The analysis of the geothermal energy capacity for power generation in Serbia

An estimate of deep groundwater temperature is necessary for the research and utilization of this geothermal resource. Geothermometers are based on the temperature relation of some chemical reactions or the solubility of some minerals. Researchers mostly use silicon-based (quartz, chalcedony, amorphous silica) and cation-based (Na-K, Na-K-Ca, Na-K-Mg, and so forth) geothermometers. Temperatures of some prospectively abundant geothermal water resources in Serbia are estimated using the silicon-based geothermometers. In the absence of hot water resources, temperature of deep thermal groundwater has to be estimated and considered for power generation with the Kalina or the Rankine binary cycle. Best thermal waters (temperatures from 130 degree C to 160 degree C) for the purpose are located in the spa of Vranjska Banja, followed by Kursumlijska, Sijarinska, and Josanicka spas and Bogatic of Macva. Pumped at the present rate of 200 l/s, the mentioned sources may generate 70 MWt, of which some 30 MWt the Vranjska Banja alone. Total power (for the five tested resources) is estimated at about 2200 TJ per year.