The VALTER project comprises two large-scale in-situ experiments at different scales: in the Grimsel and Bedretto tunnels. Both address questions associated with the validation of stimulation procedures and sustainable utilization of heat exchangers in the deep underground. Stimulation concepts are tested in-situ while hydro-seismo-mechanical key parameters are monitored at a high spatial resolution. The addressed questions are:
- Which stimulation concepts are appropriate for enhancing the permeability by orders of magnitudes while minimizing induced seismicity?
- What are the relationships between the hydro-mechanical response, the stimulation concept, permeability creation, effective porosity and induced seismicity?
- How can micro-seismicity be minimized?
- What are the heat exchanger properties of the reservoir?
Project Leader Institution
Federal Office of Energy