Rising fuel prices, changes in energy markets, and concern for the environment make it necessary to develop new solutions and technologies. The development of new technologies brings with it the need to take risks associated with unpredictable consequences, technological immaturity, and other issues. However, without these elements, technological development is not possible. In this study, installations related to two different technologies—Enhanced Geothermal System (EGS) and Carbon Capture, Utilization, and Storage (CCUS)—are reviewed. An Enhanced Geothermal System is a technology for exploiting the energy stored in hot dry rocks. Carbon Capture, Utilization, and Storage is an important technology for reducing CO2 emissions. The combination of these two technologies in CO2–EGS systems can bring significant environmental benefits. This paper reviews the most important CCUS and EGS systems in the world to form a baseline for similar, future technology investment in Poland.
In the years 2010-2013, analysis of rocks that build the sedimentary covers in Poland was carried out from the point of view of energy utilization accumulated in hot dry rocks – used in Enhanced Geothermal Systems (EGS). As a result of a number of analytical studies, the area situated in the central part of Poland was selected as one of prospective areas for location of EGS in sedimentary rocks. This area encompasses a major part of the Mogilno-Łódź Trough, a part of the Kujawy Swell and a small fragment of the Fore-Sudetic Monocline. The most favourable conditions for development of EGS occur in deposits of the Lower Triassic in the Krośniewice-Kutno vicinity where they are buried to depths greater than 5000 m b.s.l., have thicknesses exceeding 1500 m and are characterized by porosity about 2.5% and permeability about 0.1 mD. In the selected area, thermal characterization of the formation was carried out for location of the EGS in sedimentary rocks. The temperature at the top of Lower Triassic reservoir is in the range 165-175°C. Characterization of petrophysical parameters constituted the basis for further modelling of EGS utilization in selected area.
Model simulation allows to present the time-varying temperature distribution of the ground source for heat pumps. A system of 25 double U-shape borehole heat exchangers (BHEs) in long-term operation and three scenarios were created. In these scenarios, the difference between balanced and non-balanced energy load was considered as well as the influence of the hydrogeological factors on the temperature of the ground source. The aim of the study was to compare different thermal regimes of BHEs operation and examine the influence of small-scale and short-time thermal energy storage on ground source thermal balance. To present the performance of the system according to geological and hydrogeological factors, a Feflow® software (MIKE Powered by DHI Software) was used. The temperature for the scenarios was visualized after 10 and 30 years of the system’s operation. In this paper, a case is presented in which waste thermal energy from space cooling applications during summer months was used to upgrade thermal performance of the ground (geothermal) source of a heat pump. The study shows differences in the temperature in the ground around different Borehole Heat Exchangers. The cold plume from the not-balanced energy scenario is the most developed and might influence the future installations in the vicinity. Moreover, seasonal storage can partially overcome the negative influence of the travel of a cold plume. The most exposed to freezing were BHEs located in the core of the cold plumes. Moreover, the influence of the groundwater flow on the thermal recovery of the several BHEs is visible. The proper energy load of the geothermal source heat pump installation is crucial and it can benefit from small-scale storage. After 30 years of operation, the minimum average temperature at 50 m depth in the system with waste heat from space cooling was 2.1 °C higher than in the system without storage and 1.6 °C higher than in the layered model in which storage was not applied.
30 July 2015 in Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles