USquare: Geothermal energy and heat networks for an urban and ecological district
USquare: Geothermal energy and heat networks for an urban and ecological district
Equans is installing an urban network to heat or cool the buildings of former barracks, partly using the energy naturally contained close to the earth's surface
On Boulevard Général Jacques in Ixelles, in place of the former Fritz Toussaint barracks, a brand-new project will soon be launched. The 27 emblematic buildings of the former police barracks will soon give way to an open, urban and university district. The conversion will focus on reducing carbon emissions. To support this energy transition, Equans and its partner Colas are responsible for building a 3500-metre "low" and "medium" temperature heating network.
The low-temperature network is supplied exclusively by geothermal energy, while the medium-temperature network is supplied by a combination of condensing gas boilers and co-generation.
Renewable energy
With 600 student residences, university facilities, an auditorium and even a hall dedicated to renewable energy sources, Usquare aims to be an innovative development centre that will enhance the university reputation of our European capital. Led by the Société d'Aménagement Urbain (SAU), in collaboration with the ULB and VUB universities, this project incorporates sustainable and societal considerations based on the use of renewable energies, such as geothermal energy, to meet the buildings' energy needs.
Did you say geothermal energy?
The principle of geothermal energy is to exploit the heat or cold naturally stored underground to preheat or cool water, which is then distributed through a network of underground pipes to the new district.
Depending on requirements, this water is then either distributed as is, or locally heated or mechanically cooled by a heat pump system. More environmentally friendly than traditional gas heating methods, this technique offers a number of advantages, including simplicity and reliability of operation, as well as and especially reduced and stable energy running costs. It also enables buildings to be passively cooled (geo-cooling), by capturing and removing excess heat from buildings through the heating network.
Open access site
As Romain Schellens, Project Manager at Equans, explains, "We are working on two aspects of this contract. Installation of the geothermal equipment is one part and creation of the underground pipe network is the other part. The site is open to the public and the safety of passersby and co-workers is our main concern. When working with tools and rolling stock, it requires complete coordination between the partners. We scrupulously comply with directives and schedules.”
XXL drill and corrosion-resistant pipes
Installing the geothermal system requires 131 boreholes to be drilled at a depth of 115 metres. "This type of drilling is carried out using an imposing tracked drilling rig equipped with a mast that can be several metres high, depending on the depth of the borehole," explains Romain Schellens. In this case of closed geothermal energy, the aim is to insert a heat exchanger (or geothermal probe) into the drilled hole. This is then filled with a filler material that ensures both good thermal conductivity between the earth and the geothermal heat exchanger as well as an effective physical separation between them.
For the piping, our partner Colas is also in charge of all the earthworks for the heating network trenches, while Equans is responsible for installing the pipes themselves. The choice was made in favour of pre-insulated "Calpex" synthetic pipes for the medium-temperature heating network: "These pipes are made of high-quality polyurethane insulation and offer excellent results in terms of energy performance." Compared with steel pipes, they also have the enormous advantage of extending the life of the network by several decades. This is a major advantage for buried pipes in urban environments!
Open and sustainable neighbourhood
Active on the site since mid-September 2023, Equans’ teams are currently installing some 3,500 metres of underground piping to transport heat from the geothermal collectors to the boiler room and then to the site's buildings. Ultimately, heat pumps and an intelligent control system will complement the buildings' local installations.
If all goes according to plan, the work carried out by Equans should be completed in the first half of 2024. After this date, it will be possible to install substations at the foot of each building to supply this new open, sustainable urban neighbourhood with hot water for heating and sanitary hot water.
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Want to find out more about our urban heating solutions?
