Modelling and Comparisons of a sCO2 Geothermal System with a conventional Water-based Geothermal.

Institut

Lehrstuhl für Energiesysteme (TUM-ED)

Typ

Masterarbeit /

Inhalt

theoretisch /  

Beschreibung

Geothermal power plants represent a reliable alternative to conventional power generation, offering baseload electricity production without the intermittency associated with wind or solar energy. Traditionally, geothermal electricity has been generated using water-based systems, either through direct flash cycles or binary Organic Rankine Cycle (ORC) plants. Over the past decade, an alternative technology based on supercritical carbon dioxide (sCO₂) circulating in the subsurface has emerged and has been investigated in numerous research projects as a potential next-generation geothermal power (NGP) system. These systems offer several thermophysical advantages compared to classical hydrothermal concepts, such as enhanced heat transport properties, improved thermosiphon effects, and potentially reduced pumping requirements [1, 2, 3].

Previous work has demonstrated the thermodynamic potential of sCO₂-based geothermal systems across a wide range of boundary conditions, and initial system optimizations have shown promising results. Furthermore, first-order cost assessments indicate that sCO₂-based concepts may be competitive with state-of-the-art geothermal technologies under certain conditions. However, a systematic and consistent comparison with conventional water-driven geothermal systems, particularly binary ORC plants, remains limited.

The main objective of this thesis is to perform a general, technology-neutral comparison of direct sCO₂ geothermal systems and water-based ORC geothermal systems, in the spirit of the seminal comparative study by [1]. Building on existing simulation results for sCO₂-based NGP systems, this work aims to develop an equivalent and automated modelling framework for brine/ORC systems and apply both models under identical geological, technical, and economic boundary conditions.           

Leveraging extensive background in ORC modelling, experimental infrastructure, and long-term operational data from commercial geothermal plants, this thesis enables a detailed and robust comparison of both technologies.

The thesis will be in cooperation with the Start-up Factor2 Energy, based in Duisburg. While the main working place will be Garching, a paid stay for a few weeks at the office of Factor2 would be possible. 

Work steps: 

• Literature review and evaluation of previous work
• Develop a computational model to simulate the conversion of geothermal energy (heat or exergy) into electrical power
• Harmonization of boundary conditions and design constraints to run a parametric and sensitivity analysis
• Extend the analysis to include economic evaluation, comparing the two technologies in terms of LCOE
• Comparative evaluation and identification of favourable operating regimes between the two technologies
• Documentation of the work

Literature:

[1] Adams et al.: A comparison of electric power output of CO2 Plume Geothermal (CPG) and brine geothermal systems for varying reservoir conditions, Applied Energy 140, 265-377 (2015)

[2] Randolf, J.B., Saar, M.O.: Coupling carbon dioxide sequestration with geothermal energy capture in naturally permeable, porous geologic formations:implications for CO2sequestration. Energy Procedia 4, 2206–2213, (2011)

[3] Van Brummen, A. C., Adams, B. M., Wu, R., Ogland-Hand, J. D., & Saar, M. O. (2022). Using CO₂-plume geothermal (CPG) energy technologies to support wind and solar power in renewable-heavy electricity systems. Renewable and Sustainable Energy Transition, 2, 100026. doi.org/10.1016/j.rset.2022.100026

Voraussetzungen

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Möglicher Beginn

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Kontakt

Christopher Schifflechner, M. Sc.
Raum: 3730
Tel.: (089) 289 16269
c.schifflechnertum.de