Characteristics and sustainable utilisation prospects of geothermal waters of the liassic formations in the Mogilno–Lodz Trough, Poland

Mogilno–Lodz Trough is located in central Poland. It is structural basin filled with Triassic-to-Quaternary sediments. Lower Jurassic formations in Poland have one of the best conditions for the heating purposes. Presently, on the area of the Trough, no geothermal plant operates, which utilises geothermal waters from Lower Jurassic formations. Sustainable use of geothermal waters covers, e.g., effective use of thermal energy from waters, before they are injected back to the deposit. Such sustainable use can be achieved in cascaded systems, utilising thermal energy of waters, which gradually lose temperature at following stages of cascaded systems. Geothermal waters and energy occurring in Lower Jurassic formations in Mogilno–Lodz Trough have been analysed in terms of chemical composition and temperature parameters. A dominant type of water is chloride-sodium waters, with specific components contents, such as iodine, bromine, and iron. Lower Jurassic formations are deposited at different depths, which affects, to a high extent, water mineralization and temperature, as well as some elements contents. It has been demonstrated which parameters are decisive about a possibility of using them at particular stages of a cascaded system and where one should expect to find suitable conditions for particular applications.