WG3: Integration of other energy sources (M1 to M48)

The objective of task T3-1 is to better understand the response of coupled technologies, where there is an integration of closed-loop ground heat exchangers in geotechnical structures with other renewable energy-based systems, such as solar collectors or mini wind turbines. This can lead to interesting applications such as Underground Thermal Energy storages (UTES). This integration can be exploited to create an efficient district heating system based on renewable energies for the housing development, alternative to the classic fossil fuel with negative environmental impacts. A necessary step for demonstrating the attractiveness of such systems based on integrated renewable technologies to all relevant stakeholders is to develop practical documents highlighting the advantages and potentialities, as well as difficulties and limits of implementations.

Energy storage systems, which allow for optimisation and flexible consumption, play a crucial role in a cost-effective application resulting in high energy performance. In most of the possible configurations, the thermal and mechanical response of a UTES interacting with other renewables is strongly influenced by the complex thermo-hydro-mechanical (THM) behaviour of the surrounding soils. The objective of Task T3-2 is to conduct a critical assessment of the different storage methods concerning the specific ground conditions and the coupling with EGS. Developed numerical simulation tools will be used for selecting and optimising the storage design for different soil types and European climatic conditions, in order to provide the designers with reliable indications on the design of the integrated system.

Large-scale implementation of EGS can be achieved with the development of new Smart Thermal Grids or by enhancing the extension potential of existing ones). Task T3-3 aims to develop tools that promote sustainable, local and flexible systems for DHC. The geothermal map for ground temperature, the modelling of EGS impact on geothermal reservoir behaviour and best practices for a proper and efficient urban planning of geothermal systems will be developed. Subsequently, the optimum location for future installations and for improving the integration of existing DHC networks will be evaluated. Also, methods to minimise interferences with existing installations will be investigated.