Low enthalpy geothermal projects in The Azores Islands (Portugal): a contribution to the enhancement of renewable energies

Abstract

Surface geothermal manifestations in Azores (fumaroles, thermal springs and wells) are spread around the islands of S. Miguel, Terceira, Faial, Pico, Graciosa and Flores. A few of the existing thermal springs are used in balneotherapy and balneology, at least since the XVIII century. At present, the thermal baths of Ferraria and Caldeiras da Ribeira Grande (at S. Miguel Island) and Carapacho (at Graciosa Island) are operating regularly. The surface geothermal manifestations of low enthalpy are characterized by thermal springs (discharging from perched-water bodies at altitude and from basal aquifers near the seashore), lowtemperature fumaroles, boiling mud-pools and gas (mostly CO2) ground-emissions. Geothermal direct uses in Azores are still limited by several factors, including sociological, cultural and demand constrains that did not enable the spreading of the technology.