The transformation of existing heating networks plays a crucial role in the heat transition, as it enables the shift to a climate-neutral heat supply. While the electricity sector has already made significant progress in decarbonization, the heating sector still faces major challenges. In urban areas, heating networks offer an efficient solution as they can flexibly combine various renewable heat sources.

Why are transformation plans important?

The federal government not only promotes the expansion of new district heating networks but also the conversion of existing networks to climate-neutral heat sources. In Germany, federal subsidy programs of the BEW (Bundesförderung für effiziente Wärmenetze) cover up to 50 % of feasibility studies and up to 40 % of investment costs.

Challenges in the transformation

Decarbonizing existing networks is complex, as many current heating networks are historically designed for fossil fuels like natural gas. The conventional heat supply via gas networks enables flexible and demand-oriented heat provision from a central energy source with supply temperatures of up to 130 °C. With the heat transition, the focus is now on heat supply via renewable heat sources such as solar thermal energy and heat pumps. However, these fundamentally differ from the previous gas supply:

They provide heat at lower temperatures to achieve maximum efficiency.
Their generation varies seasonally and requires intermediate storage.
Heat input into the network occurs at new locations, necessitating network modifications.

Simply replacing gas boilers with biomass systems may be a short-term solution but is often considered unsustainable in the long run due to limited resources.

Practical implications for network planning

To enable a comprehensive heat transition, heating networks must be considered holistically. This requires:

a combination of non-combustion technologies like solar thermal energy, geothermal energy, or waste heat.
improved control and monitoring systems for optimized generation and consumption management.
lower supply temperatures through modernization on the consumer side.

Connection to municipal heat planning

In many European countries, heat planning laws are in effect. Municipal heat planning provides essential data on heat demands and potential heat sources. It defines priority areas for heating networks but does not detail their technical implementation. This is where transformation plans come in, analyzing existing networks, evaluating expansion options, and specifying technical feasibility. Therefore, both planning processes should proceed in parallel and in close coordination to leverage synergies.

Digital and georeferenced planning as key

Effective transformation planning relies on digital and georeferenced data. A consolidated digital representation of a heating network accelerates planning and the preparation of subsidy applications. Technical support through digital tools like nPro enables the simulation of different scenarios, system sizing, and calculation of generation shares. This provides a solid foundation for informed decision-making.

With nPro, heating networks for districts can be intuitively visualized on a map and designed according to individual requirements and optimization goals. This significantly facilitates communication with decision-makers and the public.

Are you working on a transformation plan for a heating network? Test the planning tool from nPro.

Initial steps for municipalities and utilities

In Germany, before applying for funding for a transformation plan (50% BEW subsidy), it is advisable to first conduct a concept study. This study should:

identify priority areas and potential heat sources,
sketch initial supply concepts, and
enable rough cost estimates.

Based on the results of a concept study, reliable offers can then be obtained, funding applications precisely formulated, and ultimately submitted for funding to the German BAFA (Federal Office for Economic Affairs and Export Control).