In Flanders alone, 40% of the heat demand from buildings located within one kilometre of a water body can be met through aquathermal energy.
According to Lenn Coussement, Project Engineer at EXTRAQT, this represents 33,162 GWh of sustainable heat that could be extracted from surface water and wastewater treatment plants – equivalent to roughly 15-20% of the region’s total heat demand.
These figures were presented during EHPA’s webinar, “Evaluating the potential of Aquathermal Energy systems: the do’s and don’ts of feasibility studies”, held on 3 June 2026 as part of WaterWarmth, an Interreg North Sea project co-funded by the European Union.
Aquathermal energy uses surface water (rivers, lakes, canals) as a heat source for heat pump systems, delivering a highly efficient, low-carbon heating and cooling solution for buildings close to water. Yet despite its considerable potential, the technology remains underutilised across the North Sea region and beyond.
A key message from the webinar was that successful aquathermal projects depend on a thorough, step-by-step feasibility assessment.
To support this process, the WaterWarmth project has developed a four-stage methodology that guides developers from initial screening to investment decisions. The approach covers potential mapping, quickscan assessments, pre-feasibility studies and full feasibility studies, with each stage evaluating technical, environmental, regulatory and financial considerations.
Coussement highlighted several common pitfalls, including overlooking water quality data, underestimating the need for thermal modelling, and delaying coordination with regulatory authorities. Addressing these factors early can help avoid costly delays and improve project viability.
By providing a clear and practical roadmap, the WaterWarmth quickscan tool supports municipalities, project developers and engineers in identifying promising opportunities and progressing them towards implementation. The tool is free and available on the WaterWarmth website.
Don’t miss WaterWarmth’s next webinar on 8 June to discover real-life aquathermal energy pilots and learn how the technology is developing in practice.
