There are huge spaces left under the surface after mining (e.g., shafts, tunnels, stopes). Some are backfilled while most are not, but once mining has ceased and groundwater is permitted to rebound these spaces to become flooded with water. These mine workings therefore have significant potential to be used as sites for underground thermal energy storage (UTES) to create an innovative solution to the pressing need for renewable energy storage as well as geothermal heat supply. UTES has been examined in abandoned coal mines, which underlie 25% of the UK’s population. Moreover, in the context of carbon neutral/net zero targets set out by most major international economies, lots of coal mines are to be closed and the alternative use of the existing workings would create economic and social benefits. Gold mines are generally at greater depth than coal mines, from 1km to over 4km, and therefore present the prospect of relatively high-temperature geothermal heat extraction as well as heat storage.
This project aims to investigate the transformation strategy and technology that could be used during mine decommissioning to optimise the transformation of live mine workings for reuse in UTES. The project will consider a number of related aspects including mine closure strategies, deployment of novel materials and infrastructure to optimise heat extraction and/or cycling, risk assessment, structural integrity, etc. Specifically, the project will develop a framework to assist the decision-making with regard to transforming existing live mine working spaces into sites for effective and safe operations of UTES. The student will work in partnership with some international leading gold mines and coal mines in China and the candidate is expected to collect field data from these mines. The student will need to analyse the collected data, identify the technical requirements and develop rational strategy and roadmap. Due to the interdisciplinary and collaborative nature of this project, the candidate should also be a pro-active and self-motivated person with good interpersonal skills.
This studentship will provide the opportunity to engage with and visit Chinese collaborators at the University of Science and Technology Beijing and Shangdong Gold, who are providing in-kind support and access to data from their soon-to-be decommissioned gold mines. Data may also be available from soon-to-be decommissioned coal mines in Xuzhou, associated with Yunlong Lake Laboratory in China. This project will prepare the student with a highly employable set of skills that will assist in the assessment and evaluation of mine workings for thermal energy storage and/or geothermal heat extraction and will inform the industries/practising engineers with regard to the transformation of mines workings to UTES. With ever increasing focus on delivery of a Net Zero future, the geothermal energy sector is seeing rapid growth of employment opportunities. The candidate would be well placed for career in the renewable energy, engineering consultancy, regulatory agency or governance sectors.