Danube GeoHeCo Showcased at SEE SDEWES 2026 Congress in Burgas

The Danube GeoHeCo project was presented at the 6th South East European Conference on Sustainable Development of Energy, Water and Environment Systems (SEE SDEWES 2026), held in Burgas, Bulgaria. As one of the leading international scientific forums dedicated to sustainable energy, water and environmental systems, the conference provided an excellent opportunity to present the project's achievements to researchers and energy professionals from across Europe.

Project partner University of Zagreb, Faculty of Mining, Geology and Petroleum Engineering (UNIZG-RGNF) presented the paper “Energy renovation of buildings with hybrid ground-source heat pump coupled with existing fossil-fuelled systems – experiences of Interreg Danube GeoHeCo investment pilot projects”, authored by Tomislav Kurevija, Marija Macenić, Luka Perković and Katarina Marojević.

The presentation focused on the results achieved within Specific Objective 1, highlighting the design and technology optimisation of shallow geothermal hybrid heating and cooling systems. As part of the project, technical documentation was prepared for eight pilot buildings across the Danube Region, with five pilot investments selected for implementation.

The presented pilot solutions demonstrate how shallow geothermal energy can be successfully integrated into existing public buildings with different climatic conditions and conventional heating systems, including gas, oil, biomass and deep geothermal waste heat.

The implemented bivalent concept combines a ground-source heat pump with vertical borehole heat exchangers for covering the base heating and cooling demand, while existing heating systems remain in operation only during peak demand periods. This approach enables lower investment costs, preserves existing infrastructure and supports the gradual decarbonisation of public buildings.

A key element supporting the pilot investments is the Danube GeoHeCo IT Decision Support Tool, developed within the project to assist in borehole sizing, bivalent-point analysis, LCOE/LCOH assessment and evaluation of long-term thermal sustainability. The tool provides valuable support for planning and optimising shallow geothermal hybrid systems while ensuring reliable and sustainable operation.

The experiences and results generated through the pilot investments also contribute directly to Specific Objective 2 by providing practical knowledge for the development of the Transnational Action Plan, which offers policy recommendations and strategic guidance for the wider deployment of shallow geothermal energy solutions throughout the Danube Region.

Participation at SEE SDEWES 2026 further strengthened the visibility of the Danube GeoHeCo project and promoted the exchange of knowledge and best practices with the international scientific and professional community working towards sustainable energy transition.

The Danube GeoHeCo project is co-funded by the European Union through the Interreg Danube Region Programme.