• Energy Research

The article presents environmental aspects related to the use of geothermal waters of the Lower Jurassic in the area of the Szczecin Trough. The research area located in the north-western part of the country has been successfully using underground waters of the Lower Jurassic since the 1990s to generate thermal energy at two geothermal heating plants located in Pyrzyce and Stargard. In the case of the area in question, it was proposed a hypothetical geothermal doublet located in the vicinity of the city of Choszczno, for which numerical simulations were carried out for different variants of the locations of the wells and the intake capacity. On the basis of the obtained results, the environmental effect that could be achieved in the case of the analyzed investment was estimated. Reduction in pollutants emission might be expected on the global scale. Even taking into account the emission linked to the electricity consumed (more than 81% of electricity in 2020 in Poland was produced based on fossil fuels, the share of had coal is about half of them). Local reduction in emission is obvious, and it is strictly related to the amount of reduction of fuels consumption. Taking into account the health resorts and thermal pools that utilize groundwater operating in the Polish Lowlands, the chemical composition of the underground waters extracted in the region of Choszczno was also analyzed, and the possibilities of their use for therapeutic and balneotherapeutic purposes were indicated.

Numerical models of geothermal doublet allows us to reduce the high risk associated with the selection of the most effective location of a production well. Furthermore, modeling is a suitable tool to verify possible changes in operational geothermal parameters, which guarantees liveliness of the system. An appropriate selection of software as well as the methodology used to generate numerical models significantly affects the quality of the obtained results. In this paper, the authors discuss the influence of such parameters as grid density and distance between wells on the efficiency of geothermal heating plant. The last stage of the analysis was connected with estimation of geothermal power potential for a hypothetical geothermal doublet. Numerical simulations were carried out using the TOUGH2 code, which applies the finite-difference method. The research was conducted in the Szczecin Trough area (NW Poland), based on archival data from Choszczno IG-1 well. The results demonstrated that in the studied case of the Choszczno region, the changes in the distance of boreholes can have a visible influence on obtained results; however the grid density of the numerical model did not achieve a significant impact on it. The results show the significant importance of numerical modeling aimed at increasing the efficiency of a potential geothermal heating plant.