The use of geothermal waters in Poland (state in 2009)

The area of Poland is characterized by heat flow values ranging from 20 to 90 mW/m2 and geothermal gradients - from 1 to 4°C/100 m. Thermal regime and geological conditions imply that the country possesses generally low-enthalpy resources belonging to the largest in Europe. Generally, reservoirs situated at 1 to 4 km depths are characterized by temperature varying from 30 to 130°C and TDS values from 0.1 to 300 g/dm3. The proven geothermal water reserves, evidenced on the basis of well flow tests, are estimated at several l/s up to 153 l/s. The best geothermal conditions are found in the Polish Lowlands and in Podhale Basin, the Inner Carpathians. Since 1992, eight geothermal heating plants have been brought on-line. The space-heating plants currently in operation in Poland include: four plants in: the Podhale region (Szymoszkowa and Antałówka plants in Zakopane, the plant at Bukowina Tatrzańska and the largest plant at Bańska Niżna) and four in the Polish Lowlands (Stargard Szczeciński and Pyrzyce plants in NW Poland, using water from Lower Jurassic reservoir, and Mszczonów and Uniejów plants in central Poland, using water from Lower Cretaceous reservoir). Each of these plants uses water of different type which results in differences in their mode of operation and utilization of geothermal water. Some of these are combined cycle plants which also have a gas turbine fired by natural gas to cover peak demand for heat (sometimes in large part) and and plants integrating absorption heat pumps AHP with gas boilers. Up to the present, no use of geothermal energy plants for other purposes than space heating was planned in Poland. However, similarly as in other countries, the attention begins to be focused on possibilities to build and operate geothermal binary plants run on water with temperature over 90°C water, that is water expected to be recoverable from depths 3-4 km and greater)