The INTERSTORES project was represented at the International Conference on Renewable Heating and Cooling in Integrated Urban and Industrial Energy Systems (ISEC 2026), held from 14–16 April 2026 in Graz, Austria. Bringing together more than 400 participants from across the international energy sector, the conference provided an important platform for discussing innovative solutions that support the transition to sustainable heating and cooling systems.
During the event, Dr. Abdulrahman Dahash from AIT Austrian Institute of Technology delivered an oral presentation titled “Planning and Design of the World’s Largest Cavern Thermal Energy Storage: Optimization of VECTES Varanto.”
The presentation introduced the INTERSTORES project and highlighted recent progress within Work Package 3, focusing on the VECTES Varanto seasonal thermal energy storage (sTES) site. A key focus was the development and application of DePlaTES, an advanced planning toolkit for underground thermal energy storage systems developed by AIT.
Using DePlaTES (Detailed Planning of large-scale sTES), project partners were able to optimize the design of the VECTES storage concept in collaboration with GTK. The analysis compared the original storage design with an optimized configuration, demonstrating significant improvements in overall system performance. The optimized design achieved reduced capital expenditure (CAPEX), increased storage temperatures, and enhanced operational efficiency, further strengthening the business case for large-scale seasonal thermal energy storage solutions.
The presentation attracted interest from researchers, industry representatives, and policymakers attending the conference, contributing to ongoing discussions on how underground thermal energy storage can support resilient, low-carbon energy systems.
By presenting cutting-edge planning methodologies and real-world optimization results, INTERSTORES continues to advance the development of cost- and environmentally-efficient seasonal thermal energy storage solutions across Europe.
The work presented at ISEC 2026 was conducted by AIT Austrian Institute of Technology in collaboration with project partners GTK and other members of the INTERSTORES consortium, demonstrating the value of cross-border cooperation in accelerating innovation in thermal energy storage technologies.
