Multi-Criteria Studies and Assessment Supporting the Selection of Locations and Technologies Used in CO2-EGS Systems

Abstract

The paper describes application of the cross-impact method in the process of selecting locations and technologies used in a geothermal system based on energy accumulated in a dry rock formation, where CO2 is used as the working medium. The survey is based on the opinion of a group of 20 experts representing different fields of earth and technical sciences. They represent Norway and Poland, where the location of such a system is considered. Based on experts’ experience and opinions, all factors that seem to be significant were classified into the following groups: targets, key factors, results, determiners, motor and brakes, regulating factors, external factors, auxiliary factors, and autonomous factors. Direct influences between variables were indicated. Due to major differences in geological conditions in Poland and Norway, the factor of on- or offshore technology was pointed out as the primary determiner. Among key factors, the system operation’s long-term safety and level of technological readiness were indicated. As a target factor, an interest of local authority was pointed out. Among the variables that are important when selecting locations for this type of system, nine are essential: (1) Formal constraints related to local nature protection areas—this variable is essential in the case of an onshore system; (2) Availability of CO2 sources; (3) Level of geological recognition; (4) The distance of the CO2-EGS from a thermal energy user and electricity grid; (5) Existing wells and other infrastructure; (6) Depth of the EGS system; (7) Water depth if offshore, this variable is only important when offshore systems are involved; (8) Physical parameters of reservoir rocks; (9) Reservoir temperature.

Differences in Direct Geothermal Energy Utilization for Heating and Cooling in Central and Northern European Countries

“…However, fairly extensive studies were conducted in recent years aiming to identify geothermal fields in Poland that are potentially suitable for that purpose [62]. Studies were carried out and are ongoing on the non-standard methods of obtaining geothermal energy, such as heat from hot dry rocks (HDR) [66] or the utilization of CO 2 as a working fluid in enhanced geothermal systems (CO 2 -EGS), the second of which is the subject of the EnerGizerS project [67].…”

Assessing the Geothermal Potential of Selected Depleted Oil and Gas Reservoirs Based on Geological Modeling and Machine Learning Tools

“…Projects that explore the feasibility and potential of geothermal energy from depleted reservoirs are conducted in many countries [8,[16][17][18][19][20]. In Poland, several studies have been conducted on the characterization of geological conditions of geothermal resource occurrences [21,22], analyses of permeability and porosity of sedimentary rocks in terms of unconventional geothermal resource explorations [23], and evaluating multi-criteria for supporting the selection of locations and technologies used in CO 2 -EGS systems [24]. Additionally, several rich source monographs contain information on the occurrence and exploitation potential of geothermal waters and energy in Poland [25][26][27][28][29].…”

Future Technology Mix—Enhanced Geothermal System (EGS) and Carbon Capture, Utilization, and Storage (CCUS)—An Overview of Selected Projects as an Example for Future Investments in Poland

“…The main goal of the project is development of EGSs with CO 2 instead of water as the working fluid. Analysis of key parameters [10], together with analysis of geothermal conditions in both countries, made it possible to indicate suitable geological structures for the CO 2 -EGS system. In Poland, the area of the Gorzów block was pointed out as one of the most favorable for this system.…”