District heating and cooling networks at Paris Saclay Campus
Deep geothermal energy to power the entire Paris-Saclay
The Paris Saclay Urban Campus is a major project in Greater Paris. With the planned 1.74 million sqm construction, it combines scientific ambition, economic development and sustainable management to strengthen the city’s position among the global centres of innovation. This is a unique opportunity to develop a new energy model and make Paris Saclay an Eco-Area. Establishing a smart grid for low temperature cooling and heating using deep geothermal energy will help make Paris Saclay a positive energy area.
“This new network plays a key role in the strategy to make Paris Saclay a green area. The deployment of this solution on such a scale will be a world first”
Pierre Veltz, Chairman and CEO of EPAPS (Etablissement Public d’Aménagement de Saclay)
An Energy Transition plan
A solution in line with the energy transition law and COP21 to move from a society with high fossil fuel consumption to a society that is more energy and carbon efficient.
- A solution that has a carbon footprint three times lower than conventional gas heating
- Savings close to 20% for the subscribers
The project led by EPAPS is one of 11 winning projects in the “Industrial demonstrators for the sustainable city” call for projects, launched in October 2015 in preparation for COP21. The aim of this call for projects was to select operations intended to become a showcase for French excellence in sustainable development.
The Egis/IDEX consortium won the seven-year contract awarded by EPAPS with a transfer of skills to Design-Production-Operations & Maintenance (CREM) for the provision of heating and cooling in both joint development zones. Egis is involved in the design, project management and turnkey implementation of the network within the scope of its association with IDEX.
The Egis/IDEX group proposed a temperate network via a geothermal doublet in Albian powering the blocks’ substations (distributed generation). This provides heating and cooling to the blocks, thus avoiding the need for extra/emergency gas resources in the buildings of the lessees. This system is also able to adapt to changes in the programme at block level.
In the block sub-station, the thermo-refrigerating pumps are designed to cover at the very least the entire chilled water needs for their block. To evacuate their surplus cooling or heating power to the temperate network, the block substations are equipped with heat exchangers. One exchange unit will evacuate the excess cooling power and another the excess heating power. This latter unit will have a dual function because if the requirement for heat is greater than the block’s production capacity, it will also provide extra heat. In these circumstances, the delivery temperature of the temperate network is raised in order to supplement the heat production from the thermo-refrigerating pumps. This temperature increase, which may reach 105°C, will be controlled via the smart grid. It will be activated by the operating team, during the installation process, with regard to projected demand curves.
 Corresponding to two strategic districts on the urban campus: that of Vauve (Polytechnic college) in the towns of Palaiseau and Saclay, and that of Moulon in the towns of Gif-sur-Yvette, Orsay and Saint-Aubin.
 The doublet technology helps protect the environment and ensure the sustainability of water resources. It consists of two boreholes, one for production and one for the re-injection of thermal water into its original water table.
 The Albian aquifer measures over 100,000 km², with an average depth of 600 m, protecting it from surface pollution. Its estimated temperature of between 25°C and 28°C makes it a vital source of geothermal energy. The Albian water table extends beneath the entire Paris Basin.
Deep geothermal energy to meet demand for heating, hot water, air conditioning and cooling
|Users by 2021||
|Production and consumption||
|Added value for the environment||Added value for the economy||Added value for society|
Eventually, the network will supply all the campus buildings built between 2016 and 2022
- Over 60% of distributed energy will be from geothermal power
- A network that can adapt economically to the business park’s development over 48 months
- A scalable project that can extend beyond the needs of the area.