4. A first contribution on thermodynamic analysis and classification of geothermal resources of the western carpathians (an engineering approach

Up to date, identified prospective geothermal areas cover 34 % of territory of the Slovak Republic. In a contrast to repeatedly reported basic production and wellbore characteristics, geothermal waters and geothermal resources have never been classified by operation or field thermodynamics. The paper gives a brief review on production and field enthalpy distribution, specific exergy and exergy rate capacity of available production and exploration wells, gives a complex hint on thermodynamic quality of geothermal resources by applying the specific exergy index studies, and, provides a brief review on operation parameters of sites currently online by definition of utilization and thermal efficiency and performance indexes such is the sustainable index and thermodynamic improvement potential. In gene_ral, geothermal plays of the Western Carpathians are of low quality (SExI < 0.05) and low flow enthalpy (h_field < 550 kJ · kg^-1) at depths below 1 500 m. There are moderate-enthalpy and moderate-low exergy resources within the Danube Basin Central Depression (Cilizska Radvan, Topolovec, Velky Meder, Topolniky area), the Kosice Basin (the Durkov area) and the Upper Nitra Basin (the Kos-Laskar area). If operation and performance indices are stacked, sites of the Tvrdosovce, Cilizska Radvan, Chalmova, Kos-Laskar, Oravice, Podhajska and Besenova appear most adequate for onward development. This must, however, compromise sustainability, technical, social and economical aspects of use. (authors)