Assessment of deep geothermal energy potential in Northern and Central Portugal

Northern and Central Portugal are being intensively studied to identify geological environments with high potential for Enhanced Geothermal Systems/Hot Dry Rock (EGS/HDR). The Beira granite is the selected target for geothermal feasibility studies. This granitic mass shows a heat production of 5 µW.m^-3. Surface heat flow is estimated to be 100–120 mW.m^-2. The depth for a possible geothermal reservoir suitable for electricity generation is predicted to be 6 km. Simulations carried out to assess the potential for the development of an EGS reservoir on the Beira granite show that, although these reservoirs in Portugal are not as easily created by stimulation as they might be in other regions, reservoirs of potential commercial interest were generated in the majority of model realisations.