Portugal Country Geothermal Update 2005

Abstract

The geology of Portugal determines different conditions for geothermal energy occurrences. In the mainland, where crystalline rocks outcrop over 60% of the area, thermal waters are related with active faulting. Twenty-seven springs have discharge temperatures between 25?C and 75?C and are used in balneotherapy. Three small, low enthalpy operations for direct use at existing hotels are operating normally. A dozen of feasibility studies already carried out demonstrate adequate conditions for further operations.
In the sedimentary basins, particularly in the Lisbon area where important heat consumers are located, Lower Cretaceous reservoirs with temperatures up to 50?C are adequate for small multipurpose geothermal operations, but technical difficulties resulted in the stoppage of the only two existing operations.
The already studied potential for developing geothermal heat pumps over proven aquifers is high all over the country. However, no reports are available on the application of any kind of geothermal heat pumps.
In the volcanic Azores Archipelago, the geological and market conditions allow high enthalpy electricity producing operations in some islands. In S. Miguel, the largest island, one plant operates regularly since 1980 and a second after 1994. The total production capacity of 3+13MWt is installed. At Terceira Island a drilling campaign is in due course aiming to install 12 MWt.