SolNahWal – Regenerative heat network

In the context of local government final energy consumption, around 50 % is attributable to the supply of heat energy and thus a correspondingly high proportion of CO₂ emissions. The energetic optimization of heat provision by means of regenerative technologies such as solar thermal energy offers great potential for reducing carbon dioxide emissions. With the Climate Protection Programme 2030 the German government also confirms that there are enormous opportunities for converting the heat supply to the increased use of renewable energies.

With regard to the practical implementation of the heat transition, for example, the proven technology of solar thermal energy should be established for heat supply. In combination with fourth generation heating network systems, an innovative solution for the heating infrastructure that is designed to reduce losses and optimize temperature, it is possible to implement energy-optimized and renewable interconnected systems.

With this background, the FiW investigated the construction of a new solar thermal field covering several hectares, a heat storage tank of over 40,000 m³ and a fourth-generation heating network for over 100 consumers in the project, which is called: Solar Local Heating Supply Walheim. The R&D-project was funded by BAFA and STAWAG, the local energy supplier. The feasibility of renewable generation, seasonal storage in combination with an efficient local heating network was successfully demonstrated.

Services provided by FiW within the scope of the "heat-" projects:

• Location investigation including estimation of the individual, consumer-specific heat demand,
• Development and simulation of heat network models,
• Concept development for innovative and sustainable heat supply including sector coupling,
• Concept development for short- and long-term heat storage,
• Climate impact assessment,
• profitability assessment.

Aim and outlook

After a successful demonstration of feasibility, the implementation of this project is being worked on in a targeted manner. Through political support, this lighthouse project should make a significant contribution to the CO₂-neutral heat supply of a district and advance the municipal heat transition.