Motivation and research question

The medium-sized municipality of Neutal has long been pursuing a sustainable and climate-friendly energy solution for its municipal buildings and facilities. In recent years, various photovoltaic systems have been installed on public buildings, and decentralised battery storage systems have been partially implemented alongside these PV installations. The municipality of Neutal also encompasses a so-called Technology Campus, home to the Technology Centre Mittelburgenland, where a range of medium-sized commercial and industrial enterprises are located. There is a fundamental ambition to make the municipality of Neutal as energy-independent and climate-neutral as possible in both the heat and electricity sectors, and to integrate all local stakeholders into this endeavour – in particular the businesses located on the Technology Campus.

Initial situation/status quo

The Austrian Heat Strategy envisages a stepwise decarbonisation of heat supply by 2040 at the latest (BMK, 2024). Depending on the scenario, the number of connections to local and district heating networks is expected to nearly double by 2040 (Kranzl, Müller, Maia, Büchele, & Hartner, 2018). In order to increase the technical and economic efficiency of heating networks, the underlying technology is continuously evolving into new generations. Increased efficiency, the integration of renewable heat and waste heat, the ability to provide cooling in addition to heating functions, and the enhanced potential to support the integration of renewable but fluctuating electricity through sector coupling technologies are considered key strengths of 5th generation heating networks (Wirtz, Schreiber, & Müller, 2022).

Project contents and objectives

The primary objective of the project was therefore to develop a supply concept for the municipal area of Neutal – including the adjacent Technology Campus – based entirely on renewable electricity and heat, with the following characteristics:

• A newly designed 5th generation heating grid forms the local backbone of the energy logistics system.
• The project area is characterised by a high mix of land uses, comprising single-family houses, multi-storey residential buildings, public facilities, as well as industry and commerce.
• Electricity generated by PV systems within the project area is integrated with the aim of achieving a high self-supply rate.
• In order to support the regional renewable energy system and thereby meet the ambition of decarbonising the energy supply, external electricity is to be procured during periods of high renewable generation – particularly from wind energy in Burgenland.
• The needs of local stakeholders are assessed at an early stage of the concept development process, and the resulting concepts are subsequently reflected upon with stakeholders in a structured feedback process.

Methodical procedure

The 5th Gen HG Neutal project followed a structured, multi-stage approach. In a first step, within Work Package 2 (WP2), the energy baseline of the project area was established: energy data at building, enterprise and district level were collected participatively with local stakeholders and complemented by a geothermal site assessment as well as an analysis of meteorological and photovoltaic potentials. On this basis, four fundamental concept variants for heat and cold supply were developed and, in WP3, modelled and assessed using the simulation software nPro Energy (nPro Energy, 2025) at high spatial (building level) and temporal (hourly) resolution. The assessment covered energy performance indicators such as degree of autarky and self-consumption rate, economic aspects in the form of levelised costs of heat and cold, as well as an analysis of demand-side flexibility potentials at building level. The results were discussed and validated in a stakeholder workshop involving participants from all relevant actor groups. Building on the concept identified as the reference scenario, WP4 defined spatially differentiated expansion stages, assessed them in terms of technical dimensioning, economic viability and feasibility, and derived a practice-oriented roadmap for the stepwise realisation of the 5th generation heating grid in Neutal.

Results and conclusions

The 5th Gen HG Neutal project demonstrates that the implementation of a 5th generation heating network in a medium-sized municipality in Burgenland is technically feasible and energetically sound. Concept 2 was identified as the reference scenario, combining an anergie network based on a central geothermal borehole field with solar thermal regeneration and the integration of PV and wind electricity via energy community models, achieving a balanced degree of autarky of 69%. The analysis of the six spatial expansion stages shows that the variants incorporating the industrial area exhibit the lowest levelised costs of heat and cold and are the most economically attractive. However, the overall economic assessment also reveals that, under the assumptions made, decentralised air-to-water heat pumps exhibit lower specific levelised costs than the central anergie network, attributable to the comparatively low connection density in the rural project area as well as the limited temporal overlap between heat and cold demand. Nevertheless, the 5th generation heating network offers significant advantages over decentralised individual solutions in terms of supply resilience, decarbonisation, local value creation, and the potential for integrating industrial waste heat and utilising demand-side flexibility – advantages that are not fully captured in a purely cost-based assessment.

Outlook

Whether and to what extent an investor or operator can be found for the implementation of the anergie network remains open at this stage. The economic analysis shows that, particularly at low connection densities, the levelised costs of the central anergie network are higher than those of decentralised individual solutions. A stepwise realisation – beginning with economically attractive expansion stages with high energy density, above all in the industrial area – could lower the entry barrier and lay the foundation for subsequent expansion. The potential for operational cluster formation combined with integrated spatial energy planning was also contributed to the stakeholder process of Burgenland's 2024 climate strategy. The methods, simulation models and assessment approaches developed within the project are transferable beyond the Neutal project area to comparable municipalities in rural settings, thereby contributing to the scaling of 5th generation heating network concepts within the framework of Austria's climate neutrality strategy.

Acknowledgements

The authors gratefully acknowledge nPro Energy, especially Marco Wirtz, for providing the software as well as for their support and valuable technical exchange during the modeling and execution of the simulations.

Project management

Forschung Burgenland GmbH

Project or cooperation partners

• Woschitz Engineering GmbH
• Siemens AG

Markus Puchegger
Tel.: +43 (664) 161 66 56
E-mail: Markus.puchegger@forschung-burgenland.at
Web: www.forschung-burgenland.at