Possibilities of Using Geothermal Energy In Co2-Egs Systems In Poland and Norway - The Energizers Project

The paper presents preliminary results of the work on the operational efficiency of unconventional geothermal systems using carbon dioxide as the working medium, carried out since Oct. 2020, when the EnerGizerS project (CO2-Enhanced Geothermal Systems for Climate Neutral Energy Supply) started. Within the EnerGizerS project, an international consortium of scientists is conducting studies aimed at the identification and detailed characterization of geological structures for the localization of CO2-EGS systems in Poland and Norway, combining the requirements of enhanced geothermal systems (EGS) technology and geological storage of carbon dioxide. The project includes six work packages focused on selecting suitable sites for CO2-EGS, conducting laboratory tests of drill cores, running an experimental campaign aimed at the evaluation of supercritical carbon dioxide parameters, as well as doing advanced mathematical modeling of the reservoir performance and CO2-based topside systems for heat and energy production. These activities will be followed by techno-economic and environmental assessments of the considered technology. CO2-EGS are Enhanced Geothermal Systems with CO2 instead of water as the working fluid. Due to advantageous thermodynamic properties of CO2 (i.e. low viscosity, high compressibility & expansivity) and the need to reduce CO2 emissions to the atmosphere, an EGS that uses CO2 instead of water as the working fluid seems extremely attractive. An important aspect of the system is an additional environmental benefit resulting from the geological storage of a fraction of CO2 used during the power generation process. Closing the first stage of the project resulted in the indication of important parameters for the localization of CO2-EGS facilities onshore (Poland) and offshore (Norway). The most important parameters in the case of the CO2-EGS location appear to be: existing wells and other infrastructure, level of geological recognition, reservoir temperature, physical parameters of reservoir rocks, petrogeothermal parameters as well as availability of the CO2 sources. The analysis of key parameters together with the analysis of geothermal conditions in both countries made it possible to indicate geological structures suitable for CO2-EGS technology. In Poland, the area of the Gorzów block and the region of Mogilno-Łódź basin were pointed out as the most promising for such systems, while in Norway, the Åre formation in the Norwegian Sea as well as the Ula formation and the Skagerrak formation in the North Sea were pointed out. The progress of ongoing activities can be followed on the project website (www.energizers.agh.edu.pl), and the final results of the EnerGizerS project should be known by the end of 2023.