Urban district heating extended – Development of flexible and decarbonized urban district heating systems

Development of innovative urban district heating systems by integration of long-term thermal storage, large scale heat pumps, large scale solar thermal installations, waste heat recovery and analysis and evaluation by simulation. The results of this project will provide templates for technology selection, system design and merit order for new urban district heating areas.

Short Description

Starting point / motivation

On-grid heat supply and district heating offer large potential for the reduction of CO2 emissions while offering cost-effective heat coverage, especially in urban areas. Here, district heating enables to integrate a large range of heat conversion technologies (including hybrid approaches), industrial and urban waste and thermal storage options. As a result, the use of fossil fuels could be drastically reduced or even fully replaced while increasing grid flexibility and added value on local scale.

Operators of urban district heating systems, primarily of natural gas fired CHP installations, are currently confronted with the issue of offering cost-effective or cost-neutral heat supply due to increasingly difficult economic boundary conditions: Developments on the electricity market and rapidly changing and volatile prices for natural gas and other fossil fuels are main factors leading to heightened pressure on operators and owners. Consequently, innovative approaches for district heating systems, which are independent of not local or fossil energy carriers and by possibility also increase the flexibility of our heating systems, are becoming vitally important.

Contents and goals

In this project, we will develop innovative concepts for the extension and upgrading of urban district heating systems and evaluate their added value by simulation studies. Goal of these concepts is to intelligently integrate heat pumps, long-term heat storage and large scale solar thermal installations to build a flexible heating supply system, in which large shares of renewables and / or waste heat are used. Based on three archetypal heating supply systems of different scale and number of connections and different supply portfolio during base, medium and peak load (Wien, Klagenfurt, Mürzzuschlag), we will investigate, which additional technologies, capacities, connection and merit order lead to an economic and technological optimal heating supply system. Results can be used as template for other urban district heating systems.


To allow a holistic analysis of the three case studies, we will develop and extend methods and simulation tools (e.g. in Dymola or TRNSYS) on component and system level. Based on the three archetypal case studies we will assess via a scenario study which technical configurations and merit order is the most suitable in a given situation. The specific results for the three cases will be generalized and made applicable for other urban situations.

Expected results

The developed concepts will allow the extension of existing urban heating supply systems and enable steps towards a more sustainable supply portfolio. We will provide technology selection guidelines based on technical, economic and ecological boundary conditions which technologies lead to an optimal energy supply portfolio. Furthermore we will present new simulation packages for long-term thermal storage, absorption heat pumps and heating supply networks as well as new algorithms for optimization of integrative district heating supply systems.


Project Partners

Project management

AEE – Institut für Nachhaltige Technologien (AEE INTEC)

Project or cooperation partners

  • S.O.L.I.D. Gesellschaft für Solarinstallation und Design mbH
  • Technische Universität Graz - Institut für Wärmetechnik
  • Wien Energie GmbH
  • STW Stadtwerke Klagenfurt AG
  • Stadtwerke Mürzzuschlag Gesellschaft m.b.H.

Contact Address

Dr. Ingo Leusbrock
Feldgasse 19
A-8200 Gleisdorf
Tel.: +43 (3112) 5886-261
E-mail: i.leusbrock@aee.at
Web: www.aee-intec.at