Deploying geothermal energy in Wallonia: a cross-sectoral approach 

Despite strong potential, geothermal energy remained largely underdeveloped in Wallonia for many years. High upfront investment costs, regulatory complexity and limited market maturity hindered deployment across sectors. To address these barriers, the Walloon Region chose to actively structure the geothermal sector, with a strong operational focus on shallow geothermal energy as a scalable and widely applicable solution. 

Building the foundations: knowledge first 

A key milestone was reached in 2019, when a study was conducted to evaluate the shallow geothermal potential in Wallonia. 

The study demonstrated that closed-loop shallow geothermal systems could be deployed almost everywhere in the region, while open-loop systems showed strong potential in areas with suitable aquifers. This evidence-based approach significantly reduced uncertainty and provided a robust foundation for public intervention. 

Boosting projects across sectors 

On this basis, the Walloon Region launched two calls for projects in 2021 and 2022 as part of its Recovery and Resilience Plan. With a combined budget of approximately 31 million EUR, the calls supported projects along the entire value chain, from feasibility studies and drilling to heat pumps and heat distribution networks. 

In total, 34 shallow geothermal projects were selected, spanning a wide range of sectors including healthcare, public facilities, real estate, tourism, industry and services. Most installations involve drilling depths below 200 metres and are designed to provide renewable heating and cooling tailored to local needs. 

Active regional steering and project governance 

A defining feature of the Walloon approach is the hands-on role assumed by the regional administration. Rather than limiting its involvement to funding allocation, the region acts as a programme manager throughout the project lifecycle. Feasibility studies are mandatory and validated before projects can proceed. Each subsequent phase, drilling, installation and commissioning, is subject to intermediate approvals. Once operational, projects must report production and performance data for five years, allowing the region to monitor results and build long-term knowledge. Project timelines were also adapted to account for public procurement constraints, with deadlines extended until 2028. 

Early results across sectors 

Several projects are already delivering tangible results. At the Namur Regional Hospital Centre (CHR), a shallow geothermal system supplying the hospital’s emergency department has been operational since August 2023, covering nearly all cooling needs through an open-loop installation. 

“We extract groundwater just ten metres deep and use a heat pump to recover the energy needed to heat or cool the building. With the Walloon Region’s subsidy, the payback period has been reduced from nine to just two years.” Pierre Debruyne, Director of Infrastructure, Meuse Site, CHR Namur. 

In the tertiary sector, the Mundo enterprise building in Louvain-la-Neuve has been fully supplied by a closed-loop geothermal system since November 2023. With twelve boreholes, the installation covers 100% of annual heating (27,2 MWh) and cooling (18,1 MWh) needs, illustrating the suitability of shallow geothermal energy for office and service buildings. 

Financing and regulation enablers 

Financing remains a central challenge for geothermal deployment, as the high upfront investment requires dedicated support mechanisms to enable projects to move forward in both the public and private sectors. 

“Considering the immaturity of the Walloon market, geothermal installations require significant upfront investment, even though operating costs are low and stable over time. Public support plays a crucial role in de-risking projects and enabling actors to expand forward.” Sonya Chaoui, head of Renewable Energy, Walloon Region administration 

Regulatory reform also proved decisive. For open-loop systems, permitting rules previously required complex environmental impact assessments for reinjection wells, despite the absence of pollution risks. By reclassifying these permits, the region significantly simplified procedures and improved conditions for investment. 

A pragmatic pathway for regional shallow geothermal deployment 

By combining geological knowledge, targeted investment, active public steering and regulatory reform, the Walloon Region has created a coherent framework for scaling up shallow geothermal energy.  

While the programme focuses on shallow geothermal energy, Wallonia has also taken steps to structure deep geothermal development, with two project proposals currently under examination for a potential launch in 2026. 

The approach illustrates how regions can move from untapped potential to concrete projects, while progressively preparing the ground for more advanced geothermal applications. These efforts have also contributed to local economic development, creating employment opportunities within Walloon engineering consultancies. 

This best practice is extracted from our publication ‘Sustainable Regions in Action‘. Discover more best practices here!