Friese Energietafel – Lessons from Súdwest-Fryslân
On 9 September, the monthly Friese Energietafel brought together mainly public authorities to share knowledge and experiences in the heat transition. This time, the spotlight was on Gemeente Súdwest-Fryslân (SWF), who presented the lessons learned from two ambitious aquathermal pilot projects: Warm Heeg and ’t Eiland in Sneek.
Background
Súdwest-Fryslân’s Heat Transition Vision (2021) marked the starting point of its local energy strategy, with the ambition to make around 8,000 homes natural gas–free by 2030. The municipality deliberately focused on neighbourhoods with relatively energy-efficient housing and initiatives driven by local citizens or companies. Since then, the world has changed drastically: energy crises, wars, and grid congestion have added urgency and complexity to the transition.
Pilot 1: Warm Heeg
Warm Heeg began in 2021 as a bottom-up citizen initiative, testing whether aquathermal energy (heat from surface water) could serve as a scalable local heating solution. The municipality initially acted mainly as permit provider. But in 2023, SWF took on a much bigger role: financial guarantor. A €14M guarantee was issued based on 80% participation. However, as costs escalated to €19M, financiers demanded full municipal backing. This shifted the project from low-risk to high-risk, while Heeg had already contracted builders, engineers, and financiers. The misalignment in timing, combined with spatial planning issues (e.g. impact on public space, utilities, and “behind the front door” costs), made continuation financially unfeasible.
Pilot 2: ’t Eiland, Sneek
The second pilot focused on roughly 1,000 homes, of which 400 faced demolition and redevelopment by housing corporation Elkien. A district heating concept based on aquathermy was explored, but ultimately the business case did not add up. The project faced several barriers:
- Dependency on a single heat source (aquathermy).
- Scope too limited to secure sufficient demand.
- Mismatch with Elkien’s construction timeline.
- Highly insulated new builds requiring less heat.
As a result, Elkien decided to move forward with individual heat pumps for new developments, and the pilot never reached the construction phase.
Lessons Learned
Both pilots underscore that the heat transition is complex and multi-layered, requiring a balance between ambition, feasibility, and governance.
Key insights include:
- Feasibility criteria: high heat density, large consumers, and cheap sustainable sources (e.g. aquathermy combined with rest heat).
- Governance: municipalities must clearly define their role — regulator, facilitator, or financier — and avoid role confusion.
- Financial sustainability: projects must be affordable and based on realistic risk profiles.
- Citizen engagement: although persona studies suggested enthusiasm, in practice 56% of Heeg’s residents opted out. Understanding and addressing such drop-offs is crucial.
- Strategic approach: rest heat appears almost essential as part of a mixed sources strategy; citizen-led initiatives can add value, but need alignment with municipal planning.
WaterWarmth develops tools like the Waterwarmth Quickscan and runs pilots to explore technical, financial, and governance models for aquathermal energy. The aim: to accelerate sustainable heating solutions in Europe by learning collectively and avoiding costly mistakes.
Conclusion
Although the pilots did not progress as planned, they provided invaluable lessons for Súdwest-Fryslân and beyond. They showed the importance of realistic business cases, clear role divisions, and the need for robust sources and citizen engagement. By sharing these insights at the Friese Energietafel, SWF contributes to a broader regional and European learning process — one that WaterWarmth helps to amplify.