Kickstarted by the Etablissement Public d’Aménagement Paris-Saclay (EPAPS) public development agency, the Paris-Saclay campus is a highly ambitious project. The goal here is to bring together over 1,740,000 m2 of higher education establishments, universities, laboratories, public and private research centres, and high-tech companies for a positive-energy academic and scientific hub that combines eco-friendly, sustainable, and economic development.

Injecting our expertise into renewable energy

Our cutting-edge expertise ensured we were selected to take on this high energy efficiency project. The EPAPS entrusted us with their development plans, contracting us to handle design, development, operations and maintenance for the site. The contract applies to the entire cooling and heating network set to supply the Paris-Saclay urban campus. Idex will take on responsibility for all heating, domestic hot water, air-conditioning, and cooling needs for over a hundred buildings.

A network combining recovered and renewable energy with digital technology

We set up a smart heating and low-temperature cooling network, drawing on intermediate geothermal energy to do so.

Intermediate geothermal energy refers to the solar energy stored underground in the form of calories - a major source of renewable heat. In our case, the network is structured over a calorie-distribution system fed into by the Albien aquifer groundwater in the Paris basin. The Albien aquifer contains an estimated 700 billion m3 of high-quality water reserves.

Heat pumps supply the heating and cooling system using water heated to 30°C, a temperature that ensures residual energy currently unrecovered and left over from research activities and processes on the Plateau de Saclay can be reused, with no additional energy needed.

The heating and cooling network will be linked up to a smart electricity network to form Paris-Saclay’s very own multi-energy smart grid. This network’s ground-breaking USP lies in its high-performance buildings that are interconnected to one another. Its eco-friendly design and the manner in which it is paving the way forward for smart energy management across the region and scientific cooperation make it a flagship French tech project in the energy transition sector.

Our values

Recovering local renewable energy


Getting users’ and occupants’ energy bills under control, with the focus on competitive pricing in the short term, and total stability over the long term

Harnessing the region’s incredible wealth of resources to design the energy services of the future

Slashing the urban campus’s carbon footprint (CO2 emissions of under 75g of CO2/kWh, three times less than gas).

Facts and figures

8,1 km of heating network line

5 km of cooling network line

8,9 km of warm water network line

55 substations

6 100 tonnes of CO2 saved every year

geothermal drills in the Albien aquifer (-700 m, 30°C, 400 m3/h)

heat and cold production thermal stations