Real thermal sieve, the Élysée will switch to geothermal energy to lower its (big) bill

It is undoubtedly the most famous thermal sieve of the Republic: the Élysée Palace. No double glazing, air infiltration, woodwork without insulation, too cold in winter, too hot in summer… E (on a scale of A to G), according to an association.

Heating the huge 365-room building is a headache, in addition to being a money pit. It is so cold in winter that electric space heaters have to be installed. And that’s not counting on one of the site’s boilers, which still runs on fuel!

This is a bit of a stain when we know that the candidate Macron promised, in 2017, to remove thermal colanders in France. To rectify the situation and reduce the bill, energy works have just started at the Élysée: the palace will bet on geothermal energy. This technique recovers heat naturally by capturing it in the ground.

Work began this month. At the bottom of the sumptuous gardens of the Élysée, the workers “drill the basement and bury the pipes in depth, says Le Parisien, who was able to visit the site. They cross several layers of alluvium, marl, limestone and three water tables. »

Draw from 65 meters deep

The last, 65 meters deep – the equivalent in height of the towers of Notre-Dame – offers water at 15°C all year round. This is captured, routed to the heat pump, then reinjected into the basements using wells. One is, moreover, very close to the presidential office. “The objective is not to disturb President Macron and his wife,” said Gérald Sancier, of the Sanfor company, to France Inter.

It is the circulation of water that makes it possible to recover energy and supply the secondary circuit of the palace’s radiators. “We produce four to five kilowatts of heating energy by consuming only one kilowatt of electricity”, continues Gérald Sancier on France 3.

Profitable within five years

Cost of the site: five million euros, including 700,000 euros for the drilling. But geothermal energy will cover 60% of the palace’s heating needs, reduce greenhouse gas emissions by 80% and divide the energy bill by three, ensure the palace’s technical services. Profitability is expected in five years.

The end of the project is scheduled for 2024, for start-up in the spring. Unless it takes a little longer: at the Élysée, it’s not so easy to dig wells. The basement is full of galleries, evacuation tunnels and other bunkers…