Environmental benefits from geothermal energy use with a well doublet located in the Szczecin Trough (NW Poland).

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.

Simulation study of the Lower Cretaceous geothermal reservoir for aquifer thermal energy storage.

The aquifer thermal energy storage (ATES) has gained attention in several countries as an installation for increasing the energy efficiency of geothermal systems and the use of waste heat. The Lower Cretaceous reservoir is known as one of the most prospective for geothermal purposes in Poland. However, in the southern part of the Mogilno-Lódz Trough (Central Poland) is considered to have a lower geothermal potential. The aim of this paper is to study whether the Lower Cretaceous reservoir in this area is suitable for aquifer thermal energy storage. Prior to dynamic simulations in Feflow© software, a regional Petrel© static parametric model which includes a multidisciplinary approach was prepared. A methodology of fitting Petrel's structural and parametrical model to Feflow requirements is provided within this paper. The performance simulation of 4 systems has been conducted for 30 years. Increasing precipitation potential is expected for aragonite and calcite along with a temperature increase, while silica precipitation carries a much smaller risk. The paper presents potential for ATES systems in the Lower Cretaceous reservoir of the study area with the best doublet location having thermal recovery ratio of 0.47 and 0.34 for 30 and 40 K temperature differential scenario. An imbalance in heat injection/production in the storage system can cause the reservoir to cool faster than in conventional geothermal heating installation. ATES can provide a successful geothermal reservoir boosting in the case of applying a balanced injection of waste heat.

Use of low-enthalpy and waste geothermal energy sources to solve arsenic problems in freshwater production in selected regions of Latin America using a process membrane distillation - Research into model solutions.

The challenge for many communities in Latin America is to find adequate solutions which are feasible given the local economic and technical conditions and which enable them to source water with arsenic concentrations below the WHO guideline value for drinking water (<10 µg/L) of arsenic (As) pollution, suitable for human consumption and the irrigation of crops. Three regions where geothermal fields are present were selected for study out of the several hundred locations in Latin America where the water environment is contaminated with As and where there is a critical water shortage problem. These are Cerro Prieto in Mexico, Momotombo in Nicaragua and Lake Poopó in Bolivia. The paper presents the results of research on the use of low-enthalpy geothermal energy sources and waste heat from geothermal power plants in membrane distillation (MD) processes, which is the only heat-powered membrane technology, in order to obtain potable water and/or water for crop irrigation. It was concluded that MD could be considered as a solution for obtaining water of good quality with a high retention of toxic solutes such as As as well as other different species found in groundwater. In addition, it is not only geothermal energy, but also the geothermal water itself that can be considered as a source of freshwater produced through the MD process, a process which is most suitable to be used in areas where cheap sources of heat are available.