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TY - THES AU - Colas, Elisa TI - The reuse of abandoned coal mines: geological and mining aspects from decision-making to the operation phase PB - Rheinisch-Westfälische Technische Hochschule Aachen VL - Dissertation CY - Aachen M1 - RWTH-2024-10353 SP - 1 Online-Ressource : Illustrationen PY - 2024 N1 - Veröffentlicht auf dem Publikationsserver der RWTH Aachen University N1 - Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2024 AB - The research presented in this thesis explores the innovative utilisation of abandoned coal mines for energy storage and production. This addresses the energy storage needs driven by intermittent renewable energy sources and the challenges associated with repurposing former mining sites. First, a focus has been placed on the reuse of the mine as a lower reservoir for Underground pumped Storage Hydropower (UPSH), and has been enlarged to have a larger view of the potential use of the mine as a reservoir for Compressed Air Energy Storage) CAES, heat storage and geothermal use. The reuse of these mines is an opportunity because the closure of coal mines across Europe has resulted in numerous underground spaces with potential for alternative uses. However, these abandoned mines present significant challenges due to the degradation of mine structures, including weathering, dissolution, hydration, leaching, subsidence, and other post-mining processes. These factors complicate the stability, safety, and feasibility of using these spaces as lower reservoirs in UPSP systems. Moreover, the complex geological conditions, such as variable rock mass properties, fault zones, and hydrogeological characteristics, further exacerbate these challenges, necessitating a thorough and integrated approach to site evaluation and preparation. The research highlights the critical processes involved in cyclical pumping and discharge within UPSPs, including hydraulic discharge processes, cyclic loading, wetting and drying cycles, and thermal stresses. These processes are essential to ensuring the long-term stability and productivity of the storage reservoirs. Detailed simulations and experimental studies previously conducted are compiled in order to understand the mechanical behaviour of the rock mass under these cyclical conditions, providing insights into potential failure mechanisms and mitigation strategies. Furthermore, the study presents various numerical solutions and empirical methods to mitigate these cyclical processes, enhancing the understanding of the interaction between geological conditions and engineered systems. From an economic perspective, the feasibility of repurposing abandoned mines is examined, with considerations given to favorable rock mass properties, reduced land acquisition costs, and potential revenue from excavated materials. Cost-benefit analyses are performed to evaluate the economic viability of different repurposing scenarios, considering both initial investment and long-term operational costs. The study also explores potential revenue streams from the sale of by-products such as excavated rock and the provision of ancillary services like grid stabilization. The economic model developed in this thesis incorporates various risk factors and sensitivity analyses to provide robust and realistic assessments of project feasibility. Then, the thesis details the comprehensive workflow developed to address these challenges, incorporating advanced geological modelling, stability assessments, and economic analyses. A key component of the study is the development of a 3D geological model that visualizes the stratigraphy, tectonic structures, and mining data of the Prosper-Haniel mine. This study example provides a multi-disciplinary approach to understanding the geological, hydrological, andIIengineering factors critical to transforming abandoned coal mines into effective energy storage reservoirs.In addition, this model aids in assessing the stability of underground tunnels and serves as a foundational tool for further exploration and decision-making processes. The model integrates data, including historical mining records, geological surveys, and seismic surveys, to provide a detailed and dynamic representation of the subsurface conditions.The study underscores the importance of interdisciplinary collaboration and advanced data analytics in optimizing the repurposing process, aiming to support the transition towards a more resilient and sustainable energy infrastructure. Collaborative efforts between geologists, engineers, economists, and policymakers are crucial to overcoming the multifaceted challenges associated with repurposing abandoned mines.In summary, this thesis contributes to the broader understanding of utilizing abandoned coal mines for energy storage, offering a detailed examination of the geological and engineering challenges and presenting practical solutions to enhance the viability of such projects. The findings emphasize the potential of abandoned mines to play a crucial role in the future of sustainable energy storage, promoting the effective reuse of existing underground spaces and supporting the integration of renewable energy sources. The research provides a valuable framework for policymakers, industry stakeholders, and researchers, highlighting the strategic importance of repurposing former industrial sites in the context of global energy transitions and environmental sustainability. LB - PUB:(DE-HGF)11 DO - DOI:10.18154/RWTH-2024-10353 UR - https://publications.rwth-aachen.de/record/996058 ER -