During the first reporting period FlexGeo sucessfully worked on all scientific and technical work packages and established a solid basis for the development and demonstration of flexible geothermal systems. Although a few tasks experienced minor delays, all milestones and deliverables scheduled for RP1 were ultimately achieved.
In WP2, the two reversible ORC test rigs at TUM and ULiège were completed, commissioned and successfully operated, generating an extensive dataset for heat pump and ORC mode. These data enabled the validation of detailed component models and the development of fast surrogate models that significantly accelerate system optimisation workflows. The experimental findings fed directly into the ongoing detailed engineering of the 200 kWel demonstrator, where WP5 completed the initial integration concept and prepared the ground for component procurement and installation. WP3 delivered the first systematic analysis of technical requirements for providing grid reserve power with geothermal technologies across several countries. Flexibility envelopes for reversible ORC units, district heating networks and storage solutions were derived, forming an essential input for upcoming control strategy development. Parallel to this, first versions of dynamic 4GDHC and 5GDHC network models and an expanding digital twin of the TUM test rig were created, laying the foundation for advanced control tasks in the next reporting period. In WP4, major progress was made on modelling flexible geothermal energy systems. Detailed component models for UTES, district heating networks, and advanced closed-loop systems were developed and validated. ETH and TUW completed a first integrated modelling framework capable of simulating geothermal configurations under realistic operational and market constraints. A comprehensive list of innovative system concepts was compiled and pre-assessed, laying the groundwork for subsequent optimization activities.
WP6 initiated the techno-economic and environmental evaluation of the FlexGeo concepts. A harmonised data structure was created to ensure consistency across CAPEX, OPEX and life cycle inventory inputs. Partner data collection has begun, and the framework is now ready for the first KPI calculations once finalised scenarios become available.Finally WP7 completed a comprehensive regulatory and market analysis across five European countries. This work delivered essential insights into technical requirements, policy conditions and market barriers, which will guide system design, modelling scenarios and later exploitation activities. Taken together these achievements demonstrate that FlexGeo has completed all required scientific and technical groundwork for RP1. The project is now well positioned to enter the next phase, which will focus on detailed optimisation, advanced control development, and the construction and testing of the full-scale demonstrator.
