PhD on Coupled Subsurface Processes in Mine Water Thermal Energy Storage

The Department of Earth Sciences is looking for a highly motivated candidate for a PhD position at its High Pressure and Temperature Laboratory (HPT), run by the Experimental Rock Deformation Group.

Your job
High-temperature thermal energy storage is playing an increasingly vital role in the transition to a low-carbon future. One of the most promising opportunities is the repurposing of abandoned and end-of-life coal mines as large-scale underground thermal batteries. Coupled with solar energy, these systems can deliver low-carbon, high-temperature district heating in winter.

Sustainable mine water thermal energy storage requires a solid understanding of the complicated water flow dynamics in mined geological formations, which differ fundamentally from those in natural porous media. Underground mine systems consists of mine goaf and underground workings, surrounded by saturated porous rocks. Water flows through these mined voids much faster than through aquifers, offering a significant advantage over conventional aquifer thermal energy storage. However, this also increases the risk of premature thermal breakthrough, reduced thermal longevity of solar energy-charged systems, and heat loss to surrounding rocks. To ensure reliable and efficient thermal energy storage, it is essential to understand how heat and water are stored and transported through fractured, porous, and geomechanically altered rocks under in-situ temperature and pressure conditions. This PhD project is part of the EU RFCS-funded GeoSolar project, which aims to advance high-temperature thermal energy storage technologies and support the just transition of Europe’s end-of-life coal mines. The project will involve close collaboration with mining companies, geothermal technology providers, and district heating network operators.

Within this PhD project, you will:

• perform experimental characterisation of mine goaf rocks from selected end-of-life coal mines, focusing on their thermal, hydrological and mechanical properties under in-situ pressure and temperature conditions;
• develop and apply fully-coupled thermo-hydro-mechanical models to simulate mine water flow and heat storage dynamics within underground mine systems; and
• evaluate the potential for seasonal heat storage and recovery, contributing to the optimisation of operational performance and energy efficiency in mine water thermal energy storage systems.

Throughout the project, you will regularly interact with the other consortium partners and present your findings to the broader scientific and industrial community.

A personalised training programme will be set up, reflecting your training needs and career objectives. About 20% of your time will be dedicated to this training component, which includes training on the job in assisting in the Bachelor’s and Master’s programmes of the department at Utrecht University.

We are looking for a candidate in coupled subsurface processes in mine water thermal energy storage.

You must have completed your MSc degree in Geomechanics, Hydrogeology, Geological engineering, Civil Engineering, Reservoir Engineering, or a related discipline by the time the position starts. Preferably, you will also have:

• experience or strong interest in geomechanical and/or hydrological modelling using continnum-based numerical methods (e.g., finite element method, finite difference method);
• experience or strong interest in rock mechanical experiments, or high-pressure and/or high-temperature laboratory experiments;
• strong quantitative and data analysis skills;
• the ability to work independently and as part of a team in a multidisciplinary research environment;
• enthusiasm for geo-energy and applications relevant to the sustainable use of the subsurface; and
• excellent communication and interpersonal skills.

Due to the international character of our research, good command of spoken and written English is essential. We highly encourage applicants from all members of our community and of diverse backgrounds to join us.

• A position for one year, with an extension to a total of four years upon a successful assessment in the first year, and with the specific intent that it results in a doctorate within this period;
• a working week of 38 hours and a gross monthly salary between €2,901 and €3,707 (salary scale P under the Collective Labour Agreement for Dutch Universities (CAO NU));
• 8% holiday pay and 8.3% year-end bonus;
• a pension scheme, partially paid parental leave and flexible terms of employment based on the CAO NU.

In addition to the terms of employment laid down in the CAO NU, Utrecht University has a number of schemes and facilities of its own for employees. This includes schemes facilitating professional development, leave schemes and schemes for sports and cultural activities, as well as discounts on software and other IT products. We also offer access to additional employee benefits through our Terms of Employment Options Model. In this way, we encourage our employees to continue to invest in their growth. For more information, please visit Working at Utrecht University.

A better future for everyone. This ambition motivates our scientists in executing their leading research and inspiring teaching. At Utrecht University, the various disciplines collaborate intensively towards major strategic themes. Our focus is on Dynamics of Youth, Institutions for Open Societies, Life Sciences and Pathways to Sustainability. Sharing science, shaping tomorrow.

Utrecht University’s Faculty of Geosciences studies the Earth: from the Earth’s core to its surface, including man’s spatial and material utilisation of the Earth – always with a focus on sustainability and innovation. With 3,400 students (BSc and MSc) and 720 staff, the faculty is a strong and challenging organisation. The Faculty of Geosciences is organised in four Departments: Earth Sciences, Human Geography & Spatial Planning, Physical Geography, and Sustainable Development.

The Department of Earth Sciences conducts teaching and research across the full range of the solid Earth and environmental Earth sciences, with activities in almost all areas of geology, geochemistry, geophysics, biogeology and hydrogeology. The department hosts a highly international tenured staff of over 50 scientists and more than 110 PhD candidates and postdoctoral researchers. We house or have access to a wide variety of world-class laboratories, among which are UU’s Electron Microscopy Centre, the Geolab, and the Earth Simulation Lab. We also have excellent High-Performance Computing facilities.

The department and its facilities are located at Utrecht Science Park. Utrecht is the fourth largest city in the Netherlands with a population of nearly 360,000 and forms a hub in the middle of the country. Its historical city centre and its modern central station can easily be reached from the Science Park by public transport or by a 15-minute bicycle ride. Utrecht boasts beautiful canals with extraordinary wharf cellars housing cafés and terraces by the water, as well as a broad variety of shops and boutiques.