Contents and Objectives

The exploratory project ModularHeatNet addresses this gap by developing an integrated planning and implementation approach for modular, scalable district heating networks based on locally available renewable energy sources. The central research question focused on how municipalities with heterogeneous settlement structures can gradually transition from fossil-based individual heating systems to climate-neutral, economically viable and socially acceptable heat supply systems. The project investigated suitable technical system configurations, strategies for optimally utilising local energy potentials, and the organisational and institutional framework conditions required to successfully initiate the implementation of municipal heating networks.

Methodological Approach

The municipality of Ottensheim served as a demonstration area for developing and applying the ModularHeatNet approach. Based on a GIS-based building model, heating and cooling demands were analysed at building level using building simulations. In parallel, an energy spatial analysis was conducted to identify locally available renewable energy potentials, particularly groundwater, shallow geothermal energy, wastewater heat, as well as biomass and solar energy.

On this basis, settlement energy typologies were defined and supply zones with different temperature levels and technical requirements were derived. Several supply scenarios were developed for these zones and evaluated with regard to technical feasibility, economic viability and implementability. In addition, a municipal implementation roadmap was prepared describing organisational and legal steps for selecting suitable implementation partners and defining a pilot district as a first step towards realisation.

Results

The results of the project show that a climate-neutral heat supply in Ottensheim is technically feasible and economically viable in the long term, provided that locally available renewable energy sources are systematically utilised and modular network structures are implemented step by step.
Particularly high potential was identified in the use of groundwater as a central heat source for future low-temperature and anergy networks. Wastewater heat and shallow geothermal energy can additionally contribute to supplying individual districts, while biomass is primarily suitable for peak load coverage in the study area.

The spatial analysis further showed that the historic town centre as well as areas with high heat density represent suitable starting areas for network development. Another key project result is the development of a structured selection process for future heat service providers that equally considers technical quality, pricing structures, environmental criteria and long-term security of supply.