Turning Drinking Water into Homegrown Energy: The De Voerman Citizen Heat Network

Anzegem is a municipality in Flanders, Belgium, and part of the Leiedal intermunicipal cooperation structure representing 13 municipalities. Like many European municipalities, Anzegem faces the challenge of decarbonising heating while ensuring affordable and resilient energy systems.

The De Voerman project transforms a former industrial brownfield into a mixed-use neighbourhood combining housing, SMEs and public green areas. The redevelopment aims to create a gas-free neighbourhood by integrating renewable heating directly into the planning process. The site will include around 30 homes and several SMEs.  

The energy community is being created before residents move in. Future residents and businesses connected to the system will become co-owners and managers of the heat network through a renewable energy community model.  

Enabling community energy projects by planning in advance  

The De Voerman project illustrates how local authorities can actively enable energy communities rather than only supporting existing citizen initiatives.

The redevelopment process started when Leiedal acquired the former industrial site in 2016 on behalf of the municipality. By acting before residents existed, the public authorities created the conditions for collective renewable heating to become possible.  

This anticipatory approach was essential: once residents had installed individual heating systems, creating a shared network would have been significantly more difficult.

During the planning phase, several renewable heating solutions were assessed. The partners identified an opportunity to recover thermal energy from a drinking water pipeline operated by De Watergroep. The system uses aquathermia: a heat exchanger extracts energy from the drinking water network, which is then distributed through a low-temperature heat network. Individual heat pumps in each building upgrade the temperature when needed.  

The project follows a “low-tech” approach. There is no central heat pump and no central circulation pump. Instead, individual heat pumps contribute to the functioning of the network. This reduces complexity and makes the model easier to manage and replicate. 

One infrastructure, two complementary uses

The De Voerman heat network will provide heating and cooling for around 30 homes and several SMEs. The system will deliver approximately 720 MWh/year of renewable thermal energy with an installed capacity of 230 kWth.  

The project provides several environmental benefits. It replaces fossil-based heating systems with a fully renewable solution and enables both heating and passive cooling. The network operates at neutral temperature (10–15°C), reducing infrastructure needs and improving efficiency.  

Beyond energy benefits, the project strengthens local ownership. Future residents are not only consumers but become collective owners of the infrastructure. This creates local value, strengthens community involvement and reduces dependence on external energy providers.

The project also demonstrates the value of existing infrastructure. A drinking water network, originally designed only for water supply, becomes an energy resource supporting the local transition.  

Lessons learnt

Several factors contributed to the success of the project:

• Local authorities can play a decisive role by planning energy infrastructure before buildings are constructed.  
• Collective systems do not necessarily require complex technology; simple and robust solutions can be highly innovative.  
• Combining collective infrastructure with individual heat pumps creates a balance between community ownership and user autonomy.  
• Existing local resources can become valuable renewable energy sources.  

A key lesson was that innovative neighbourhood heat networks require significant preparation. Technical, financial and governance aspects must be assessed before construction begins. 

Next Steps

The main challenge is ensuring that small-scale collective heat networks can operate within existing regulatory and market frameworks.

Private operators were not interested in managing the system because the scale was considered too small. Public leadership and collective ownership therefore became essential.

Future steps include completing the neighbourhood development, connecting residents and SMEs, and monitoring the performance of the system once operational. 

Replication Potential

The De Voerman model has strong replication potential because it combines innovation with simplicity.

Its strength lies in its adaptability: municipalities do not need identical conditions but can identify locally available renewable heat sources such as drinking water networks, wastewater or other environmental heat sources.

The project shows that local authorities can act as initiators of energy communities by integrating energy planning into urban development from the beginning. Intermunicipal cooperation, such as Leiedal’s model, can also help smaller municipalities access expertise and reduce risks.

By combining local renewable resources, simple technology and citizen ownership, De Voerman provides a transferable model for neighbourhood-scale homegrown energy across Europe. 

Anzegem, Belgium 

Stage of implementation: Funding Secured

Key Energy Figures

• Total capacity installed: 
  • 230 kWth installed thermal capacity 
  • Potential expansion to 460 kWth
•  Annual renewable energy production: Approx. 720 MWh/year 
•  Number of future users: Around 30 homes and several SMEs 

Type of support from the Municipality

• Direct involvement: co-investing in the project, leading the community.

Covenant Figures

• The Intercommunale Leiedal has been a Covenant Coordinator since 2012.
• Anzegem is Covenant signatory since 2013. 
• Emission reduction ambitions: 
  • - 40 % GHG emissions reductions by 2030
  • Climate neutrality by 2050