CERN's energy at home

(This is the English translation of this post)

This morning, after dropping off Giulia at school and on my way to CERN, I noticed a sign in front of a road closed for construction that caught my attention. It was raining cats and dogs, but I still stopped to take a photo:

The sign, placed at the exit of the village of Ferney-Voltaire, reads roughly as follows:

Work in progress from September 2024 to Summer 2025

CERN's energy in our homes

The "Pays de Gex Énergie" heating network is being installed in Ferney-Voltaire: an eco-responsible infrastructure serving the region's energy transition.

Once I arrived at the office, I looked into what this was about, and within a few clicks, I landed on the project's page. Essentially, the idea is to recover some of the heat released by the cooling systems of the LHC, particularly from the experimental area at Point 8 where the LHCb experiment is located, and channel it into a district heating system for one of Ferney-Voltaire's new neighborhoods, located a few kilometers from Point 8.

The page from the Ferney-Voltaire municipality describing the project is a bit vague about the source of the heat, mentioning both "heat from CERN's particle accelerator" and "CERN’s energy," which could give the misleading impression that the LHC produces energy that could then be used for home heating. The CERN page on the project is, of course, more precise and clarifies that:

“At CERN, many systems and installations (cryogenics, electronics, ventilation, etc.) are cooled using water: cold water is injected into the cooling circuit and the hot water produced is then collected and cooled by cooling towers, before being reinjected into the circuit, The hot water leaving the circuit can reach a temperature of 30°, which is very useful in the context of energy recovery.”

The heat, therefore, is a recovery rather than production, but it remains a smart way of not releasing it directly into the atmosphere, making an important contribution to energy efficiency, which is essential given today’s economic and ecological climate.

The environmental impact of CERN’s facilities is certainly a hot topic. One of the most debated aspects of the proposed Future Circular Collider (FCC) at CERN is its energy consumption. Various energy recovery systems are also being studied for the FCC’s cooling systems, but it seems evident that convincing the local population that these systems can genuinely work will be much easier with a concrete example like LHC’s district heating system for Ferney, already tested and operational.