Pilot - Kortrijk Havenkaai, Belgium
The site
The use of AE to regenerate the soil temperature in a bore field (the primary energy source), as well as use the bore field as a heat storage for heat extracted from De Leie when the river temperature is high enough.
Governance
Investors are building the site, an ESCo for the site has been designated, an energy cooperation is being established to manage the district heating network; feasibility study on AE integration into the district heating.
Current status
Development phase - technical reports with the SWHP and GSHP system schematics and characteristics have been developed; integration into the district heating is still under research and evaluation.
What can we learn from the pilot?
How to enhance geothermal with aquathermal; how to theoretically evaluate the potential for cost efficient AE integration in existing heat network through modeling .
Challenges
Convincing the investors to implement AE; keeping up the communication with the various executive parties of the project; critically evaluating the technical details around AE integration with district heating; limitations regarding min return temperature.
Building
Kaai City is located on Havenkaai in Kortrijk. Starting from 2026 Kaai City will bring living, studying and doing business together in a new piece in Kortrijk, on the banks of the Leie. Sparkling, full of innovation and always on the move, it is a unique project that endorses public-private partnership between project developer CAAAP and the Hogeschool West-Vlaanderen (Howest).
Heating - Geothermal and Aquathermal energy
The buildings of Kaai City will be heated utilizing geothermal energy though a closed circuit of pipes in the ground. In the winter months, heat is extracted from the soil and distributed via heat pumps to the buildings of Kaai City. In the summer months, the opposite will happen, allowing the buildings to be cooled.
Kaai City can be also heated and cooled through aquathermal energy. Thanks to a pump and a filtration system, water is abstracted from the Leie. Using a heat pump, the heat from the river water can be distributed to the building.
Water source - the Leie
The Leie is a river that springs in France and flows through West Flanders, Belgium. Historically significant for the economic development of Flanders, it suffered heavy contamination and pollution. Substantial improvements have been made, and local authorities and citizens are now keen on maintaining its good state. This has led to the enforcement of regulations that make water abstraction costly and require extensive monitoring and reporting.
However, the Leie also has great physical properties for aquathermal energy generation, with a stable flow, water levels that fluctuate by only 2 meters, and seasonal temperatures between 2°C and 30°C.
Seasonal use of the Leie
In the Spring and the Autumn water from the Leie is extracted and directly used for heating or cooling of the buildings depending on the demand. The water temperature is boosted up with a heat pump and the heating is then provided to the buildings via floor heating. During these seasons the river alone is likely to be enough to meet the heating and cooling demands of Kaai City and they are expected to be relatively low.
In the Winter, when the river water temperature is too low, aquathermal energy is not used but heating is provided only from the geothermal field.
Finally, in the Summer is when the aquathermal energy unravels its full potential. Water from the river is extracted and used to regenerate (increase) the temperature of the soil in the geothermal field. The filed acts as a thermal battery in which the heat from the river is stored to be later on used when the heating demand of the buildings is high.
Valorization
Once the first buildings of Kaai City become operational, we will be busy with managing the thermal supply to the them. Via a network of sensors, measuring devices and control strategies, we will evaluate the true potential of the Leie while maintaining comfortable habitable conditions within Kaai City.
