Classification of geothermal resources in Poland by exergy analysis—Comparative study

Geothermal resources in Poland are of growing importance for the production of renewable energy. The total installed geothermal capacity (including heat pumps) at the end of 2008 was ca. 281 MWt, while heat sales about 1501 TJ. Poland is characterised by low-temperature geothermal resources connected mostly with the Mesozoic sedimentary formations. In the paper the estimation of thermodynamic potential of Polish geothermal fields in comparison with selected global resources was presented. Geothermal resources were classified with reference to their specific exergy and specific exergy index (SEI). These indices define the quality of the energy content of a geothermal fluid better than conventional temperature criterions.