down the LHC until summer 2030 for maintenance and upgrades.

According to the CERN announcement, at least some systems at point 8 will remain active during this time. They will therefore continue to be cooled, so that the cooling water will typically contribute between 1 and 5 megawatts to the district heating network. Ferney-Voltaire is not dependent on waste heat from the LHC because it also receives district heating from geothermal sources, among others.

The Large Hadron Collider is located near Geneva in a ring-shaped tunnel. Among the greatest scientific achievements of the world's largest research instrument is the discovery of the Higgs boson. In the long tunnel, protons are accelerated towards each other at nearly the speed of light. The connected large-scale experiments ALICE, CMS, ATLAS, and LHCb analyze which particles are produced in these collisions. Through years of work, new insights into the fundamental properties of the universe are gained from the immense amounts of data.

(dahe)