| Abstract |
In Portugal, the presence of high temperature geothermal resources is restricted to the volcanic islands of Azores Archipelago, which are located at the triple junction of the North American, Eurasian and African (or Nubian) plates. Present investment projects at the Ribeira Grande Geothermal Field on S. Miguel Island, implemented by EDA RENOVÁVEIS, S.A. (former SOGEO, S.A.), led the installed generation capacity in Azores to a total of 23 MW net, with the contribution of two power plants. Thus, power production from geothermal resources in Azores presently meets 42% of the electrical consumption of S. Miguel, and over 22% of the total demand of the archipelago. On Terceira Island, deep exploratory drilling at the Pico Alto Geothermal Field during 2003-2010 conducted to a maximum reservoir temperature of 312 ºC. New short and long term tests were performed in 2013-2014 to evaluate the production capacity of the existing evaluation-production wells. The well tests pointed out the capacity to support a 2.5-3.0 MW pilot power plant. Geothermal is expected to assume an even more impressive role for electric power self-sufficiency of this Autonomous Region of Portugal, particularly in S. Miguel and Terceira Islands. However, its development is now considered in conjunction with other renewable energy sources, particularly wind energy. Low-temperature resources in Mainland Portugal are exploited for direct uses in balneotherapy and small heating systems and shallow geothermal with heat pumps is gaining increasing importance. At present, new regulations for shallow geothermal purposes are being prepared to regulate the new installations and to avoid bad practices. These regulations will also include the obligation to register all new GSHP’s installations in order to get more realistic statistical data on the new installations. After the aborted intention in 2008, when private investors obtained concession rights for exploration of geothermal EGS resources for a total area of 2,655 km2, no activity is presently reported in this field. |